Offshore Hotel Ship Kept Steady by 'Built in Waves'
This accommodation vessel makes it easier for offshore industry workers to find their sea legs, thanks to opposing waves created in specially-designed tanks fitted in the hull. It is designed by the Stord-based maritime design company SALT, and is being built under contract for ship owner Østensjø.
“This concept provides an alternative to the semi-submersible platforms commonly used at present. The aim is to create a more mobile hotel unit which can be leased by oil companies which operate in several parts of the world. Our job has been to give the ship characteristics which make it more comfortable to live on at sea,” explains Sverre Anders Alterskjær of MARINTEK, the Norwegian Marine Technology Research Institute.
The integrated system designed to reduce rolling of the vessel has been developed by Hoppe Marine and thoroughly tested by Alterskjær and his research colleagues at MARINTEK who are specialists in investigating new ship and hull concepts using the unique test basins in their laboratories.
The roll damping is achieved using tanks integrated into the bottom and sides of the hull – called “U-tanks” because of their shape. “The tanks are filled with water which is set in motion in opposing phase to the wave forces acting on the hull,” Alterskjær explains.
- The tanks are fitted with air valves at the top which partially control the water motion in the tanks.
- Valve opening can be adjusted depending on the ships roll period
- The result is reduced rolling and improved comfort for those on board.
The researchers investigated the optimal opening of the valves at the top of the U-tanks and the correct water level relative to the ship design, as well as measurement of the motion of the ship during voyages and in hotel mode.
MARINTEK is a company within SINTEF, the largest independent research organization in Scandinavia, and develops and verifies technological solutions, business and operating concepts for the shipping, marine equipment, ocean energy and petroleum industries. MARINTEK’s headquarters and laboratories are in Trondheim, Norway, with subsidiaries in Houston, Texas and Rio de Janeiro, Brazil.