The immersed part has a length of approx. 425 m and consists of three elements of 142 m. The two track metro tunnel is 11.25 m wide and 7.55 m high. The northern most element is partly located in the IJ embankment and subjected to a high ground load. At the south end the immersed tunnel has to deal with very poor soil conditions.
The tunnel elements were constructed in the building pit of the northern approach. After completion the building pit was flooded, the tunnel elements were floated up and transported to the Suez Harbor in the western Amsterdam Port. The elements were moored for 4 years to wait for the completion of the northern approach and the metro station Central at the south end. The tunnel elements were immersed in autumn 2012.
The northern approach was constructed using conventional cut&cover techniques.
The consultancy services included: