The Race Bank Wind farm is being constructed by DONG Energy approximately 27 kilometres off Blakeney Point on the North Norfolk coast and 28 kilometres off the Lincolnshire Coast and Chapel St Leonards. It covers an area of 7511ha.
Export cables bring the power from the wind farm to the substation onshore. These export cables run through the Wash and come ashore east to the mouth of the river Nene and approximately 6 km northeast of Sutton Bridge. The cables ashore run further in a southerly direction to the connections point at the existing Walpole Substation.
The two export cables are both approximately 70km long and the two Offshore Substations (OSS) are linked with an interconnector of 4km. In March 2015 Jan De Nul was awarded a contract for the installation and burial of both export cables and the interlink cable.
Here we focus on the installation of the intertidal parts of the export cables and its special challenges.
Environment
The intertidal areas of The Wash compromise up to 10% of England’s saltmarshes and form one of England’s most important natural habitats. Mitigating any potential for the installation works to impact on these habitats is a key priority and measures to ensure that works would be conducted in the most appropriate and least invasive ways possible was agreed in accordance with the project’s consents.
Bathymetric levels in the intertidal areas vary between +7m LAT to -8 m LAT with tides ranging up to 7 m during spring.
