JD-Contractor A/S relays cables in Copenhagen harbour

Page updated 2010/03/11

Client: Københavns Energi A/S

Date: October 2009

Copenhagen harbour lies in an area with a very hard seabed consisting of extremely hard clay and chalk with flint and large stones. JD-Contractor A/S has vessels and equipment specially designed for shallow waters and hard seabed; which is why JD-Contractor A/S was commissioned to install a 132 kV sub-sea cable to replace the current land cable.

Prior to instillation, a 540 m long and 2 m deep trench was dug into the hard seabed.

The sub-sea cable consisted of 3 cables bundled together. As they were not protected, the cables were taped together and encapsulated in a PVC pipe before being laid. After being laid into the trench, the cable was covered.
All aspects of the assignment were controlled and monitored by divers and multi-beam sonar.

The following vessels from JD-Contractor A/S’ fleet were used:

M/S Marcos was the main vessel used for digging the trench, encapsulating the cable and laying the cable along within the dug trench and finally to cover the cable.

C/S Cable One and M/S Honte were employed as dive support vessels and accommodation.

T/B Lille Bjørn was used for anchoring, servicing and survey work.