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A model 'whale's tail' wave foil that can be attached to ships to improve fuel efficiency is being tested by researchers at the Norwegian University of Science and Technology (NTNU).

The tests are being conducted at the Norwegian Marine Technology Research Institute (Marintek) Towing Tank in cooperation with Rolls-Royce and UK firms Seaspeed and MOST.

A 1:16.57 scale model ship is attached to the back of the platform that sails the man-made waves of the Towing Tank. It takes just a few seconds to cross the 200-metre-long tank, but valuable information is collected during the process. Cameras and advanced measuring equipment show how the model moves, the resistance against it, and how changes affect it.

Eirik Bøckmann [pictured in photo], a postdoctoral fellow at the Department of Marine Technology at NTNU, is the person responsible for testing the invention. He has been working on the concept for several years.

The principal objective of the whale's tail is to help reduce fuel consumption by using wave energy to assist in moving the vessel forward.

The waves hit the ship model and cause it to move. This causes the fins to move up and down just like a whale's tail would. The shape of the fins then allows energy from the waves to help the vessel move forward.

The shape and angle of Bøckmann's fins are said to be unique, but similar inventions have been tested and used in the past.

Bøckmann said: "The foils reduced resistance on the ship by between 9 and 17 percent at wave heights of under three metres, under the conditions that we've tested.

"The resistance can probably be further reduced by optimizing the ship's hull for the wave foils. The foils also reduced the ship's heaving and pitching by about the same amount as for resistance," he added.

Alastair Sim, a technologist at the Rolls-Royce Strategic Research Centre, is responsible for evaluating new marine technologies and deciding what Rolls-Royce should fund.

Sim remarked: "We need to see how things work, and then choose the best way forward based on that."

Sim added that he sees a lot of potential for this invention if it works the way it is intended. However, it is not enough for the wings just to work. For example, they also need to be able to take a beating and not destabilize the ship.

"Experience from similar ideas shows that collisions where the wings are damaged doesn't affect the actual stability of the ship," Sim said.

Managing director of Seaspeed, Stephen Phillips, has more than two decades of experience of working with and improving high-speed ships. Seaspeed has experimented with fins, or 'wave foils', for a number of years.

"British authorities wanted to include us in this project," said Phillips.

In addition to working with Rolls-Royce - a company that has collaborated with researchers at the Towing Tank for several years - Seaspeed is supported by a British innovation programme intended to help develop fins for use in commercial marine transport.

Rolls-Royce Marine also recently signed a long-term research and development agreement with NTNU and SINTEF MARINTEK.