UK: Tough Conditions in Irish Sea
Orsta Marina Systems Nederland BV announced it has been selected to provide the inshore berthing pontoon for renewable energy company Dong Energy at Barrow in Furness on the north west coast of England.
The pontoon will form part of the onshore O&M facilities supporting the construction of 108No offshore wind turbines in the Irish Sea, west of Duddon Sands, a partnership project between Dong Energy Denmark and Scottish Power UK.
What makes an excellent location for wind power generation poses challenging conditions for pontoons. Following a competitive tender process Orsta were appointed by main contractor Commercial Marine & Piling Ltd (CMP) to design and manufacture the 68 metre long x 5 metre wide pontoon for the fleet of support and maintenance vessels. The exposed local conditions include a tidal variation 11 metres and average wind speed of 63km/h.
The precast concrete pontoon units will be manufactured close to the site within the Port of Barrow. Each unit will be 22.65 metres long x 4.8 metres wide x 2 metres depth and will weigh between 70 and 80 tonnes. The pontoons will be moored on 4No 1220mm diameter steel tubular piles which will be installed into rock sockets by CMP. Access and egress to the pontoon will be provided by a 34.5 metre long tidal access bridge and in addition to electrical light and power services the pontoons will be installed with high speed re-fuelling services, sewage and bilge water pump out services and a dockside crane such that turnaround times for support vessels are minimised.
Press release, May 3, 2013; Image: orstamarina