Wärtsilä Propulsion Package for AHTS
Wärtsilä Corporation has received a contract from Ulstein Verft AS in Norway for a package of generating sets, thrusters, control system and seals for an anchor-handling towing supply (AHTS) vessel ordered by Bourbon Offshore Norway AS. Due for delivery in May 2006, the new AHTS vessel is the Ulstein AX104 design from Ulstein Design AS, with an inverted bow intended to eliminate slamming and allow higher speeds in all sea conditions.
The vessel will operate in the North Sea and will be equipped with six Wärtsilä generating sets having a combined electrical output of 14 850 kWe. Four of the generating sets are driven by six-cylinder Wärtsilä 32 engines and two by nine-cylinder Wärtsilä 20 engines. The propulsion and manoeuvring system will include two Lips CS3500/3500WN main steerable thrusters, a Lips CS250-250/MNR retractable bow steerable thruster and a Lips CT250M-D bow tunnel thruster. The main steerable thrusters, each with a power of 5000 kW, will have controllable-pitch (CP) propellers of 3.6 m diameter running in Lips HR nozzles. The 1800 kW bow steerable thruster will be equipped with a 2.4 m diameter CP propeller, while the 1200 kW bow tunnel thruster will have a 2.5 m diameter CP propeller. The four thrusters will be fitted with JMT MkII Unnet shaft seals. The thrusters will all be controlled through a Lipstronic/T control system which provides both joystick control for manoeuvring and full dynamic positioning.
Measuring 83.6 m long by 18.5 m broad, the vessel will have a speed of 17.5 knots and a minimum bollard pull of 180 tonnes and is reportedly one of the world's first AHTS vessels with diesel-electric propulsion. It also has innovation in safety, being equipped with a newly-developed system for safer anchor handling. It has a DP2 dynamic positioning system.