Page 47: of Marine News Magazine (February 2014)

PROPULSION : POWER , SPEED AND PERFORMANCE, TOO With four 2880kW MTU engines each turning 900mm diameter waterjets expected top speed is 36 knots with an efÞ cient service speed of 30 knots at full load and 90% MCR. This speed performance will make the vessel more cost effective than helicopter transfer of crew and cargo, while the semi-SWATH hull design of the vessel, along with active ride control, will reduce stress on passengers so they arrive at an oil platform Þ t to work. OPTIONS & MORE ADVANTAGES A new optimized compact astern deß ector retains the performance of HM series type ducts but with reduced weight and width for installation in narrow hulls. The de- ß ector is actuated by two fully inboard hydraulic cylin- ders. The HT waterjet models are Þ tted with the JT nozzle steering system, also actuated by two fully inboard hydrau- lic cylinders. Shafts for both steering and astern deß ectors are protected from wear and marine growth through the use of sealed rubber bellows on external shaft surfaces. In- stallation of HT series waterjets has been simpliÞ ed by the use of a compression seal type transom plate arrangement, which allows for an increased tolerance for transom axial alignment. The transition duct extends from the ß at sur- face aft of the intake opening to an area forward of the front intake screen mount (HT900 & HT1000 only). For an aluminum hull, the transition duct casting is sur- rounded by a section of 5083 aluminum plate so the ship- yard does not need to carry out plate-to-casting welds. As the HT series waterjets utilize a tapered outside diameter impeller, the mainshaft axial position is adjustable in or- der to set and maintain impeller tip clearance. Aluminum anodes are used throughout HT series waterjets, with tail- pipe internal anodes able to be replaced without remov- ing the tailpipe. Like other HamiltonJet waterjet models a jet mounted and driven hydraulic power unit (JHPU), driven via multiple vee-belts from the jet coupling, is used for normal hydraulic operations. An optional auxiliary AC hydraulic pump (one per jet) is also available for actuation of the steering and reverse without the gearbox engaged. Hydraulic and thrust bearing oil cooling is provided by oil coolers integrated on the waterjet.www.marinelink.com MN 47MN FEB14 Layout 32-49.indd 47MN FEB14 Layout 32-49.indd 471/20/2014 10:21:23 AM1/20/2014 10:21:23 AM