Powerful twin tugs make Texas debut

These two powerful new escort tugs have been delivered to their owner, Signet Maritime Corporation of Houston, Texas. They were built to provide marine support services to Angola LNG Supply Services (ALSS) in the Port of Pascagoula, Mississippi. Designated as RAstar 3100s and designed by naval architects Robert Allan Ltd. of Vancouver,, they were constructed by Trinity Yachts LLC at their Gulfport, Mississippi shipyard. The names of these vessels pay tribute to past America’s Cup winners, the 12m yachts Constellation (winner in 1964) and Stars & Stripes (winner in 1987).

The Signet Constellation and Signet Stars & Stripes areclassed for harbour, escort and emergency towing duties, with the ABS notation; XA1, XAMS, Towing Vessel, Escort, Fi-Fi 1.

Propulsion comprises a pair of CAT C175-16 diesel engines, each rated 2,550 kW (3,418 BHP) at 1,800 rpm and each powering a Rolls-Royce model US 255 drive, with 2,800mm diameter controllable pitch propellers through a composite shafting system.

The Signet Constellation and Signet Stars & Stripes are outfitted for a crew of eight persons, in modern, well equipped, air conditioned accommodation. They have capacities for 62.000 gallons of fuel oil, 3,600 gallons of fresh water, 700 gallons of lube oil, 300 gallons of waste oil, and 300 gallons of oily water.

The main hawser winch is a dual drum Markey model DESDF-48, 200 HP, electric escort render/recover winch. The aft deck is equipped for emergency towing with 96 tonne SWL towpost.

Electrical power is provided by three Northern Lights M1066 generator sets rated 99 kW at 1,800 rpm, all connected in parallel.

The tug has a full Fi-Fi 1 rating in accordance with Class notation requirements. The fire pumps are driven through a gearbox with integral clutch and cooling system, which is driven off a main engine front power take off via flexible coupling.

The RAstar series of offshore/escort tugs by Robert Allan Ltd have a unique sponsoned hull form, which has been proven in testing and real-world applications to provide significant enhanced escort towing and seakeeping performance. Accelerations and motions are less than half those of comparable sized ‘standard’ tug hulls. They are high powered and manoeuvrable, typically intended for operations in weather and sea exposed areas where a high standard of seakeeping is required. The RAstarhull form is also energy efficient, as the reduced waterline beam reduces free running resistance considerably in comparison to other tugs of similar overall proportions.

Tech Spec

LOA 100’- 0”

Beam, Moulded, 40’- 0”

Depth, Moulded 17’- 5”

Bollard pull 81 tonnes

Speed 13.5 knots