Marine construction contractor Red7Marine has supported subsea solutions specialist N-Sea Group in a critical export cable repair project for the 576 MW Gwynt y Môr offshore wind farm in the Irish Sea.
With complete delivery of two jack-up barges, supporting tugs, a 220t telescopic crawler crane, accommodation and catering service, Red7Marine’s end-to-end package enabled N-Sea to focus on its project goals of completing the repair project.
N-Sea Group was contracted by an Offshore Electricity Transmission (OFTO) to complete the repair of an export cable in the Irish Sea.
In total 950 m of submarine cable has been replaced, 400 m off the beach at a challenging shallow water location with a large tidal range.
Cable installation and an offshore repair joint have been executed from Red7Marine’s Haven SeaSeven 400t jack-up barge.
With involvement in the early stages of N-Sea’s bid, Red7Marine’s in-house team fabricated bespoke temporary works for the project to execute the cable installation and jointing works, and modifications were made to one of the company’s existing cantilever platforms to support the jointing habitat and cable chutes
Red7Marine’s 250t Haven Seariser jack-up barge acted as the accommodation and cable reel storage/spooling platform, working adjacent to the Haven SeaSeven with gangway access between the barges.
Both barges had recently completed long term charters in Germany and were towed from Red7Marine’s headquarters in Ipswich to Vittoria Dock in Birkenhead for mobilization ahead of the project taking place.
“We take immense pride in being a dependable partner for our clients, especially when facing complex challenges. Working with the N-Sea team in the initial stages of the bid, we devised a methodology utilising two assets, with our engineers handling all feasibility, floating and jacked stability, leg penetration assessments and RAMS. It was great to push the capabilities of the barges and end with a solution that worked for N-Sea and the project requirements,” said Kristen Branford, Managing Director at Red7Marine.
The repair works were completed within three weeks, with the barges returning to the Port of Mostyn for demobilization.