In November 2023 Bezemer Dordrecht added a remarkable milestone to their history of projects. Bezemer provided six linear winches, capable of delivering a total of 3300 metric tonnes of pulling force, all working simultaneously on a single project. These winches were supplied for the Blankenburg connection A24, where Bezemer was involved in the positioning and immersion of one of the tunnel elements. 

Using linear winches for a tunnel immersion

The tunnel element forms part of the Maasdeltatunnel, which crosses the Scheur River. The tunnel will link the A15 and A20, enhancing accessibility by creating a new river crossing in the Rotterdam region. The Maasdeltatunnel has a total length of 945 meters and consists of a north and south ramp and two underwater tunnel parts. Bezemer got involved after the initial attempt of the installation operation of the second tunnel element unfortunately failed, and provided technical advice and operational support for the immersion operations in November.

The tunnel section, named ‘Isabella’ is the largest tunnel element ever constructed in the Netherlands. This element spans 205 meters in length and weighs 56 thousand tons. Working with these weights requires high pulling capacities and reliable equipment. The six utilized winches had pulling forces varying between 400 and 800 tonnes. Four of these winches were placed on barges, while the remaining two were positioned on the north and south riverbanks.

High pulling forces with extreme precision

The element had to be positioned between the already submerged 1^st element and the entrance ramp on the north side. This means that the 205-meter element should be placed accurately to the centimetre, a precise operation to say the least. Following the guidance of the immersion commander the tunnel element was positioned perpendicularly to the river. Once in this position, the tunnel element was gradually submerged by pumping water into its ballast tanks. The winches continuously made small adjustments to the element’s position until it was perfectly aligned.

This project shows the versatile application of Bezemers linear winches, which are often deployed offshore but have proven equally effective in diverse infrastructural projects. With the tunnel in position, the project which started in 2018 is now ready for its final stages. The tunnel will open at the end of 2024. Calculations show that by 2030, approximately 68,000 motor vehicles per day will make use of the Blankenburg connection.