The combined efforts of Stone Marine Propulsion, the NPT propellers designers and manufacturers, Grontmij/Schmidt Maritime the vessels designers, Becker Marine and builders Yangzhou Guoyu has produced some excellent results for the latest Seahorse 35000 deadweight bulk carrier recently launched. The vessel recently completed sea trials and has exceeded all the performance requirements built into its contract.
Powered by a Wartsila engine, MCR 6350kW @ 99 rpm, and fitted with a 5.9m NPT propeller, the contract originally required 14 knots at 5700kW in 10.1m draft conditions. With a Becker Mewis duct fitted, model tests, conducted at FORCE Denmark and SVA Potsdam Germany, indicated that the power required would be reduced to 5440kW.
An analysis of the sea trials results shows that the actual power demand to achieve 14 knots was only 5252kW, 3.5% better than the model tests showed and an excellent 8% better than the contract power requirement.
The number of vessels fitted with Stone Marine Propulsions NPT propeller is growing rapidly as more naval architects and ship owners appreciate the benefits of fitting the propeller, not just to vessels like this one where the engine and propeller have been chosen to provide optimum performance but also to other vessels adopting a slow steaming policy where significant improvements can still be obtained. Generally, an NPT costs no more than a conventional propeller but brings with it lower weight and inertia and delivers its considerable power with reduced noise and vibration.
Owners of the trial ship, Nordic Hamburg, now have three more ships of this class on order, all of which are being fitted with NPT propellers and, in total, NPT’s have been supplied, or are on order, for 20 ships in the Seahorse 35000 class.
Stone Marine Propulsion, March 25, 2013