Robert Allan Ltd. RAstar escort tugs selected again for LNG terminal support

July 13, 2015


The Robert Allan Ltd. RAstar Series tugs are well proven LNG terminal support/escort tugs, in operation at major LNG facilities worldwide, including terminals in the United Kingdom, Yemen, Mexico, Indonesia, Norway, and the United States. Now Smit Lamalco has introduced five new RAstar 3400 escort tugs to the Port of Gladstone in Australia for LNG terminal support with the fifth and final vessel having just safely arrived in the Port. The five tugs SL Curtis Island, SL Quoin Island, SL Boyne Island, SL Heron Island, and SL Wiggins Island are named after local islands and will serve LNG export terminals in the Port. The tugs will be required to escort LNG carriers through an exposed channel which can be subject to adverse environmental conditions, and then assist them safely to the berths.

The RAstar Escort/Offshore Terminal Tug is a unique class of very high-performance ASD tugs, designed with a sponsoned hull form which has been proven to provide significantly enhanced escort towing and seakeeping performance. The escort forces are enhanced by the effects of the sponson as well as the foil-shaped escort skegs fitted. Roll motions and accelerations are less than half those of comparable sized “standard” tug hulls. These tugs are high-powered and are ideally suited for escort operations in weather and sea-exposed areas such as many new LNG terminals where a high standard of sea-keeping is required.

Beyond the high performance hull form, the customized RAstar 3400 design for Smit Lamnalco has numerous other features for LNG terminal support. The bow fendering system is designed for an extremely low contact pressure requirement of 14 T/m². A gas detection system is fitted to warn the crew of any potential hazardous vapour situation. Ventilation dampers can all be remotely closed. All essential electrical equipment on deck is “Ex d” or “Ex e” certified safe type suitable for use in a Zone 2 LNG environment and all non-essential electrical equipment is able to be electrically isolated from the wheelhouse. Fi-Fi 1 capability with water spray is provided along with a large capacity of fire-fighting foam.

Main particulars of the tug are as follows:


Length overall:
Beam, moulded:
Depth, least moulded:
Draft with 200 DWT:
– 34.00 metres
– 14.50 metres
– 6.07 metres
– 6.00 metres


Tank Capacities at 98% are:

Fuel oil:
Potable Water:
Main engine lube oil:
Fire Fighting Foam:
Grey Water:
Sewage holding tank:
Fresh Water Ballast:
– 215.9 m³
– 57.5 m³
– 7.2 m³
– 22.8 m³
– 3.6 m³
– 3.6 m³
– 69.9 m³


Propulsion machinery consists of Wärtsilä 8L26 main engines, each developing 2,720 KW of power at 1,000 RPM driving Rolls Royce US 35 controllable pitch Z-drives, all delivering a minimum of 86 tonnes bollard pull.

Escort forces were predicted by Robert Allan Ltd.’s Computational Fluid Dynamics escort performance prediction tool for departure and arrival drafts and for both 8 and 10 knots.



RAstar 3400 for Smit Lamnalco:  Positions of Maximum Indirect Escort Steering Force

Robert Allan Ltd. worked closely with Smit Lamnalco in laying out the design of this class of new tugs to suit their specific operational requirements and preferences for day to day operations, ease of maintainability, and flexibility for future duties. For example; the vessel is fitted with a hydraulically operated folding mast for working under the flare of assisted ships, there is extensive use of stainless steel for exterior deck fittings and plated-in bulwarks to reduce future maintenance requirements, and the aft deck is designed for future fitting of an aft towing winch. The accommodations are designed to a high standard in accordance with MLC 2006 regulations. The main deckhouse contains the galley, galley store, mess, Master’s cabin and a common WC. The lower deck contains the Chief Engineer’s cabin, 3 double berth cabins, and a laundry. All cabins have en-suite WC’s. The forward hold area below the lower deck contains additional galley stores, miscellaneous storage and winch electrical equipment. The wheelhouse is compact with a split console and provides excellent all-round visibility. Adjacent to the engine room is a large air-conditioned switchboard room accessible from the main accommodation area.



Ship-handling fenders at the bow comprise an upper row of 1,000 mm diameter cylindrical fender and a lower course of 450 mm deep W-fender working together to provide the extremely low contact pressure requirements. Sheer fendering consists of 350 mm D- rubber. A 600 mm diameter cylindrical fender is fitted at the stern.

Typical of Robert Allan Ltd. tug designs, significant noise and vibration reduction measures have been implemented throughout, resulting in an exceptionally quiet vessel.

The vessel is equipped with the following deck machinery:

  • Electric double drum escort winch with a maximum pull of 850 KN at 0-8 m/min
  • Forward dual lead staple complete with removable stainless steel fairleads (“Smit Eyes”)
  • 100 T SWL Data Hidrolik tow hook
  • Aft H-Bitt
  • 100 T SWL gob eye
  • Manually raised tow pins in aft bulwark

The tug was constructed by Sanmar to BV Class requirements with the following notation: BV I ✠ HULL, ✠ MACH, Escort Tug, Fire Fighting Ship 1, Water Spray, IWS, Cleanship 2

These tugs are a significant addition to the Smit Lamnalco escort tug fleet and help to set a new standard of tug performance for LNG terminals anywhere.

For more information on the RAstar Series tugs, or any other high-performance vessel designs developed by Robert Allan Ltd., please contact