Macleod a unique ‘dual-draft’ ASD

Each design has been carefully configured to fit the particular client’s needs and often a new variant has been added to the RAL portfolio. One completion not previously mentioned is the Macleod, a vessel customised with some unusual innovative features.

Macleod was built by Uzmar Shipbuilding in Izmit, Turkey and delivered to its owner, Rio Tinto – Dampier Salt Ltd, during 2012. The vessel is designed to operate at the Cape Cuvier bulk terminal in Western Australia. The tug’s home port is in a shallow harbour with an approach channel requiring a maximum operating draft of 4m. Such a low draft would normally have a negative impact on the vessel’s performance, with resulting high accelerations. RAL’s solution was to develop a quick acting ballast system allowing the tug to enter the dock with a 4m draft and ballast to a deeper operating draft of 5m when required, thus enabling the full performance capabilities and much better seakeeping characteristics for the tug when operating at sea.

The primary role of Macleod is to carry out shiphandling and heavy duty mooring operations. A vessel of 30.8m in length overall, with a beam of 12.0m, it meets the class requirements of Bureau Veritas with the following notations: BV 1 X HULL, X MACH, X AUT-UMS, TUG, Unrestricted Navigation, AUT-UMS, IWS.

Macleod has a main propulsion system comprising a pair of Caterpillar 3516C diesels generating a total of 5,150 bhp (3,840kW) at 1,600rpm to drive a pair of Rolls-Royce US 205 propulsion units with fixed pitch propellers.

On trials, Macleod met or exceeded all performance expectations, with a bollard pull of 63 tonnes towing ahead and 58.5 tonnes astern and a free running speed ahead of 13.7knots.

Deck machinery installed includes a Ridderinkhof single drum towing winch mounted on the foredeck for shiphandling duties. The winch has a maximum brake load of 180 tonnes, a maximum line pull of 15 tonnes, and can accommodate a 150m of 60mm diameter high performance synthetic towline.

An unusual and prominent feature is two very large powered mooring line reels, complete with spooling gear, located on the aft deck, each with a capacity of 1,325m of 76mm line. The open stern incorporates a stern roller and the line handling equipment includes, a tugger winch, three ‘gob eyes’, a capstan and a single set of tow pins and a shark jaw. Fittings are also provided on the aft deck to accommodate a 20 ft diving/stores container.

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.

Macleod has been fitted out to the highest standards for a normal operating crew of four, with provision for two supernumeraries and four riggers on transit trips.