A flock of three new tugs for Signet

The first pair, constructed by Trinity Yachts LLC at its Gulfport, Mississippi shipyard, bear the names Signet Constellation and Signet Stars & Stripes in recognition of past America’s Cup winners. They were constructed to provide marine support services to Angola LNG Supply Services (ALSS) in the Port of Pascagoula, Mississippi.

Designated RAstar 3100s, they are intended for harbour, escort and emergency towing duties, with the following ABS notation; XA1, XAMS, Towing Vessel, Escort, Fi-Fi 1. They are high powered and manoeuvrable tugs, intended for operations in weather and sea exposed areas where a high standard of seakeeping is required.

Signet Constellation and Signet Stars & Stripes are vessels of 30.48m in length overall with a breadth of 12.19m and maximum draft of 5.23m. A pair of Caterpillar C175-16 diesel engines power the vessels with a total of 6,834bhp (2x 2,550 kW) at 1,800 rpm. Each engine drives a Rolls-Royce US 255 azimuthing propulsion unit incorporating 2,800 mm diameter controllable pitch propellers.

On trials Signet Constellation met or exceeded all performance expectations, with a bollard pull ahead of 81 tonnes and a free running speed of 13.5 knots

Electrical power is provided by three Northern Lights M1066 generator sets rated 99 kW at 1,800 rpm, all connected in parallel. The fire pumps are driven via gearboxes off front end of each main engine.

Located on the foredeck is the main towing winch, a double-drum Markey Model DESDF-48, 200 HP electrically powered render/recover winch, intended for escort and shiphandling duties. The aft deck is equipped for emergency towing only with 96 tonne SWL towing post.

Signet Constellation and Signet Stars & Stripes are fitted out for a crew of six persons, in modern and well equipped, air conditioned accommodation.

Signet Weatherly, the third and quite different completion, was built in-house by Signet Shipbuilding & Repair at Pascagoula, Mississippi. Yet another example of a Robert Allan RAmparts 3200 class vessel, the new tug is based in Corpus Christi, Texas, to enhance Signet’s Gulf operations, providing both shiphandling and long range towing services.

In keeping with many RAmparts 3200 tugs this vessel is configured for a low manning operation, with a high standard of machinery automation. The tug is equipped with both a bow winch for shiphandling and a winch aft with tow pins for towing over the stern and other offshore duties. Extended fuel capacity gives extended range for towing rigs in and around the Gulf of Mexico and the Caribbean.

Signet Weatherly was built in accordance with American Bureau of Shipping notation:

X A1 Tug, Towing Vessel, X AMS Unrestricted Voyages. The tug is 31.0m in length overall, with a breadth of 11.58m and maximum draft of 5.26m. Tank capacities for 92,000 gallons of fuel, 3,760 gallons of fresh water, 500gallons of lubricating oil and 21,051 gallons of water ballast reflect the services the tug is built to fulfil.

Propulsion machinery comprises a pair of MTU 16V 4000M60 diesel engines, each rated at 1,760 kW at 1,800 rpm, a total of 4,720 bhp. The engines drive a pair of Niigata ZP31 propulsion units with 2,600mm diameter fixed pitch propellers.

On trials, Signet Weatherly achieved a bollard pull towing ahead of 60 tonnes, 55 tonnes towing astern and a maximum speed of 12 knots.

Deck machinery includes two Markey electric towing winches, a 50HP Markey DEPC-48 render/recover towing winch on the foredeck and a 100HP Markey TESD-32 side-by-side double drum towing winch located on the after deck, along with tow pins, roller and hold-down block in the aft bulwark.

Accommodation is provided for a crew of up to 10 persons. The large main deckhouse contains a spacious galley and mess, and two cabins with shared en suite WC for the Chief Engineer and Master. The lower deck contains three crew cabins, WC and two showers, a galley store and a deck stores room. 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.