The increasing concern about reducing the impact of shipping on the environment has provided an incentive for marine designers to look again at the potential of the wind to propel ocean-going ships. Japan, which seriously became involved in this field as a marine fuel-saving effort in the 1970s and 80s and constructed a number of “wind-assisted” ships, is now looking again at the potential for wind, this time with far larger ships. One of the most interesting projects – still on the drawing board at the University of Tokyo – is a design for a large Capesize bulk carrier which will employ sails as its main power source. With nine holds in the conventional bulk carrier configuration, the UT Wind Challenger, as it has been named, will have nine massive aerofoil sails on masts placed between each cargo hold. Both masts and sails will be telescopic, enabling the ship to sit comfortably under the loaders in bulk terminals and permit cargo handing to take place. Accommodation and a low navigating bridge will be right forward.
The project is supported by a group which includes some of the country’s biggest shipping lines, major shipbuilders and the Japanese classification society Class NK. It is hoped that the design will be completed in 2012. Whether such a ship will ever be built will clearly depend on the feasibility of the project, and the question of whether sufficient sail area can be provided to propel such an enormous weight of ship – perhaps 170,000 tons – at a reasonable speed. It will be recalled that the biggest pure sailing ship ever built in the 19th century was under 6,000 tons!
But the sails proposed for the giant bulk carrier would be very different from the crude canvas of the traditional sailing ship. These huge aerofoil shapes will be made of carbon fibre reinforced plastic, designed by computational fluid dynamics and set by computers so that the optimum setting is provided for the wind strength and direction blowing at any time. And while the old sailing ship Masters were dependent on their own skills to find the best wind conditions for their ocean passages, modern navigation and meteorology will enable the Masters of the bulk carriers to seek out optimum wind conditions at any time. If the maximum sail area is spread, the bulker will have five connected sails on each mast, towering into the sky. The ship would have conventional power for navigating through areas of calm and getting the ship in and out of port.
Will the UT Wind Challenger ever see the design translated into reality? Much will depend upon economics in the shape of relative energy costs and the price we are prepared to pay for really sustainable shipping. But we should watch this space!
Source: BIMCO