1 Introduction [link id=”nnz7g”]

Many tunnels in the Netherlands need to be renovated in the coming years in order to keep them safe. Many tunnels also need to be adapted and smartly maintained to meet changing requirements. The required maintenance and renovation tasks raise all kinds of questions. The COB network seeks to jointly develop, combine and utilise knowledge. This includes knowledge of both organisational and technical aspects. This digital living document bundles this knowledge. Names of all persons involved can be found in Appendix 1: Participants.

Objective of this living document

The living document aims to inspire all professionals involved in tunnel renovation to come up with new ideas and solutions. This applies not only to making use of the experiences of previous renovation projects, but also to putting ‘learning’ on their agenda and sharing experiences and acquired knowledge with other projects. In this way, every project can benefit from lessons learned and add new lessons/chapters to this document. In this way, the document grows, the knowledge grows, and every renovation project gets a little better.

Although this living document contains much useful knowledge, it is not a renovation manual. Each tunnel project is unique and requires specific solutions. In this living document, methods and solutions are presented that have worked in certain situations, but that may not produce the desired result in other places or under different circumstances. Besides methods or solutions, this document also contains the questions, doubts and uncertainties that occupied and continue to occupy the authors. The motto for readers and users is therefore: always think critically!

Examples

The first version of part 1 of this living document was drawn up in 2016 by a COB expert team in collaboration with experts from the Velsertunnel Project. This project is often cited as an example in popup boxes, as well as experiences from other tunnel (renovation) projects. More extensive experiences are included in the appendices.

Growing the living document

This document is called a ‘living document’ because it is a document that can easily be expanded with new experiences and new knowledge gained and developed in tunnel renovation projects. Already this living document has been updated and supplemented with numerous new practical experiences.

Reading guide

The first five chapters of this living document contain basic information about tunnel renovations. Chapters 6 to 14 deal with all kinds of specific matters that are important for renovation projects, such as the preparation, the system architecture, the main tunnel technical installations and, for example, logistics management and the licensing process.

The appendices contain relevant background information, but we recommend that you especially look at the COB knowledge products and projects that are referenced. That is the most up-to-date and in-depth knowledge.

Introduction workshop ‘Learn to renovate’

Would you like an introduction to tunnel renovation and the most important lessons from this living document, so that you and your team can start with a comparable level of knowledge? Please contact COB via info@cob.nl to discuss whether the one-day training is useful for your organisation.

2 Why renovate? [link id=”dl676″]

Much of the infrastructure in the Netherlands was built from the 1960s onwards and has therefore been in use for quite a long time. There may be all kinds of reasons that make the partial or complete renovation of a tunnel necessary. These are discussed in this chapter.

2.1 End of expected lifespan tunnel technical installations (TTI) [link id=”zmlmg”]

Over the past few decades, an increasing number of safety requirements have resulted in the addition of many technical facilities in tunnels. Besides familiar tunnel technical installations such as ventilation, pumps and lighting, these include traffic detection and congestion avoidance installations, public address installations, camera systems and installations for a safe escape route. Since the early 1990s, integrated operating and control installations have been added to tunnels. These installations enable operators and managers to control the traffic in tunnels and the technology required to do so. More and more, the control systems are operated remotely in road traffic control centres, which in turn places demands on the operating procedures.

Some of the tunnel technical installations that could no longer be maintained have been replaced over the years. Installations have also been adapted to the requirements of European tunnel legislation. But especially the extensive and more complex (sub)installations such as power supply, ventilation, operation and control are at the end of their lifespan and await replacement.

When a road tunnel is renovated, it must immediately be brought up to the level of the Dutch safety regulations, which in some respects go further than the European regulations. Furthermore, tunnel managers may have drawn up additional regulations which also apply to existing tunnels. All existing Dutch tunnels must comply with the Tunnel act (Warvw) since 1 January 2019. It was also decided that when major renovations are carried out on state tunnels, the aim should be for the renovated tunnels to meet the requirements of the National tunnel standard (Dutch: Landelijke Tunnelstandaard, LTS) as much as possible.

2.2 Halfway point expected lifespan structure [link id=”gd60s”]

Many tunnels have reached the halfway point of their theoretical lifespan of one hundred years. In the years to come, it will have to be investigated how these structures are holding up and which life-extending maintenance is necessary to keep the tunnels in use for the next thirty years without major interventions. Important issues here are material degeneration, settlement and the incremental loading caused by the increase in traffic volume.

2.3 Unexpected failure [link id=”2b8qc”]

The technical residual lifespan of a tunnel and its subsystems (structural, ICT and installations) is usually not known and only becomes clear shortly before or during a renovation. Tunnels in the Netherlands are inspected periodically and this shows that structural safety is assured in the short term but predicting the scope of a renovation with certainty is very difficult. It is also very difficult to make predictions about the life span in the longer term. It is clear, however, that installations last significantly shorter than the concrete and that installations also have a varying life span, especially those that have a large ICT component. Think, for example, of the various software updates with adjustments to the hardware that will then be required.

2.4 Changes in legislation [link id=”lm6w4″]

Following the disasters in the Mont-Blanc and Tauern tunnels, European tunnel legislation was made more stringent. Subsequently, the Member States translated the European legislation into national legislation. In the Netherlands, the requirements for tunnels are laid down in the Tunnel act (Dutch: Wet aanvullende regels veiligheid wegtunnels, Warvw), in the accompanying regulation (Rarvw) and in the tunnel-specific requirements of the Buildings Decree. These regulations set out the technical, organisational and safety management requirements a tunnel must meet. A distinction has been made between tunnels shorter than 250 metres, tunnels between 250 and 500 metres in length and tunnels longer than 500 metres. Tunnels managed by the Dutch State are also subject to standardised equipment (laid down in the Rarvw). The various laws and regulations are explained in the publication Tunnelveiligheid verklaard (in Dutch only) from the Tunnel safety knowledge platform (KPT). For more information, see also Appendix 2: Warvw on role of competent authority in tunnels.

To implement the regulatory requirements, Rijkswaterstaat has drawn up the National tunnel standard (Dutch: Landelijke tunnelstandaard, LTS) for tunnels in the trunk road system. If a tunnel verifiably meets the LTS – and thus the tunnel legislation – then the tunnel is safe enough and the competent authority can grant the opening permit. The LTS is in principle written by Rijkswaterstaat and is mandatory for state tunnels. Subsequently, the municipalities of Amsterdam and The Hague drew up a similar standard for their municipal tunnels. Dutch government-owned railway manager ProRail has drawn up a similar standard for railway tunnels in the form of a design regulation, OVS00201.

2.5 Postponed maintenance [link id=”48750″]

Although Dutch tunnels are maintained to a high standard, it does happen that sub-installations unexpectedly fail or have to be renovated due to unexpected wear and tear or deferred maintenance. Tunnels are often owned by the government, which is dependent on the budgets made available by politicians. In times of crisis or infrastructure expansion, maintenance does not always get the attention it needs.

Maintenance may also have been postponed because a renovation usually involves extensive closures that were impossible to reconcile with other infrastructure projects at the planned maintenance time. It may also be that there was no sense of urgency to start the work. As long as the tunnel and the technology in it continue to work, another project may take priority. The impact on traffic may be so serious that work is postponed as long as possible.

2.6 Standardisation in operation [link id=”z9xrq”]

The introduction of the various standards has led to the standardisation of tunnel technical installations and ensured that the operation of new tunnels is largely the same. This creates opportunities for centralised operation. Most older tunnels still have their own operating systems which sometimes differ considerably from each other. It is desirable from several points of view that the operation of tunnels should be as uniform as possible with uniform primary processes (UPPs).

• Enhanced safety: in the event of an incident or calamity the road traffic controller always knows which actions must and can be taken, irrespective of the tunnel concerned.
• More effective: road traffic controllers often operate several tunnels at the same time and this can be done most effectively if the operation of the various tunnels is the same.
• The quality and the level of training increase.
• More efficient training: the training and retraining of traffic controllers is much more efficient if road traffic controllers learn one generic way of operating tunnels and do not have to follow a separate training course for each tunnel.
• Increased deployment of road traffic controllers: when all tunnels are operated in the same way, it will be easier for road traffic controllers from the various control centres to replace each other, for example in case of illness.

2.7 Climate change [link id=”ch7r2″]

Climate change leads to different precipitation patterns and, for example, longer periods of drought. What consequences do these kinds of changes have for Dutch tunnels? What effect, for example, does salinisation of the groundwater have on the tunnel structure? Is the installed pump capacity sufficient to cope with increasingly extreme rainfall? The renovation of a tunnel is an appropriate time to consider what measures are needed to make the tunnel climate-proof. This calls for a broad view. Rising sea levels, for example, can affect the primary water defences of which a tunnel forms a part. And what do other energy sources for road traffic mean for the safety of tunnels? How can we use durable sources of energy in tunnels? These are all questions that we are now faced with. If we do have to work on our infrastructure, this may be the best time to tackle these types of social issues as well.

2.8 Change in mobility [link id=”qfk41″]

Since the opening of a tunnel, traffic has often increased considerably. Increased traffic volume increases the risk of incidents. In response, the level of service provisions (technical installations in the tunnel) has often increased as well. Particularly in older tunnels, installations such as power supply systems have grown, cable provisions have become overcrowded and technical areas are overflowing with installation cabinets. Furthermore, the composition of the traffic has changed. Lorries have become larger, there are more electric cars, and vehicles are equipped with new technology. Thus, ‘smart mobility’ has entered the scene.

The above developments do not have to be a reason to renovate a tunnel, but when a renovation is necessary, it is important to think about how these developments can be anticipated in the design of the tunnel. For instance, can a new technology be applied without having to overhaul the existing installations? Is it possible to take future space requirements for new installation cabinets, power supplies, cooling, etc. into account during renovation?

3 Renovation methods [link id=”k22wr”]

What needs to be done in a tunnel renovation project differs from tunnel to tunnel. There are specific points of interest for the various types of tunnels. In this chapter various renovation methods are described as well as options for limiting the disruption to traffic.

3.1 Types of tunnels [link id=”22307″]

A tunnel can be constructed in various ways, which has consequences for the construction/design of the structure and therefore for the renovation. This section provides a very global overview, as basic knowledge for the various renovation methods. For more background information, visit www.cob.nl/over-ondergronds-bouw (in Dutch only).

Immersed tunnels

The first tunnels in the Netherlands were all built as immersed tunnels. For these tunnels, several tunnel elements are built in a construction dock: long concrete tubes, the ends of which are temporarily sealed with so-called end walls. This sealing enables the tubes to be transported afloat to the location where the tunnel will be built. There, each element is sunk in a controlled manner. To ensure that the elements are watertight, they are fitted with a rubber sealing profile, called a gina profile, at their ends. When the elements are positioned watertight against each other, the temporary bulkheads are removed and a so-called omega profile is applied to the inside of the joint between the elements.

A tunnel element for an immersed tunnel under construction.

Bored tunnels

For the construction of a bored tunnel, a special tunnel boring machine excavates the soil. To start boring, a so-called launch shaft must be made, a deep excavation pit in which the tunnel boring machine is placed. At the end of the boring section, the machine ends in a similar reception shaft. Every time the tunnel boring machine has bored a few metres, concrete tunnel segments are placed behind the boring head, forming a ring. The boring machine then moves against these segments to dig another section. Most bored tunnels consist of two bored tubes, one for each direction of travel.

A major difference between an immersed and a bored tunnel is the escape scenario. Bored tunnels do not have a separate escape route. This means that in the event of an incident in one tunnel tube, the other tube must be used as an escape route and must therefore be completely closed. Another difference is the location for cables and installation cabinets. In bored tunnels, each tube under the road surface contains a corridor with cableways and cabinets (often in niches). Newer immersed and land tunnels have a centre tunnel channel, containing cables and system parts for both the left and right traffic tube.

The start of the two bored tunnels of the Noord/Zuidlijn of the Amsterdam metro, which is under construction, in the launch shaft below Damrak.

Surface tunnels

Land or surface tunnels in the Netherlands are at ground level as well as below ground level and are usually built on site. Some surface tunnels are semi-submerged. Generally speaking, the area on top of a surface tunnel is not suitable for building on. Sports fields or city parks are often built on tunnel roofs. Furthermore, houses or utility buildings can often be built right next to the tunnels. This type of tunnel is comparable in design to recently built immersed tunnels and has a central tunnel channel.

3.2 Renovation methods [link id=”fqvsh”]

This section discusses the various ways in which a tunnel renovation can be carried out. The advantages and disadvantages of each variant are discussed. Which method is most suitable depends on many factors that differ per tunnel. As a result, the choices for each tunnel project are different.

The most decisive question is whether large-scale civil engineering works are necessary during the renovation. Work on the civil main structure easily takes more time than is available in regular ‘maintenance windows’. In addition to night and weekend closures, it is sometimes possible to close a tunnel for a few weeks during a holiday period. However, in view of the high traffic volumes, this is an option with fewer and fewer tunnels. If the work can be divided into smaller blocks and thus into separate time units, there are often still options.

If spreading the work is not possible, the only option is to close the tunnel (tube) during the renovation. The reason for this may be that the construction work is so drastic that no regular traffic is possible in the meantime or that safety cannot be guaranteed due to the lack of facilities. Traffic must then be diverted via alternative routes, as happened during the renovation of the Velsertunnel.

If long-term tunnel closure is not possible, one of the following options can be considered:

3.2.1 Parallel construction [link id=”48rvp”]

In this variant, all tunnel technical installations to be replaced are built in parallel at the same time and as far as possible tested integrally. The tunnel will remain operational on the old installations, while the new installations are installed and tested. In a relatively short time – for instance during a number of weekend or night closures – the old provisions are shut down and the new ones are connected to the active tunnel system. A limited subset of tests is carried out again, after which the tunnel can be put back into operation. The old installations are then removed.

For all imminent major renovations, parallel construction is a promising method. In most cases, many or even all systems need to be replaced. If there are also several tunnels to be worked on in the same region, there are not many time windows available.

An important precondition for parallel construction is that there must be sufficient space (physical space in the tunnel and service buildings) to build the new system cabinets, cables and second set of installations.

Advantages

• Work in the traffic tubes can be carried out at low-impact times, with minimal disruption.
• Detours are only active for a short time, so that the danger on the detour is limited.
• For the outside world (operators, emergency services, management) there is one clear moment when the tunnel will be migrated.
• Because many systems are replaced, there is also the opportunity to set up the system architecture of the tunnel in such a way that micro-renovations can be applied in the future.

Disadvantages

• Sufficient building space must be available or made.
• Additional cable facilities may be required.
• The temporary situation requires more electrical power and cooling capacity. A certain amount of oversizing will therefore be required for the basic installations.
• Working in a tunnel where the existing installations must remain reliably operational is complex. Older cables are especially sensitive to movement.
• Because work is done more often within small time slots, short-term barriers may have to be placed more often. The work area is also more sensitive to motorists driving through the barriers. Often you will also have to work at night. The working conditions (health and safety) are therefore less favourable.
• Varying traffic measures; which is less clear for the environment.

3.2.2 Tube-by-tube approach [link id=”9pxf5″]

Several tunnels have more than one traffic tube per direction of travel or have a reversible tube. It is possible to carry out the renovation work one tube at a time in these tunnels. This limits the disruption, as not all the traffic needs to be diverted. At the same time, work can be carried out relatively unhindered in the closed tunnel tube.

In a tube-by-tube approach, specific attention should be paid to the escape route. The plan of attack for calamities must also be considered at each stage. The operation of the tunnel must also be taken into account and attention must be paid to training. The consequences for the control system (and possibly the old and new mixed together) may be considerable, whereby the full operation of the tunnel must be guaranteed in every situation. The required permits, such as the building and operating permit and the opening permit, as well as the safety documentation for each stage must also be taken into account.

Advantages

• This variant is also applicable if large-scale civil engineering work has to be done in the tube.
• Road traffic does not have to be taken into account in the work area.
• Working safely in the tunnel (verifiable health and safety working conditions environment), barriers and diversions can be installed ‘firmly’.
• Because many systems have to be replaced, there is also the opportunity to set up the system architecture of the tunnel in such a way that micro-renovations can be used in the future.
• Work can be performed consecutively.
• Work can be (also) be done during the day.
• Learning possibilities from the first to subsequent tubes.

Disadvantages

• Major impact on traffic, major stagnation is possible, unless good diversion routes are available.
• Various changes in traffic measures (habituation).
• High costs for traffic measures.
• The approach of cross-tube systems requires a lot of extra attention and is in some cases not possible.
• Additional permits and tunnel safety documents may be required.

3.2.3 Closure in one direction [link id=”zrg8f”]

It is possible to completely close off a tunnel in one direction and carry out all necessary work in the closed tube. The other tube will then remain available to traffic. One may opt to let each tube keep its ‘own’ direction or, as in the case of the Maastunnel, to keep a preferred driving direction. During the renovation, this tunnel was always available from south to north so that hospital was easily accessible.

When the work in the first tube has been completed, it can be put into operation immediately with the new control system and the other tube can then be closed. Subsequently, the second tube is renovated and put into operation. In situations such as that of the Maastunnel, several tunnel technical installations in one of the tubes had to temporarily work in the reverse direction because the traffic travelled through one of the tubes in the opposite direction during the renovation. This has the disadvantage that either double installations are required or that installations must be reversed during the final migration. With both variants, escape routes and disaster control must be considered carefully. For example, in the event of a fire, the fire brigade will have to approach from the tube where the work is being carried out.

Advantages

• This variant is also applicable if large-scale civil engineering work has to be done in the pipe.
• Road traffic does not have to be taken into account in the work area.
• Working safely in the tunnel (verifiable working conditions environment), barriers and diversions can be installed ‘firmly’.
• Because many systems have to be replaced, there is also the opportunity to set up the system architecture of the tunnel in such a way that micro-renovations can be used in the future.
• Work in a tube can be performed continuously.
• Work can be (also) be done during the day.

Disadvantages

• Complex situation with escape routes and disaster plan of attack.
• Major impact on traffic, but it is possible that simpler diversion routes can be realised for one direction of travel.
• High costs for traffic measures.
• An oncoming traffic situation is more dangerous.
• The approach to systems that transcend driving direction (for example liquid drainage) requires a lot of extra attention and is in some cases not possible.
• Additional permits and tunnel safety documentation may be required.

3.2.4 Micro renovation [link id=”xnb3m”]

In a micro renovation, only one or a few systems are replaced at a time. If the steps taken are not too large, their impact remains small and controllable. With the right plan, this work can be carried out in short timeframes and optimum use can be made of low-traffic periods.

In the most limited form of micro renovation, a new component/part is exchanged within the regular maintenance period. In its most extensive form, a system (or a limited number of systems simultaneously) are replaced by a new (parallel) system to be built and tested, which is then commissioned during a short closure. Minor software modifications can also be carried out in this way.

Advantages

• Work in the traffic tubes can be carried out at low-impact times, with little disruption..
• Diversions are short, limiting hazards on the diversion.
• The clearer the system architecture, the more efficient the replacement can be (better verifiable, lower risk, less disruption, less impact on system, less labour).
• Systems can be replaced when they are due (appropriate to lifespan).
• Replacements can be carried out as part of the regular maintenance process or in small-scale projects.
• Updates/changes of usage can be planned and implemented faster.

Disadvantages

• The key systems (power, communication and control) must be flexible and modular enough.
• There should be enough room to build new alongside old (may limit number of systems to convert simultaneously).
• If the system architecture is not clear, a lot of reverse engineering and testing is necessary to get a good understanding of the existing situation.
• Because work is more often carried out within short time slots, short-term cordons may have to be placed more frequently. The work area is also more vulnerable to motorists driving through the cordons. Work will often have to be carried out at night. Occupational health and safety conditions are thus less favourable.
• Highly variable traffic measures can be inconvenient for the surrounding area.
• Costs will be higher across the board due to a team working longer on replacements.
• Maintenance staff and operators will have to be trained on the new situation each time.
• Maintaining asset data requires more attention.
• Night-time working hours are expensive and often only a limited number of hours can be worked, which means that it is not possible to work full shifts. In practice, total working hours turn out to be up to three times higher than when working during the day.

3.2.5 Oncoming traffic [link id=”b7vgd”]

Although not often used in the Netherlands, the method of closing one tube and using the other tube in both directions is a possible alternative. In the tube that is closed, all work can be carried out while all traffic passes through the other tube. This approach is appealing if the traffic volume is so limited that it can be handled on one lane. This approach is not uncommon for maintenance work, as one can choose for low-traffic periods and short-term work. However, many tunnel technical installations will have to be set up accordingly. Emergency situations in particular will have to be carefully considered: what is the escape route, how to deal with smoke exhaust and what is the plan of attack?

Advantages

• For a single tunnel, this method may allow room for renovation.
• There is no need to consider road traffic in the work area.
• Safe working in the tunnel (controllable occupational health and safety environment), cordons and diversions can be installed ‘firmly’.
• Replacements can be carried out as part of the regular maintenance process.
• Updates/changes of usage can be planned and implemented faster.

Disadvantages

• The danger to road traffic is high in this option, but can be controlled by additional risk-mitigating measures such as speed adjustments, temporary rerouting of trucks and/or hazardous materials, escort and enforcement.
• The tunnel tube through which traffic travels will have to be suitable to safely facilitate traffic in both directions. Many tunnel technical installations will have to be carried out on both sides.
• Part of the tunnel will remain operational. Working in a tunnel where the existing tunnel technical installations have to remain reliably operational is complex. Especially older cables are sensitive to movements.
• Dealing with systems that go beyond the tubes requires a lot of extra attention and is not possible in some cases.

3.2.6 Big-bang renovation [link id=”lm3v5″]

Sometimes good alternative routes are available and it is possible to completely close a tunnel to traffic for a longer period of time. If that is the case, one can opt for a so-called big-bang renovation. Only the health and safety working conditions apply as a safety requirement and the contractor can go to work freely. Work on civil structures or removal of the tunnel technical installations is possible. Long-term civil engineering work can be carried out and the old tunnel technical installations can be removed first, after which the new installations can be set-up and tested.

Advantages

• There is no need to consider road traffic. However, do consider emergency services: often one lane needs to remain available or can be cleared quickly.
• Safe working in the tunnel (controllable occupational health and safety environment), cordons and diversions can be installed ‘firmly’.
• Net shorter turnaround time.
• Unambiguous and long-term traffic measures for the area.
• Since many systems must be replaced, there is also the opportunity to design the architecture of the tunnel in such a way as to be able to work with micro renovations in the future.
• Work can be carried out without interruptions.
• Lower costs for work in the tunnel.
• Work can (also) be carried out during the day. The effectiveness of labour deployment is thus higher than in other variants.

Disadvantages

• (Very) high impact on traffic. Major traffic congestion is possible unless good diversion routes are possible.
• Increased risk of incidents on diversion routes.
• Relatively higher costs for traffic measures.
• Once started, there is no way back (risk of irrecoverable overrun in case of setbacks).

In addition to the above considerations, there are other aspects that determine a renovation strategy. Chapter 5 Roadmap for renovation method describes in detail which aspects must be taken into account and how you can make a choice based on this.

3.3 Full renovation vs respecting old age [link id=”k841w”]

Prior to renovation, consider to what extent the tunnel should be renovated to new condition and whether the tunnel should fully meet current requirements? Quality is important, but a renovated tunnel will never be like a new one. The appearance of the tunnel, for example, is mainly about the appearance for passing traffic. Remember that the appearance is experienced differently at a speed of 100 km/h than when you judge the appearance while walking through the tunnel.

Apart from that, the risks of bringing the tunnel up to current requirements may be unacceptably high. Consult thoroughly with competent authorities about this in advance and inform them early on about the work and the challenges of the project. That way, a proper assessment can be made and there will be an understanding of the choices to be made. In addition to deciding on the extent of the renovation of a tunnel, a decision must also be made on how the renovation will be handled.

3.4 Big-bang renovation as preparation for micro renovation [link id=”mwknk”]

Tunnel technical installations in tunnels need to be replaced at regular intervals. As long as the installations are not too complicated, replacements can generally be done with limited impact on traffic. That does not mean it is always easy. Due to the interconnectedness of systems, controls and the power supply, those involved must always carefully examine how everything fits together. This is difficult when there is no reliable asset data. It is not always possible, for instance, to see in the software which pieces of code belong to which installations. This makes every replacement a risk.

For more complex installations, such as power supplies and the operating and control system, a partial replacement has never been carried out and, given the many interfaces with other systems, is in fact not manageable either.

For some old tunnels, a big-bang-style renovation may be the only approach. Given the adverse effects of long-term closures of tunnels, it is then worth considering how to ensure that a next renovation can avoid the need for a big-bang approach. For example, it can be smart to do a little more, so that less needs to be done in subsequent renovations and a complete closure is not necessary.

There are several considerations for a major (all inclusive) renovation in preparation for later micro-renovations:

3.5 Future-flexible renovating by standardisation [link id=”k82lr”]

Now that we are on the eve of major renovations, it is important to take a good look at the future: if we want to replace installation(s) in the future with less disruption and at the right time, we must build tunnels now according to a clear system architecture (see Chapter 7 Modular design and system architecture. It is also important that we substantively describe how the various systems are linked to power and control. The description must be about the operation and behaviour of the tunnel and all systems. In order to properly transfer this information, all functionalities must be accurately documented. If we do this it will be possible to carry out replacements of systems and components fairly easily in the future.

The above in no way implies that any specific products are prescribed. Within a certain prescribed architecture, products from multiple suppliers can be used, provided they are designed according to the specifications of that architecture.

3.6 Using a test environment to increase availability [link id=”lsrsz”]

In new tunnel construction projects a lot of time is allocated for testing all tunnel technical installations and their integral operation. Testing is included in the planning and as long as the traffic is not yet used to the new tunnel, this is not an issue. Meanwhile, you see that in DBFM contracts, a great deal of testing is already carried out outside the tunnel to be able to commission the tunnel sooner after completion.

With existing tunnels, it is at most possible to take the tunnel out of service for a few weeks and then really only if there really is no other way, for example because of civil engineering works. In a renovation where many systems will have to be replaced in a short period and/or major modifications are needed such as replacing the control system, closing the tunnel for work and testing is not possible. Not even if parallel construction has already taken place. So many tests need to be carried out that a full closure would take too long. It is also not possible to do the tests in a series of short-term closures as tunnel safety must be ensured after each closure.

One solution is to set up a representative test environment outside the tunnel, with which a large part of the tests can be done and it can be digitally verified and validated that everything works as it should.

Throughout the test chain, systems are tested after design from top to bottom (from preliminary design to implementation design), each time in a larger context. It often starts with the manufacturer of components or subsystems. At some point, those subsystems have to come together and be tested in context. When setting up a test environment (test centre), all these systems can be set up after which (long-term) testing can start. It is also possible to train operating personnel in advance, run through several emergency scenarios with the emergency services and introduce maintenance personnel to the new technology.

After testing in the test environment has been carried out, the installations can be moved to the tunnel, where only the new additions (the final cabling and the physical tunnel) then need to be tested. This can then again be done in parallel with the existing installations as described earlier. The time a tunnel needs to be closed for testing and training can be greatly reduced by using a test environment.

Setting up a test environment can offer more benefits for tunnel managers who need to renovate several tunnels. Much will have to be learned about testing, test scripts and training the people involved when renovating the first tunnel. This will already be a lot easier for the second tunnel and it will be almost routine for the third tunnel. This can lead to less deployment of (scarce) human resources, it can increase the quality of the test result and it can also help to obtain the opening permit more efficiently for all parties.

3.7 Railway tunnels as source of inspiration [link id=”3s3g2″]

The railway system is a complex system with many tunnel technical installations, interfaces and high availability requirements. Maintaining the railway system has many parallels with the renovation of road tunnels. This section provides some suggestions for a different way of thinking and working based on railway projects. These projects focus on the minimisation of nuisances, collaboration between the parties and the prevention of bottlenecks in system integration.

3.7.1 Examples [link id=”23pxx”]

Out-of-service periods

The railway industry works with out-of-service periods, or train-free periods (Dutch: treinvrije periodes, TVPs). These are prepared meticulously, using five-minute schedules, and ensure that the infrastructure remains in operation as much as possible even during maintenance and renovation. The activities during TVPs are as short as possible and prepared in detail in work plans. The basic principle is that tests on the infrastructure are limited to what is strictly necessary. This significantly reduces the costs of non-availability.

This way of working has become part of the DNA of railway engineers. With regard to road tunnel renovations, it is interesting to see which aspects of this approach can help reduce stoppages and traffic disruption.

Simple interfaces between safety systems and other systems

Track safety systems have a high degree of safety. By and large, these are SIL4 systems. The safety level of other systems is lower. Take a railway bridge with mechanical and hydraulic controls as an example. Only the safety lock of such a bridge is included in the track safety system. The interface between the latch and the track guard contains only three or four inputs and outputs (I/Os). By separating these functions, it is possible in design and renovation to carry out maintenance activities and replacements without compromising the safety level.

Use of typicals at interfaces

A metro line such as the Amsterdam Noord/Zuidlijn has several stations with similar installations. These stations and installations are controlled by a ’traffic control centre’ and control room. The systems of underground stations, such as public address, camera, fire alarm system and (emergency) lighting are similar to a tunnel system. The various stations involve different contractors, subcontractors and suppliers, who can make their own trade-offs about inputs and outputs (I/Os) and installations based on functional specifications. This creates problems with system integration and maintenance. This has been solved at metro lines by developing ’typicals’ for client interfaces. This specifies in detail all I/Os and contacts between the individual plants and the controller. These are framework-prescribed to the suppliers.

Release management

A second aspect that can contribute to reducing traffic disruption and failure costs is release management, as applied in the Amsterdam Noord/Zuidlijn, for example. In release management, joint milestones are formulated with the client, stakeholders and contractors in UAV-GC contracts. This also happens during the implementation of the contracts. This requires collaboration with all parties and a willingness to make contract adjustments (within the contractual frameworks) where necessary. Starting conditions and exit criteria are formulated per release and a process is set up to be able to take decisions in case of deviations. It is important here that the client has an active role within the contractual framework. Splitting up the project into releases also creates an iterative process to optimise development, testing and releases throughout the project.

3.7.2 Effects and risks [link id=”23smm”]

Effect on achieving the contracting party’s objectives

The examples described can help the contracting party meet its objectives. This applies in particular to:

• Getting requirements clear
• Control and specification of interfaces
• Early testing and reduction of testing
• Collaboration between parties
• Minimisation of disruption

Effect on preparations

The testing of tunnel technical installations can be done in parallel with civil construction, for instance in a test environment. This puts more pressure on preparation and incremental testing. Basic principle is that new components will be tested before they are installed in the available infrastructure.

Risks

Working practices in the railway industry focus on quality and planning: meeting the target of a release at the agreed milestone. The risks are:

• The cost and lead time of preparation, because the starting point is that all components that can be pre-tested, are actually pre-tested. This can involve substantial costs, e.g. for a full Factory Acceptance Test (FAT).
• With the emphasis on collaboration and an active role of the client and stakeholders, the contract scope can become blurred. This is where a best practice should emerge for how to proceed.
• Not all contractors have the necessary open attitude and it is usually not a selection criterion.

4 Preconditions for tunnel renovations [link id=”qz9ln”]

The approach and outcome of a renovation assignment depend on a large number of requirements and preconditions. This chapter discusses a number of preconditions that typically play a role in tunnel renovation.

4.1 Digital verification and validation as a key precondition [link id=”g5hmv”]

The verification and validation process also plays an important role in renovation projects, because the renovated tunnel must be proved to be safe (again). Improving this process makes it possible to work more efficiently and predictably.

The COB network believes that digital verification and validation of changes in organisation, processes and technology as much and as early as possible is an important precondition for low-noise renovation. In new construction projects, too, a great deal of attention is being paid to digital verification and validation as a tool for opening a tunnel without problems. In order to investigate the opportunities and possibilities for the latter, the living document Digitaal aantonen (in Dutch only) has been compiled within the tunnel programme.

Digital verification and validation is, for example, about:

• Digital verification and validation of the complete control software.
• Validation of the complete control software.
• Development of camera plans (camera simulation).
• Optimisation of design (creating support among future users, competent authority).
• Testing using calamity scenarios.
• Schooling and training of operators.
• Assessment of functionality of software updates.
• Testing of software updates.
• Validation of software updates.

Obstacles to digital verification and validation are the confusion of concepts, the lack of a framework and the lack of support from important stakeholders such as the competent authorities. The COB network has described what each form of digital verification and validation is and what it is not, and its advantages and disadvantages compared to regular verification and validation. This makes the decision to go for digital verification and validation a considered one, thus developing support among important stakeholders such as the competent authorities, clients and contractors.

The results:

• The formulation of unambiguous expectations, definitions and a joint ‘framework’ from the experts in the field (both clients and contractors): what exactly do we mean by digital verification and validation, how far have we got, what do we do and when, and especially: what can and what cannot be verified and validated digitally?
• Formulating the right preconditions on the part of all stakeholders, in particular the competent authorities.
• Initiating and facilitating a dialogue with, and cultivating the trust of, important stakeholders such as the competent authorities.
• Supporting practical projects in thinking about digital verification and validation, forming a vision and showcasing the possibilities thereof.

In the meantime, a work programme for digitisation up to 2030 has been designed, see www.cob.nl/tunnelprogramma/digitaal (only in Dutch).

4.2 Ensuring safety [link id=”z0dck”]

The law and additional documents lay down requirements for the level of services in tunnels to ensure their safe operation. For some subjects, it is very precisely prescribed how safety is to be guaranteed, in other cases it is described functionally. Functional requirements give room to temporarily organise and guarantee the safety level differently during renovations. Sometimes it is also possible to temporarily achieve the desired safety level by using procedural measures instead of technology. If safety cannot be guaranteed in any way during the renovation, the only option is to temporarily close the tunnel. This section outlines a number of possible scenarios for guaranteeing safety during a renovation project and presents a number of best practices.

The tunnel manager and the competent authority must of course agree and record any temporary deviations from the safety requirements. The LTS contains several documents for state tunnels in which further information is given.

4.2.1 Definitions and principles of safety [link id=”xff5m”]

• Tunnel safety concerns the safety of users in tunnels, formulated on the basis of functionality (functional based): if all functions are fulfilled in a sufficient manner, the tunnel is sufficiently safe.
• ‘Sufficiently safe’ means guaranteeing the safety of users and the environment with, on the one hand, an accepted (small) probability of a group risk and, on the other hand, the structural integrity. This probability is laid down in the Warvw and amounts to 0,1/N2 per kilometre tunnel tube per year. N stands for the number of victims among road users, where that number is 10 or more. The probability must be determined according to a prescribed method (quantitative risk analysis, QRA).
• Tunnels managed by the state must be fitted with standardised equipment, in addition to the requirements laid down in the Building decree (Warvw, articles 6a and 6b and Rarvw, articles 13 and 13a). This does not apply to tunnels for which a route decision has already been taken on 1 July 2013 or which were opened or have been opened before 1 July 2013 (Warvw, article 18(3)).
• All safety provisions serve the functional safety purpose and are not a goal in themselves.
• Within the above definition, safety provisions are also functionally interchangeable (within the legal frameworks), whereby tunnel safety remains guaranteed.
• The safety level is qualified in the given definitions and functions by good is good enough (safe is safe enough), demonstrated by the QRA.

During renovations, there are specific options to temporarily provide for the level of safety:

• Minimum required level of safety provisions
• Compensatory measures

4.2.2 Minimum required level of safety provisions [link id=”cwtst”]

The conditions for a road tunnel to be safely operated are laid down in failure definitions and obstruction criteria. During renovations,one could opt for temporarily disabling some of the safety provisions. As a result, the safety functions that these safety features fulfill are temporarily unavailable or less available. In order to determine whether the tunnel can continue to be used in that case without compensatory measures, it must be verified together with the competent authority and the tunnel manager whether the tunnel system still works within the established failure definitions.

4.2.3 Compensatory measures [link id=”ptpz2″]

If the way in which a tunnel technical installation contributes to safety is known, it can be assessed whether this contribution can also be realised in a different way.

For example by:

• giving existing systems an extra task
• offering an alternative with the same result (equivalent fulfilment of function)
• temporarily positioning the tunnel differently in the transport chain.

The simplest example of adding extra value to an existing system is a temporary quick response team or quick intervention team which, for example during renovation or maintenance of the fire extinguishing water system in a tunnel, is positioned near the tunnel mouth and can intervene immediately in the event of a fire or other incident, thus preventing the incident from developing. The quick response team compensates for the temporary absence of the fire extinguishing water supply by being able to intervene very quickly – considerably quicker than when the fire brigade arrives from a fire station – minimising the risk of threatening fire incidents developing further. Safety can thus be sufficiently guaranteed and the renovation or maintenance work can take place.

Examples of an ‘equivalent fulfilment of function’ include:

• When the overpressure in the central tunnel channel (the escape route) is not functioning, escape to the adjacent traffic tube can sometimes be used as an alternative strategy. This is on the condition that the adjacent traffic pipe is then made free of traffic (for example by agreeing in advance that in the event of an incident in one of the pipes the other will be closed off to traffic immediately). Good smoke dispersal must also be provided. This will enable escapees to reach a safe area even though the escape route is not available.
• In surface tunnels, one option is to provide them with exits directly to ground level, which are only opened during maintenance and renovation. These escape routes with short escape distances provide an equivalent level of safety if the longitudinal escape route is not available. The exits can be designed and provided with limited functionality in a relatively simple way.

When the standstill detection system fails, the road traffic controller can actively monitor the traffic in the tunnel by means of the camera systems in the tunnel (CCTV) for timely intervention. This measure can be combined with a lowering of the maximum speed in the tunnel to reduce safety risks.

An example of ’temporarily repositioning’ a tunnel is temporarily banning freight traffic. By not allowing any freight in the tunnel during renovation works (such as during the renovation of the Piet Heintunnel), the possible fire load in case of an emergency is much smaller. It is also possible to lower the permitted speed or to close lanes in order to reduce the risk of incidents and/or their impact.

4.3 Acceptance by competent authority [link id=”l05l6″]

From previous explorations with competent authorities (Dutch: bevoegd gezag, BG), we know that approval by this important group of stakeholders strongly influences or even determines the applicability of new practices and methods. It is therefore of key importance that parties considering new practices and methods take the following points into account:

• The BG must be timely informed about the implementation of new practices and methods.
• Ways of working and methods must be clearly defined and agreed in advance with the BG on at least the following aspects:
  • What can be achieved with this approach (and what cannot)?
  • Which means are used and how do they correspond to reality (and what is not possible)? The virtual development must in principle fully correspond to reality (visualisation, man-machine interface/MMI, used instruments/communication tools, etc.). Any deviations must be clearly indicated and coordinated in advance.
  • Times and duration of applications.
  • Which aspects must still be physically run through in the tunnel?
• Acceptance and rejection points must be unambiguously recorded. The process must be fully documented and verifiable, traceable and reproducible.

Furthermore, everyone must understand and be assured that the independence and integrity of the competent authorities and their advice may never be called into question.

4.4 Working safely [link id=”d6c3r”]

When working on existing tunnels, the focus is primarily on the safety of and availability to road users. This sometimes jeopardises occupational safety. Safety must always be approached as a whole, with traffic safety and occupational safety being considered alongside tunnel safety.

Parties must make a well-considered assessment of the various safety aspects which then leads to an acceptable risk level. Furthermore, working methods and choices must be laid down in an overall safety plan. This plan is primarily drawn up in the planning phase by the client, is then shared with the contractor and will evolve during the project.

Traffic safety in this context concerns the increase in safety on the underlying road network in case the tunnel is closed, especially for a longer time. More traffic on the diversion routes leads to an increased risk of incidents. Intersections and roundabouts become busier and the likeliness of slower moving traffic must be taken into account. Especially when diversions have to be implemented during the day or for long periods of time. A traffic management plan may be drawn up to lay down how to deal with traffic during full or partial closure of a tunnel or tube. This plan must be discussed at an early stage with the responsible authorities.

Occupational safety refers to the safety of the people working in or on the tunnel, such as the workers placing traffic signs or carrying out activities in the working area. Aspects such as working conditions and the tunnel environment are also covered by occupational safety. Renovation and maintenance work often takes place at night and under time pressure, which makes it difficult to work safely. According to Dutch legislation (Working conditions act), attention must be paid to occupational safety already when designing a renovation.

The client is largely responsible for ensuring a safe operation. By means of structural, technical and organisational choices, the client bears co-responsibility for a safe working environment.

4.5 Limiting traffic disruption [link id=”xd8dd”]

Existing tunnels are often an important link in the traffic network and the handling of traffic. Closing a tunnel will in all probability have a major impact on mobility and cause great social losses. In the case of the Eerste Heinenoordtunnel, for instance, it has been calculated that the damage due to the closure amounted to approximately two million euros per working day.

There are several possible strategies to limit the impact of the traffic disruption during a renovation. Chapter 3 Renovation methods discusses these renovation strategies.

4.6 Sustainability [link id=”g57tg”]

In a letter to the Dutch House of Representatives, the minister of Infrastructure and Water Management stated that all national infrastructure must be energy-neutral by 2030. Since tunnels are still often energy guzzlers, this means that a renovation will always include a sustainability component. For the time being, it does not seem likely that a tunnel renovation will be set up purely on the basis of sustainability objectives, but politicians could well demand this.

In recent years, various clients and contractors have developed initiatives with a strong focus on energy reduction. Examples include the Rottemerentunnel (Rijkswaterstaat), the Victory Boogie Woogietunnel (municipality of The Hague) and the RijnlandRoute (province of Zuid-Holland). These new construction projects have provided various learning experiences that are also often applicable to renovations. During the renovation of the Eerste Heinenoordtunnel, Rijkswaterstaat will also focus on the local generation and sustainable buffering of energy for daily use (= consumption excluding emergency operation). The exact details will be determined during the design phase to ensure that the most recent developments can be used.

An energy reduction of at least fifty per cent can be achieved relatively easily, as is apparent from the Energy reduction measures catalogue (in Dutch only), compiled by the COB network. The living document describes practical measures for technical aspects, the process and for contracts.

Before a tunnel is renovated, it is important that there is an overview of the main energy consumers of the tunnel. The COB network has made a checklist that shows which energy-saving measures can be interesting. It is advisable to read chapter 10 of the catalogue of measures after completing the checklist.

4.7 Cybersecurity [link id=”bkkc7″]

In all stages of a renovation, digital security is an important concern for all parties involved. Digital resilience, or cybersecurity, is the effort to prevent damage caused by disruption, failure or misuse of ICT and/or industrial automation (IA) and, if damage does occur, to repair it. The damage may consist of a reduction in reliability, a reduction in availability or a breach in the confidentiality and/or integrity of stored information. Cyber security is a critical requirement for renovations.

The COB network has compiled an extensive living document for cybersecurity in tunnels, in Dutch and in English. There is also a section specifically on cybersecurity during renovations.

If a tunnel is completely closed off and disconnected from its environment, such as the traffic centre or the Rijkswaterstaat network, then we are dealing with a clear and unambiguous situation. In renovations, we are dealing with a constantly changing picture in terms of cybersecurity, such as changing locations, changing development and operational systems, old and new technology, partly old and new interfaces, not to mention the number of parties involved. Digital resilience must be verified and validated, and guaranteed at all times and in all situations. This involves not only the IA systems, but also access to rooms and locations, staff deployed, development systems and tools (such as laptops). It is also important where and how data is stored, both during development and after realisation.

4.8 Future changes [link id=”qntbs”]

Renovations must also take future changes into account. Those have important consequences for the design and renovation of tunnels:

• Safety challenges will change. New fuels and forms of transport will lead to additional safety challenges. Not just in tunnels, but throughout the entire urban system. It is no longer just about tunnel safety, but about integral safety within the city. The COB has worked on this topic in the project From object to system safety (Dutch: Van object- naar systeemveiligheid. The Tunnel safety knowledge platform, together with ITA COSUF, is considering the consequences of alternative energy carriers for safety in tunnels and other underground structures in a European context.
• The spaces adjacent to and on roads are almost the only places where cities can still grow. This calls for smart multiple use of space and smart integral design of tunnels in their environment. Of all kilometres driven by car in the Netherlands, 21% are in built-up areas, while 39% of the total travel time is spent in built-up areas.
• Apart from the autonomous growth of car mobility, there has also been an increase in small-scale freight transport, as more and more purchases are being made on the Internet. In cities especially, this increase leads to extra congestion, CO2 and particulate matter emissions. Making better use of the subsoil and utilising the space on roads and/or motorways will be necessary to make and keep cities liveable and economically healthy.
• There is still much uncertainty about the consequences of smart mobility developments and the speed of change. When constructing and renovating tunnels, where the lead time from conception to realisation can take 10 years or longer, the aforementioned uncertainty can have a paralysing effect. We can say with absolute certainty that the tunnels being devised today will no longer meet the requirements and expectations in 10 years from now. We also know that due to automation tunnels will increasingly be part of traffic networks and systems.
• It is not yet clear how the development of self-driving cars will proceed. The transition to predominantly electric cars and the impact this will have on the provisions in tunnels may also be a factor of significance. It seems right to assume that in the future it will be possible to drive cars closer to each other. As a result, the capacity of roads will increase and lanes can become narrower. However, it is unknown when that will become possible. It is also not yet possible to predict when smart in-car safety systems can (partially) take over the role of safety systems in tunnels, and if specific tunnel safety systems will still be required. Another question is whether it will be possible to use systems developed for tunnels in the future for integral road systems. And does the rapid development of sensor technology offer opportunities to optimise tunnel management and increase availability?

As we do not yet know the answers to these questions, it makes sense to organise the whole tunnel construction and renovation process in such a way as to make interim adjustments possible.

5 Roadmap for renovation method [link id=”d2pm2″]

This chapter describes a roadmap that can help in achieving an optimal renovation method. The roadmap provides an opportunity to assess the effects of measures and can hopefully inspire parties.

This roadmap or step-by-step plan was developed during the planning phase of the renovation of the Eerste Heinenoordtunnel and the planning phase of Programma tunnelrenovaties Zuid-Holland (PTZ) and helped both projects to gain more insight into important aspects.

The roadmap has six steps, the first four involve gathering data and in steps five and six considerations are made. The text below the diagram explains the various steps.

5.1 Step 1: Activities in the tunnel tube [link id=”2lm1w”]

What is the scope of the renovation? Which tunnel technical installations need to be replaced? How are those installations intertwined in the tunnel? What is the quality of the asset data and what still needs to be sorted out? In almost all cases, there will be renovation or replacement of installations, but often the civil structure also needs work. Civil engineering work quickly determines the closures required, both in duration and extent, and thus also traffic disruption.

As a contractor, verify all your assumptions to minimise risks. Do not just rely on visual observations, but carry out actual tests to determine the current condition and, for instance, the need for repairs. When doing so, define the scope broadly. For example, test extensively for harmful substances. Do not limit yourself to asbestos, but also test for other substances that were commonly used in the past and are now banned, such as PCBs, PAHs and exhaust pollution.

Also check how the tunnel construction and the bottom beneath it behave, find out what the associated failure mechanisms are and which control measures are necessary and effective.

No matter how good the preparation, the possibility of unexpected issues remains. Therefore, make sure there is enough buffer space in the schedule to absorb any setbacks. If there is no room in the schedule, setbacks mean that more work has to be done in the same time.

As well as identifying risks, it is important to examine the options for parallel construction: (3.2.1 Parallel construction): is there sufficient building space, what are the options for cable routes, what is the state of the power and cooling supply and are they expandable?

Once the scope of a renovation project is known, the following steps can be taken:

• List all tunnel technical installations to be replaced, as well as any civil engineering work.
• Place all activities required to carry out the replacements and civil engineering work in a table and examine whether the activity required should be a continuous activity or whether it can be carried out in parts.This not only concerns the actual replacements or repairs but also preparatory work such as measuring, testing, and demolishing old parts.
• Determine for each installation/activity in what way it contributes to tunnel safety and whether there are options to (temporarily) reconfigure safety. Is it really necessary to close the tunnel (tube) for that activity? Are there any activities which can be carried out that allow interim opening of the tunnel (e.g. a day with one fan less where a replacement can be carried out in two different closures)? See 4.2.2 Minimum required level of safety provisions and 4.2.3 Compensatory measures.
• For each installation, determine which activities must take place inside the tunnel (tube) and which activities can or do not (need to) affect traffic outside the tunnel tube.
• Determine where the activity should take place and examine to what extent different activities can be performed side by side (logistics management).

If the work can be split into blocks that fit into night or weekend closures, there is much more flexibility in choices for closure. If the work cannot be split up or when doing so makes it too inefficient, the only option is to close the tunnel for a longer period.

5.2 Step 2: Possible time windows [link id=”kmkd8″]

Information about the surrounding area is needed in addition to data about the tunnel. This information is needed, among other things, when determining the time windows for closing the tunnel.

Traffic data

• Is the traffic volume in the tunnel known at different times? Consider not only weekdays, but also weekends, the traffic pattern over the year, the influences of seasons and holiday periods, for example.
• What diversion routes are available? Take a road map and draw the variants on it. Find out the capacity of those diversion routes and the traffic volumes.
• Once the maximum volume of a diversion route is known, it can be established whether it is possible (at certain times) to divert the traffic that normally passes through the tunnel. If a diversion route has periods of capacity for additional traffic outside the planned (night-time) closures, consideration can be given to carrying out work during those periods as well. Keep in mind that road capacity may vary by direction of travel.

Dependencies

Identify the tunnel users and the activities that depend on the tunnel. A tunnel is not only a link in the traffic road network, it often has a particular function in the surrounding area. For example, the Tweede Heinenoordtunnel is located in the route to the vegetable auction in Barendrecht, which means it is heavily used by farmers, especially early in the morning. The Sytwendetunnel is particularly important at weekends for the many visitors to the Mall of The Netherlands in Leidschendam. And the Maastunnel fulfils an important function in ambulance routes to the Erasmus Medical Centre. Any renovation with closures must take these special users into account.

In tunnels with multiple functions and modes of transport (road, rail, tram, bicycle, pedestrian), the intertwining of tunnel technical installations and facilities can greatly complicate a renovation project. It would be well-advised to research the intertwining and dependencies on other projects/works beforehand.

• Are there factors in the surrounding area that may affect certain window times?
• Are any other projects being planned or implemented that may affect tunnel closures?
• Find out in the surrounding area to what extent people accept nuisance outside the scheduled closures. Given the major renovation challenge over the next decade, it is clear that the surrounding area will face regular nuisance. By clarifying the need for a renovation and the nuisance involved, the surrounding will accept closures and nuisance sooner.

5.3 Step 3: Safety aspects [link id=”smk5p”]

When traffic passes through a tunnel, the tunnel must comply with the Tunnel act (Warvw) and established safety requirements. At every stage, it must be verified and validated that these requirements are met, and the tunnel manager must be able to ensure this.

It is strongly recommended for tunnel managers to discuss at the planning stage with the competent authority the plans and how safety will be ensured during the renovation.

• Is there a ‘substantial modification’ as referred to in the Tunnel act?
• In what way will the project verify and validate that the design is compliant and when will testing take place? Can new techniques be applied here (digital verification and validation)?
• In what way will the project verify and validate that safety is sufficiently guaranteed during the renovation?
• In what way will the emergency services be involved in the renovation?
• When will the new facilities be commissioned and does this tie in with the opening permit? It must be avoided that a tunnel cannot be put into operation after renovation because the opening permit is missing.
• When will operating personnel be trained? It is important to note here that if the renovation is carried out in several steps, new or modified training may need to be provided for each step.
• If the emergency services attack plan changes, when will the change take effect? Again, if the renovation is done in several steps, a new or adapted response plan may need to be available and known for each step.
• Do the emergency services want to conduct additional exercises?

The renovation challenge for all tunnels in the Netherlands and Flanders is enormous. Besides the renovation of state-owned tunnels and those of the municipality of Amsterdam, for example, there is also a major task surrounding Antwerp. And in addition to the renovation of tunnels, there are also other infrastructure objects in need of renovation. Given the shortage of engineers, it is important to make the work as attractive as possible. Working for long periods exclusively at night does not fit in with this. Apart from that, clients have a major (legal) responsibility for carrying out the work safely and night work is known to be detrimental to safety.

Given the above, it is important to think carefully about when work should be carried out and how it should be performed.

• Is it really necessary to have all the work done at night? Nights are disruptive for personnel and their family members. In particular, the journey home after a night’s work is dangerous. There are plenty of stories of people calling each other on the way home just to stay awake.
• Tunnel closures are usually subject to time pressure. The time windows in which work can be done effectively are often short. There is often a perverse (economic) incentive to work with less nuisance. This is at odds with working safely and to a high standard. Clients often do not realise that this incentive introduces a work risk and is therefore a trade-off for which the client is responsible.
• Check the working conditions (air quality, fine dust, noise, and so on). How can this be changed to make the work more attractive?
• Obviously, issues such as Chromium-6, asbestos and PFAS and so forth, should be identified in advance, as these types of problems heavily affect the work and lead time. Consider the burden of working with extra protective equipment and the fear of health risks.
• Pay attention to the safe closure of (parts of) the tunnel. Every measure comes with risks! Are there (innovative) solutions to reduce these hazards?

By taking the above aspects into account, a kind of health and safety plan can be drawn up that applies to the specific tunnel for each renovation method and is given its rightful place in the overall assessment.

5.4 Step 4: Project interests [link id=”pchcd”]

To weigh up the options, it is important to know the elbow room of a project. This not only involves issues such as budget and planning, but also any political and administrative objectives. For example, what are people prepared to pay for nuisance-reducing measures? And, for instance in the case of urban tunnels, what is the political or administrative significance of a temporary, or perhaps even permanent, ban on hazardous substances and/or freight traffic through the tunnel? Issues such as project financing and the desired tendering and contracting strategy can also strongly determine the room for manoeuvre. Furthermore, account must be taken of other projects in the area, which are taking place more or less at the same time.

Finally, developments in the overall infrastructure market are also important. It is known that there is a shortage of available manpower, while the challenge is immense in the coming years. When planning a renovation, it is therefore a good idea to make a market analysis. In the spring of 2022, the COB network started making an inventory of the renovation task for the next ten years.

5.5 Step 5: Analysis [link id=”1ph3q”]

For each activity, estimate the number of labour hours required for the whole and any parts (to determine whether splitting up is efficient). In what time frame does an activity fit? See also 10 Logistics management.

Once it is known which activities need to be carried out in the tunnel and how much time they take, that data can be matched with the various renovation methods. To minimise the amount of work, a first round may already be able to determine which renovation method is promising and which is not/less so, by only looking at the activities and the big picture of the environment and the nuisance it will cause. Several variants will then most likely already be discarded.

5.6 Step 6: Trade-offs [link id=”bz99p”]

A table showing the activities on the one hand and the renovation methods on the other, combined with the available time windows and other factors (safety, project interests), will provide insight into the extent of the disruption. This will reveal preferred variants. Then, using e.g. the suggestions in this living document, one can examine which measures can help to reduce the nuisance. This may also provide a basis for making investments. For example, if it becomes clear that the activity ‘measuring in the tunnel tube’ causes 500 hours of closures, an investment in a 3D scan might well be a good idea.

The challenge will be to balance the various aspects. Traffic nuisance can be mapped reasonably well, as can its social costs, but how do you balance these issues against aspects such as occupational safety or political objectives? Trade-offs will have to be determined per project. Each client will also have its own preferences.

6 Preparation [link id=”fwkd6″]

When working out the possibilities of a renovation approach, the following aspects should definitely be included:

• What are the opportunities and threats from the perspective of general project management, contract management, stakeholder management, project control, technical management and system integration?
• What are the interests of the stakeholders? Is the solution positive or negative for them, does it raise dilemmas, and if so, which ones?
• Specifically: what is the importance of and the vision on the solution from the perspective of the competent authority?
• Specifically: what are the effects and necessary preconditions from a contracting perspective?

The top risk of a renovation project is the emergence of surprises regarding the state of the area during the implementation. This is discussed in section 5.1 Step 1: Activities in the tunnel tube.

6.1 Goals [link id=”9ksqq”]

Setting goals differs from one contracting party to another. Setting a goal is one thing, sticking to it until the end is another. Going through an assessment framework as described in chapter 5 Roadmap for renovation method should support the definition of the contracting party’s goals by covering a number of aspects:

• The intended use of the system, the required availability and reliability in the end situation.
• The permissible degree of disruption during renovation.
• The required degree of uniformity in operation. Operation for one tunnel, or from one control centre, or all tunnels on the same control centre?
• Maintainability: for example, should it be possible to replace 3B without hardware modifications? Should it be possible to replace hardware without 3B modifications?
• The degree of future flexibility: how do we look at maintenance and renovation in fifteen years’ time? Renovation with or without a major disruption?
• The degree of (in)dependence on the platform and (in)dependence on suppliers?
• What do I do myself and what can I do as an asset manager and project organisation and what do I leave to the market?

Implications for organisation of tunnel owner

The organisation must be capable of realising the ambitions and objectives. Choosing a particular course of action is possible thanks to knowledge and skills in one’s organisation. The choice may also result in changes to one’s organisation.

• What responsibility for design and system integration can and will the contracting party itself bear? What is the consequence of this choice for the preparation, execution and management phases?
• The choice of goals has an impact on the organisation of the project and the asset manager.
• What is the organisation capable of?
• What additional people are needed?

6.2 Contract and tendering strategy [link id=”tph7f”]

A contract that fits well with the objective acts as a catalyst because of the right incentive. A contract that does not fit works as an obstacle and frustrates. And in all cases, cooperation between parties is essential.

The following issues are relevant here:

• Select a form of contract that supports the goal. Forms and duration: service contract, E&C, D&C, DBM, DBFM, DBFMO, alliance, construction team. Which form suits which objective?
• Incentives in a contract, contracting party gets what it asks for, function of selection criteria, price versus quality (BPVK, former EMVI): incentives on nuisance and technical quality for which the contracting party is willing to pay serious money usually lead to a fertile soil for new developments and innovations. Especially if there is an interaction between less nuisance and smart solutions in the execution.
• How to deal with subcontractors, management deliveries and their embedding in modular contracts? This is very much related to the responsibility that the contractor has for a working system. If the contractor is responsible for a working system, it is also important that the contractor has the opportunity to ‘embed’ the building blocks, preferably by participating in the team as a subcontractor. If the client retains this responsibility, each party can do its own job, but then the client must steer very strongly towards a working system.
• The relationship between a modular renovation and an existing maintenance contract will become fundamentally different. It makes sense to put the M-component out to tender again as well or to integrate it into the renovation contract.
• A maintenance contract appropriate to a modular tunnel: longer contract duration in combination with an availability payment stimulates optimisation of the renovation effort.

6.3 Integrality of design and technical specifications [link id=”2ddkq”]

The importance of integrality is clear to everyone: a working whole as the end result. An integral approach prevents the reinvention of the wheel in each project (with the certainty that different considerations will be made each time) and limits the risks of exceeding the time and costs.

The integrality of technical specifications in fact means that an integral list of requirements is drawn up by the client at the level of the depth of the request, to verify whether a design can be made that meets all requirements.

Points of attention:

• The level of detail of the specifications must be appropriate to the contracting party’s objective. This determines the degree and depth of the functional specification and of the technical specification. For example: if all tunnels have to be operated from a single control centre and the operation has to be uniform, a fully functional design and an MMI design are required. If an LFP (logical function provider) or building block is to be renovated in a ‘plug-and-play’ manner, this requires not only functional but also technical and contractual preconditions. On the other hand, if a tunnel with local control can also be (partially) blocked during renovation, no regulation is needed.
• Differentiation of the implementation level on request MMI/3B/LFPs/civil engineering; again depending on the objectives. The principle is to specify the implementation level in more detail ‘wherever there is an operator’.
• Embedding standards in the request (LTS, HTS, ATS, cybersecurity, basic specifications, prescribed building blocks). The more standardisation is desired, the more the standards must be aligned because of possible contradictions. Do not force projects to make choices based on functionality or technical frameworks for interfaces between modules.
• Integrality in technical specifications of the installations, partly dependent on chosen implementation level. Incorporating RAMS, cybersecurity, constructability, testability, maintainability, replaceability, education, training and practice; see reasoning in previous point.
• Specifying is also designing; verification and validation by the client must be appropriate to the degree of depth. The request too must be verifiably safe and comply with the user’s wishes.

6.4 Business case [link id=”w1btl”]

Every project will involve considerations that must be presented to administrative decision-makers. In many technically oriented projects, people appear to have trouble with this. The Public business case guide (Dutch: Handleiding publieke businesscase) of the Ministry of Finance outlines a working method that can be used to produce a broad substantiation and that may allow decisions to be made more quickly.

A business case provides an analysis of all business economic aspects of a project. The parties involved in the financing or operation must make agreements on this. A business case involves annual costs, revenues and a possible government contribution. A business case can also be used to manage a project (monitoring and steering) and can be used for projects relating to investment, sourcing and (re)organisation issues. The use of a business case for scope changes in a project with impact on a programme is an option to be considered.

A business case is a tool to:

• arrive at good (economically substantiated) decision information;
• use, justify and select verifiable and justifiable methodologies, alternatives and assumptions;
• take a broad view;
• think in a structured way;
• present a concise and clear story to the decision-maker and thereby support decision making.

6.4.1 What can the business case do and what not? [link id=”7h9qg”]

Besides the public business case, there are other instruments for assessing and selecting projects. One example is the social cost-benefit analysis (SCBA). Each instrument has its own specific purpose and applicability. The SCBA assesses projects from a broad prosperity perspective of social costs and benefits. This also includes effects on health, the environment and so on. Non-financial benefits and costs are also quantified and given a financial value. This concerns the effects on society as a whole. The public business case only looks at the financial consequences. The SCBA and the business case are therefore not mutually exclusive; a project can require both an SCBA and a public business case.

Rijkswaterstaat often deals with projects which are not profitable in purely financial terms but which are still carried out for other reasons, such as political or social ones. In the public business case, the focus is specifically, and in detail, on the financial effects for Rijkswaterstaat in terms of expenditure, revenue and risks.

Advantages

• As well as the content of a business case, the process of its creation is also important. By using the process to justify which alternatives you have researched, which methods you have used and which assumptions you have made, the business case becomes understandable, verifiable and justifiable.

Disadvantages

• The benefits from the business case do not always end up with the party who incurs the costs.
• There is no cash flow in relation to the social benefits that can justify the payback period.
• It is not always possible to activate the value from the business case on the balance sheet.
• It is not a panacea to force decisions.
• The social costs and benefits are not part of the public business case and are therefore not included in the decision-making process.

6.4.2 Effects and risks [link id=”fq5qd”]

The financial effects in terms of costs and benefits and their distribution across multiple projects are clear. The business case facilitates discussion about scope and money and contributes to considering alternatives. Hereby the business case has an impact on the support for decision making: questions can be answered by calculating and presenting alternative scenarios.

Drawing up and executing the business case takes time. Knowledge of the business case will have to be introduced into both the project organisation and the management organisation.

Decisions based on the business case will be reflected as requirements in the contract. In case of contract transitions, any price development of energy tariffs, material costs and management and maintenance costs constitute a risk.

The costs of the traffic measures are included in the business case. The benefits will not directly accrue to the project. The reduction of hours lost for motorists indirectly contributes to the economy, but cannot be directly estimated as a value. However, the client (financier) can assign a certain value, which can then be included in the business case. This can then make a virtual contribution to a possible positive result.

Sustainability is part of the business case. By using calculation tools such as Dubocalc, costs can be made transparent. CO2 reductions can also be valued in monetary terms and thus made part of the business case. The COB has developed a separate business case for circularity, which focuses on the harvesting, reuse and deployment of a priori circular installations.

6.5 Ingredients for a collaborative culture [link id=”4nzt0″]

Projects are becoming increasingly complex. This is especially true of projects that take place underground, such as tunnel renovations. Complex projects require collaboration between all those involved: one simply needs each other to bring the project to a successful conclusion. This chapter describes the ingredients for successful collaboration between client (CL) and contractor (CO). Chapter 11 Licensing process takes a closer look at cooperation with other parties (both formal and informal).

Appendix 6: Selection based on KIS describes how quality, integrality and cooperation were included as selection or award criteria in the tendering process and project implementation in the renovation and restoration of the Maastunnel. Appendix 8: Stakeholder management and communication discusses the collaboration with the environment during (especially) the renovation of the Velsertunnel.

A successful collaboration is one in which the challenging task is realised within the preconditions, i.e. with the desired quality and within the scheduled time and budget. This sounds simple, but in practice this is far from always the case.

6.6 Shared vision on collaboration and team dynamics [link id=”sql26″]

Every project team wants to start as soon as possible. Therefore, projects are increasingly organising a project start-up (PSU). A PSU, however, is not enough. Collaboration must be given structural attention in separate team sessions throughout the project. In many cases, an external organisation is brought in to support the team with a collaboration-focused session once every three to five months throughout the project. Hence, a project start-up is followed by several project follow-ups (PFU). It is important to pay attention to and share knowledge about team dynamics and systems thinking during these sessions.

Teams become more effective when attention is paid to team development. Actively paying attention to team patterns (dynamics) accelerates this process. Based on a systemic view of teams, this process proceeds in a predictable way about which much has been written. See, for example, Aan de slag met Teamcoaching (Getting Started with Team Coaching), by Marijke Lingsma (Boom/Nelissen Publishers, 2nd edition, 2005) and Forming Storming Norming Performing, by Donald B. Egolf, Ph.D. (Writers Club Press, 2001).

For project teams in the construction industry, two phases are particularly important, the so-called forming phase and the storming phase.

A second important perspective is systems thinking. Systems thinking is a way of always looking at the whole (the system, the team) rather than the separate parts (the individuals). For example, if things are not going well in a team (the team is not achieving enough results), people often tend to look at who is to blame. As a result, people start withdrawing or defending themselves. That way, the person in question goes into ‘survival mode’. As a result, effective information exchange between team members falters. And that is precisely an important reason to work together: the exchange of information.

If you apply systems thinking, you look not only at those responsible (that remains necessary!), but also at the group as a whole. How does the team deal with not getting enough results? After all, all team members are responsible for that. Each team member observes behaviour (consciously or unconsciously) that does not contribute to achieving results. For example, a team member who repeats himself ad nauseam. Other team members also notice this, but they may think the chair should lead the discussion better and should cut off the person in question. You could therefore argue that the team lets this happen and makes no effort to use time effectively by holding him accountable for repeating moves and to investigate why this team member repeats himself every time anyway. This usually contains information not yet heard by the group.

In Appendix 9: Lessons learned from Velsertunnel renovation are more learning experiences to be found gained during the renovation of this tunnel.

7 Modular design and system architecture [link id=”12×75″]

The system architecture of a tunnel – an unambiguous description of all aspects of a system and the interrelationships – determines to a large extent how the renovation can be carried out. If modular design and construction is chosen for a new-build, future renovations will be considerably simpler.

Modular design and construction means that the entire tunnel system is divided up into logical building blocks. These building blocks are then connected via defined interfaces. The logical structure makes it easy to replace parts in the future.

Although modular design and construction is not a prerequisite for renovations, it does have several (major) advantages:

• It may prevent large-scale renovations in the future: if a tunnel is built according to a certain structure, it is easy to replace a building block. Modularity could even lead to the disappearance of large-scale renovations because replacements become possible within regular operation and maintenance. This is especially true if the next renovation takes into account matters such as extra building space, power supply and (network) infrastructure.
• It reduces the design effort: when a managing organisation operates several tunnels, an unambiguous and modular concept can be advantageous. A good design must be made for the first tunnel (as always), but when subsequent tunnels are renovated, the first design can be largely copied. This repeating effect simplifies the design, but also the validation and verification for the next tunnels, increasing the reliability (quality) of the whole.
• It makes the operation and maintenance of tunnels simpler: if several tunnels are built using the same methodology, their operation and maintenance will become simpler. Operating processes can be carried out uniformly and matters such as spare parts and/or future replacements can be organised more simply.
• Safety can be verified and validated: if several tunnels are constructed in the same way, it is also possible to uniformly organise the verification and validation of safety. Discussions with the competent authorities can be avoided, also in the case of future (small-scale) replacements.

7.1 The importance of system architecture [link id=”p3b5k”]

When a system is built according to a certain system architecture, it offers a handle for thinking about the replacement of (partial) systems and/or the expansion/addition of functionality. Adhering to/modifying the system architecture keeps the system transparent for all stakeholders. A uniform system architecture can have many advantages for an administrator with several similar systems.

System architecture structures both the analysis of an existing system and the design of a new system. A good system architecture also makes the implementation of the needs and wishes of the various stakeholders transparent. This makes a system architecture an essential source of information for non-technical stakeholders as well.

The creation/ modification of a system architecture is an iterative process that starts with the desired functionality and continues through to the final solution to be implemented in hardware and software. It is important to formulate clear requirements/starting points when designing a system architecture.

7.2 Aspects of system architecture [link id=”4pnqs”]

A system architecture is determined by the following aspects:

• Functionality: the primary functions must be clearly expressed in the system architecture. What must the system be capable of?
• RAMS: reliability, availability, maintainability and safety. Based on these four aspects, the desired quality of the primary performance for each system can be described, determined and monitored during its lifespan. Maintainability includes, in addition to periodic maintenance, the renovation of (sub)systems that have reached the end of their lifespan or must be replaced by systems with changed functionality. (Sub)systems that contribute to safety must be clearly recognisable in the system architecture.
• Segmentation: a system with a lot of repetition in its architecture can benefit from segmentation, especially in the context of renovation. The repetition in a tunnel, for example, is in the location of emergency stations and escape doors.

Three-layer structure

Tunnels built before the introduction of the LTS were not always built according to the currently prevailing three-layer structure. The sub-installations are interwoven in the operating and control systems and in the distributed input/output (I/O). Classically built operating and control systems are characterised by a flat architecture, in which all individual control and monitoring signals are connected by means of distributed I/O over the entire system; wherever this was most convenient, not based on a structure/architecture (technical distribution). To put it more succinctly, a tunnel was built, equipment was installed and a control system was built on that technology; in other words, it was designed from the perspective of technology.

The result is that in the various PLCs (programmable logic controllers) and within specific I/O blocks, elements from several systems are present at the same time. The exchange of data on these I/O blocks and PLCs is therefore less transparent and, in the case of modifications, requires much effort from the programmers.

Depending on the size of the tunnel, the number of I/Os is different, which means that each tunnel has a unique solution. This makes it very difficult to replace a sub-installation, because you have to carefully find out how things are built in the specific tunnel for the specific installation to be replaced, in order to avoid hitting other installations unintentionally.

7.3 System architecture methods [link id=”hgwc7″]

Model-based systems engineering (MBSE) is increasingly being used to define a system architecture and to develop it further. In this model, a design is no longer described in text, but with several diagrams. Modelling languages such as UML and SysML are used for the sake of clarity. Well-known packages in which such models can be documented are Enterprise Architect and ArchiMate.

The system architecture must be developed from the point of view of various stakeholders, such as end users, developers, system engineers and project managers. Philippe Kruchten’s ‘4+1’ model is very useful for this purpose. The model is designed for ‘describing the architecture of software-intensive systems, based on the use of multiple, concurrent views’. The four views in the model are the logical view, the development view, the process view and the physical view. Furthermore, selected use cases or scenarios are used to illustrate the architecture (the ‘+1’ view).

Philippe Kruchten’s ‘4+1’ model

The four main views in the model:

• Logical view: the logical view is concerned with the functionality that the system provides to end-users (UML: class and status diagrams).
• Process view: the process view deals with the dynamic aspects of the system, explains the system processes and how they communicate, and focuses on the runtime behaviour of the system. The process view addresses concurrency, distribution, integrator, performance, scalability, etc. (UML: activity diagram).
• Development view: the development view illustrates a system from a programmer’s perspective and is concerned with software management. It uses the UML component diagram to describe system components (UML: component diagram and package diagram).
• Physical view: the physical view depicts the system from a system engineer’s point of view. It is concerned with the topology of software components on the physical layer as well as the physical connections between these components (UML: implementation diagram).

The architecture is illustrated by several use cases or scenarios, which become a fifth representation; the ‘+1’ representation in the centre. The scenarios describe sequences of interactions between objects and between processes. They are used to identify architectural elements and to illustrate and validate the design of the architecture. They also serve as a starting point for testing a prototype architecture.

7.4 Structure of the system architecture [link id=”mwzsl”]

The starting point for a system architecture is always the desired functionality. This must become clearly visible to the users of the system. The systems to be used are designed on the basis of functionality. The cohesion of these systems is worked out in a system breakdown structure (SBS). Once the SBS has been worked out, it is important to determine for the various systems whether they will be realised in hardware, software or a combination of the two. This leads to a hardware and software architecture.

The hardware architecture shows the physical components of a system and their mutual relationships. It enables hardware suppliers to recognise how their components fit into a system architecture and it provides designers of software components with important information needed for the development and integration of software. By clearly defining a hardware architecture, the various traditional technical disciplines (e.g. electrical and mechanical engineering) can work together more effectively in developing and producing new machines, devices and components.

A software architecture is the structure or set of structures of a software system, consisting of software elements, the relationships between these elements and the properties of both. The term software architecture is also often used to refer to a coherent description in which the aforementioned structure is documented. A software architecture typically focuses on the external characteristics of a software element. The design usually focuses more on the internal characteristics. However, there is no clear dividing line between software architecture and (system) design.

When the system architecture contains repetition to a greater or lesser degree, it may be useful to consider segmentation in the system architecture. A tunnel, for instance, has a repeating pattern of escape doors and emergency station units with associated systems for indication. A Speed Discrimination System (SDS) and the lighting system also have sections in them. In the case of an SDS, they are even divided up into lanes. By placing these systems in a system architecture per segment, it becomes possible to renovate each one separately. However, this is subject to the condition that the basic systems such as power supply and communication are also designed in segments. If, eventually, such segmentation is also realised in the software of the coordinating control system, it will also become possible to update the software per segment.

The above also touches on the possibilities of modularity in the system architecture, especially if the full functionality of operation, control and associated hardware can be included. Modularity is also the basis for the so-called building blocks. Both functional and physical interfaces are important in modularity.

7.5 Renovation from within existing system architecture [link id=”qv9t9″]

To arrive at a well-founded approach to a renovation based on the desired system architecture and the specific project opportunities, we outline the following approach:

1. determine desired system architecture
2. take stock of current system architecture
3. determine impact of differences between desired and current architecture
4. determine scope of renovation.

We do this by dividing the tunnel technical installation system in hardware and software terms into parts that can be replaced and/or changed within the system, independently of other parts. Such parts are also called configuration items (CIs). A CI can be a primitive system building block or a collection of CIs that form a subsystem. We distinguish between hardware CIs (HWCI) and computer software CIs (CSCI). The latter are also called applications. A HWCI consists of hardware and possibly embedded software that offers a specific functionality.

7.5.1 Determining desired system architecture [link id=”zt82n”]

The flow chart below shows the steps to be taken and the necessary questions to be asked when developing a desired system architecture. The numbered steps are discussed below the chart.

1. Make an inventory of the smallest possible functional units (CIs), both for the hardware and the software architecture. Regarding hardware, stop dividing at commercial-of- the-shelf (COTS) products, for example sensors, such as temperature and light intensity gauges, and actuators such as fans, pumps, lamps, etc.

2. Determine whether this unit is a buy, make, or buy and change part:

• For hardware buy parts (COTS products), check whether the current functionality and the desired future functionality and the quality standard can be delivered by at least three suppliers. For quality, consider accuracy and measuring range (sensors) and in general reliability, availability, lifespan, maintainability and safety (RAMS).
• For software buy parts (COTS parts), check whether it concerns internationally generally applied and accepted software, for example UNIX, Windows, SQL services, Enterprise Architect, etc. Also check whether the version in question is still supported for at least seven years. If this is not the case, reconsider the choice.
• Make parts: will the part be built in-house or will the construction be outsourced?
• Buy and change: in this case, a COTS product is adapted to the desired functionality. This variant must take into account both the concerns and disadvantages of both a buy and a make part. A buy and change part is a ‘special’ and is therefore not preferred. If a buy and change part is chosen, it is good to reconsider whether a standard functionality of the COTS product will suffice or whether it would be an option to build the part yourself (make).

Note:

By this we do not mean the PLC with its programming tool (buy) and the configuration using the programming tool (make).

3. Present the architectures schematically. See below for an example of a road traffic control centre, as drawn up for the market consultation for the CHARM-project in 2013.

4. Map the software architecture onto the hardware architecture. If this mapping does not make sense or if there are conflicts at any point, these bottlenecks must be resolved by going through steps 1, 2 and 3 again for these bottlenecks.

5. Further detailing of interfaces between the units (happy and un-happy flow):

• What information must be exchanged (now and in the future)?
• Which data transmission technology is used: push, pull or polling?
• Which are the critical, primary and secondary processes/functions?
• Which processes/functions are time-critical, which are not, and what are their performance requirements?
• Data quality:
  • Reliability, availability, serviceability, usability and installability (RASUI).
  • Functionality, usability, reliability, performance and supportability (FURPS) in relation to software requirements.
  • Fault finding, extensibility, portability, scalability, security, testability and understandability. Often referred to as agility in software.
  • For databases: reliability, availability, serviceability and recoverability (RASR).
  • Compare and check the hardware and software architecture again. If this check does not appear logical or if there are conflicts at any point, these bottlenecks must be resolved by going through steps 1 to 5 again.

Example of the public address system for a safe escape route and traffic conduit. Each new installation is held against the current or new energy and network design to monitor its integrality. With the standardisation of the coding, the cable list can be generated from this, including power balance, cable length and cable labels.

7.5.2 Taking stock of current system architecture [link id=”3gcg7″]

This includes developing the current system architecture into the design of the desired system architecture. This will definitely not result in a one-to-one comparison. At best, the interfaces of a collection of CIs will match. At worst, the interfaces are located within a different part/component.

7.5.3 Determining impact of differences between desired and current architecture [link id=”m99ng”]

An overview of all differences is made based on the desired and current system architecture. The impact of each difference is determined using, for example, a trade-off matrix to arrive at the desired system architecture. A possible trade-off matrix is shown below (this matrix is only an example and certainly not complete).

7.5.4 Determining scope of current renovation [link id=”nfcqm”]

The final scope of the renovation is determined on the basis of the impact analysis (trade-off matrix). If the conversion to the desired system architecture is realised in phases (read: several renovations), this can be included in a multi-year plan.

7.5.5 Advantages and disadvantages of this approach [link id=”w48vv”]

Advantages:

• Systems with a component-based architecture are easy to expand, are transparent and comprehensible and promote the reuse of certain parts of the code.
• As systems become increasingly larger, the importance of a good architecture increases.
• Documenting a software architecture facilitates consultation with stakeholders, makes fundamental design decisions transparent, and enables the reuse of elements and patterns from the designs for other projects. A software library may then even be included, which further guarantees uniformity.
• By selecting COTS products in this way, a vendor lock (dependence on one supplier) is avoided as much as possible and a level playing field is maintained.
• Development of the desired system architecture will provide direction for further standardisation.
• Doing more things at the programme level and fewer in projects. (This can also be regarded as a disadvantage.) For example, release management at programme and/or Enterprise Architecture level.
• Projects become less complex with fewer risks during system integration.
• Greater certainty of a verifiably working and safe tunnel.
• More transparency in the design process of the contractor.
• Once the desired system architecture has been established throughout the organisation (see disadvantages), determining the scope of the renovation will be faster.
• Faster understanding of tunnel configuration (and common cause effects).
• By renovating on the basis of a well-developed system architecture, it can be expected that the effort, and therefore the costs, will be lower during a following renovation.

Disadvantages:

• This approach requires thorough and intensive preparation of the renovation.
• Development of the desired system architecture requires a one-off pre-investment (higher project costs for the first renovation).
• The desired system architecture must be broadly defined and supported by the entire tunnel organisation.
• The desired system architecture must be managed and safeguarded centrally.
• Who is responsible for managing the system architecture, module definitions, specifications, files and implementation?
• If the responsibility is properly organised, the following risks arise:
  • Projects start to convert/project specific modules without reporting.
  • Reference design is not kept up to date.
  • Nobody is/feels responsible for the quality.
• Doing more things at the programme level and fewer in projects. (This can also be seen as an advantage). For example, release management at programme and/or Enterprise Architecture level.

7.6 System architecture of existing state tunnels [link id=”4fz2f”]

In terms of system architecture, there is a clear distinction between tunnels realised before and after the introduction of the National tunnel standard (LTS). Most pre-LTS tunnel control systems were realised on the Sattline platform based on a tunnel library and have an architecture based on one or more PLCs per civil object (e.g. a traffic tube). Converting to the LTS system architecture will be a challenging task. Unless a method is found for a gradual transition from old to new, a big-bang renovation seems the most obvious method. After renovation, the system architecture of the Velsertunnel, for example, remained unchanged in the various versions of the LTS.

In the VIT2 project, experience was gained with the replacement of several subsystems (logical function providers) based on limited modifications to the coordinating control system (CCS). In terms of hardware, there is a diversity of platforms within LTS tunnels on which the coordinating control system is realised: PLC systems from Siemens, ABB and Schneider as well as an implementation on a VMWare Linux Platform by Technolution. The CCS is characterised by variations and project-specific deviations from the LTS. The LTS is still evolving and experience has shown that no tunnel in the civil sector is constructed as a standard, which requires project-specific modifications.

A large-scale renovation of a tunnel built according to the LTS is not yet imminent, but when it does it will be an interesting challenge. From a management and maintenance point of view, scenarios can be developed to bring all tunnels up to the same level in advance.

In terms of architecture, a CCS in accordance with the LTS acts as ’the man in the middle’ in several areas. This results in the following architectural features:

• CCS controls the entire tunnel complex: not only the tunnel tubes, but also the service buildings and their grounds.
• Interaction between underlying subsystems always takes place via CCS.
• CCS has commands on a functional level, but also commands to control components directly.
• CCS takes care of all storage to the event recorder, both for alarms/notifications and for all collected measurement values.

This functionality is contained in a collection of closely linked self-contained modules (SCMs) that together form the coordinating control.

Modular software architecture

The following suggestions for a possibly slightly different modular software architecture are undoubtedly not new, but they are listed here for the sake of completeness. They are mainly aimed at breaking down the renovation task into smaller bite-sized chunks that can perhaps be tackled more or less independently of each other. The suggestions given below are in no particular order. The starting point remains that everything runs via the CCS, but that a number of coordinating tasks have been placed at a lower level (LFP). The CCS will consequently act at a somewhat higher/abstract level.

• Operating and monitoring of service buildings: operating and monitoring of service buildings and surrounding areas is not really a core task of the road traffic controller. This task can also be assigned to another party through its own service building/terrain application. Building management systems generally available on the market will be able to provide much of the required functionality. Only a general status of the service building/terrain and a limited number of alarms are then linked to the CCS. This could already be done prior to the renovation. This reduces the complexity of the actual renovation.
• Merging and digitising of all voice communication: the LTS distinguishes between intercom, emergency telephone, telephone and public address. With today’s technology, all these types of voice connections, including audio storage and digital telephone connections, can be implemented in a VOIP/SIP switchboard. All connection-related commands as well as queues and audio storage can be handled there. Since the CCS only has to handle the status of such a switchboard, this leads to great simplification. Such digitisation can be prepared fully in parallel prior to a renovation.
• An autonomous traffic tube closing system: the traffic tube closing system is an assembly of a traffic management system, a warning sign, barriers, traffic lights and an external connection. The CCS takes care of the functional handling of the closure of a traffic tube by addressing these objects in a certain sequence. This coordination can also be put at a lower level in an LFP Traffic Tube Closing System. The CCS can then suffice with the functional open/close commands and monitoring of the process. This makes the traffic tube closing system become available as a separate functional component with a simpler interface to the CCS. This offers opportunities to quickly place such a functional component in front of a tunnel in case of a renovation. The more so if it also has extensive local control outside the CCS. It can also be used as an emergency control. Besides, an autonomous traffic tube closing system would be a good ‘building block’ candidate.
• Escape door system: the area around the escape door contains several systems (lighting and audio) that draw the attention of the road user to the escape door in case of an emergency. In the current architecture, these systems are controlled by multiple LFPs. In current implementations a module that combines several such functions is often already deployed in the tunnel. This could also be considered in terms of system architecture.
• Automatic and manual operation: both automatic and manual operation are made available in the CCS. Automatic operation is aimed at providing functionality, manual operation at directly controlling components of the LFP. The question can be asked whether it is necessary that a CCS, besides indicating (for instance) a desired ventilation percentage, must also be capable of switching each ventilator on and off manually. The latter could also be achieved by a separate interface on the LFP.
• Tunnel control with configurable command structure: a tunnel control system with configurable menus could be useful during a renovation process. A functionality that is being worked on during the renovation process can be made temporarily ‘unavailable’ (‘greyed out’ for the experts). This would allow a tunnel control to be operated, with for example manual controls for certain subsystems that have not yet been tested and under certain conditions, until the next test moment. Obviously, this should be accompanied by a thorough risk analysis with control measures to ensure safety in the tunnel.

8 Tunnel technical installations [link id=”hfdch”]

The traditional view of tunnels is that, when designing and installing tunnel technical installations, limited attention is paid to the replacement of those installations. For systems with a lifespan of 25 years or more – think of the energy system – it holds true that aspects such as lifespan and replacement are less urgent than with ICT technology, particularly control systems, where the lifespan is increasingly determined by things such as software updates and their rapid development. However, even for installations with a longer lifespan, replaceability is becoming increasingly important to reduce renovation time and traffic disruption. These developments increase the need for a different type of construction.

The available building space and the (modular) construction of the tunnel technical installations are the most important aspects when replacing and renovating installations. For example, building space ensures that new installations or components can already be built and tested while the existing installations are still in operation. Access to these components outside of the traffic tubes is, as far as possible, a distinct advantage. Another important condition is that the power supply, network and control system, including cabling, are or can be prepared for parallel construction.

8.1 Construction of installations [link id=”832bx”]

When renovating, one can choose between big-bang and micro renovations amongst other things. In making this choice, it is important to know what the remaining lifespan of existing tunnel technical installations is and whether, and if so how, individual installations can be replaced while taking into account the safety of personnel, tunnel users and the environment.

If replacements are required in the current situation, it is necessary to investigate (per tunnel) how the systems are constructed, how the various functions such as the power supply and control have been organised and how adjustments can be made. Projects are therefore often costly and time-consuming, especially since it must be verified and validated time and again that a tunnel can be used safely after having been renovated.

When Rijkswaterstaat is preparing for a renovation, a document entitled ‘LFP replacements’ (Dutch: LFV-vervangingen) is being drafted during the tender phase to give project teams an idea of the possibilities (see pop-up box). This document can help to determine the impact of the conversion when preparing for a tunnel renovation. Also for tunnels which have not been built or are not built according to the LTS the ‘LFP replacements’ document can provide insight into how to deal with the tunnel technical installations in tunnels. Because many non-state tunnels are still ‘inspired’ by the LTS, for example the Hague tunnel standard (HTS) and the Amsterdam tunnel standard (ATS).

In total, a (state) tunnel has approximately 50 functions that are described in the LTS as logical function providers (LFPs). For each LFP, the document provides an overview of its purpose, the function to be provided, the way in which the installation is traditionally controlled, how, according to the philosophy of the LTS, control should be carried out, in which way any parallel construction could take place and what points of attention are relevant. Insight is also given (from the LTS perspective) into how tunnel safety can be managed.

As indicated, an important condition for the parallel construction of new tunnel technical installations is that the energy supply, the network and the control system, including cabling, are or can be prepared for this. This is discussed in more detail in the following sections.

8.1.1 Energy supply [link id=”l42ld”]

A renovation also provides an opportunity to make the energy supply more sustainable and future-proof. The power supply is a fairly flexible system that is robust, reliable and very long-lasting. However, in most cases – especially if the previous renovation was a long time ago, or if the energy supply was not included in the previous renovation – a great deal of work will have to be done on the energy supply when carrying out a renovation.

In major renovations, the main features of the energy supply should be known more than two years before the tender. In case of minor renovations, this is one year. Shortening these periods increases the risk of renovation disruption.

To be able to handle tunnel equipment replacements flexibly in the future, it is recommended to already take this into account when replacing the power system by incorporating ‘conversion capacity’. In practical terms, this implies incorporating:

• spare capacity in distributors and cabinets
• spare capacity in power
• spare capacity in cable paths
• easily accessible connection points across the entire area. Examples include e-spaces underneath the road surface at bored tunnels (Victory Boogie Woogietunnel, Westerscheldetunnel), roadside system houses (Coentunnel), a cluster of cabinets around an escape door, or other solutions appropriate to the project. These service hubs can be combined with communication, control, etc.

In a power supply system with sufficient conversion capacity, it becomes possible to build and power replacements of one or several installations in parallel. This allows for replacements with less impact and risk. The right plan may avoid having to carry out a lot of (inconvenient) digging work. It may be helpful here to introduce a system house (if not already present) at strategic locations all around a tunnel in which provisions such as energy and communication are provided.

As in older tunnels the spare capacity from the past is usually already used up, additional materials will initially be needed to realise the conversion and spare capacity: thicker cables, extra-large cabinets with extra groups, possibly even ‘uniform’ cabinets that are only used to a limited extent. This will lead to additional costs that will only pay off at a later stage, although these additional costs are easily manageable if they are taken into account in the design.

Appendix 3: Renovation-proof energy supply contains more information about a renovation-proof energy supply. Appendix 4: Renovation-proof EMC and earthing discusses the importance of EMC (electromagnetic compatibility) and earthing in renovations.

8.1.2 Information exchange (network) [link id=”h2xqg”]

Operating and using the equipment in a tunnel currently requires a large number of cables. Although many connections are already possible via existing systems in so-called ‘distributed I/O’ solutions, there are many thick bundles of cables. More modern systems often use ethernet. This reduces the number of cables.

Unfortunately, current practice often shows that each supplier uses its own solution or protocol and that various networks exist side by side. As each network also needs its own routers and the like, and such equipment often has a limited lifespan, this results in a relatively high level of maintenance and possible traffic disruption.

A possible solution is the creation of a universal system for information exchange. This could range from the installation of a dark fibre network with patch panels at strategic locations to an intelligent system where any kind of information can be presented and transmitted to where it is needed. An example of a fibre infrastructure is the laying of a 96-core cable where the fibre numbers are assigned to installations according to a fixed pattern, for example SATO coding (cores 20-29 for lighting). This variant allows each supplier to maintain its own communication system, but still requires a lot of peripheral equipment. It is therefore better to work with V-Lan per installation, as applied in the Westerscheldetunnel.

Another option is the application of industrial systems where a wide range of signals can be connected to a node (intelligent junction box). These signals can then be made available on another node. This type of system has a very high degree of reliability and guaranteed connection and has been specifically designed for industrial environments.

When building such an infrastructure, attention must also be paid to redundancy. If all devices use the same cables, there is a chance that all systems will fail in the event of a cable break. A ring structure solves this problem, as each intelligent junction box can then be accessed from two sides.

8.1.3 Sectioning of installations [link id=”zsrs4″]

Certain tunnel technical installations occur more frequently in a tunnel tube. Think of escape doors, first aid stations, cameras and loudspeakers. This repeating element can serve as a basis for the design and execution of work, possibly even for software construction and testing. Particularly when a lot has to be done in a short time, it can limit the disruption during renovation.

By dividing a tunnel tube into a number of ‘repeating’ sections, it is possible to make a ’typical’ tunnel section and repeat it in terms of design, but certainly also for production, assembly and commissioning. This involves ‘sectioning’ in the longitudinal direction of the tunnel. Other sections are also possible, such as a ventilation cluster that is repeated several times, or a carriageway of which several are situated next to each other.

Sectioning can help in the design of the equipment, in organising the work in the tunnel and in improving quality by improving routines and learning from mistakes. Smart sectioning can also offer many advantages in management and maintenance.

Sectioning can also be designed in such a way that a section can be taken out of service without affecting other sections. By making smart choices, the tunnel can remain in service in the event of a failure or deliberate shutdown of the tunnel technical installations in a section, by jointly determining the correct oversizing and/or the correct failure definitions for each subsystem. With smart sectioning, it is even possible to take a part of the control system out of service for maintenance work and/or functionality upgrades.

A typical or section can also be simulated/virtualised/physically built, allowing designs to be reviewed and tested at an early stage, both via the OTAP and the OTO route. By establishing a typical/section as an architecture decision (architecture principle) within an organisation, knowledge is secured and this architecture can then be applied in many tunnels. Attention must of course be paid to the unique physical properties of the relevant tunnel.

It is not necessarily required to prescribe specific products. Components with a similar performance and a form-fit compatible interface and mounting method can enable a fast exchange (restoration of function) in case of failure or replacement. A major advantage for management and maintenance!

Further details on sectioning

For sectioning at lane-carriageway level, consider:

• Traffic detection
• Dynamic route information
• Height detection
• Traffic control, matrix signs (informing road users)
• Barriers with traffic signals or traffic lights

For sectioning at tube level, consider:

• Escape door control
• Escape route lighting and indication
• Low-voltage distribution
• Ventilation
• First aid stations
• Tunnel lighting
• Visibility meter
• CCTV
• Speed Discrimination Systems (SDS)
• Public address/intercom
• Control and local network infrastructure

For other tunnel technical installations, a tube or tunnel network solution may be chosen. Consider, for example:

• Power/lighting in service buildings
• Fire alarm system in service buildings
• HVAC: heating,ventilation and air conditioning
• Liquid pump installation
• Tunnel operation

Advantages of sectioning

• Greater availability in case of failure, faster function recovery.
• Greater availability during regular maintenance.
• Easier for maintenance personnel/simpler to transfer when changing contract partners.
• Repeatable work from design to dismantling.
• Simpler acceptance.
• In case of several tunnels: standardisation.

Disadvantages of sectioning

• (Possibly) more complex software.
• (Possibly) more hardware, oversizing.

When parties opt for self-configuring systems, they should realise that the scope becomes broader than the primary renovation scope. Both the client’s management and project organisation should be aware of this. For example, additional budget in terms of time and money should be made available.

Effects

Opting for sectioning can affect several aspects:

8.2 Building space [link id=”zbxrx”]

In renovations, parallel construction can be a practical approach to reduce traffic disruption. This involves disconnecting and dismantling the old components once the new tunnel technical installations are shown to be functioning properly. Parallel construction requires (building) space for the relevant tunnel technical installation elements, both in the tunnel and in outside areas.

It is important here that the functioning of the existing installations should not be undesirably affected by the construction of the new installation elements.

Installation elements may include installation cabinets, cables, fans or pumps. The following sections contain some advice on installation cabinets and cables.

8.2.1 Installation cabinets [link id=”4z095″]

For installation cabinets, additional space should be sought or built primarily in the service buildings. In current practice, standard 19′ installation cabinets of about 1x1x2 metres with doors, in which system components can be mounted, are often used. Adding new cabinets requires more space. There are various options:

• Investigate whether any old cabinets have been left behind from the past (however well-intentioned) that can be removed (tidying up before renovation). Is it perhaps possible not to order complete cabinets, but rather mounting plates that can be screwed into existing cabinets?
• Look for additional space in service buildings. Often spaces can be freed up (temporarily or otherwise), such as archive rooms, offices or warehouses. Especially with large-scale projects, old spaces become available again.
• Consider whether it is still necessary to equip a whole cabinet for an installation. Nowadays, an equipment cabinet often contains little more than a power supply, PLC and a lamp. Can installations be placed together in a cabinet? Should an equipment cabinet still be this big?
• Consider whether it is necessary to have a separate PC for each function. Perhaps multiple applications can be run on one PC? (This is what data centres do.)

8.2.1 Cable provisions [link id=”ftb9z”]

Space should also be provided for cable provisions (cable ducts, conduits, casing tubes) and any new space provided must be limited.

• Create extra space by investigating whether any old cables have been left behind that can be removed. Be aware that when moving old cables, there is an increased risk of malfunctions and failure of tunnel technical installations.
• Explore options to reduce the number of new cables.
• Consider installing cable provisions outside the tunnel as well. Components are placed in often predictable locations outside the tunnel. If provisions such as cable ducts are installed and system boxes are used, the excavation work during future replacements is much less.

Below some possible solutions are listed. In all examples, additional investment is required, but there are benefits with each replacement thereafter.

9 Reduce nuisance [link id=”wv3q1″]

A tunnel renovation always causes nuisance to the surrounding area and road users. There are ways to mitigate this nuisance. This chapter looks at nuisance mitigation through the non-technical aspects of a renovation project. Not only examples from road tunnel projects are described, but also from the rail sector. Although the various nuisance-reducing measures are presented by topic, in most cases a combination of measures have the most effect.

9.1 Time [link id=”sxvcf”]

When looking at time, the following questions are key: What is the most favourable or least unfavourable time to carry out the renovation work? How to make the most of that moment and what measures will help?

To properly weigh up the options, it is important to analyse which periods are most suitable for carrying out the renovation work. The starting point here is to minimise disruption to traffic. Night and weekend closures are therefore obvious, but there may be specific periods during the day or during the year when traffic intensity is lower, allowing for periodic or even regular closures.

Heartbeat

The technical lifespan of the various sub-installations varies. In the past, a general service life of fifteen years could be assumed for the tunnel technical installations in tunnels. This has also been used for years as a basis for investments, designs and maintenance plans. Empirical data were often not available for each sub-installation. A tunnel was fitted with new equipment and then, in accordance with the maintenance plan, only regular preventive maintenance was carried out, based on those 15 years. In current practice, this no longer seems realistic. This is due to:

• Technological developments (e.g. from analogue cameras to digital).
• The tunnel has become part of a much larger network and therefore dependent on a larger system.
• Changes to laws and regulations.
• Changes in use (e.g. permitted traffic or traffic intensity).
• Increase in ICT components with shorter lifespans in installations.
• Necessary software upgrades and security updates are often reasons to have to replace computers and sometimes installations.

More intervention moments are therefore required and a much more erratic pattern of replacements emerges. In practice, tunnel technical installations experiencing problems are kept running longer or, on the contrary, installations are replaced early to fit into a renovation project. The consequence of this grouping is an increased risk of failure and higher maintenance costs or early depreciation.

The heartbeat of the (installations in the) tunnel.

Based on the specific lifespan (the heartbeat) of the various tunnel technical installations and based on the amount of traffic, you can arrive at a working method where you carry out maintenance and replacements during regular management and maintenance (thus keeping renovations ‘small’).

Location of work

When replacing tunnel technical installations in tunnels, some work does not take place in the tunnel tube. Depending on the nature of the installations, on average about half of the work takes place outside the tunnel or in the technical area of the service building.

Much of the work takes place in the service corridor of the central tunnel channel. Additionally, much work has to be done inside the tunnel tube itself (assembly and performing tests, repair work). Auxiliary stations, escape doors, middle pump basement, main pump basement, emergency crossing, traffic loops, additional conduits, drilling require a lot of time. VIT2 has shown that this is fairly extensive. It often seems simple, but working at nights is extra tiring and many unexpected events interrupt the work. This work will be carried out with the tunnel fully or partially closed.

Smart distribution

To use the available time efficiently, it is a good idea to explore the following options:

• What effect does low-nuisance modular renovation have on the overall lead time of tunnel renovation?
• What options are there to extend the life of a tunnel and its systems, thus reducing the frequency of renovations?
• Is it necessary to replace all systems at the same time during one major renovation, or can some of them also be replaced as part of normal maintenance when a tunnel technical installation needs to be replaced?
• What options are there to divide the work into daytime, nighttime and weekend activities?
• Is it possible to use components pre-assembled in the factory or assembly hall (pre-assembly, see 8 Tunnel technical installations so that shorter assembly time in the field can be achieved? In railway and aircraft construction, for example, as many pluggable connections as possible are used. This reduces costs when replacing defective components, amongst other things.

Reliability

Several tunnels need to be renovated in the coming years. All these projects need to be closely coordinated and sometimes they are scheduled years in advance. To meet the schedules, it is important that the design and procurement processes are not delayed. Even more important is that the renovated tunnels reopen at the agreed time. ‘Scheduling reliability’ is therefore very important, alongside, of course, operational reliability.

9.2 Programme approach [link id=”whmr5″]

9.2.1 Description [link id=”1xx3h”]

Renovations can be programmed in a multi-year plan for several tunnels in conjunction with work on other parts of the traffic system. Such a programme offers several opportunities:

• Standardisation of products and processes to allow large-scale replacement during maintenance.
• Co-programming renovations/major replacements into the multi-year maintenance of the tunnel.
• Further integration by aligning the maintenance (and replacement of components) of several tunnels.

Advantages

• Less (additional) nuisance for surroundings.
• Much more uniformity in design and execution.
• Higher efficiency: being able to do more work with fewer people.
• Greater predictability of availability and cash flows over the years. A multi-year planning covering several tunnels determines in which tunnel a tunnel technical installation will be replaced and when. This also allows for economies of scale.

Disadvantages

• Renovation spread over a longer period.
• Budgets must be available at planned renovation times.
• Scalability depends on the size of the renovation. Civil renovations are difficult to carry out during the short maintenance periods.

9.2.2 Considerations [link id=”zp294″]

• How should we deal with interim modifications/addition of functionalities during the programme? Are we going to build in parallel first, then test and then deliver in multiple phases?
• How does this fit in with the current renovation challenge, where many renovations have to take place in a relatively short period of time? Does this depend on the size of the renovation?
• Combining blockages for a tunnel renovation with other activities on the same route.
• Coordination of blockages on main traffic arteries.

When opting for a programme approach, it is important to develop a long-term vision, whereby:

• Renovation is no longer seen as a separate project, but as part of a long-term (maintenance) task.
• Renovation is not carried out per object, but per part of the area (e.g. replacing CCTV in all tunnels within the management area).
• Choices are made regarding:
  • Contract size (area-based vs. object-based)
    • What is the impact on traffic management?
    • Scope of the contract (how many tunnels in one contract?
    • The contract lead time must be long enough to be able to carry out the renovations according to the programme, but not too long.
  • Scope (which systems can be replaced area-wise?)
    • What are the preconditions with regard to traffic flow and safety?
    • What is the expected procurement advantage?
• One can consider using one tunnel as a pilot.
• For each tunnel, it will be considered whether a big-bang or micro renovation is the most appropriate way to proceed.
• An asset management vision will be developed, in which management and maintenance of the work site in a certain area will be related to renovations in the same area.

9.2.3 Effects and risks of a programme approach [link id=”q3zq0″]

Effect on achieving the contracting party’s objectives

• Setting longer-term goals.
• Less nuisance, but longer lead times.
• Constant level of safety and quality of the tunnel as a whole.
• Fixed scope during contract period.
• Spreading of finances over time.
• Better predictability of throughput/finances over time (as long as one sticks to the plan).
• Long-term uniformity in technical solutions/functions (one contractor on multiple objects will make the same choices on these objects as much as possible).

Effect on preparations

• Unplanned renovations (corrective maintenance) should be scheduled into the tunnel maintenance cycle as much as possible.
• Configuration management must be and remain in order.

Effect on organisation of tunnel manager/owner

• Substantive expertise of the client is needed to assess the results.
• Asset management expertise is needed to define the right contract scope and assess the contractor’s approach.
• Expertise in tunnel safety and traffic management is needed to assess the effects of the approach.
• Knowledge of contract management is needed to choose the right contract form.

Effect on contracting and tendering strategies

• The renovation programme should be translated into projects to be placed on the market (multi-year contracts covering several objects).
• Take into account what fits within the European regulations regarding uniformity/standardisation.
• Take into account when to tender (consider ongoing maintenance contracts).
• The relationship between maintenance and renovation is becoming closer. One should consider bringing maintenance and renovation to the market in one contract (management contract with defined quality level on completion).
• Large-scale renovation/function changes after the end of the contract. This means that the contract period should not be too long to allow for timely function changes.
• Contract size should suit market participants.

Effect on technical management/project control

• Far-reaching standardisation of components/modules.
• Managing standardised technology.
• Knowing what is available in the market, so that innovation can be promoted/assessed within standardisation.

Effect on stakeholders and surroundings

• Stakeholders should be involved early on in the coordination process to consider the impact of the work to be carried out on traffic flow and safety across the area and over a longer period of time. Several objects may have their availability reduced for shorter periods of time, but in quicker succession. This requires looking not only at the objects, but also at the surrounding area. For example, are there any events planned during this period?

Risks

• Financialising the risk of delayed replacement. Deferring maintenance, creating a ‘maintenance mountain’.
• Risk related to knowledge of existing area (configuration management).
• Risk of changes affecting the programme. This can lead to a domino effect (if one renovation component is delayed, the whole programme is delayed).

10 Logistics management [link id=”6b3gk”]

Large-scale renovations require many partial and full closures where the tunnel is (partially) available to the renovation contractor. The most efficient way is to schedule as much work as possible during these closure periods. This proves to be a complex puzzle, because activities are sequential, the workspace is very limited and the tunnel must always remain safe after the work.

Recent experiences, see for example Appendix 10: Lessons learned from VIT2 project, showed how important logistics management is, especially in complex, all inclusive renovations. Standard level-4 schedules are useful for reasonably straightforward activities that can be combined and which can be carried out during night closures.

In tunnel renovations, logistics basically means everything that has to be moved during the work in order to carry out the work. This includes the decentralised storage of materials and equipment, as well as emergency services and buses of a public transport company that sometimes have to pass through the tunnel. Logistics processes are closely linked to the various phases. Therefore, the logistics equipment usually has to be built up and dismantled several times. For example, a series of night closures requires a different approach than a full 24/7 summer closure.

10.1 Basic design [link id=”8h8rs”]

A simple basic design is needed for logistics planning. After all, it has to be clear what will be built, what is needed to do so and how all this can be supplied and removed in accordance with requirements. Moreover, after each temporary closure, it must be verified and validated that the tunnel can be reopened (sufficiently) safely. Answering all these questions is not easy. The use of BIM-360 and carrying out various inspection rounds help to form an initial picture of what will and can be built in any phase of the renovation. In fact, thinking about this starts as early as the tendering stage, when the client starts thinking about how the work can be done in parts.

Once a basic design is in place, it is important to find the connecting thread in the major activities. For example, certain activities block the tunnel or are hazardous – think of asbestos removal – so they have to be carried out separately and other activities on a section of the site are temporarily impossible.

An important part of logistics planning is determining the sequence of activities. For example, the structural work of the tunnel must be completed before the tunnel fans can be installed. And there are all kinds of dependencies like that.

Ingredients for logistics:

• Basic design for the infrastructure, civil engineering and tunnel technical installations with numbers per phase.
• A common thread with complex, defining activities.
• A BIM environment in which old and new are projected (including insight into how much space is taken up).
• A schedule for emergency services and public transport companies by type of closure.
• Insight into the duration of the works based on previous projects.

Using the above ‘ingredients’, a start can be made on designing a logistics plan. Once it is clear where work will take place, safe areas and parking zones can be indicated. These may vary from day to day, as emergency services must be allowed to pass if the diversion route is too long. In practice, therefore, the available free lane may not be the same every day.

At a detailed level, side effects can be worked out further:

• Can the drive-up time be reduced by building a storage as close to the tunnel as possible? This should already be considered when building the storage chain park.
• Can emergency services still reach the tunnel even from the adjacent feeder roads?
• What are suitable marshalling areas and approach routes for large equipment (e.g. cranes)?

10.2 Visualisation [link id=”g9h2v”]

Logistics planning requires an overview. Most people are visually oriented. Therefore, discussions on logistics work best by visualising and discussing the entire process together. This can be done in various ways, from sticking post-its on walls to developing comic books and creating 4D plans for complex issues. All three options are recommended for tunnel renovations. Don’t start planning too quickly in the BIM model; first, there should be support and a common thread on how the whole thing will be addressed. Then you can work out the steps for each phase.

Working out the steps is made more difficult, among other things, because the project team does not experience many renovations and therefore needs a long time. A further inconvenience is that traffic measures have to be applied for at the very start of the project. This is a point of interest for the client, as clients often over-optimistically estimate the number of closures required. A big issue when creating logistics plans for renovations is always whether there is enough time to carry out the work on time, safely and reliably. It is also worth bearing in mind that renovations ALWAYS involve surprises!

Once the logistics plan has been worked out for the various phases, it is then possible to draw up detailed plans. We can distinguish a few main phases:

• Phase 0 = Design phase.
• Phase 1 = Preparations and clearance of tunnel structure (walls, lining) without major impairment of function.
• Phase 2 = Parallel construction of basic infrastructure such as power supplies, network facilities, cabinets/boxes and cabling.
• Phase 3 = Installation of speakers, cameras, etc. including alignment and adjustment.
• Phase 4 = Migration and testing.
• Phase 5 = Dismantling of old tunnel technical installations.

Essentially, phases 0, 1, 2 and 3 are important, but the most complex is phase 2, because during this phase, all disciplines will be working at the same time. Some of the lighting has to be removed for example to fit the lighting grid, and because a longer tunnel closure is needed to do that, the Infra department decides to asphalt right away. And then what to do with the loops? Saw them straight away, or in phase 3 after all. And so forth …

Some useful tips based on practical experience:

• More can be built simultaneously than is often thought (ensure that during closures as much work as possible is planned in, near and outside the tunnel).
• Identify what can be done in parallel.
• Fully plan as much as possible in a safe way, with backup possibilities in other time slots.
• Work towards a result in several steps (sketch on A0, comics in 4D);
• Have a good idea of what you will build with numbers, space requirements and substantiated lead times.
• If activities are not dependent on other work, schedule them all at the beginning of Day 2, for example. The first day is always needed to getting things ready in terms of logistics.
• Bear in mind that the other traffic tube is sometimes still operational and make sure people can escape to the central tunnel channel or the tube where work is being carried out. Never block doors or escape routes.
• Organise the work permit system wisely.
• Ensure that the process is not disrupted during repeating work. In case of incidental problems, it is important to let the regular work team continue and to deploy a ‘solution team’.
• Use 3D simulations, especially for major works or time-critical operations, for example for checks on workspace collisions, training people and planning aspects.
• Deploy a robust team; ensure that employees can (partially) replace each other so that sickness can be absorbed. Keep people as back-up, if necessary.

11 Licensing process [link id=”hzzw8″]

From 1 May 2019, all tunnels in the Netherlands that are 250 metres or longer must meet the safety standard mentioned in the Warvw (article 6, paragraph 1). If an existing tunnel does not meet this standard, a decision can be made to renovate the tunnel. Such renovation takes place within legal frameworks and rules, which are reviewed and enforced with permits.

In Appendix 2: Warvw on role of competent authority in tunnels, a brief summary can be found of the various articles of the Warvw which are related to the competent authority.

The building and operating permit and the opening permit are of specific importance for tunnel (renovation) projects. This chapter takes a closer look at these two permits and the processes surrounding them. Particular attention is paid to the role of the municipal executive (the competent authority). When renovating a tunnel, the competent authority, the licensing authority that issued the opening permit at the time, must be convinced that the tunnel will continue to comply with the permit issued at the time following the renovation.

Service provision level

Standardised equipment is usually not legally required for renovations. The Warvw states in article 18.3, paragraph 3, among other things, that article 6b (the tunnel manager shall use standardised equipment in the tunnel) and article 8, paragraph 5, part a (the opening permit may not be granted if no standardised equipment has been used) do not apply to tunnels that are (have been) already open before 2013. However, it can be decided to use standardised equipment anyway.

Rijkswaterstaat’s guide to opening permits.

11.1 Stakeholders [link id=”l8bd1″]

Applying for and granting the environmental and opening permits for renovating and opening a tunnel requires the interplay of many stakeholders who each have their own responsibilities and roles, interests and own objectives. This often makes renovation projects not only a technical challenge, but also organisationally complex.

By setting up an informal process for coordination and consultation in addition to the formal process right at the start of the project, there is a higher likelihood that the formal process can be completed without surprises. The informal consultation should focus on both substantive issues and progress. These consultations should be attended at least by the competent authority, tunnel manager, contractor and client (other stakeholders are also welcome). It is important that those present can represent the organisation (have a mandate), so that the absence or replacement of certain persons does not lead to a delay in decision making.

11.2 Legal framework of competent authority [link id=”ltkv9″]

The Warvw states in article 1 that the municipal executive acting as the competent authority is the municipal executive of the municipality in which a tunnel is wholly (or mainly) located or will be located. In article 4, the Warvw says that for tunnels crossing national or municipal borders, one municipality shall act as the competent authority and shall do so in consultation with the other administrative body.

In article 11, paragraph 1, the Warvw states that officials appointed by the municipal executive are charged with supervising compliance with the Warvw. Besides this general task (checking compliance with the law), the competent authority has a role in renovation projects at two other times: when granting the building and operating permit and when granting the opening permit. These tasks are explained in more detail below. The emphasis here is on the granting of the permits: their enforcement and verification (is the renovation carried out safely on the basis of the building and operating permit and is there safe operation on the basis of the opening permit?) are indeed tasks of the competent authority, but are not described in detail in this chapter.

11.3 Building and operating permit [link id=”pxgdw”]

Under the Spatial planning act (Dutch: Wet ruimtelijke ordening) and the General environmental law act (Dutch: Wet algemene bepalingen omgevingsrecht), the competent authority is responsible for granting the building and operating permit, including the associated supervisory and enforcement tasks.

Specifically for tunnel projects, when granting the building and operating permit, the competent authority tests the construction plan attached to the application, as described in the Guideline on safety documentation for road tunnels (Dutch: Leidraad veiligheidsdocumentatie voor wegtunnels). In addition, based on the Warvw article 6b, paragraph 6, the competent authority must approve the standardised equipment to be used. Specifically for renovations, based on Warvw article 18, paragraph 3b, the standardised equipment is not mandatory if the tunnel is (was) open to traffic on 1 July 2013.

11.4 Opening permit [link id=”14xbr”]

The role of the competent authority with regard to the opening permit is legally guaranteed in articles 7, 8, 8a and 11 of the Warvw. In summary, these articles state that:

• the competent authority is interlocutor in drawing up and/or adapting the safety management plan
• the competent authority grants the permit for opening to traffic
• the competent authority monitors compliance with the legislation, with the ultimate power to revoke the opening permit.

Because of the different backgrounds of organisations and persons involved (and because the legally established role-play regarding tunnel safety is not yet common everywhere), agreements made are interpreted differently. Therefore, make sure that agreements are made as specific as possible on the basis of for example pilots, examples (when agreeing on formats), first drafts, etc. Make specific agreements on the desired depth/development of designs (per technical discipline) for the permits to be applied for and the frameworks against which the applications will be assessed.

11.5 Substantive frameworks [link id=”cqm7k”]

The substantive legal frameworks against which the competent authority tests permit applications are described in the Warvw (e.g. whether the legal safety standard is met), Rarvw (e.g. whether the standardised level of provisions is implemented, or whether an advice from the safety officer is added to the permit application) and the Building decree (e.g. technical requirements for an escape route).

Frameworks and guidelines drawn up by managers (e.g. Rijkswaterstaat’s National tunnel standard), national umbrella and knowledge organisations (e.g. CROW guidelines) and international standards (e.g. ISO or NEN standards) do not constitute substantive frameworks for the competent authority’s assessment.

The responsibility for complying with all substantive frameworks lies primarily with the tunnel manager.

11.6 Opening permit during phased renovation [link id=”1k0g0″]

Completely decommissioning a tunnel is by no means possible everywhere. The Maastunnel is a good example. Prior to the renovation of this monumental tunnel, the decision was taken that one tunnel tube should always be available for traffic from south to north, to ensure that the hospital remained easily accessible. Because of this decision, the renovation was carried out in stages, with one tube being renovated while the other was in use for road traffic.

During the preparations and renovation work in the Maastunnel, only one tunnel tube was closed at a time to keep the city centre and hospital accessible. (Photo: Vincent Basler)

Such a phased renovation risks running into restrictions in the law. This is because the Warvw does not provide rules for carrying out a renovation in stages, with the tunnel to be renovated remaining in use for traffic. For instance, the Warvw states in article 8a, paragraph 1 that it is prohibited to open a tunnel after a substantial modification without a permit from the competent municipal executive to that effect. During a renovation, adjustments soon become ‘substantial modifications’ because the safety management plan has to be amended, the construction is changed in such a way that the assumptions for the QRA are no longer correct and/or a building and operating permit for the construction is required. According to the letter of the law, this means that each time a substantial change is made, an opening permit must be applied for. However, an opening permit cannot be granted until all the requirements of the Warvw and Rarvw and the 2012 Building decree are met. And that is usually the case only after the complete renovation of the tunnel and not after the completion of one of the stages. This creates an unsolvable situation.

To make phased renovation of the Maastunnel still possible, Pels Rijcken & Droogleever Fortuijn lawyers and civil-law notaries, together with the municipality of Rotterdam, have developed an approach that fits the spirit of the law, see Appendix 7: Maastunnel open during phased renovation. In short, this approach means that the contractor carrying out the renovation will make agreements with the tunnel manager and the competent authority on how safety will be guaranteed and verified and validated during the renovation while keeping the tunnel open. The guiding principle is that the tunnel will be safe to use during the renovation and will be at least as safe, and preferably even safer, than before each step of the renovation process.

11.7 Process to follow [link id=”n14bv”]

Once the building and operating permission has been granted, renovation can begin. This will also allow the process of obtaining the opening permit to start.

Building and operating permit

The first diagram in the box shows the interaction between the tunnel manager (with the construction consortium behind it) and the competent authority in the design phase of a tunnel project, leading to a building and operating permit. This process diagram is included on page 32 of the Bestuurlijke handreiking openstellingsvergunning wegtunnels (English: Administrative guide to opening permits for road Tunnels, IFV publication, ISBN: 978-90-5643).

Opening permit

Once the building and operating permit has been granted, construction/renovation of the tunnel can start. The process of obtaining the opening permit can also be started. The second diagram in the box shows the steps in this process.

The Velsertunnel renovation broadly followed the processes shown schematically in the diagrams in the box. In completing the process for the opening permit, the steps were followed as much as possible that are also common for the building and operating permit. One difference between the two applications is that the application for the building and operating permit was contractually lodged with Hyacint. It was also agreed that Hyacint would draw up the safety management plan for the opening permit on behalf of the tunnel operator.

Because the production and coordination process has a different dynamic from the formal administrative process, separate plans of approach for the opening permit were drawn up for both processes during the renovation of the Velsertunnel.

11.8 Safety officer’s advice [link id=”d3klh”]

Applications for permits are accompanied by an opinion from the safety officer. For national tunnels, the safety officer of Rijkswaterstaat bases his advice on an unambiguously established assessment framework: the Rijkswaterstaat Safety Officer’s Assessment Framework. This assessment framework has an option to select requirements applicable to existing tunnels/structures. In addition to requirements for the safety provisions, tunnel technical installations and safety documentation, the assessment framework also contains requirements for the civil structure. However, in renovations, it is often very costly to make major changes to the civil structure. This means that in some areas not all the requirements in the assessment framework can be met (or only at a very high cost). To avoid this, customised solutions can be agreed between the safety officer, tunnel manager and the competent authority.

It is important to prepare consultations well: provide documents and clear understanding of the objectives of agenda items. This ensures that there remains energy and enthusiasm for the consultations and that parties are willing to do some extra work when necessary. Build on the existing relationship between tunnel manager and competent authority; so start very early in the process. Make sure the joint ambition is carried through.

It also makes sense to distinguish between the administrative process, its official preparation, substantive discussions and agreements, and the supervisory task. Make sure that coherence and information exchange between these consultations is guaranteed. Also ensure there is an intermediate layer for escalation in place.

It is also important to substantiate choices transparently. This includes the choice of standards (standardised equipment, LTS, assessment frameworks to be used), current internal policy, planning, mutual expectations and concerns. Openness removes distrust and produces mutual understanding, although not always agreement on choices made.

It is worth remembering that each review may lead to new comments, including on parts that have been previously reviewed. By reviewing too often, you make it difficult for yourself and also impose additional workload on others.

Appendix 1: Participants [link id=”3lm3b”]

The first version of this living document (only in Dutch, then called ‘Renoveren kun je leren’, published in October 2016) was compiled based on the experiences at the Velsertunnel renovation project. COB put together an expert team for this purpose in September 2015. Given the stage of the project and the type of renovation, a broad team was selected:

• Chairman Roel Scholten, from his role as coordinator of Tunnels and Safety at COB and coordinator of the Knowledge Platform Tunnel Safety (KPT).
• René de Koning of the Sluiskiltunnel, in his capacity as planning specialist.
• Alex Sheerazi of the municipality of Amsterdam, in his capacity as an expert in stakeholder management and communication.
• Brenda Berkhout of TEC/Witteveen+Bos and Arie Bras of the Kiltunnel, in their capacity as experts on (old) structures and their relationship with the physical environment.
• Paul van Rossum, municipality of Amsterdam, on the basis of his involvement in the renovation of the IJtunnel.
• Karin de Haas, based on her involvement in all COB learning projects in practical projects.

In addition to the expert team, the following people were present at the two plenary meetings for the evaluation:

• Martin Bouma – RWS project manager
• Armand Elsworth – Hyacint project manager
• Theo van Maris – RWS technical manager
• Bart Ranke – Hyacint technical manager
• Ilkel Taner – RWS stakeholder manager
• Marie-Jose Knapen – RWS opening manager
• Stephan van der Horst – RWS project manager civil engineering
• Hugo Kruk – Hyacint assistant technical manager
• Albert Maneschijn – Head of department for tunnels and wet structures at RWS
• Ine Hidding – RWS risk manager

An internal report of these meetings was prepared for use by the expert team. The people mentioned were subsequently interviewed. Saskia Blaas (RWS communications) and Ron van den Ende (head of tunnel management at RWS) were also interviewed.

The basis for the chapter on collaboration was written by Motion Consult in 2016. This company was not involved in the COB team, but because the method of collaboration within the Velsertunnel renovation project was handled in such a successful and structured way, their knowledge on the subject should definitely be shared.

In 2019, the COB working group on low-nuisance renovation was set up. They recorded their findings in a second living document. The following experts were involved in this project:

• Dick Aantjes, Final Goal Solutions
• Bauke Eggenkamp, Heijmans Infra
• Aris van Erkel, Ballast Nedam/COB
• Leen van Gelder, Soltegro/COB
• Maarten Giltaij, Arcadis Nederland
• Ronald Gram, Covalent/COB
• Adriaan Hage, Infram
• Erik Holleboom, Strypes Nederland
• Jan Holsteijn, Installatie Groep Spijkenisse
• Tjalling ten Hove, Movares
• Danny Janssen, Vialis
• Arie de Jong, BAM Infra
• Jan Jonker, Movares
• Johan Naber, Rijkswaterstaat GPO
• Arjan Neef , Innocy
• Timo Neuteboom, Arcadis Nederland
• Peter Overduin, Movares
• Sijmen Robers, Rijkswaterstaat GPO
• Aryan Snel, Witteveen+Bos
• Robert Surquin, Croonwolter&dros
• Tom van Tintelen, Technolution
• Ton den Toom, Gemeente Amsterdam Metro en Tram
• Arjan Tromp, Vialis/COB
• Remmy Uffen, Croonwolter&dros
• Leon Uijttewaal, Rijkswaterstaat CIV
• Peter van Velden, Vialis
• Jasper Venema, Rijkswaterstaat GPO
• Frank de Vries, Covalent
• Ronald de Weerd, Croonwolter&dros
• Jelmer Wittebol, ENGIE Infra & Mobility

In 2021 the two living documents, ‘Renoveren kun je leren’ and ‘Hinderarm renoveren’, were merged, since it is not convenient for users to have two documents about tunnel renovations. Johan Naber (Rijkswaterstaat) has critically examined both publications before this merger and indicated which parts should and should not be maintained. This has led to the living document ‘Doordacht renoveren’, still only available in Dutch.

This current living document, which is now also available in English, is the result of a thorough update in 2022 by the COB expert team Civil-TTI led by Rob Riemers and Jan Holsteijn (Installatiegroep Spijkenisse). The following experts from the COB network were involved:

• Maria Angenent, Rijkswaterstaat
• Wim Baars, Imagine
• Ben Bastiaanse, ICT Group
• Cedric Both, Datadigest
• Rob van Dijk, ICT Group
• Wendy Kniestedt, Croonwolter & Dros
• Johan Naber, Rijkswaterstaat
• Wout van Oostrum, Dura Vermeer
• Peter Overduin, ODC
• Nelson Perez Medina, Elumint
• Bart Ranke, Projectbureau Ranke
• Bart-Willem van Rijn, Dura Vermeer
• Berry Roelofs, Vialis
• Okke Sanderink, TEC
• Edwin Schippers, Innocy
• Frank de Vries, Covalent
• Frederik Wagenaar, TEC

Appendix 2: Warvw on role of competent authority in tunnels [link id=”wg4r6″]

Appendix 3: Renovation-proof energy supply [link id=”3n2tv”]

A3.1 Definition and terminology [link id=”1rrsl”]

Power supply: all tunnel technical installations and installation parts that supply power to the tunnel technical installations, including:

• Procurement facilities/installations
• MV mains connection (MV= medium voltage)
• MV distributors
• Transformers
• No-break
• Emergency power generator
• LV distributors (LV= low voltage)
• Power cables up to the installation cabinets
• Input load breakers of of the installation cabinets
• Solar panels, inverters and other renewable energy sources of the tunnel system itself
• Possible energy buffers

Not included is the energy supply for traction (train, tram and metro tunnels).

The energy supply is responsible for the electrical power supply of all tunnel equipment. It generally consists of three components. The first is a mains voltage connection from the public grid. The second component is an emergency power supply in the form of emergency power generators (EPGs) such as diesel generators or a second mains supply. The third component is an uninterrupted power supply (UPS) that continues to provide power to the basic installations in the event of a failure of the mains supply. This is done with a battery system as long as the back-up has not started.

Electricity is often supplied to the systems in a service building by means of a low-voltage distributor. This involves the installation of many supply cables that ultimately deliver energy to every user in the tunnel. In today’s tunnels, this results in many cables, which take up much space in the service corridor. During renovations, the question always arises as to the extent to which the existing cabling can be reused. Moreover, the problem is often that existing distribution boxes and distributors are fully used. This means that, for example, additional connection points are temporarily required during parallel construction.

A possible future-flexible solution could be to rearrange the construction/architecture. Looking at the distribution of energy, it is clear that there are several locations with many heavy users and that there are only light users in the rest of the tunnel, but in larger numbers. For example, on the one hand the traffic tube ventilators and lighting at the entrance and on the other hand the cameras throughout the entire tunnel. There is also a concentration of power consumers near the escape doors in the tunnel and the barriers outside the tunnel.

By analysing the location of the consumers, a certain architecture emerges with which a new power supply system can be built. The heavier energy consumers are often concentrated near the service buildings; the installation of a few extra fields in the low-voltage distributors makes it possible to connect several heavier consumers. Heavier energy consumers are often more difficult to build in parallel, but they are easier to exchange one on one.

For the distribution of electricity in tunnels, a repeating universal distributor can be considered, e.g. near an escape door. The lighter consumers can be supplied from here and several spare groups could be created. When replacing a component, a new one can then be simply and predictably supplied with energy. When the old component is subsequently removed, capacity becomes available again for the next replacement. In complex rural areas, several ‘system houses’ may be installed to which local users can be connected. This was implemented at the Coentunnel at the time, but it only works in complex situations. It is not used at the Heinenoordtunnel because many of the systems require local operation at the roadside, which means that the cabinets would still be needed near the road.

A3.2 Further details [link id=”pqkrh”]

General description of the installation

The power supply is one of the most robust tunnel technical installations in a tunnel. Moreover, if some conditions are met, the power supply is also very flexible for conversions. These conditions have more to do with construction and dimensioning, rather than special provisions or a substantially different installation (barring measures such as roadside system houses).

Connections are made at terminals. Any low-voltage (LV) cable generally only needs to be stripped to be connected in any cabinet. There is no advantage for a renovation to switch to special plugs, special connection methods, or the like. This will actually slow down connecting, as connecting to terminals in a cabinet is fastest and easiest.

For a quick switch in, say, the tunnel tube, the use of plugs may be of some benefit (provided the plugs can withstand the very aggressive tunnel atmosphere). However, this is attractive only for maintenance: a new piece of equipment will almost always have a different plug as well because of the overwhelming number of types of industrial plugs. There is hardly any standardisation in this area, a marked difference from industrial automation (IA).

No improvements can be made in using power supply cables that can be laid in parallel and wind through all situations. However, there are some other things that can help a renovation to make maintenance and future adjustments easier and have less impact. These are detailed further in Chapter 5 and in some other sections.

The number of cables is always a compromise. Single cables can be used to power service hubs, but it is also possible to use a loop-through cable that powers service hubs. However, some cautions apply here:

• Such a central cable will be very thick, which may cause practical problems with bend radii, problems in pulling the cable, size of connections, and so on. In other words, such a cable will soon become impractically bulky and unwieldy.
• Achieving selectivity is an issue in every tunnel. This issue is chronically underestimated. Make sure there are as few ‘steps’ as possible in the power supply. By ‘steps’ is meant: a main distribution unit feeds a subdistribution unit, which in turn feeds another subdistribution unit, etc. This quickly creates major problems in a tunnel.

Effect on project/programme management

Energy supply is mainly an ‘internal’ object. There are generally few stakeholders and limited impact on surroundings, design (architects) and space. However, the use of solar or wind energy can have a significant impact on the project, especially in terms of design and environment.

Nevertheless, energy supply should not be underestimated. Paying proper attention to the energy supply at a very early stage minimises the risk of the project overrunning. Indeed, it is very possible that the project will fall behind if grid reinforcements or modifications are not requested in time. Examples:

• The modification of a substation by the energy supplier to accommodate an increase in voltage or a second mains supply can take a year or more.
• Installing a different medium-voltage distributor (MV distributor) or a larger power transformer may require major structural modifications. Especially if parallel construction is required.

Effect on achieving the contracting party’s objectives

• Energy supply requires thorough analysis and decisions before tendering. This subject cannot just be outlined in a DBM contract as something that can be filled in later in the design. The project risk then becomes too high.
• Discussions with the energy supplier must be started at an early stage. This can only be done by the client, as the contractor is often not taken seriously enough by the energy supplier.
• The outline of the conversion needs to be determined in advance to allow for a good offer in the tender. The more careful the analysis, the lower the price (less risk for the contractor) and the smaller the chance of disproportionate additional work.

Effect on preparations

In case of a long-term full closure, there is little impact beyond the usual work. A construction power supply for the temporary situation will then suffice.

A thorough conversion/renovation of the power supply for a tunnel that remains (partially) open is an involved process, requiring resources and space. This can hardly be solved or accelerated by smart working or smart planning. Cables can often be installed in parallel though, which – given sufficient spare space in cable ducts and lead-throughs – saves the most time during conversions.

Once a power system has conversion capacity, it will be easier to replace installations.

Improving sustainability

The power supply itself is already inherently very sustainable (with the exception of a diesel emergency power generator) due to its robustness, very long lifetime, flexibility and reasonable recyclability. The only method by which sustainability can be further increased is the method of generation and conservation. However, energy conservation is not an issue here. For more suggestions on sustainability, see the Maatregelencatalogus energiereductie in tunnels (Catalogue of measures for energy reduction in tunnels – in Dutch only). This living document focuses on improvements to be achieved during or after renovation. This can be done by:

A3.3 Preparation [link id=”1khns”]

For a successful renovation, the following steps are important at a very early stage (realising a more powerful mains connection can take six months to a year):

Clarify the current situation:

1. Update the ground plans
2. Ensure the accuracy of the main power cables
3. What are the capabilities of the installation:
   • Maximum power the installation can handle
   • Short-circuit capacity
   • Expandability in power and in physical space (per distributor and in space)
   • Scope for reuse (what is the condition of the installation?)
4. Update the energy balance or perform some measurements (load) in normal use and in emergency operation.

Look at the options:

• Consult with the energy supplier whether there are options to expand, should this be necessary.
• Consider whether the system set-up could not be simpler and/or more convenient.

Appendix 4: Renovation-proof EMC and earthing [link id=”75dwg”]

A4.1 Definition and terminology [link id=”h4lpk”]

This appendix is about EMC performance, not safety. It is not about individual equipment, but mainly about infrastructure. Individual tunnel technical installations must themselves have sufficiently low emissions and sufficiently high immunity. This is not discussed further in this appendix. Preconditions and details can be covered in the EMC plan, but are also outside the scope of this document.

EMC: all installation elements involved in ensuring sufficiently low electromagnetic emission of electromagnetic interference fields and sufficiently high resistance to electromagnetic interference fields (high ‘immunity’ / low ‘susceptibility’). These include (not exhaustively):

• Earthing plan
• Lightning protection installation (plan and realisation details)
• Cables and pipes
• Cable support and routing (cable ducts and ladders and the like)
• Connection details.

Not related to this topic:

• Safety earthing for the most part
• The equipment itself.

A4.2 General description [link id=”819d4″]

Safety earthing is well provided for in all tunnels and, in general, hardly anything needs to be done about it. However, for good EMC (electromagnetic compatibility) performance of the tunnel, more is needed and the entirety of earthing, conductive parts and power circuits and pathways must be considered. Since most tunnels under renovation date from a time when EMC was not an issue or still ‘emerging’, or was solved by clean earthing, this is certainly a focus of any renovation. One can assume that there is work to be done here.

EMC refers to electromagnetic interference in and between electrical and electronic products and systems. The objective is to prevent the tunnel itself from adding interference to its electromagnetic environment. Good EMC performance consists of a chain of measures: from draft to careful implementation. A weak link will break the chain.

EMC is not about safety earthing or lightning protection. While these are related, they are different aspects. Because safety earthing and lightning protection per se are in good order in almost all tunnels, sometimes only minor adjustments need to be made to incorporate them for good EMC performance.

The cost of EMC measures included in the design is marginal. Subsequent correction of errors in the plan or implementation are very costly and time-consuming.

Not having the EMC performance of a tunnel in order will usually not be noticed until extreme situations (such as lightning or switching) or inconvenient unexpected failures occur. In cases where EMC performance is not properly regulated, major damage can then occur unexpectedly, resulting in a prolonged tunnel closure.

A ‘meshed’ earthing network, as is already present in most tunnels, gives the possibility to start (part of) the work in advance, without having to close the tunnel. Changing the earthing does not require the installation to be taken out of service. When it comes to taking more drastic measures, such as replacing plastic cable ducts with metal ones, work unfortunately does have an impact.

A4.3 Further details [link id=”43×51″]

• Assume there is work to be done.
• The use of fibre-optic cabling does not impact the work to be done.
• Unfortunately, the EMC knowledge of the average engineer/consultant/project leader is substandard. Hiring a practical EMC specialist with good tunnel knowledge at a very early stage is recommended (specifically: it pays for itself quickly).

Ensuring good EMC performance is no longer a matter of ‘advantages’ but is simply a necessity from the point of view of reliability and laws and regulations.

The big disadvantage of EMC is that it is difficult to capture in rules, such as a NEN standard. An earthing plan and various instructions can be found in, for example, NPR-EC/TR(nl) 61000-5-2, but it can be fleshed out in a number of ways. If not properly stipulated by a client, ‘where does it say that it should be that way? will become a hated sentence for the responsible consultant/project manager of the client.

Further remarks:

• Interfaces must be properly secured. If, for example, the reinforcement earthing is not in place, the EMC plan can no longer be realised and expensive measures must be taken that are technically and aesthetically unsatisfactory and may also be vulnerable (copper theft).
• It must be guaranteed that all parts of the suppliers have the provisions required by the EMC plan.
• The work of subcontractors must be checked for correct execution of plans and regulations. EMC is largely down to the correct execution of details. Subcontractors should be aware of this.
• Details outside the earthing plan are also important in EMC. This is why proper supervision is important. Consider, among other things, paying ample attention to embedded provisions and connection of reinforcement.

Risks during design

• Less optimal solutions due to not properly defining the work and poor discussion with the contractor (not quite realising what is good for EMC performance).
• Design lags behind execution of civil engineering work, resulting in provisions not being put in place.
• Insufficiently secured interface management or supervision makes the EMC concept unrealisable (e.g. reinforcement found not to be earthed after pouring the concrete, or Cadweld earthing plates that cannot be recovered).

Risks during execution

• Too little supervision: work is not carried out to a good enough standard.

A4.4 Preparation [link id=”kpm79″]

A system that is fully future-proof and easily expandable can be secured by:

• Modernised installation ‘earthing, lightning protection and EMC’
• EMC plan kept up to date
• Effective maintenance of the ‘earthing, lightning protection and EMC’ object.

For a successful renovation, the following steps are important at the tender stage:

• Check for presence of EMC plan. If not present, or of insufficient quality or depth: make a plan.
• Update the as-built data of the current situation (earthing, lightning protection, cable ducts, provisions).
• Have a specialist draw up a plan for changing from old draft to new draft – if necessary.
• Prepare a good overview of the activities and include this in the demand specification.
• Pay sufficient attention to the subject in the demand specification via process requirements, product requirements and requirements in the general technical provisions (GTP), and explicitly point out to the contractor that there are explicit requirements in the GTP regarding EMC.

A4.5 Tips and tricks [link id=”6tk1p”]

In addition to the advice already mentioned, below are some specific tips.

For the demand specification:

• Demand an EMC plan for the entire work (civil engineering, completion, tunnel technical installations, all sites). Demand a meticulous description of the scope of the EMC plan. Or better still, provide the EMC plan yourself and attach it as a binding document.
• Have plastic cable ducts replaced by metal ones. Perhaps only partially, or only for the signal cable duct.
• Demand that the use of the following document be explicitly demonstrated:
• NPR-IEC/TR(nl) 61000-5-2, Electromagnetic compatibility (EMC)-Part 5: Installation and mitigation guidelines – Section 2: Earthing and cabling, (IEC/TR3 61000-5-2:1997,IDT).
• Devote a separate chapter in the GTP to earthing, EMC and lightning protection. Or preferably a separate document (see below for an example).

In the design:

• Earthing, lightning protection and EMC is one object in the object tree.
• Use parallel conductors as much as possible: pipes, cable ducts, etc.
• In new builds or additional building sections:
  • Use reinforcement as earthing, with round steel
  • Steel tubular piles: earth the outside of each pile. Steel sheet piling: earth them in various places (a finely meshed earth network/grid).
  • Also locally earth lighting poles, outdoor boxes and anything external.

In execution:

• First earth the cable ducts, then pull the cables.

A4.6 Inspiration: example of specification for GTP [link id=”31h80″]

1. Introduction

The purpose of the demands in this EMC Guideline is to ensure that the tunnel technical installations are realised with a high level of quality, appropriate to the project in terms of service life, availability, reliability and maintainability. This level of quality must be maintained throughout the entire lifespan of the relevant installations, systems and subsystems.

The demands laid down in the present document are binding for the entire work.

Where reference is made to standards or guidelines, the version in force at the time of tendering is referred to.

Text in italics is intended as an explanation.

2. EMC, earthing and lightning protection

General

Earthing in general

Overvoltage protection

Descending lightning leaders

Connections from and to reinforcing steel and foundations in new builds or extensions to existing buildings

Connections to electrically earthed metal parts

Connections to metal poles

Verification and validation

Appendix 5: Planning as a tool in renovation projects [link id=”wkx35″]

A project is successful when expectations are met. In particular, when carrying out renovation projects for which an existing road link is to be temporarily blocked, there is an expectation that no additional disruption will be caused. Planning is key to meeting this expectation.

A5.1 Lean approach [link id=”t510q”]

Lean planning is very well suited to tunnel renovations. In this type of planning, the next activity is carried out only when the previous one calls for it, not before and not after. This way, value is created continuously, no one has to wait and no unnecessary stocks or idle periods are created. This is ideal in renovation projects, because these projects are characterised by a succession of interdependent activities, within a limited space, within a predefined period, carried out by many different stakeholders.

Commitment through involvement

To ensure that the planning of the main contractor and the subcontractors are well aligned, it is useful to organise planning days. On such days, the main contractor can present its planning to the subcontractors and discuss with them how their schedules can best fit in with this. Practice shows that planning days with subcontractors create commitment, provide insight into possible bottlenecks and offer room for creative solutions and clear agreements.

If the project team is not sufficiently involved in the planning, there will be insufficient support, the results end up in a drawer and everyone continues with the order of the day. Commitment to such a planning has an integral character and it goes beyond client, contractor and its subcontractors. Does each stakeholder identify with the planning?

Instant insight into effects

For the Velsertunnel renovation project, work was done with and from a single master planning, in which all phases and activities were integrated. The planning was done according to the lean approach. Related projects were linked to this project schedule with milestones and dependencies. As a result, for every change, the impact on other parts of the planning was immediately clear. Because Rijkswaterstaat (client), Hyacint (contractor) and Hyacint’s subcontractors all worked from joint planning sessions in this schedule, all parties had immediate insight into the effects of changes on their own schedule and those of other parties.

Specifically, the successful application of lean planning in the renovation of the Velsertunnel meant that the project was manageable within the set timeframe, budget and quality requirements. As a result, there were considerably fewer uncertainties during project execution: everyone was informed and committed to the schedule, and planning optimisations were made possible. Daily stands (‘are we on schedule?’) at the operational level and daily scrums (’there is a problem, let’s solve it together’) at the tactical level ensured continuous commitment to the schedule everywhere. In the case of the Velsertunnel, this resulted in the key milestones from the schedule set at the time of award being achieved.

A5.2 Managing planning risks [link id=”7082g”]

A renovation project is characterised by a certain degree of unpredictability. Unforeseen issues can arise during the implementation phase, jeopardising the schedule, resulting in missed deadlines, failure costs and irritations. Accepting that unexpected events may occur is not the same as accepting the consequences. It is important not to overestimate risks and not to see the consequences as inevitable. Also, try to address unexpected events with as few consequences as possible.

During the renovation of the Velsertunnel, efforts were actively directed at identifying potential planning risks, defining measures to prevent their occurrence and analysing fall-back scenarios for when they do occur. The focus of the entire project team (client and contractor) on risks and how to manage them, both in the preparation and execution phases, was decisive for the successful approach at the Velsertunnel project.

Preparation

During the preparation phase of the Velsertunnel renovation, extensive attention was paid to the identification and analysis of potential risks. This was done in the form of risk sessions, which were attended by both Rijkswaterstaat and Hyacint and its subcontractors. This mobilised a great deal of implementation knowledge, allowing the risks, their causes and also possible control measures to be made very specific immediately. Identified risks were each assigned directly to risk owners: the action holders for controlling these risks. Space was also created in the schedule with so-called time buffers to accommodate unwanted events. These time buffers are set aside for nights and weekends based on the risk file.

By working with time buffers, activities could be accommodated that threatened to overrun the reserved time frame. This working method ensured that overruns in one part of the schedule had no (or less) impact on the schedule of other activities. Given the – especially in the initial phase – frequent use of these buffers, it can be concluded that the usefulness of working with time buffers has been proven in practice.

Another successful preparatory measure was organisational in nature. Detailed and comprehensive escalation and decision-making procedures were drawn up in consultation between Rijkswaterstaat and Hyacint. These were aimed at ensuring rapid decision making and thus rapid progress in the event of unforeseen issues arising. At the heart of these arrangements was the distinction between substantive and technical decision-making on the one hand, and its contractual settlement on the other. To achieve this, adequate capacity was ensured within both organisations: the expected peak in the number of requests for change (VTWs) fell during the holiday period. This full engagement and attention to the work of both parties helped to achieve the set objectives.

At the Velsertunnel renovation project, the focus on scheduling risks during preparation continued during the execution of the renovation activities. During the demolition phase (traditionally the phase when most unforeseen issues emerge in renovation projects), risks and progress were discussed daily in daily stands with delegations from Rijkswaterstaat, Hyacint and subcontractors. This made it possible to decide quickly, or adjust immediately, where necessary. Over the course of the installation work, these daily meetings were reduced in frequency to weekly stands.

During the first months of the execution phase of the renovation of the Velsertunnel – even day and night during the demolition phase – a joint team (engineering, execution and contract matters) was present every day at or near the construction site in order to be able to immediately evaluate any technical problems. Decisions by the contractor regarding the solution direction could thus be evaluated and endorsed immediately. This prevented unnecessary loss of pace.

The planners of the contractor and the client also held daily consultations in the same period. At these consultations, the previous day was discussed and details for the coming day were reviewed. They also discussed the impact of current developments on the various milestones. The client’s planner then reported a summary of this to the project management team.

A5.3 Probabilistic approach [link id=”l2wvz”]

Although deterministic planning methods (such as lean planning) use the risk file to take control measures such as time buffers, it makes sense to consider project risks (risk = probability of occurrence times consequence) more explicitly. A risk with a low probability of occurrence and a relatively limited consequence can in fact have greater consequences for the project planning than is expected from the risk file. This has to do with the moment of occurrence. If this moment is very unfavourable to the critical path, the consequences can be significant. A well-executed probabilistic analysis makes this clear.

The Velsertunnel renovation used a ‘manual’ approach to consider the planning probabilistically. This involved cutting the planning into phases. Each phase was then analysed separately, looking closely at probabilities and time risks.

Besides a manual approach, so-called Monte-Carlos simulations can also be used to examine schedules probabilistically. This involves using a planning tool, which calculates the project schedule and the associated risk file (in which time risks are linked to the schedule) very many times (up to 10,000 times). The calculations produce the following information:

• Feasibility of the schedule: the percentage of calculations indicating that the planned milestones will be met, taking all risks into account.
• Expectation value: the average outcome of the calculations.
• The so-called P85 value (85% of the calculations are within this value) can also be included. This implicitly indicates when a project milestone is almost certain to be met.
• The time risks that are most sensitive to the project milestones are also called the top time-risks. They are also part of the analysis.

A key concern with Monte Carlo simulations is the usability of the planning. The project or execution schedule is regularly found to be unsuitable for probabilistic analysis. Important reasons include too many planning relationships, float (time reservation for accommodating overruns in the schedule) that is not sufficiently visible and constraints, fixed times in the schedule. Another reason may be that the level of abstraction of the risk file and the schedule are too different. This creates too much pressure (overestimation of the lead time) when calculating the schedule on the one hand, while on the other hand delays due to risks are negated by the applied constraints. As a result, unreliable and unrecognisable outcomes are generated.

It is important that the results of a probabilistic analysis, especially regarding the risk profile, match the so-called gut feeling of those involved. That is why it is a good idea to always discuss the results of a probabilistic analysis with each other. After all, if the results and the gut feeling differ too much from each other, support for the probabilistic analysis within the project organisation will quickly disappear.

When conducting risk sessions, it is good to think in scenarios: ‘if that happens, we can …’ Thinking in scenarios and including probabilities ensures that the outcomes of a risk session do not become too pessimistic and the outcomes are more in line with the gut feeling.

If the periods up to the milestones to be considered in the schedule and the work are easy to oversee (because the time to reach a milestone is limited or the work is highly routine), project teams can usually do an excellent job of identifying appropriate time management and risks themselves. An additional (probabilistic) analysis will then not add much.

If a project already has a very extensive execution schedule – which was the case with the renovation of the Velsertunnel – this schedule cannot be used for the Monte Carlo simulation. In such cases, it is necessary to perform the Monte Carlo simulations based on a separate planning model (an abstract translation of the project schedule). This planning model can also be used to guide risk sessions and provide support in making the risk file more complete. If this approach is followed, the project team is taken through the project schedule in a risk session so that team members get a feel for the schedule and the associated time risks and opportunities.

Appendix 6: Selection based on KIS [link id=”cv1r0″]

When renovating the Maastunnel, the municipality of Rotterdam chose a construction partner based on quality (kwaliteit), integrality (integraliteit) and collaboration (samenwerking), or KIS. The KIS concept was substantiated in cooperation with a COB team of experts.

>> KIS Maastunnel report in COB’s knowledge bank (in Dutch only)

>> COB project page KIS Maastunnel (in Dutch only)

The Maastunnel is an extraordinary work of art. The oldest immersed tunnel in the Netherlands is a national monument and an important north-south connection in Rotterdam for cars, cyclists and pedestrians alike. The municipality therefore faced a major challenge when the Maastunnel had to be renovated. The renovation was needed to rectify defects and bring the tunnel up to current safety requirements. It was soon concluded that for a good result, the future construction partner would have to excel in three aspects: quality, integrality and collaboration (KIS). The municipality asked a COB team of experts to advise on operationalising KIS. How can quality, integrality and collaboration be included as selection or award criteria in the tendering process and project implementation?

The interpretation and operationalisation of KIS by the COB team of experts for the Maastunnel. (Image: COB)

A6.1 Wish list [link id=”dqq1z”]

KIS requires an innovative process and not the introduction of innovative criteria into a proven process. In selection aimed at (among other things) collaboration, the collaboration should already be sought as much as possible during the selection process. In this way, it is possible to select on empathy and also encourage collaborative behaviour. Collaboration is based on empathy: being able to empathise with the other party’s processes, interests and motives. In a complex project such as a tunnel renovation, such ‘soft’ aspects also contribute to the success (or failure) of the project. By managing soft factors structurally and systematically, joint project objectives become achievable.

Vulnerable attitude and collaborative maturity

The extent to which collaboration can be achieved depends mainly on the extent to which the parties’ collaborative qualities and characteristics match and the way in which differences are made open to discussion. Building up a collaboration therefore requires an open and vulnerable attitude from both the contractor and the client. The extent to which the client and contractor can work together is not so much determined by the quality of the contractor’s cooperation, but much more by the extent to which the two parties’ collaborative qualities and characteristics fit each other and the way in which differences are open for discussion.

The COB expert team KIS Maastunnel identified two methodologies for measuring collaborative maturity: The Alliance Maturity Model and Sorting out the essence of owner. Both methodologies were translated by COB’s expert team into specific questionnaires/assessments for both the selection and award phases. Candidates were asked, for example, to indicate how collaboration fits into the strategy of the organisations in the consortium. They also had to describe how knowledge about and experiences with collaboration are structurally embedded in their organisations. They were also asked to name at least three processes and techniques for the management of collaboration that they and their partners/clients apply in their mutual collaboration.

Representation of sorting of statements. (Image: Suprapto et al.)

Preliminary projects

COB’s team of experts has also described several specific tools for moving from the collaborative process to quality plans. For example, the client can already collaborate with candidates in preliminary projects. The quality processes in these smaller projects should, as far as possible, be set up in the same way as in the final renovation project. Candidates and the municipality thus practice working together, and the ‘collaborative maturity’ of the candidates (and of the client!) is tested. At the same time, the quality of the completed processes and delivered products can be tested.

The expert team also recommends improving and detailing products such as the Operational Concept Description (OCD), the description of the operational quality to be achieved, in interactive sessions with candidates. The client can also ask candidates to describe several projects in which they have worked in a manner they now advocate (reference projects). The advice is to visit at least one reference project per candidate, together with the candidate and the client of that project. Such a visit gives an impression of how the candidate’s quality plans work out in practice.

A6.2 Contracting context [link id=”fm7qc”]

Not all guidance fits (entirely) within the frameworks of European and Dutch tendering legislation. COB’s expert team therefore also advised on how to introduce the core of the wish list into the procurement process. This was based on the phasing envisaged by the municipality of Rotterdam. The advice is summarised in the diagram below.

Proposal of the COB expert team for the implementation of KIS in the procurement process drawn up by the municipality of Rotterdam. The report details all activities and products. In consultation with the expert team, the municipality of Rotterdam translated the expert team’s vision into project reality, see the section below. (Image: COB)

A6.3 Application in the project [link id=”9sxhr”]

The municipality of Rotterdam prepared its tender documentation partly based on the input of the COB expert team KIS Maastunnel. Selection/award criteria and submission requirements for KIS are included in both the selection guideline and the award guideline. The definitions of the COB expert team (see above) can be easily identified in these. You can find the full criteria in the report.

Table: the topics that had to be addressed to meet the ‘collaboration’ award criterion.

In the selection process, candidates were asked to provide reference projects via the submission requirements. The award criteria were similar to those in the selection guideline, but the sub-award criteria were adjusted: for selection these focused on the reference projects, for the award on their embedding in the candidate’s project approach for the Maastunnel.

Meeting

The award process included an interaction between the contracting party and the candidate. This meeting consisted of a presentation of the submitted tender and subsequent discussion with the evaluation committee. The purpose was twofold. First, it was about getting to know each other. Second, the meeting also provided better (further) insight into the submitted project approach and the underlying considerations and choices. The discussions consistently focused on monitoring the level playing field and the transparency of the process.

A6.4 Lessons learned and instruments [link id=”01k0r”]

The main conclusion of COB’s expert team and the municipality of Rotterdam is that it is quite possible to make the KIS aspects of quality, integrality and collaboration specific and use them as criteria in a contracting process. Despite the frameworks within which KIS was shaped as a criterion for the tender, it can be concluded that a large part of the formulated ‘wish list’ can be found in the final selection and award guidelines of the Maastunnel.

The KIS Maastunnel project has also identified specific instruments for selecting on the basis of integrality, collaboration and quality. This makes the report very interesting for other projects as well. You can find the instruments, among others, in Appendix C of the report.

Positive

The candidates for the renovation of the Maastunnel were also questioned for evaluation purposes. Among other things, they concluded that the KIS aspects and the underlying intention were sufficiently clear in the documents. They also found it positive to base scores in the selection phase on reference projects; this allows one to demonstrate that the plans on the KIS aspects are not empty promises.

According to the candidates, the KIS aspects could have been highlighted even better if discussions between the contracting party and the candidates had been organised to discuss the aspects, or if the appreciation of KIS within the EMVI score had been higher compared to the value of the offered price.

More lessons learned

To draw a definitive conclusion about the selection based on KIS (has this method of selection actually contributed to better collaboration, greater integrality in approach and a qualitatively better product? Has it, in short, become a better project?), the municipality of Rotterdam and the COB have agreed to review the project at a later stage and to incorporate the conclusions into this living document.

Appendix 7: Maastunnel open during phased renovation [link id=”qrvhz”]

The large-scale renovation of the Maastunnel, which dates from 1942, started in summer 2017. Because of the phased renovation while the tunnel remains open, the decision-making process on tunnel safety was different from, for example, the one for the Velsertunnel (see Appendix 9: Lessons learned from Velsertunnel renovation).

In order not to have to apply for an environmental permit after each renovation step with a ‘substantial modification’, Pels Rijcken & Droogleever Fortuijn lawyers and civil-law notaries, together with the municipality of Rotterdam, have developed a different approach. In short, this approach means that the contractor develops an emergency plan and construction safety plan prior to each step of the renovation and coordinates these plans with the tunnel manager. In these plans he describes the measures to guarantee the safety of road users and personnel during the work. The guiding principle is that the tunnel will be safe to use during the renovation and will be at least as safe, and preferably even safer, than before each step of the renovation process.

The tunnel manager subsequently keeps a continuous record of the safety level during the renovation in a tunnel safety file. If additional measures need to be taken by the tunnel manager during the renovation to ensure the safety of road users or the contractor’s staff in the event of incidents or emergencies in the traffic tube – for example, additional facilities to regulate emergency assistance or self-rescue – these must be recorded in a ‘safe operation phasing plan’.

The diagram below shows the different steps of the decision-making process.

Some administrative decisions were taken prior to the phased renovation of the Maastunnel:

• After coordination with the municipal executive and the safety officer, the tunnel manager has decided that no interim opening permits will be applied for during the phased renovation, as the laws and regulations cannot yet be (fully) complied with during the renovation.
• It has been agreed that for each phase of the renovation, the safety level will be assessed against the then current situation. The new safety level should not fall below the current one. The assessment includes the following four processes: self-rescue, emergency response, incident management and traffic handling. The assessment itself can be qualitative and quantitative, with only the quantitative assessment having a legal basis.
• The tunnel manager ensures that the tunnel safety file is updated each time to reflect the next phase of the renovation.
• The tunnel manager obtains evidence from an independent expert that at each phase of renovation, the tunnel is at least as safe as in the previous situation. The assessment of the safety level in relation to the current situation is laid down in a report. A ‘Safe Operation Phasing Plan’ will also define the measures and preconditions needed to implement the next phase safely.

Prior to each phase of the renovation, the tunnel manager asks the safety officer to assess the safety justification and provide an opinion on it. If the tunnel manager decides to deviate from the safety officer’s advice, he records this in writing and justifies why he deviates.

Appendix 8: Stakeholder management and communication [link id=”1n7pq”]

Since a renovation is an intervention on an existing structure, it will always inconvenience the surrounding area; ’their’ tunnel is undergoing renovation and, in most cases, will have less availability. That is why stakeholder management and communication deserve special attention during a renovation.

This chapter contains some lessons learned during the Velsertunnel renovation and the construction of the North/South metro line in Amsterdam. When this chapter was written, the Velsertunnel renovation was nearing completion. With timely completion, limited nuisance and positive sentiment among stakeholders and the general public, the project can be described as successful. In the case of the North/South metro line, stakeholder communication had an unhappy start, but became more professional and successful.

This chapter zooms in on lessons learned that may be useful for other tunnel projects. It is therefore not a complete evaluation of stakeholder management and communication, nor an exhaustive list of all lessons learned.

A8.1 Strategy [link id=”7lp66″]

As with brands, companies and organisations, for large or major infrastructure projects, stakeholder trust and social credit are crucial for a successful project realisation. It is therefore important to work on a good reputation so that there is sufficient ‘credit’ in case of a setback or calamity. A solid reputation strengthens relationships with stakeholders and increases the return achieved from those relationships (return on relations), acts as a magnet for talent and reinforces internal pride and employee commitment. The opposite holds true for a weak reputation. Building a strong reputation is not an end in itself, but a crucial means to support the organisation’s or project’s primary processes and objectives.

According to Van Riel, reputation is the degree of admiration, positive feelings and trust someone has for someone else, an organisation, an industry or even an entire country (Cees B.M. van Riel: The Alignment factor. Bouwen aan duurzame relaties, 2012). It is largely based on an appreciation of the organisation’s performance over time, including the past and expectations for the future.

To connect the outside world to a project, it is crucial to build lasting relationships with stakeholders in a broad sense. Stakeholders are the ones who ultimately judge the organisation and the project: support or oppose it, give it the benefit of the doubt or not and give it a licence to operate. Hence, long-term relationships with stakeholders have a major impact on the organisation’s reputation.

Reputation is not a PR trick or the result of an effective image campaign. Reputation is the outcome of an organisation that performs excellently, manages expectations and gives individual customers good experiences when interacting with the organisation. In other words, to successfully build lasting connections and a strong reputation, it is crucial to balance performance, expectations and (customer) experiences.

Reputation as a result of performance, expectations and (customer) experience.

The basic condition is that the primary process is under control. The products and activities must be of good quality and the service provided of a constant and good level. In short: it must be performed and what is performed must be of a good standard.

But while ‘performance’ is crucial, it is not enough for a good reputation. The individual experiences of road users, local residents and entrepreneurs with (the services of) the project or the project organisation are also of major importance. Frequent, extensive or drastic bad experiences with the service of or in interactions with the organisation will irrevocably lead to negative judgements about the organisation and thus damage its reputation.

During the Velsertunnel renovation, much time and attention was also paid to services for road users and stakeholders. A communications consultant from RWS stated: ‘It is key that you actually show that you are mindful of other people’s interests. Through your behaviour and actions, you have to show that you really take the other person’s interests seriously. This is often not necessarily a grand gesture, but rather that little extra step. For instance, make accessibility maps for a beach entrepreneur, involve a local transport contractor in testing a calamity arch, and place a sign referring to a company or a location when it is not officially required.

‘Also think carefully about the organisation’s attitude and tone when interacting with stakeholders. Government communication, however well-intentioned, is often formal, aloof, preachy or patronising. We tried to find a human tone, with room for human aspects when we were not sure and also admitted our mistakes. Also, don’t immediately get defensive when faced with criticism. If you communicate in a positive and pleasant way, people want to commit to the organisation and come up with their own ideas and compliments.’

Good customer experience due to the way progress is reported and appreciation for the responsiveness of the Velsertunnel renovation project.

Personal experiences are not only largely the result of delivery (performance) by the organisation, they are also influenced by the expectations created by road users and stakeholders as well as the organisation itself.

Good expectation management includes drawing as realistic a picture as possible of the impact of the work on the area’ accessibility in particular. This involves striking a good balance between sketching horror scenarios and overly positive images.

Risk communication is not yet commonplace in the world of major projects. During the Velsertunnel renovation, it was argued that if openness and realism are important principles, then they should also apply when it comes to risks and possible setbacks. The contractor also endorsed this approach. If you want to be a credible and reliable party for your stakeholders, you have no choice but to communicate proactively about risks. At the Velsertunnel renovation project, risk communication was accompanied by a central place for risk thinking within the project organisation. The communications manager: ‘Our director put enormous emphasis on thinking in terms of risks. The word opportunities was not allowed to appear in the communication plan. That prepares you for any situation rather than only starting consultations/work when a doomsday scenario arises, you have already anticipated it.’

Reputations are increasingly made and broken online and in social media. Not being present not only means not having an impact on image, it also means missing opportunities to create new connections with the organisation or project. The experience of other projects shows that being open (e.g. about your performance and progress) and responsive on the web can lead to an increase in engagement, sympathy and support for the project’s mission and approach and its objectives.

Paul Polman (58), Unilever CEO since 2009, on the role of the internet and its social networks during the Arab Spring in 2011.

Truly effective online communication and webcare consists of a constant dialogue with audiences, followers, fans, critics and stakeholders. In good times and even more so in bad times. By establishing real relationships with followers and interested parties. Both on social media and on its own online resources. Both online and in the physical world. Both by the stakeholder team and by other departments of the project or organisation. By working systematically on online dialogue and discussion, you account for your performance, manage expectations in the outside world and ensure good contact experiences. In doing so, you build up, day by day, a reputation buffer, which, in times when things go wrong – and they go wrong regularly in every project or organisation – can partially absorb the blow and soften the negative impact.

The centralisation of the web with a central identity, appearance and standardised information, makes it increasingly difficult for the public (citizens) to connect with that digital organisation. Standardisation often makes information impersonal and procedural and provides no way to collectively customise and interpret this information. Interaction therefore takes place on social media such as Facebook and Twitter. This seems a plausible and effective solution, but there is also a drawback to outsourcing online discussion to social media. You run the risk that the discussion about your organisation or topic will be mainly linked to the social medium used, with its own rules, appearance, image and reputation. Online discussion is not a fun extra, it is a necessity to build an authentic, strong and sustainable relationship with your audience. It is necessary to introduce your audience to your organisation’s values and way of working. You want to have that discussion on your own terms, in your own environment, with the functionalities that you yourself consider important, with your own house rules, without advertising or with the advertising you choose. All this is really only possible within your own web environment.

The attractively presented content, the speed of response and the attitude and tone of the Velsertunnel renovation project on Facebook led to a rapid growth in followers, high appreciation and online collaboration and co-creation. Photos of the outside and inside of the bunker were taken at the request of followers of the project and were highly appreciated.

Today’s society is fluid, evolving as a network and changing rapidly. It is therefore important that basic communication is in good order, that the most important resources are available and that there is an unambiguous understanding of which values, vision and strategy will be acted upon in all those situations and circumstances, windfalls and setbacks, calamities and risks that we can partly foresee, but a larger part of which we probably don’t even know yet exist.

RWS stakeholder manager: ‘With this type of project, you know that you start with a recipe that you won’t be able to follow one-to-one during execution. You will have to adjust the ingredients and quantities as you cook. The approaches, theories and frameworks are there to help prepare this kind of project properly. However, it is crucial that there is enough room for manoeuvre, that you can deviate and act according to your findings. Reality is many times more complex, unexpected and changeable than you can foresee and prepare for. That requires flexibility, good anticipation and quick responses. The fact that we were able to do that here has been key to the success of this project.’

A8.2 Stakeholder management and communication disciplines [link id=”0xhsx”]

It is important that stakeholder management has a central place in a project. It is shaped by the vision that not the positions, but the interests of the project and those of the various stakeholders are the cornerstone. This involves identifying the shared interests. Strategic stakeholder management is a crucial part of overall reputation management as it coordinates or controls the building of lasting relationships. Stakeholder management is closely intertwined with issue management. Stakeholder management and communication should therefore work together as a well-oiled tandem when it comes to managing stakeholder relations and all the issues that affect them.

Reputation (in this case of the stakeholder and communication function) also has an internal effect: the stronger the reputation, the stronger the position and the more you are able to influence the choices that are made. The same applies, for example, to the financial resources budgeted for the stakeholder and communications team (the number of FTEs and resources and activities). It prevents this aspect from being a balancing item on the budget, as is still regularly the case. You obviously acquire that solid position by making sure you deliver, know how to manage expectations and can advise authoritatively, especially in those situations that matter.

Managing issues is a key part of managing reputation. It consists of analysing and prioritising issues according to their impact on the organisation, service, project and business. It is important to not only act reactively, but also proactively on image-defining issues and dossiers. Based on a thorough analysis, a strategy can be determined for the most important issues and a lean and mean methodology of permanent monitoring of the (development of) issues should be implemented.

Internal communication is undergoing a stormy development from a supporting, facilitating and mostly executive internal role to a more strategic role. Internal communication makes a crucial and indispensable contribution to the development of a desired identity, based on the awareness that identity is important for strengthening internal pride, solidarity and commitment. Identity also gives direction to the organisation’s actions and offers action perspectives for employees. Internal communication is therefore about activating and internalising core values (internal branding), building a desired corporate culture and working on a communicative project organisation. Internal communication therefore deserves an important place in project communication.

A8.3 Critical success factors [link id=”wv59f”]

The success of stakeholder management and communication hinges on the importance given to good relations with the stakeholders by both client and contractor management. This requires more than just good stakeholder and communication staff. Stakeholder sensitivity should not only be the domain of the stakeholder team. The client and contractor organisations as a whole must be aware of its importance and then translate it visibly and noticeably into their attitudes and behaviour. Because no matter how good the stakeholder and communication officer is, he or she loses credibility and position when agreements are not kept, stakeholders are inconvenienced unnecessarily, or do not feel heard or recognised. To achieve sensitive organisations, it is important that management is selected not only on the basis of traditional management skills, but also on stakeholder and communication awareness. The idea ‘as above so below’ makes clear why this is important.

Many quality requirements for stakeholder management and communication can, of course, be contractualised. This obviously has an effect, but it is impossible to draw up a comprehensive list of requirements and agreements. Renovation projects are too complex for that, the environment is too dynamic and circumstances change too much. It is therefore crucial to invest in a good relationship between client and contractor from the very beginning, and in creating or strengthening stakeholder sensitivity on both sides. Good mutual relationships, a collective interest in good (managerial) relations and a culture in which stakeholder sensitivity is one of the supporting values have more effect than a contractually defined division of tasks and responsibilities. The longer the list of requirements and agreements, the more likely everyone will do only that and nothing more. Putting too much on paper leads to an instrumental implementation of stakeholder management and communication, missing opportunities and responding to risks too late.

Collaboration and joint responsibility for environment and reputation require equivalence. When the client grants the contractor his moments of exposure, it will have an effect on the contractor’s commitment and pride in the project. There is still much to be gained in this area. By the way, it is also true that contractors, commissioned by their parent organisations, sometimes want to stay out of the picture when there are setbacks or calamities. In such cases, the media face a fog of formal, legal arguments ‘from headquarters’ and their questions are not answered. Equivalence then also applies to the moments when things are a little less rosy.

Projects which enjoy broad support, such as the Delft railway tunnel, for instance, must be especially vigilant not to lose the support and consent of stakeholders and the city. This calls for a different and certainly less intensive communication approach than when there is no or only limited support. The Betuwe Route and the North/South metro line show that even in the construction phase, there is significantly less willingness to accept the nuisance and impact of the project. Discussions about the usefulness and necessity also often continue deep into the construction phase. This requires permanent (communicative) attention.

The degree of impact that the execution of a project has on the surroundings naturally affects the relationship and relations between the project and those surroundings. The greater the impact, the more intensive the communication effort. The attitude of the project (client and contractor) greatly influences the willingness to accept the nuisance and inconvenience. Lack of empathy, care and consideration for the people facing the nuisance can lead to profoundly troubled relations and relationships and a rapidly shrinking reputation buffer.

The time that elapses between the start of the planning process and the final delivery of the project is so lengthy in large-scale projects that original objectives and solutions can be overtaken or reinforced by time. This requires the communication team to be permanently alert to trends and developments in society. These may develop into issues that (again) call into question the usefulness and necessity of the project.

Major projects have to contend with changing times, thinking, economic conditions and all kinds of other developments in areas such as mobility, the environment and cultural views. When the Betuwe Route received final approval from Parliament, the Netherlands was still thinking in terms of main ports, strong hinterland connections, explosive economic growth of the port of Rotterdam, among others, and an open and active relationship with the European Union. When the project reached completion 15 years later, the Netherlands experienced a time of economic hardship, the port of Rotterdam was facing increasing competition from Antwerp, and love and enthusiasm for the EU had cooled considerably. The HSL-South railway line, initially embraced by all as an undisputed fast connection to Brussels and Paris, suddenly faced unforeseen competition from low-cost carriers such as Easyjet and Ryanair during its realisation and all of a sudden sentiment turned against this enormous investment.

The ambition of the client also influences how communication is shaped. If a project is seen as an opportunity to strengthen the reputation and identity of the client, the city or society, or a combination thereof, it requires more communication efforts. More effort in any case than when the project is considered regular work. For a project such as the renovation of the Rotterdam Central Station, ProRail and the municipality of Rotterdam deployed significantly more communication capacity and resources than for many other projects for which they are responsible. The A2 Maastricht tunnel and the North/South metro line in Amsterdam are also good examples.

Based on the idea that ‘measurement is the key to knowledge’, research was conducted into the frames used and public opinion before the start of the communication about the project and the accessibility campaign. That study was repeated three more times during execution. Although there are varying opinions about the value (and especially the applicability) of these studies, it was useful in the case of the renovation of the Velsertunnel. It made it possible to focus communication even better on what was going on. Furthermore, the study results also provided legitimacy and support for communication activities. The sentiment, discussions and questions about the project were also monitored. RWS: ‘Without a good monitoring system, we would have had a problem using Facebook. The structure is too opaque to keep track of all the questions. You also need it to be able to answer questions with several people. That does require an investment.’ As is now the case in many projects and organisations, the Velsertunnel renovation project used the online monitoring tool Coosto.

In renovation projects, opportunities for stakeholders and interested parties to visit the workplace are usually very limited. Yet it is very important for acceptance and understanding of the work (and the associated inconvenience) to show what the work entails, to demonstrate its scope and complexity, but also its ‘magic’. Visits to the work site make communication come ‘alive’ by seeing, hearing and experiencing the project (and the challenge).

During the new construction of the Gaasperdammertunnel, the surrounding area was invited to the construction site a few times. In addition, local residents and local companies were involved in the project as much as possible in the context of ‘neighbouring construction’. For example, local entrepreneurs were called in to cater for project meetings and classes on technology and safety were given at secondary schools. You can read more about this in book 1 of the Gaasperdammertunnel knowledge trajectory (in Dutch only), for example in section 6.5 ‘Environmental management anchored in IXAS organisation’.

Appendix 9: Lessons learned from Velsertunnel renovation [link id=”6lm8l”]

Grip on collaboration

With the knowledge of team dynamics, the phases of team development and systems thinking, collaboration has become as tangible as a schedule or any other project management tool. This allows team members themselves to get a better grip on how they work together. Teams can also take more control of this. How did the Velsertunnel renovation team deal with these concepts? What did they do to achieve successful collaboration? This is described in this section using several statements and observations from team members that have been translated into lessons.

Too high a price for the construction project puts the client’s team members on edge and a too low one achieves the same thing. It evokes a stereotypical attitude and the contractor is viewed through those glasses. ‘Too high’ or ’too low’ are of course perceptions, stemming from expectations. A high price often evokes disappointment, and a low price an anxious thought (‘help, this will be a difficult project’). Too high or too low a price puts people in an extra alert state (survival state of fight or flight). This makes collaboration more difficult. A good price, on the other hand, keeps people in ‘normal’ mode. In the process of agreeing on price, it becomes easier when there is a good price. Such was the case with the Velsertunnel renovation. On the other hand, a less good price would require something extra from the team members. They will then have to make extra efforts to understand each other properly and make their perception of the price specific. And that is precisely what is so difficult in the early stages of collaboration.

Openness

Creating openness started as early as the dialogue phases of the Velsertunnel renovation. This was mainly due to team members’ belief that openness – putting everything on the table – works. Where the client has already been working on the project for a long time, a potential contractor only just starts reading up. The client quickly tests whether the contractor has properly understood the request for proposal (and the contract).

>> Also see ‘Renovatie Velsertunnel voorbereid met intensieve scrumsessies’ (in Dutch only).

What happened in this process at the Velsertunnel renovation is that time was taken to work out each subproduct together in a short time. Everything was put on the table with the support of the management. The management stood up to remove all ambiguity at the front end. Especially in the initial phase, there is a tendency to push difficult problems to the future. In this phase, the management encouraged people to enter the difficult conversation, because there were sometimes doubts among team members about being open and putting everything on the table. It helped that both project directors told the team: ‘First solve the project together in terms of content. Come up with the best proposal, and outline the consequences for planning and costs. Then it is up to us – the management – to resolve the business part.’

For example, the team encountered ambiguities in the contract, with the clients’ response sometimes being: ‘it’s a fine contract’. Such a response is, of course, not immediately helpful. It is a primary reaction that reflects disappointment more than that it solves the problem. It reflects the fear that everything will be called into question again. For however you look at it, there are differences in the team on how to deal with a demand. And as outlined earlier, it is effective to let the vagueness decrease in the first phase of team development, and that entails bringing differences to the surface. Many projects, including the renovation of the Velsertunnel, face differences in interpretation. And that requires team members to learn to deal with differences, or with a stronger word, conflicts.

PFUs

The core team, consisting of the key officers of client and contractor, held three PFUs a year under the supervision of Motion Consult’s coaches. Despite the time pressures involved, their project managers and management have worked hard to periodically pause. ‘On these days, we managed to speak our minds again’, management said. It provides an opportunity to share experiences with each other and look back for a moment.

During the PFUs, they worked on the common standard for collaboration. This created commitment in the team to work together to make it a success, with the motto being: first focus on quality and time, and only then on money. Or in other words: focus on comfort rather than security.

On the other hand, the Velsertunnel renovation team also looked ahead: in each case, a three-month focus was formulated and recorded on a poster displayed in the portable cabin. In the team sessions, the team was always made aware of their dynamics and interaction patterns in the here-and-now, without looking for blame. The question always was: how does the behaviour you are displaying now help you achieve your goal? Examples of common team behaviour include interrupting each other, thinking in the classic client versus contractor relationship, but also going off in all directions in a meeting without any focus. Patterns and team behaviour are always present in the here-and-now and as such can be observed by every team member. The team itself has become increasingly skilled in this and has also started to identify them (‘oh, we’re doing it again!’). This gave the team a new way of always looking at the team as a whole in difficult meetings and thus at what they could do to break the pattern.

By regularly joining team meetings and regular PFUs, Motion Consult’s team coaches were able to see clearly what the team was struggling with and make appropriate interventions. In their experience, here-and-now interventions (identifying the dynamics occurring at that specific moment) are the most powerful. It combines the team’s development with the substantive team task. As a result, the team learns, and simultaneously achieves substantive team results.

What goes well in the collaboration within the Velsertunnel renovation team?

Mediators

Another important intervention in the renovation of the Velsertunnel have been the mediators. Project management realised that projects such as these always encounter conflicts. And conflicts create distancing: ‘listening is lost’. This is why the team chose to have some experienced veterans advise them on conflicts – the mediators. First the team tried to resolve the conflict itself, but if that did not work (quickly enough), there was an agreement to refer the conflict to mediators and ask them for non-binding advice. It is a very powerful tool to ask for help in time instead of muddling through.

To achieve this, explicit deadlines for decision-making at a certain level were agreed at the Velsertunnel project. Once these deadlines passed, the issue was escalated to a higher level. Lingering conflicts are never good for any collaboration. They create emotional baggage and often things get mixed together. Moreover, conflicts then escalate. Something may start as a disagreement and end up in a personal conflict, where the solution has not yet been found. The mediators were successfully used several times during the Velsertunnel renovation project.

Appendix 10: Lessons learned from VIT2 project [link id=”8p8ft”]

Between March 2017 and March 2019, Rijkswaterstaat replaced a number of similar tunnel technical installations and updated software in seven national tunnels in North and South Holland. This was done as part of the VIT2 project, which stands for tunnel replacement investments, project 2. This section discusses the lessons learned and knowledge gained from this project. The Beneluxtunnel, Drechttunnel, Eerste Heinenoordtunnel, Noordtunnel, Schipholtunnel, Sijtwendetunnel and Wijkertunnel were all included in VIT2.

A10.1 VIT2 in brief [link id=”bhf95″]

As part of VIT2, camera security systems (CCTV), a number of public address systems and high-frequency systems for communication via C2000, among others, were replaced in the seven tunnels. Operating and control systems were also adapted and improved where necessary. Various tunnel technical installations such as fire extinguishing pipes and ventilation systems were also renovated.

All work was carried out during night and weekend closures to minimise disruption to traffic. The first priority was to adopt reliable traffic measures. The work also had to be carried out safely, both for traffic participants and the client’s and contractor’s employees. Another requirement was that the work should not have a negative impact on the availability and reliability of the tunnel as a whole. Furthermore, the modifications had to be carried out in accordance with the National tunnel standard (LTS 1.2, service pack 1, batch 2) as much as possible and be right the first time. To achieve the latter, there was intensive collaboration and open communication between the client and contractors during the tender, and the design and realisation phases.

Rijkswaterstaat deliberately split the procurement for VIT2 into two parts. The first part included the replacement of the tunnel technical installations, the second the modifications to the existing hardware and software for the operation and control of the tunnels. Rijkswaterstaat opted for this separate procurement to be able to select parties that really have the specific expertise required and to avoid automation problems at the end of the project. On the one hand, Rijkswaterstaat wanted a party with proven experience in replacing tunnel technical installations and everything around it, such as traffic measures and maintaining safety levels, and on the other hand a party with expertise in adapting or further developing industrial automation (IA) in an operational environment.

All new installations were built in parallel with the existing ones. As a result, it was possible to keep the tunnels in operation during the renovation and, in the meantime, already set up the new installations. Initial testing took place mainly in a test environment, temporarily using a parallel control and operating system. The new interfaces were also tested in a test environment beforehand. Then, during a migration shutdown, the old installations were disconnected, the new ones connected and the new control software loaded. The combination of new installations and control software was then thoroughly tested in the tunnel.

A10.2 Workload [link id=”glvlv”]

The renovation of the seven tunnels was carried out as a single project, with the tunnels being worked on one after the other. The decision not to close tunnels for long periods in succession, but to carry out all the work during night and weekend closures created a very high workload. Work was carried out in a tunnel every night for over two years. This caused a decline in enthusiasm among contractors’ staff and eventually made it difficult to find enough staff.

Working during night closures also has another disadvantage. Working hours are linked to the so-called tunnel closure window times (VTA times). In practice, only part of the available VTA time is actually usable. If the VTA time starts at 10 p.m. in the evening, in practice, work can only start at around 11 p.m. After all, before the tunnel can be released for work, temporary road closures et cetera have to be put in place. At the end of VTA time, the same applies. If the tunnel reopens to traffic at 5 a.m., work crews have to start packing up at about 3.45 a.m. to ensure that the tunnel can be inspected and released on time. This means that of the seven hours, a maximum of five hours can effectively be worked. This puts additional pressure on the effectiveness of the already costly night working hours – which cost almost three times as much as normal working hours.

A10.3 Safety [link id=”xfqgt”]

No serious incidents occurred during VIT2. According to the Rijkswaterstaat staff involved, this was partly a matter of luck. Although the safety level was high due to so-called safety walks, safety audits and an active role of Rijkswaterstaat to make traffic measures as safe as possible, several ‘near incidents’ did occur. For example, because road users bypassed barriers, ignored speed limits or drove against the traffic into a tunnel tube where work was in progress. Furthermore, dangerous situations regularly occurred during the installation and removal of temporary signalling, barriers, crash barriers, pylons and arrows on tunnel ramps. Thanks to safety awareness, continuous attention to safety during toolbox meetings and LMRAs, no accidents occurred.

Unwanted entry into a tunnel tube can be prevented relatively easily by closing the barrier. A mobile barrier can also be used to close the exit to traffic. Dangerous situations during the installation and removal of temporary traffic facilities are more difficult to prevent. One option is to opt for longer-lasting closures to reduce the number of times temporary facilities need to be placed and removed. For example, close a tunnel more often on weekends, thus reducing the need for night closures.

A10.4 Asset data [link id=”570vp”]

Although steps were taken prior to the project to get all asset data in order as much as possible, the contractor for the tunnel technical installations soon discovered that the data was incomplete. Coordinates on drawings turned out to be wrong and due to incorrect asset data, electrical safety could not be guaranteed without additional measures, according to the contractor. Consequence: additional work and extra costs.

A10.5 Unexpected events [link id=”lr6tx”]

When working in existing tunnels in operation, unwelcome events occur more often than expected. This is partly because the condition of existing components is worse than expected or because hidden defects turn out to be present. In several tunnels, for example, the existing power supply system was found to no longer meet today’s requirements. For instance, some cables had been ‘re-coloured’ in the past, which is no longer allowed, the core thickness of cables was sometimes insufficient and in some cases the earthed shields in cables were missing. Also, new tunnel technical installations sometimes lacked sufficient power supply points, requiring additional work. Another unexpected event was the discovery of soil contamination, which led to additional costs and a considerable delay.

A10.6 Efficient logistics [link id=”gq4s7″]

Due to unwanted events, additional work and the limited number of workable hours per closure, considerably more night closures were needed than expected. According to the RWS project organisation, the number of night closures can be controlled by better planning and careful prior consideration of which activities can be combined during a closure. This not only involves work in the tunnel, but also, for example, maintenance work around the approach roads.

A10.7 Split tendering [link id=”qqlm9″]

Splitting the work into two contracts worked well. Splitting was possible in part because the interfaces the installations had to meet were well described in the National tunnel standard. This made it relatively easy to split. The decision to split the contract into two parts did require extra attention from the Rijkswaterstaat project team during the tendering process. Furthermore, based on the idea ‘he who cuts must also paste’, a conscious choice was made to have a lot of technical expertise within the Rijkswaterstaat project team. It was also decided to have a shared office, where both contractors and the RWS project team were present every Friday to consult with each other and coordinate the work. In the end, the tunnel technical installations were tendered nine months earlier than the IA part. As a result, the contractor for the installations was more or less forced to design the important interfaces on its own. It would have been better if this had been done in consultation with the IA contractor.

A10.8 Coordination with other parties [link id=”dlmqm”]

Renovating existing tunnels that remain largely in use requires continuous good communication with other parties, such as the road manager and the organisation managing and maintaining the tunnels. At VIT2, the project organisation sometimes failed to realise sufficiently that this is also necessary when the other parties are part of the same organisation.