Gardline Environmental was contracted by SCIRA to provide Seabed Intervention Services including UXO clearance operations on the Sheringham Shoal Windfarm site and export corridors. Target locations were provided by SCIRA from data acquired by previous surveys. The investigations were concentrated on targets identified within 25m of proposed inter-turbine array cables, turbine locations and the exclusion zones related to forthcoming jack-up vessel operations. The vessel OMS Pollux was utilised as the survey platform with surface and sub-surface positioning provided by Gardline Environmental. Specialist UXO services were provided by MACC EOD International with diving operations being performed by Red7 Ltd. ROV operations were carried out by Eriksson Diving Ltd. Field work was carried out between January and April 2010. The survey instrumentation on the OMS Pollux included two Hemisphere VS110 DGPS systems with one system receiving beacon corrections based on the IALA network and the other receiving SBAS corrections. Subsurface positioning was provided by an Applied Acoustics Easytrak system with micro beacons being used to position the divers, ROV and crane hook during lifting operations. A total of 52 targets were investigated over the course of the project. Objects were identified at 36 of these targets. Of these objects, 6 were recovered to deck, 3 were relocated in the field, 1 was disposed of by explosives and the remainder were left in-situ as they did not meet the criteria warranting further action. At 16 of the 52 reported targets, no objects were identified.
UXO Target Status