On the A9, between the junctions Holendrecht and Diemen, the Gaasperdammerweg, extra traffic lanes and a tunnel are being built. This project is the third one for the the expansion of the roads between Schiphol, Amsterdam and Almere. The Directorate-General of Public Works and Water Management is expanding the A9 from two to five lanes and a reversible lane. Part of the road will be in a tunnel with a large park on its roof. ”When you realize that the children who are being born now, will be living on a construction site for the first six years of their lives, you can imagine the enormous size of this project”, explains Aris van Erkel, project manager Tunnel Technical Installations (TTI) of contractor combination IXAS.
Article from Objective 27, 2017
More than construction
“It is impressive due to the impact it has on the area. Even for Dutch construction standards, these projects are enormous. I think that this is currently the largest dry infrastructural project in the Netherlands that is being run via a Design, Build, Finance and Maintain contract (DBFM). These are complicated contracts, because there is more to it than just construction”, Aris explains. “These projects often require five years of construction with an additional twenty years of maintenance.
“The scale alone makes it complicated. The tunnel will be the largest land tunnel of the Netherlands with a length of three kilometers and includes access and exit roads. In addition, we have to deal with railroad crossings and the underlying road network. Also, there will be a huge park on the roof”, he continuous. “The tunnel will have five tunnel tubes which is another first for the Netherlands. Another unusual aspect is the roof of the tunnel, on which there will be, halfway down, a roundabout with onramps and offramps to the the tunnel. This is something with which we only have limited experience in the Netherlands. It requires a lot of installations, because more traffic movement provides a high risk of incidents. You do not want to see, for example, an incident with smoke in the tunnel. Therefore, TNO and Efectis have done special research regarding our situation, in order to establish how we can create enough ventilation thrust in case there should be a fire in the tunnel. This wasn’t described yet and thus has to be worked out in great detail”, he says enthusiastically. “That shows just how special this project is.”
“People often think that a tunnel can be done by simply hanging some lights. But if you only consider the installation engineering and ICT, so excluding the maintenance, you are already talking about a quarter of the total costs of the entire project. They underestimate how much installation engineering is required to guarantee the safety of the road users. Think about the fire extinguishing equipment and such. The majority of the time that the tunnel is open, these installations will be inactive. But when there is an incident, they really need to do their work. We call them the RAMS: Reliability, Availability, Maintainability and Safety. This is quite a challenge, because: what if the powergrid fails? Will they still work?
“Look”, Aris starts to draw, “during the tunnel design, a local control layer will instruct the lighting and machines. A general control layer coordinates issues such as the right ventilation thrust of the tubes. With the status of the reversible lane, dependencies from the city and the area around Schiphol to Almere can be controlled via the reversible lane program. You cannot simply order to go from left to right, just in the tunnel; the entire program needs to follow, otherwise cars will run into each other. In the end, everything is being controlled via a GUI, a graphical user interface. Traditionally, this is done with a SCADA/PLC solution with programmable logic controllers. These are reasonably accessible, constructed logically and simple to manage. But for this tunnel, PLCs are rather old-fashioned.” “That is correct”, says his colleague Jan Snoek, project manager of software development TTI with a smile. “Processing many interactions quickly is not something PLCs are cut out for. That is why automation in tunnels often leads to problems.” “So we had to come up with something new”, adds Aris. “The coordinating controls and the GUI were replaced by an ICT environment. That has never been done before in this entire branch!”
Creating software before the design is finished
“We create that ICT environment in collaboration with Technolution. What is truly extraordinary is that we had to establish all the functionality features before we had even broken ground. Better yet: we had not even started the installation design. That is quite difficult and requires a lot of trust in each other”, Aris reflects. “There are definitely people who wonder: innovation during such a large project, is that really something you want to do? Construction workers are not that familiar with ICT. Yes, of course, this makes it more of a challenge. But until now, all has been going according to plan. The involvement and commitment of the employees of Technolution with this project has been remarkable. That is why they make such a great performing team. They have helped us enormously with making this project more manageable. Now, with about eight iteration prints, over 75 percent of the work has been created. You can already tell a lot about how things will function later on.”
Proof of concept
Aris laughs when Jan speaks about their first test: “Our client, the Directorate-General of Public Works and Water Management, came to visit to see how the project was going. It all seemed a little bit primitive; switches were literally simulated by someone holding two wires together. The man asked a lot of critical question of the team. But then the performance results came in. He tried to keep a straight face, but you could see how happy he was. It was then that I told him that this was our proof of concept. ‘What?!’ He almost did not believe me. Isn't that cool!” “See, that candor, I think that is great”, Aris adds. “While you do not even know whether it would work properly or not. That takes guts! But that has been Technolution's attitude during this entire project. That benefits the collaboration immensely.”
Until cars come into the mix
“Now the software is ready to be tested, a year and a half before the hardware installation”, Aris comments. “Until now everything was small-scale”, Jan adds. “We are now establishing a test center in Delft. This allows us to see what the controls from the traffic center in Velsen will look like. In the summer of 2017, we will test everything. But, of course, it only becomes a reality when the tunnel is connected, so people are currently being trained on the installation of hardware. An impressive job, considering there is an corridor of only 70 centimeters wide, with cable trunking on the left and right. I am looking forward to the moment that all the control layers are connected and everything is implemented into the traffic center. Controls and hardware will then come together, which is kind of cool!” “That is right”, Aris agrees. “And eventually the tunnel must, of course, connect to the traffic center in Velsen. And the traffic must start rolling.” He starts to laugh: “But first: testing. When all the software is working properly, I think there will be a sigh of relieve, from both Technolution as well as IXAS. How exciting!”
Aris van Erkel