Renovation weirs combination Nederrijn and Lek weir

Renovation Nederrijn and Lek weir

After extensive renovation, Nederrijn and Lek weir combination equipped with high-tech central-control system

After an extensive renovation, the weir complexes at Driel, Amerongen and Hagestein, which are all at least fifty years old, can to continue to function safely and reliably throughout the coming decades. What’s more, from now on, the weirs and locks can be controlled from one central location.

Based on the criteria of ‘the most economically advantageous tender’, the Rijkswaterstaat awarded the Design & Construct contract to Siemens Mobility as the main contractor within a consortium including Solidd Steel Structures for the steel construction and DIMCO (DEME Infra) for the hydraulic engineering work. “Projects of this size and complexity must be handled using an interdisciplinary approach,” explains Jaap Rebel, Project Manager at Siemens Mobility. “The only way to offer the commissioning party a total solution is to work in close coordination with partners from various disciplines.” The work was started in 2015. On December 18, 2020, the renovated weir combination was completed.

The only way to offer the commissioning party a total solution is to work in close coordination with partners from various disciplines.
Jaap Rebel, Project Manager


The complexity of the project lay in the fact that the weirs and the locks had to remain functional throughout the renovations. They have a vital function in the Dutch network of inland waterways. The weir at Driel is called the ‘crane of the Netherlands’. It distributes the water that comes from the Rhine across the Nederrijn, the Lek and the Ijssel Rivers. On the one hand, this ensures that sufficient fresh water flows into the IJsselmeer. On the other hand, it ensures that the Nederrijn and the Lek remain adequately navigable for the approximately 39,000 vessels that sail through the sluices.

“Working in an operational environment places stringent demands on safety, risk management and planning and involves complex logistical systems,” says Rebel. “In addition to our three consortium partners, a multitude of subcontractors were also involved in this project. During the past five years, we have trained and certified almost 1000 people to work safely on the site. We had to carefully coordinate with one another who would do what when. Planning and coordination were crucial.”

The weirs at Driel, Amerongen and Hagestein are fitted with so-called visor gates. These semi-circular steel gates in the water stem the flow of the water and act as a dam. At low or normal water levels, the visor gates are partially or entirely closed. At these times, the ships pass through the weir complex via the lock which is located next to the weir. Fish can pass through the weir via a fish ladder. At higher water levels, the visor gates open, so that the water can easily flow toward the sea. Ships can pass freely under the opened gates. In the context of the renovation, both of the visor gates at each weir were replaced, including the hoisting cables. Only at the weir complex at Hagestein, which is an official National Monument, was the old visor gate returned to use after a complete renovation. Thanks to a temporary retainer system, the weirs could maintain their retaining function even while the gates were being replaced. The hoisting and positioning of the new gates were indeed spectacular moments. 

The locks also underwent a thorough makeover. In addition to sustainable LED lighting, new public address systems, cameras, and radar systems were also installed. One set of lock gates from each lock complex was replaced. The old mechanical system used to drive the lock gates was replaced with hydraulic cylinders.

The weirs, as well as the locks, were also fitted with new operating and control systems. As a result, they can now be centrally controlled from a new control building in Amerongen. Rebel: “In the past, the locks were not operational at night, in the evenings or during weekends. From now on, inland vessels can use them 24/7. This central control of the weirs and locks allows the Rijkswaterstaat to regulate the water management and the shipping on the Nederrijn and on the Lek in a more integrated way. During maintenance and breakdowns, the locks and/or weirs can be operated locally on a temporary basis. Each complex has its own service building containing a completely furnished control room.”

As the main contractor, Siemens Mobility was in close contact with the project team from the Rijkswaterstaat. Supporting them were many other important stakeholders, such as the Oost-Nederland District and the Shipping Services of the Rijkswaterstaat. “You need everyone to ensure that all the interests are adequately safeguarded and that the time slots available for the work activities are being optimally utilized. Our scheduling was even stricter than it was for the work done on the railway. A train can be stopped, but if there is a lot of water coming from Germany, then the weir must be opened. We had to temporarily stop the work activities a few times due to high water levels. Highly critical situations, which could have resulted in damage to the works if we had had to evacuate the entire terrain, did not occur, even though we had taken precautionary measures in preparation for that eventuality.”

All of the weir combination's technical installations meet the requirements specified in the European Machinery Directive. The operating and control systems are easy to maintain so that breakdowns, and the shipping disruptions that result, are prevented. A variety of civil and mechanical engineering work has also been done on the three weir complexes. The locks have been adapted for larger ships, and the lock at Hagestein has been equipped with new bollard recesses for recreational vessels. Everything has been freshly painted, and the weirs’ support arches have been refurbished.

The Siemens Mobility project organization has now handed the baton over to the maintenance division, Siemens Customer Service. This department will maintain the technical installations for one more year. “Each installation has its own maintenance regime,” explains Service Delivery Manager Chek Lee. “We also perform breakdown analyses to resolve any issues and to remove any systemic problems in the installations themselves. And, if the Rijkswaterstaat wants a specific adjustment or expansion made to the installation, our service organization will also handle that. This way, we continue to work on the development of the weir combination, together with the Rijkswaterstaat, even after the official completion of the renovation.”

For this project, we were able to successfully transform the lessons learned from the previous renovation of a series of virtually identical engineering structures into an impressive and sustainable end result. With this, we have all taken one more step toward the digitization of our vital infrastructure. We thank the Rijkswaterstaat and our subcontractors for this pleasant and constructive collaboration.
Jaap Rebel, Project Manager