Thrustmaster tunnel thrusters on new Seacor FSV

Seacor Marine's new Alex F. McCall

DECEMBER 10, 2014—Earlier this year, Seacor Marine took delivery the 10,800 hp Fast Supply Vessel Alex F. McCall from Gulf Craft, Inc., Franklin, LA.

Classed as a DP2 vessel, the 202 ft by 34 ft monohull Fast Supply Vessel (FSV) is fitted with fixed pitch, 200 hp, Thrustmaster 30TT200ML-AL tunnel thrusters. Each tunnel thruster is driven by a directly mounted electric motor that is capable of operating continuously at variable RPM in both directions of rotation, providing infinitely proportional thrust in the athwartship direction.

Thrustmaster tunnel thrusters are of exceptionally robust design capable of producing lateral thrust under extreme load conditions in demanding offshore applications for dynamic positioning or for slow speed maneuvering and are available from 150 hp (100 kW) up to 5,000 hp (3,500 kW), with tunnel diameters from 30 in. (762 mm) up to 136 in. (3,455 mm).

All components that come in contact with seawater are constructed of marine grade aluminum, bronze or 316 series stainless steel to insure longevity and prevent galvanic corrosion. The thrusters do not require external cooling. Any heat generated by the gears and bearings is dissipated through the pod housing to the surrounding seawater.

The thruster pod housing is an aluminum casting and is bolted in the tunnel. The pod contains the propeller shaft, right angle gears, input shaft, bearings, and seals. The geometry of the pod housing is hydrodynamically optimized to minimize drag resistance.

The new vessel has a light ship displacement of 277 long tons (281.45 mt). Interior capacities include 92,418 US gallons of fuel, (349.8 cubic meters), 10,848 US gallons of drill /fresh water (41.1 cu. met.) and 3,200 US gal. of potable water (12.1 cu. mt.). Discharge rates are: for drill water 300 gallons per minute at 380 feet, for fuel oil 354 gpm at 394 feet.

The 132 by 27 foot (40.2×8.2 m.) cargo deck is estimated to have a 400-long ton (406.4 metric ton) capacity. Crew accommodation includes eleven berths in six cabins. Seating is provided for 64 passengers

Main engines are four Cummins QSK60-EPA Tier 3 compliant diesels, each delivering 2,700 hp at 1,900 rev/min. Each engine drives a Hamilton HT810 water jet to give the boat a 32-knot maximum speed. At a cruising speed of 26 knots (1,800 rev/min) the mains burn 366 gallons per hour. At the economy speed of 22 knots (1,500 rev/min) this drops to 264 gallons per hour.