Polar Prince’s Cable-Laying Milestone
Using its specially-adapted cable installation vessel, the Polar Prince, the Subocean Group installed four power cables 1 m under the seabed in 30 m of water on Vattenfall’s Thanet Offshore Windfarm, off Ramsgate on the Kent coast. Subocean is the first company to use a DP vessel equipped with ploughing technology to install cables in the windfarm market.
Subocean chartered the Polar Prince, a DP2 subsea support vessel, in what represented a GBP 30 million investment for the company. The vessel was installed with Subocean cable laying and burial equipment including tensioners, haulers, cable tank and plough. The subsea construction company’s innovative approach has cut cable installation time by 50%. The cables were each installed within 24 hours which, compared with conventional methods, represents a significant timescale reduction in both operational activity and exposure to adverse weather conditions.
Mike Daniel, Subocean’s operations director, said: “The Polar Prince’s capabilities are much more advanced than conventional barges because it does not require anchors to be run while manoeuvring and the vessel is therefore significantly quicker. Traditional barge methods take at least two days to lay and bury one cable so for Subocean to save a day’s operational activity for one cable is exceptional particularly when you put it into full project perspective – the Thanet project alone involves laying 100 cables. The Polar Prince also withstands hostile weather conditions. During the cable installation on Thanet, the Polar Prince remained on site during winds of up to 60 knots when all other vessels retreated to the port for shelter.”