MAN B&W Diesel has been awarded the contract to supply complete twin-screw medium speed propulsion packages for six Anchor Handling Tug Supply Vessels (AHTS). The newbuildings, which will be built by Labroy Shipyard, Batam, Indonesia
(Labroy Shipbuilding and Engineering Pte Ltd
) are to be operated by Swire Pacific Offshore Limited
, Singapore. The first newbuilding is expected to be launched in the beginning of 2007, and the following vessels are planned to follow at two-month intervals. The 120-ton bollard pull AHTS vessels have been designed by the U.K.-based IMT Marine Consultants Ltd.
, with specific optimization for the worldwide operation of Swire Pacific Offshore activities.
A total main engine output of 2 x 3,285 kW will supply the propeller thrust, for a bollard pull of more than 120 metric tons. The ship service speed is optimised for 13.5 knots. The MAN B&W Diesel twin-screw Alpha Propulsion System type 9L27/38-VBS, which has been specified for the newbuildings, include:
• Main Engines Two MAN B&W 9L27/38 engines, fitted with full engine power PTO and integrated journal bearing at the front-end, driving a fire-fighting pump arrangement.
• Reduction Gearboxes Two MAN B&W Alpha AMG55 gearboxes, type 57VO55EV, with a speed reduction ratio of 800:141. Additionally, each gearbox is equipped with a 1,800 r/min PTO shaft for a 1600 kVA shaft alternator.
• Propellers Two MAN B&W Alpha type
VBS980 four-bladed controllable pitch propellers. The 3,800 mm ducted CPP systems are complete with tail, intermediate shafts and bearings, stern tube equipment
, and MAN B&W fixed propeller nozzles type AHT.
• Control System In addition to the engine room control station, the Alphatronic 2000 Monitoring, Control and Safety System includes a main bridge control station and an aft bridge slave control station. The propulsion control is interfaced to a Joystick/Dyn Pos System, which manages the overall ship maneuvering via gyro compass, rudders and thrusters.