Mathias Gistelinck

DENYS Tackled Complexity on Multiple Fronts

The 30-kilometer onshore pipeline is a key component of the Porthos route. Shell, ExxonMobil, Air Products, and Air Liquide will soon connect to a single large collection pipeline for the CO₂ they capture in the Rotterdam port area. In addition, the onshore pipeline must be integrated into the existing infrastructure. The high concentration of crossings, busy traffic, and the number of stakeholders make this one of the most complex projects in recent years for contractor DENYS, according to Mathias Gistelinck, construction manager responsible for part of the onshore pipeline’s realization.

Challenging Environment
The Maasvlakte is a complex work area. Gistelinck explains: “This is mainly due to the environment in which we are working. We have to take into account various owners of cables and pipelines, each with their own requirements and expectations. Additionally, the area is extremely busy in terms of traffic. Road closures needed for the works must be carefully and precisely planned in consultation with the competent authorities and other parties operating in the same area to minimize disruption. All these conditions make this one of the most challenging projects I’ve worked on in my career.”

Unique Route
Although the onshore pipeline is ‘only’ thirty kilometers long, it contains many so-called special crossings: pipeline corridor crossings, road crossings, horizontal directional drillings (HDD), open front drillings, and a microtunnel. In total, DENYS will construct around forty special crossings.

Stalled Drilling
Gistelinck elaborates on three crossings that make this route truly unique: “For the HDD – a horizontal directional drilling – under the Caland Canal, we drilled 1.2 kilometers beneath the canal. We did this from both banks to achieve maximum precision and minimize risks. While pulling the pipe string into place, it got stuck. We had to act quickly. A small team devised a solution, which was then aligned with the various stakeholders. Everything was done in a short period to get the pipe moving again – safely and thoughtfully. Using a so-called pipe pusher and a special suspension structure, we were ultimately able to complete the drilling quickly and successfully.” This situation showcases the high level of flexibility and expertise available within DENYS, its subcontractors, and Porthos.

On-Site Welding
The second special junction is the Welplaat viaduct over the Botlekweg, along the A15. Here, the pipeline crosses the road above ground via a pipe bridge. Gistelinck: “Lifting the pipe onto the bridge was a feat of engineering. Due to the pipeline’s weight, we had to use two heavy cranes positioned on the road. The road was temporarily closed over the weekend for this purpose. Once the pipeline was in position, we built the bends and welded everything together on the bridge. Despite the complex execution, everything went according to plan, and we were able to reopen the road to traffic on Monday.”

Underground Congestion
The final special feature in the Porthos route Gistelinck mentions is the pipeline corridor along the Botlekweg. Although this part of the route is only a few kilometers long, it required special provisions to complete the work. “The existing corridor was extremely congested; there was just enough room to add the Porthos pipeline. This pipeline had to be connected to a newly built valve station on the opposite side of the corridor. To reach the valve station, the pipeline had to loop underneath the existing corridor. All intersecting pipelines had to be exposed while remaining operational. A massive support structure was needed to suspend these pipelines. After connecting to the valve station, the Porthos pipeline had to cross back under the corridor using a similar structure to continue along the parallel route beside the Botlekweg.”

Alignment Across the Board
The complexity of realizing the onshore pipeline is not limited to technical aspects. Organizationally, it’s also a challenge to align all stakeholders. Gistelinck: “Every stakeholder has their own requirements and ideas, while as a contractor, you want to complete the work safely and with high quality, within the set timeline and budget. This requires the right balance between stakeholder demands and execution methods. It’s great to be able to rely on our partner LBITA and the Porthos managers, who take on much of the environmental management. They handle coordination with the various cable and pipeline owners and authorities, allowing us to focus more on execution.”

Lessons Learned
At 28, Mathias Gistelinck is the youngest construction manager on the job. In addition to managing the work preparers – or site managers as they’re called at DENYS – he also guides them during execution. “I’ve been able to progress quickly within DENYS, which is why I’m now involved in one of the most complex projects we’ve ever undertaken. A personal challenge for me is getting the older generation on board. Nowadays, there are many more rules in the construction sector that must be followed. It’s my job to ensure everyone is aligned. Thanks to my experience on complex international projects, I’ve learned that you need to stay close to your people. Be open and listen to those with experience. By involving everyone and respecting their input, mutual respect is built – and that’s the foundation of good collaboration.”