Rolls-Royce has developed the world’s most powerful waterjets for a Japanese super-ship.
The jets will propel the 700-passenger and cargo-carrying Techno-Superliner between Tokyo and the Ogasawara Islands, which lay 1,000km south, at 38 knots, cutting the journey time by ten hours to just 16 hours.
Two Rolls-Royce Kamewa VLWJ235 waterjets will absorb 27MW of power, which is said to be an 8 per cent improvement over systems currently available worldwide.
For a contract worth more than £5 million, the waterjets will be built at the Rolls-Royce facilities in Kristinehamn, Sweden, and delivered to shipbuilder Mitsui Engineering and Shipbuilding’s Tamano works in 2004. The ship, which can carry 210 tons of cargo, is due to begin service in 2005.
The 14,500 grt Techno-Superliner will be constructed from aluminium and will be 140m long with a breadth of 29.8m. The ship will be owned by Techno-Seaways, a consortium of Japanese companies and chartered by the Tokyo based operator Ogasawara Kaiun.
The Kamewa VLWJ235s will be 2.35m diameter, compared with the current largest Kamewa size of 2m, and will also use a new construction method.
The VLWJ235 is divided into a series of elements. Integrated into the hull structure is the inlet duct. To this and to the transom is bolted the impeller chamber. Outboard of this is the guide vane chamber and the steering and reversing unit, which is operated by a hydraulic steering actuator located inside the vessel and stem that protrudes downward from the compartment over the jet units.
The impeller shaft is supported by a water lubricated bearing in the guidevane chamber, has the seal box at its inboard end on the inlet duct, and is supported within the hull by a split bearing. The thrust is taken by a separate thrust block in the hull, connected to the impeller shaft by a stub shaft and coupling.