MAY 17, 2018 — Star Marine Ltd. of Jeddah, Saudi Arabia, has taken delivery of four Robert Allan Ltd. (RAL) RAstar 3400 escort tugs. Named i Murjan 1, 2, 3, and 4 they will be stationed in the Red Sea port of Rabigh, Saudi Arabia, and managed by Marine Services Co. Ltd. The vessels were constructed at the Triyards SSY shipyard in Saigon, Vietnam, under contract to Greenbay Marine Services Pte. of Singapore.
The RAstar 3400 escort/offshore terminal tug designation is a distinctive class of very high-performance ASD tugs, designed with the Robert Allan sponsoned hull form. Proven in both model and full-scale testing, it provides significantly enhanced escort towing and seakeeping performance. Escort forces are enhanced by the effects of the sponsons, as well as by the prominent foil-shaped escort skeg forward. This combination also reduces roll motions and accelerations to less than half those of comparable sized “standard” wall-sided tug hulls.
These particular vessels were designed to the following Bureau Veritas class notations:
BV 1 ✠ HULL, Escort Tug, ✠ MACH, Fire-Fighting Ship 1 water spraying, Unrestricted Navigation ✠ AUT-UMS
Length overall: 34.00 m
Beam, molded, extreme: 13.50 m
Depth, molded (hull): 6.18 m
Maximum draft: 5.71 m (to bottom of the skeg)
Fuel Oil: 180 cu.m
Potable Water: 70 cu.m
Foam: 20 cu.m
Dispersant: 20 cu.m
On trials, the vessels exceeded all performance expectations, with the following results:
Bollard pull ahead (100% MCR): 73.8 metric tonnes
Bollard pull astern (85% MCR): 66.1 metric tonnes
Bollard pull astern (100% MCR): 71.5 metric tonnes
Free running speed ahead: 14.1 knots
The vessels have been arranged and outfitted to a high standard, with facilities for up to ten officers and crew in fully air-conditioned accommodations. A well-appointed mess/lounge and a modern fully-equipped galley are located on the main deck, as are the Master and Chief Engineer cabins. Three double cabins and two single cabins are located on the lower accommodation deck, and a walk in provision store and laundry space occupy the lowest deck, where access is also gained to a domestic machinery / bow thruster room.
Deck machinery is powered by an HPU located in the engine room, and powers a pair of DMT winches; a double drum ship-assist/escort synthetic hawser winch forward, and a single drum towing winch fitted with 850 m of SWR, on the aft deck. Two of the four vessels also have Palfinger knuckle boom cranes installed on the Port side with a lifting capacity of 10 tonnes at 4.0 m. The other two vessels have identical pedestal / foundations fitted for a crane installation of up to 49 tonne-meters.
The wheelhouse is designed for maximum all-round visibility with a forward control station providing maximum visibility to both fore and aft deck working areas.
Main propulsion for each tug comprises a pair of Wärtsilä 8L26 diesel engines, each rated for 2,610 kW at 1000 rpm, but limited to match the Schottel, SRP 1515 controllable pitch azimuth-drives.
The electrical plant features two identical MAN diesel gensets, with a power output of 300 ekW. The fully automated switchboard – located in an air conditioned control room – is also fitted with the facility for shore power distribution (100 A), and a harbor generator with power output of up to 140 ekW.
The bow thruster is electric and rated for 200 kW.
The fender arrangement is extensive with a cylindrical fender on the bow, augmented by a 480×300 mm “W” fender below. 300×300 mm hollow “D” fender provides protection at the water line, main, and forecastle deck sheer lines, and a 480 × 300 mm “W” fender is used at the stern. Each vessel is also fitted with a streamlined 480 ×3 00 mm “W” fender mounted on a low down push knee for handling low freeboard coastal vessels and oil barges.