MT Chong, sales manager, engine Business unit of Scott & English Sdn Bhd, of Miri, Sarawak, says azimuth systems far outnumber full tractor tugs with the azimuthing drives set forward.
For those new to the concept, an azimuth thruster is a configuration of marine propellers placed in pods that can be rotated to any horizontal angle (azimuth), making a rudder unnecessary.
They now far outnumber the full tractor tugs with the azimuthing drives set forward under the house as do they the cycloidal drive tugs.
Often, the ASD tugs are dedicated shiphandling units with a single hawser winch forward.
Sealink Marine Shipyards have recently launched one of these versatile tugs from their facility in Miri, Sarawak, Malaysia, said Mr Chong.
The 32 by 11.8-metre tug has a 5.2-metre molded depth. Mounted forward it a Macgregor: MG-HAT/GDG22-0115U02080 combination anchor and hawser winch with 150-ton braking. Mounted aft is a Macgregor: MG-HTW1-0218008048 towing winch also with a 150-ton holding brake.
Power for this capable vessel derives from a pair of Cummins QSK60M diesels each generating 2,300 HP at 1900 RPM.
These turn 2.4-metre controllable pitch propellers on Rolls Royce azimuting drive units. This power gives the tug a 57.56-ton bollard pull ahead, a 53.87-ton bollard pull astern and a 13.6-knot free running speed.
The one-man bridge has a 360-degree view along with extensive electronic navigation and communications equipment. Accommodation for up to eight crew is provided in two one-person and three two-person cabins. All accommodations are centrally air-conditioned.