Offshore staff
DERBY, UK -- Rolls-Royce has unveiled the new UT 790 CD vessel design, which features wave piercing technology.
The hull pierces through the water rather than riding on top of the waves, allowing the vessel to run continuously at service speeds regardless of the sea state, reducing fuel consumption and improving crew comfort, the company says.
The technology eliminates slamming and allows for a smooth ride even in extreme weather conditions. At speeds of 14 knots and violent storm conditions, tank tests have shown no water above forecastle deck level, the company reports.
In extreme wave heights, water will be visible at the forecastle long before the situation gets critical, giving the captain an early warning which allows him to reduce power to maintain generous safety margins.
The vessel meets all existing regulations from the Norwegian Maritime Directorate and all latest international regulations such as SOLAS2009 and Special Purpose Vessel codes and regulations.
The engine room on the UT 790 CD has been moved astern. The new design also includes the Mecmar wet exhaust system, where the exhaust is cooled from above 300° C (572° F) to approx. 60° C (140° F), leaving the saturated and cooled exhaust at sea level. The distance from the engines to the exhaust outlet ducts is then left to a minimum. With the engines and exhaust outlet astern, there are no casings limiting the view from the bridge. The 360 degree view significantly improves safety, the company says.
Locating the engine room to the rear of the ship provides a number of benefits; engine noise is reduced and spare room for winches created at the front of the vessel. The UT 790 CD has the same fiber and rope capacity operating with four secondary winches as a traditional anchor handler has with six. The vessel has the power and capacity to handle cable, chain and rope down to 2,000 m (6,562 ft), and fiber rope down to 3,000 m (9,843 ft).
Another feature on the UT 790 CD is the extra buoyancy in the cargo railings. This provides extra stability and safety in case of extreme heeling levels.
The UT 790 CD comes with a full Rolls-Royce Safer Deck Operations (SDO) system, including anchor handling cranes, chain wheel changer and torpedo anchor handling system. The purpose of SDO is to keep the crew away from danger zones to improve safety, while maintaining operational flexibility and efficiency.
One of the new features on the vessel is the introduction of a three-screw propulsion system, combining a center controllable pitch propeller with two azipull thrusters with nozzles. As with all other generic anchor handlers from Rolls-Royce, the UT 790 CD comes with a hybrid propulsion system. The multi-drive power electrical system gives flexibility in different modes -- maximum power operating in anchor handling mode with both mechanical and electrical power engaged, to electrical only in dynamic positioning (DP) or slow maneuvering mode and mechanical only in transit mode.
This flexibility optimizes fuel efficiency and substantially reduces emissions compared to conventional propulsion systems. All Rolls-Royce Bergen engines meet Clean Design class rules without further exhaust clean-up, but catalytic converters can be fitted to the generator sets, giving 90% NOx reductions.
The three-screw solution adds to the vessels flexibility and improved fuel economy. Combining the Azipull thruster with a large single screw controllable pitch propeller ensures superior power and maneuverability, the company says. The Azipull also creates less resistance in transit position compared to conventional azimuths.
With its special redundant drive solution, the forward azimuth thruster can be powered by two independent switchboards, and the vessel can achieve the same DP-2 capability with its three thrusters then conventional solutions with four.
06/12/2009
