First IMT 948 for North Star on trialsVessel & ROV News // August 26, 2005
Grampian Commander, the first IMT948 safety standby vessel or 'Emergency Rescue Response Vessel (ERRV)' is currently on trials from Astilleros Balenciaga shipyard in Spain and is due to be delivered early in September during the forthcoming Offshore Europe exhibition and conference in Aberdeen.
This latest project between North Star, IMT, the ship's designer, and the Spanish yard, arose as a result of a close collaboration in 2002, during the construction of North Star’s IMT 977 ROV support vessel Grampian Surveyor.
During the ROV support vessel project, IMT was asked to present a proposal for a newbuild standby safety vessel design as part of a fleet replacement programme, the owner requesting a vessel “which could be also built at an effective cost.”
Through experience of operating standby safety vessels for a number of years, North Star has found that the most comfortable seakindly hullforms are associated with converted stern trawler hulls, but that these hullforms have limited flexibility for changing requirements due to their narrow beam.
So, although based on an IMT 344 stern trawler design, the resulting design that IMT produced is somewhat modified for the new role, the beam of the basic trawler hull form having been increased to give more deck area and stiffer stability characteristics without the use of high levels of solid ballast normally associated with this type of design. The design can also be changed to meet different market or chartering requirements, such as being fitted with daughter craft or other configurations.
The IMT948 is a single-screw two-deck safety standby vessel. A 1,520kW MaK 8M20 medium speed diesel engine drives through a through a Volda vertically-offset marine gearbox and stern gear system to turn a 2,500mm-diameter CP propeller operating in open water and optimised for the speed condition.
The vessel is also fitted with a 280kW Schottel retractable azimuth thruster unit driven by a speed-controlled electric motor. Power generation for ship’s equipment and the forward azimuth thrusters is provided by a 612kW(e) 765kVA shaft generator driven from the primary side PTO.
In the forward thruster space, two diesel-driven generator sets each developing about 350kW(e) provide independent electrical power to the azimuthing thruster and ship systems in the event of loss of the main engine room, as a ‘get-you-home’ device allowing the vessel to return to port. The engine room and thruster rooms are protected by side tanks and double bottom tanks.
All survivor areas are located on one deck and are fitted out in accordance with the UKOOA Code of Practice and comprise a reception area, treatment area, recovery area, survivor seating area, and two survivor toilet/washroom areas.
Two fast rescue craft (FRCs) for survivor recovery are provided, each with a heave-compensated single-point-lift davit system and towing boom. In addition, survivor rescue zones, Dacon scoop and rescue basket, deck crane and survivor recovery facilities are provided, and a helicopter winching zone is located at the stern on the upper deck. The vessel is fitted with a water drenching system.
A full width bridge design is arranged based on feedback from crews on North Star Shipping’s ships, and is fitted with central control positions and wing joystick-control positions providing excellent vision of the navigation areas, rescue zones, and FRC positions.