AALST, Belgium – Jan De Nul Group has repaired TenneT’s AC108 cable in the German Bight.
The cable connects the Trianel Borkum offshore substation with TenneT’s DolWin alpha convertor station.
The repair job is part of the service level agreement for cable repairs that the two companies entered in 2019.
Jan De Nul was tasked to repair a cable fault located within the 500-m (1,640-ft) zone around the DolWin alpha platform, 75 km (47 mi) offshore northern Borkum. This offshore platform connects three wind farms in the German North Sea to the country’s extra-high voltage grid.
Within less than 50 days, the company completed detailed engineering and vessel mobilization, replaced the damaged cable section, and buried the new cable and joint.
Jan De Nul mobilized its cable-laying vessel Isaac Newton and multi-purpose vessel Adhémar de Saint-Venant. First, the Adhémar de Saint-Venant de-buried the damaged cable section, including its cable protection system which was buried under large armour rock.
The Isaac Newton loaded the spare cable and repair joint in Emden, recovered the damaged cable section offshore, and subsequently installed the new cable and joint. The company’s jet-trenching vehicle PT1, installed onboard the Isaac Newton, completed the repair campaign by burying the new cable section 1.5 m (4.9 ft) below the seabed.