Recently delivered by GMG Shipbuilding & Heavy Industry Co. Ltd., China, to Atlantic Maritime Group, Sharjah, UAE, the tug AOS Power is the first Robert Allan designed RAmpage 4500 Class Offshore Support Tug. The RAmpage Class was developed by Robert Allan Ltd. to address a perceived gap in the market for high-performance towing and anchor-handling tugs for critical offshore terminal and oil-field duties. The tugs are designed to be able to maintain station in extreme ocean conditions, with enhanced maneuvering and sea-keeping capabilities.
The vessel is fully equipped for anchor handling, ship-assist, long distance towing operation, fire-fighting, deck cargo transfers, personnel transfer and other offshore support duties.

Main particulars are:
Length overall - 45.00 m
Beam, molded, extreme - 15.00 m
Depth molded (hull) - 6.75 m
Design draft, to USK - 4.60 m
Summer loadline draft - 5.55 m

Tank capacities are:
Fuel oil-525 cu.m
Potable water-115 cu.m
Drill water-140 cu.m
Ballast water-145 cu.m
Foam-20 cu.m
Oil dispersant-15 cu.m
Lube oil, main engines-12 cu.m
Lube oil, auxiliary engines-2 cu.m
Z-drive gear oil-2 cu.m
Hydraulic oil-3 cu.m
Dirty oil-7 cu.m
Oily water-6 cu.m
AOS Power has been built and classed to Bureau Veritas notations: BV 1 + HULL, + MACH, Tug special service, Anchor handling, Fire-Fighting ship 1+ Waterspray, Unrestricted navigation.
The vessel has been outfitted for a crew of up to 25 people, although normal operating crew is 15.
The deck machinery comprises a single drum hawser winch at the bow, a water-fall double drum towing winch on the aft deck together with other deck machinery to fulfill operation requirements such as stern roller, shark's jaw-top pin unit, gobeye, deck crane, tow hook, tugger winches, capstans, storage reel, etc.
The large main deckhouse contains a spacious galley and mess, cabins for senior officers, guests are placed on "A" deck, HVAC room, lockers, etc. The lower deck contains galley stores, cold storages, laundry room, engineer stores, workshop, etc. The wheelhouse is designed for maximum all-round visibility with forward and aft control stations providing maximum visibility to both fore and aft deck working areas.
Propulsion is by a pair of Wärtsilä 6L26 diesel engines; each rated 2040 kW at 1000 rpm and each driving a Lips CS250 CP unit.
Electrical power is supplied by a pair three Cummins 6CTA-M diesel gensets, each rated at 95 kW.
Ship-handling fenders at the bow consist of rubber fenders of 900 x 500 cylindrical and W48-30. A 300 x 300 hollow "D" fender and aircraft tires provide protection at the main and forecastle deck sheer lines, and 300 mm "W" block type fendering is used at the stern.
On trials, AOS Power met all performance expectations, with the following results:
Bollard Pull, ahead-70 tonnes at 100% MCR
Free running speed-13.9 knots
This new RAmpage 4500 class tug is the newest member of the very successful RAmpage series of offshore support tugs.