Sub-sea cables

JD-Contractor A/S works with sub-sea cables throughout their lifespan: from their initial laying; to inspections, repairs, and finally their exhuming and disposal. To ensure the highest professional standards, JD-Contractor A/S has specialised vessels, equipment, trained technicians, and divers to deal with every aspect concerning sub-sea cables.

Our cable works can be generally divided into 6 tasks: transport, laying, embedding, recovery, surveying, and repairs.

Transport

JD-Contractor A/S is able to transport the cable direct from the producer, where it is assembled. In our fleet, we have several cable transporters and a mobile coaster system that can load, transport and lay cables from a chartered cargo ship.

Our main cable vessels are C/B Henry P. Lading and C/S Cable One.

See Fleet for more details.

Laying

JD-Contractor A/S has laid sub-sea cables and pipes all over the world. One of our strong points is that most of JD-Contractor A/S’ vessels can sail in very shallow waters, so they are often used to support landings where cables are hauled ashore, or in areas with shallow water i.e. offshore wind parks.

Embedding

Technicians working for JD-Contractor A/S have developed and constructed machines and equipment used to embed sub-sea cables safely into the seabed. Over time these machines have been enhanced; not only to protect the sub-sea cables, but also to decrease damage to the seabed, thus limiting the environmental destruction caused by sub-sea cables.

See Embedding for more details

Recovery

When an installed sea cable is no longer operational, it has to be removed. JD-Contractor A/S has over the last two years recovered more than 1000 km of outfaced sub-sea cables.

Related links:

Recovery of more than 500 km Outfaced Cable in the North Sea

Emergency Recovery of Cables from 300 meters deep in Norway

Surveying

JD-Contractor A/S carries out surveys of existing cable routes and trenches. For these assignments we use divers, ROVs, multi-beam sonar, or acoustic location equipment.

Reparation

Every year, JD-Contractor A/S carries out repairs of underwater cables. Repairs can be complicated as cables are often embedded into the seabed. Firstly the fault needs to be localized; only then can the cable be carefully lifted free of the seabed making sure not to cause extra damage to the cable. JD-Contractor A/S has specialised persons and equipment to lift the cables onto one of our cable vessels where it can be properly repaired, before being lowered back into the seabed.

Related links:

7 Repairs to Subsea Cables

Kontek repairs 2008

repair between Vestmanna and mainland of Iceland

Blackout on Bornholm

Cable repair between Bornholm and Sweden

Cable repair between Rødvig and Rønne

Reparation of terminal strip on the Kontek cable

Repair of 250 kV submarine cable between Jutland and Læsø

Repair of the main cable at Utgrunden Wind Turbine Farm