Offshore unexploded ordnance disposal campaign now complete
Inch Cape contractor N-Sea’s work to clear the wind farm’s offshore array site and export cable corridor of unexploded ordnance is now complete.
For the past six-months, the N-Sea team onboard offshore support vessel 4Winds has carried out a comprehensive pre-construction campaign to ensure the 150 square-kilometre site and 85-kilometre cable corridor were clear and safe in advance of the project’s offshore installation activity.
A total of 395 potential unexploded ordnance (UXO) were identified and investigated using a remotely-operated vehicle (ROV) with a total of 86 confirmed UXOs found. These ranged from projectiles, anti-submarine weapons and British buoyant sea mines to depth charges and German Luftmine B (LMB) parachute mines.
Most of the confirmed UXOs will be avoided or worked-around however a total of 38 had to be disposed of to enable the project’s offshore installation activity to go ahead in safety.
A low order deflagration technique was used for the disposals, meaning that the explosive content inside the ordnance is ignited and burnt out in a controlled process without detonation, with the debris removed once complete.
Specifically designed and shaped charges were placed next to target ordnance using Dorset-based ECS Special Projects’ Cobra System. This modular, historic ordnance disposal solution is one of only two systems recognised by the UK Government for this type of activity. It has been used in military situations and for civil works including oil and gas pipelines, capital dredging and offshore wind farms, including Inch Cape.
depth charge
Inch Cape’s unexploded ordnance clearance activity now finalised and the site is ready for the start of installation of the project’s monopile foundations in December this year.
