AHTS vessels with innovative propulsion system to operate for BP and Topaz Marine
Drawing of the 67.4m-long Topaz newbuildings from Adyard, Abu Dhabi
The two 67m-long, 16m-wide 80-tonne bollard pull vessels are ready for anchor handling tug supply services and the transportation of dry and liquid cargo to and from pipe-laying barges, drilling platforms and production platforms for offshore operations.
“Topaz Dignity” will operate on behalf of BP on a long-term-contract basis in the Caspian Sea, while “Topaz Triumph” may remain in the Middle East and be operated by Topaz Marine MENA. The vessels are equipped with the latest technical equipment and are custom-built for Fi-Fi Class I and DP2 operations.
Propulsion package
The twin-screw propulsion package for each vessel comprises eight-cylinder, medium-speed MAN L27/38 engines of 2,720 kW each, horizontal offset reduction gearboxes with a CPP servo oil distribution unit, and a 1,500 kW shaft alternator PTO. The gearboxes drive an approximately 18m intermediate shafting, and 13m propeller tailshafts in oil-lubricated stern tubes. The MAN Alpha CP propellers are 2,800mm diameter ducted, turning 198 r/min at MCR. The propeller thrust and pulling power is boosted by Alpha High Thrust nozzles, customised to hull integration with a length/diameter ratio (L/D) of 0.6. The Alphatronic 2000 propulsion control system is configured with twin control stations on both main bridge, aft bridge and in the engine control room, including interfaces to joystick and dynamic positioning systems.
