Rolls-Royce has successfully completed sea trials for its first S4 series of waterjets, which have been to designed to provide higher efficiency when vessels are travelling at lower speeds.
First introduced at the SMM Hamburg maritime exhibition this September, the S4 waterjet has been developed to meet the reduced speed requirements of many high-speed ferry operators. Previously, high-speed ferries were designed to operate at speeds of 45 knots or more, but increasing fuel costs are forcing operators to use waterjets optimised for lower speed and fuel consumption.
“Efficiency is improved over the whole speed range, matching the increased demand requirement for vessels operating around 30 knots, where waterjet propulsion has traditionally been less efficient,” said Daniel Wikström, Rolls-Royce Product Sales Manager, Kamewa Waterjets. “This translates into reduced fuel consumption for a given workload and, consequently, reduced carbon dioxide emissions and increased range for the ferry. Environmental benefits are achieved not only by increasing efficiency, but the inboard hydraulics also reduces the risk of oil spill.”
Rolls-Royce trialled the new waterjets on the recently upgraded Tangalooma Jet, a 350-passenger high-speed catamaran, which sails to Tangalooma Wild Dolphin Resort on Moreton Island, about 75 miles off the coast of Brisbane, Australia.
Previously equipped with Rolls-Royce’s Kamewa 63SII waterjets, the ferry was retrofitted with two 63S4 units, which involved a complete repowering of the drive train and engines.
During sea trials, the 63S4 waterjets achieved a 3% increase in thrust and offered enhanced manoeuvring capabilities, marking a significant improvement on the propulsion performance of the ferry’s previous propulsion system. Noise and vibration levels were also lower, which improved passenger comfort.
“The owner is very happy with the improved performance, which is easily understandable since the new arrangement can save the operator about AUS$80,000 per annum in fuel costs,” said Reima Aartojärvi, manager of the Rolls-Royce Hydrodynamic Research Center.