Build of world-first amphibious offshore wind farm crew transfer vessel delivered in under a year. Vessel passed initial testing phase in readiness for commercial rollout. Potential future world-wide application for wind farms in very shallow waters.

RWE, in partnership with Commercial Rib Charters (CRC), can share a first look at the innovative amphibious vessel ‘CRC Walrus’ which has been designed by Commercial Rib Charters and built in the Isle of Wight to reach offshore wind farms in shallow waters.

The unique crew transfer vessel was specifically commissioned to access turbines at Scroby Sands, which have become stranded by the natural rising tide of the sandbank on which it is built. The vessel, which can also drive on land, provides access to generation assets affected by dynamic seabed conditions.

From first concepts less than 18 months ago, the project has been developed, designed and built with collaboration between RWE and Commercial Rib Charter (CRC). Naval architects Chartwell Marine carried out design specifications and the vessel was constructed by Diverse Marine in their Isle of Wight boat yard.

CRC Walrus took its maiden voyage in early January and results are positive, achieving speeds of 24 knots on water and 6kmh on land. The 12-meter vessel has a 1000kg cargo capacity and is capable of safely transferring 10 technicians and two crew to any of the turbines within the Scroby Sands array, including on the raised sandbank. The innovative design means that the two wheels at the front and one at the back can be deployed, similar to an aircraft, when transferring from deeper water into shallow water and sand.

CRC Walrus has now been working on site successfully for the last four weeks providing a safe method of access to turbines that have been out of reach for considerable time. Trials continue in order to thoroughly optimise the operation and performance of the vessel.

It will be operated for RWE by CRC, via a six-year contract.

Stuart Hedges of Commercial Rib Charter says: ’We are thrilled to have had the opportunity to build this vessel for RWE, specialising in shallow water operations has always been our niche so building a conventional CTV with amphibious capabilities has been very exciting. We are very pleased with trials that have been 100% successful.

Phillip Croston-Clegg General Manager at Scroby Sands said:” This new vessel is a successful innovation and testament to the fantastic collaboration between Commercial Rib Charter and the RWE team. Working with experienced vessel operators to design a unique solution to a problem that was impacting our maintenance, has been invaluable. In addition, this could pave the way for broader applications in similar areas.”

RWE’s 60 megawatts (MW) Scroby Sands Offshore Wind Farm was one of the first of a group of projects to be built in the UK, and all in coastal locations with relatively shallow waters close to shore. Scroby Sands was built on a prehistoric sandbank and, because of natural changes in the marine environment and coastal erosion, this has risen over time effectively isolating four turbines from being accessed by service vessels.