Umoe Wave Craft enhances windfarm access

Actively controlled air cushion technology reduces vertical motion on the Wave Craft, allowing a smooth ride and improved windfarm access Actively controlled air cushion technology reduces vertical motion on the Wave Craft, allowing a smooth ride and improved windfarm access

Norwegian shipbuilder Umoe Mandal has demonstrated its new windfarm service vessel at Seawork 2015, featuring an actively controlled air cushion to minimise vertical motion in high sea states.

The 12-passenger vessel, one of 13 finalists in the Carbon Trust’s Offshore Wind Accelerator (OWA) competition, was delivered in February. It is owned by Umoe Wind and chartered under an initial eight-month contract to DONG Energy to serve the Borkum Riffgrund 1 offshore wind farm in the North Sea. The craft is managed on behalf of Umoe Wind by Danish ship management company Valling Ship Management.

The Wave Craft, with a crew of two or three people, uses an air cushion between catamaran hulls to lift 80% of the vessel out of the water. The small draught enables easy access to ports as well as high speeds at low fuel consumption – on the way from Germany to Ramsgate for Seawork International 2015, the vessel achieved an average speed of 32 knots in wave heights of around 1m. Maximum speed (as demonstrated at Seawork) is in excess of 40 knots, and the vessel has a range of more than 700 nautical miles.

More importantly for its windfarm service, the pressure of the air cushion is actively managed according to wave height by a series of valves. This reduces wave induced motions – eliminating 60-70% of vertical motion in waves of 1.5m in full-scale tests - and allows for a far smoother voyage, as well as a larger operational window for maintenance teams accessing wind farms. According to Umoe, the craft allows access to turbines in wave heights of 2.5m, or even higher in swell.

The 27.2m vessel, classed by DNV GL (+ 1A1 HSLC R1 Windfarm Service 1) and flagged in Denmark, features water jet propulsion powered by high-speed, 16-cylinder MTU engines delivering 1,440kW. The lift fans for the air cushion are powered by Scania diesel generators. In total the craft houses six engines.

According to Trygve Halvorsen, section manager naval architecture and hydrodynamics at Umoe Mandal, the Wave Craft has attracted a lot of interest. A second vessel is already under construction for Umoe, for delivery later this year.

“The main difference with the second vessel will be the weight,” explained Halvorsen. “We are working with DNV GL on reducing the thickness of the carbon fibre in the hull. The existing rules did not account for this type of material so the first vessel had some added thickness that is not necessary.”

The OWA has supported the de-risking of the Wave Craft design, providing technical insight from offshore wind developers and financial support. As one of 13 finalists drawn from 450 applications for the Offshore Wind Accelerator competition, the project received a third of its funding from the UK and Scottish governments, while the Research Council of Norway’s regional MAROFF programme is also a contributor. But Halvorsen said that the funding was not the main reason for partnering with the Carbon Trust. Rather it was the involvement of the nine offshore win developers in the project – among them DONG Energy, Statoil, Vattenfall, the Scottish government and the UK Department of Energy and Climate Change.

The vessel is also the first commercial build for Umoe Mandal, which has previously specialised in high-speed craft for the Norwegian navy. It has delivered six 47m Skjold-class corvettes, also deploying air cushion technology, which are said to be the fastest vessel of their type with a speed in excess of 60 knots.

Featured Videos

Latest Press Releases

Damen signs maintenance contract with Netherlands Ministry of Defence

On 11th July, Damen Shipyards Den Helder signed a midlife upkeep (MLU) contract with the Netherlands... Read more

Damen signs contract with Karachi Shipyard & Engineering Works for Material Package of two ASD Tugs 2009

On 5th July, Damen Shipyards Group signed a contract with Karachi Shipyard & Engineering Works (KS&E... Read more

Damen signs contract with Karachi Shipyard & Engineering Works for Material Package of two ASD Tugs 2009

On 5th July, Damen Shipyards Group signed a contract with Karachi Shipyard & Engineering Works (KS&E... Read more

Multraship holds naming ceremony for two new Damen tugs

Multraship holds naming ceremony for two new Damen tugs Read more

Damen releases annual Corporate Social Responsibility Report

Latest editions details group alignment with UN Sustainable Development Goals Read more

Damen signs contract with Baleària for Eco-efficient tug in Port of Ciutadella

Damen Stan Tug 1606 E3 the first IMO TIER III compliant harbour tug in the Mediteranean Read more

View all