PT May a tough KIWI TUG
The towboat PT May is the first small tug of her type to be built in New Zealand for some time, as our ports and workboat operators cool their heels and wait for the economy to lift.
grip on it as well. Designed for Pacific Tug Australia and built by Shipco in Whangarei, she incorporates a heap of new features, with many of her innovations leading the way in new tug and towboat development in this part of the South Pacific. Her twin Cummins KTA 19–M3, rated 447kW (600bhp) each at 1800rpm, are air-started and keel-cooled. They drive through detached model W 1800 ZF 6.16:1 island-mounted gearboxes connected via a Centa CX-55-LFS2 input coupling.
T Another significant difference is the
hat is if you can call this tug small. At nearly 16m overall, including the fenders, a 7m beam and drawing 2.7m aft, she takes up a fair hunk of water space and makes sure she has a good
propeller shafts are of mild steel running in oil-lubricated bronze bushes driving twin 1494mm-diameter four- bladed manganese bronze propellers with a blade skew of 20 degrees. Engine and gearbox control is by a three- station ZF controller with one MC2000 and two 760 control heads. The propulsion train is remarkably free of vibration both ahead and astern and at all speed ranges, giving a no-load service speed of 10.5 knots. The main engines are mounted on LO-REZ BR4LS
spring-type vibration isolators. They have a high load capacity, incorporating safe limit stops and neoprene dampers to prevent excessive vertical or rocking motion of isolated machinery. The exhaust pipes and mufflers are also resiliently mounted, so the overall result is very good noise control. Electrical power is generated by two Cummins generator sets. One genset, a keel-cooled 6B-CP80DM/5 rated at 80kW 380 volts 50Hz and with electric start, is for general on-board power. The other, larger genset, a keel-cooled and air-started 6C-CP136DM/5 rated at 136kW 380 volts 50Hz, supplies the power to drive the towing winch. Although her propulsion is by twin screws through conventional drives, the PT May stands out from her
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NZ WO KBOORKBOAT REVIEW 2012 WORKBOAT REVIEW 201 WORKBOA VIEI W2012 12
REVIEW 2012
