The third lock of Princess Beatrix lock complex officially opened

Princess Beatrix lock. Rijkswaterstaat
Princess Beatrix lock. Rijkswaterstaat

It was the Dutch Princess Beatrix herself who on 6 February 2019 performed the official opening ceremony for the opening of the third lock of the Princess Beatrix lock complex, which is one of the most important lock complexes for inland navigation in the Lek Canal in Nieuwegein.

The Lek Canal connects the Amsterdam – Rhine Canal with the River Lek and as such constitutes a vital link in the inland waterway connection between the ports of Amsterdam and Rotterdam.

In its original state, built in 1938, the complex had two lock chambers, each with a length of 225 m and a width of 18 m. It was named after Princess Beatrix as she was born shortly before its completion.

With larger vessels and more ship traffic, it has become a bottle neck in this shipping route during recent years, with an average traffic of 50,000 ships passing the locks annually, and waiting time at the complex increased significantly. It was expected that if nothing would be done, it would rise to about one and a half hour in 2030.

To tackle this, it was decided to add a new and larger lock chamber to the complex, known as the Princess Beatrix third lock.

Immediately after Princess Beatrix had given the opening signal, the first ships entered the new lock, led by Rijkswaterstaat’s vessel – Josephus Jitta – that was named after the principal architect of the original lock complex.

Building the lock

The third lock has been built by a consortium known as Sas van Vreewijk, which consists of the companies Besix, Heijmans, Jan De Nul Group and Rebel Group.

Rijkswaterstaat has awarded a so-called design, build, finance, maintenance contract to this consortium, which means that Sas van Vreewijk is responsible for all these four aspects of the project.

One of the requirements of Rijkswaterstaat was that the new lock chamber’s length would be 270 m, in order to be able to handle a 135-m-long vessel and a 110-m-ong vessel simultaneously.

Due to an ingenious design, the lock as built by the consortium is now able to even handle two 135-m-long vessels simultaneously.

Part of the design is the application of four identical sliding lock gates, two at either side of the lock. This configuration guarantees a high level of redundancy and reliability.

A high degree of availability is of the utmost importance and the double sets of gates allows for continuing operations during maintenance to one of the gates or in case of damage after a collision.

But on top of that, it also offers the advantage that when on both sides of the lock the most outward gates are used, the lock chamber becomes almost 300-m-long, enough length for two 135-meter-long ships. Under normal circumstances, all gates are deployed randomly.

Maintenance and upkeep

Besides the construction of the new lock chamber, the project also comprises a large amount of dredging and dry earth moving operations to be carried out, in total some 2.5 million m3 of material.

A large portion of it had to do with the widening of the Lek Canal adjacent to the lock complex to make the new lock, which has been built at the east side of the existing locks, accessible for ships. To the north, the extra widening of the canal resulted in 1,200 m of extra berth capacity.

As a result, the existing dike south of the lock complex that constitutes the primary water defence had to be moved eastward.

Furthermore, the dredging obviously also comprises the excavation of the new lock chamber itself. For the earth moving operations, the consortium subcontracted the specialised company Martens en Van Oord from Oosterhout.

As part of the DBFM contract, the consortium is also responsible for the maintenance of the lock complex, including both the original locks as well as the newly built lock. The contractual maintenance period is exceptionally long, with 27 years.

Representatives of the consortium have said that not only the construction of the new lock has been challenging, due to difficult soil conditions and the requirement to keep the navigation going on without disruption, but that also it has been a major challenge to predict the costs of the renovation and its maintenance over 27 years.

Already in its design, based on a life cycle analysis, the consortium has strived to keep the necessary maintenance interventions as easy as possible, minimising both costs as well as hinder to navigation.

For example, the recesses of the lock gates have been designed in such a way that they are suitable for all maintenance activities to be carried out in there.

Specially for maintenance, two companies have joined the consortium, i.e. Martens en Van Oord and the consulting and Belgian engineering company Agidens.

Via its executive agency Rijkswaterstaat, the Dutch Ministry of Infrastructure and Water Management is currently investing heavily in other new building and renovation of locks. This comprises those in IJmuiden and Terneuzen.