Cavitation curtailed

Water jet manufacturer MJP has introduced new outlet nozzle and inlet duct geometry which it says significantly improves the cavitation performance of its waterjets. This allows the rating of the waterjets to be increased, leading to an increase in vessel speed of several knots, says the company.

There are now three ships operating with the new pump geometry including the fast ferry Patricia Olivia which has two MJP 950DD waterjets rated at 6,200kW, (8,310 bhp) powered by twin AlliedSignal TF80 gas turbines. On the first sea trial the vessel bettered its anticipated speed, reaching over 50 knots and is claimed to be the world’s fastest passenger-only ferry.

A second application involves a 25m multi-purpose catamaran fitted with twin 910kW (1,240 bhp) MWM engines coupled to MPJ 550DD waterjets. In trials the vessel achieved 28 knots, pulling a 40m (120t) catamaran at almost 11 knots and maintained an average bollard pull of 7.5t for ten minutes.