24 March 2023
The Blankenburg connection is an ambitious project by Rijkswaterstaat to make the Rotterdam region more accessible and stimulate economic activities. The region is under pressure from congested roads, creating a need for a new connection. The Blankenburg connection, a new motorway (A24), is the solution. This connection connects the A20 near Vlaardingen with the A15 near Rozenburg and is being built by construction consortium BAAK (a combination of Ballast Nedam and DEME Infra) on behalf of Rijkwaterstaat.
An important part of the Blankenburg connection is the Maasdeltatunnel, which forms the link between the north and south banks of the Blankenburg connection. The tunnel will be immersed in the river Scheur at a depth of about -30 metres NAP. The immersion of the two tunnel elements is one of the biggest challenges within the project.
Strukton Immersion Projects made the tunnel elements watertight by fitting the four end surfaces of the tunnel elements with bulkheads. The tunnel elements were built in a dry dock close to the construction site in Rozenburg. The tunnel elements have been christened Alara and Isabella. Tunnel element Alara is 205 metres long and tunnel element Isabella is 185 metres long. It is the first time in the Netherlands that tunnel elements of this size have been built and immersed, and that too at a depth of -30 metres NAP.
After fitting all mooring wires and winches, the tunnel elements were carefully checked against checklists. By the end of April 2022, the tunnel elements were ready for transport to the temporary mooring location, Damen Verolme’s 1st working port. On 2 May 2022, the signal was given to fill the construction dock with water during the Go/No-go consultation. On 2 and 3 May 2022, the tunnel elements were transported to the temporary mooring location with precision and craftsmanship.
The tunnel elements remain at the temporary mooring site awaiting immersion.
For an impression, see the video of the raising, unloading and mooring of the elements:
In November and December 2022, Strukton Immersion Projects installed the foundation tiles on behalf of BAAK. These foundation tiles are 7×7 metres and weigh more than 100,000 kilos. They form the temporary foundation for the tunnel elements of the Maas Delta tunnel.
Currently, the ramps on the banks of the Scheur are being completed to ensure that the first tunnel section can be immersed on 31 March.
The immersion of the tunnel elements can be followed live on 31 March and 15 April.Follow the immersion live
There is no substitute for experience
Peter van Westendorp
Directeur Strukton Immersion Projects