James Fisher Subsea (JF Subsea) in cooperation with their German partner GSS Hansa Offshore (GSS) were contracted by the windfarm developer OWP Nordergründe GmbH & Co KG to help clear unexploded ordnance (UXOs) from the site of the proposed Nordergründe wind farm.

The Nordergründe 111 MW offshore wind farm is located 15 kilometres north-east of the island of Wangerooge. It comprises 18 Senvion turbines being set up in water up to ten metres in depth.

JF Subsea and GSS together utilised divers and remotely operated vehicles (ROVs) on two dive support vessels (DSVs), Offshore Beaver managed by Workships Contractors BV and the Smit Orca of Boskalis Offshore.

The UXO’s, which had been released by Central Powers and Allied forces during WWI had delayed planned construction works and was at risk of costing the developer millions as a result.

“Offshore wind turbine sites are often plagued with UXO’s and are a continual problem we come up against during construction,” Jan Patrick Daniel, offshore project manager at wpd was quoted in JF Subsea press release.

According to the company, together with GSS, JF Subsea identified 224 targets, of which 72 were deemed to be UXO’s and had to be detonated with minimal impact to sea life.

Photo: Workships Contractors BV