2013, Walney Extension Offshore Wind Farm, BACTEC International Limited, Topographic and Magnetic Survey at Middleton Sands for the Landfall of the Export Cable

Description

As part of the Walney Extension Windfarm project, DONG Energy has identified the landing location of the export cable within a defined corridor in the intertidal zone. The Main Array Site is located approximately 19km west of the Isle of Walney coast in Cumbria, approximately 35km northwest of the Blackpool coast and 31km southeast of the Isle of Man.
Due to the presence of important weapons manufacturing and industrial sites around the Bay, including the Trimpell Oil Refinery that was key to the development of new aviation fuels and identified as a primary target by the Luftwaffe, therefore there is a threat posed by German air delivered ordnance (bombs). Additionally there is a high probability of encountering artillery/mortar projectiles in the Morecambe Bay area, due to WWII training activities in the area.
DONG Energy UK Limited commissioned BACTEC International Limited to carry out a topographic survey and magnetic anomaly assessment of the proposed cables corridor, from a cable installation point on the land inshore of the beach dunes, out to the offshore limit of the tidal sand flats.

The aim of the works was to carry out a Magnetic Survey in order to locate magnetic anomalies that might indicate the presence of UXO. Based on a UXO Threat and Risk Assessment undertake by 6Alpha Associates “the smallest potential threat item within the near shore Morecambe Bay area, near to where the Export Cable will make its landfall is assessed to be mortar rounds (of which the smallest is 2 inches in diameter) and varying lengths.
Smaller items could also be present (i.e. small arms ammunition), but they present a lower risk generally, as the consequences of initiating them are far less severe.”
A topographic survey was also to be undertaken in conjunction with the magnetic survey using the Real Time Kinematic (RTK) GPS data collected during the magnetic survey.