Walney Substation (Offshore Wind Farm)

Project Summary

Construction of civil works packages for the new substation to service Walney Offshore Wind Farm in Morecambe Bay on a greenfield site of 8 acres.

Project Description

Construction of civil works packages for the new substation to service Walney Offshore Wind Farm in Morecambe Bay on a greenfield site of 8 acres.  Once completed, the substation will service the largest offshore wind farm in the world.  Works have included topsoil strip, construction of complex foundations for numerous structures, including the G.I.S. Building, North & South 220kV Shunt Reactors, North & South 400kV Shunt Reactors, North & South Transformers and the North & South DRC Transformers, main site platform construction, ducting, drainage, access roads and a box concrete culvert.

Project Delivery

Site clearance consisted of scraping back the existing vegetation (largely grass) followed by a topsoil strip.  We prepared a platform for deep soil mixing ground improvement works (carried out by others) and also the permanent sub-station platform, which consisted of a layered stone construction averaging 1m deep over an area of approximately 20,000m2.

Coffey constructed the 50m by 7m wide site access for the works during the construction period, and this is to become the permanent finished access road once site works are completed.  This access road crossed a culvert which was part of a land drain across the site.  CCL constructed the 2m by 1.5m high precast concrete culvert, which included the construction of headwalls and wing walls and the placement of gabion baskets as an extension of the wing walls.

At peak times during the construction of this project, Coffey managed in excess of seventy employees and worked extended hours, weekend shifts and through holiday periods to achieve key milestones.