Macleod – A unique dual draft RAmparts 3000 series line-handling tug
January 22, 2013
The Macleod is the latest addition to the RAmparts 3000 series of ASD tug designs by Robert Allan Ltd., delivered to its owner; Rio Tinto – Dampier Salt Ltd. in the summer of 2012. Constructed at Uzmar Shipbuilding in Izmit, Turkey, the Macleod will operate at the Cape Cuvier bulk terminal in Western Australia. The tug’s home port is in a shallow harbour connected to the ocean via a shallow channel, requiring a maximum operating draft of 4 metres. This low draft would normally have a negative impact on the seakeeping performance, with resulting high accelerations. Robert Allan Ltd. proposed a solution which was to develop a quick-acting ballast system that enables the tug to reach the dock at the 4 m draft and then ballast to a deeper operating draft of 5 m, thus enabling the full performance capabilities and much better seakeeping characteristics for the tug when operating in the open ocean.
Particulars of the Macleod are as follows:
| Length overall: Beam, moulded, extreme: Depth, moulded (hull): Full load navigational draft: Ballasted (operating) navigational draft: |
– 30.80 m – 12.00 m – 5.35 m – 4.00 m – 5.00 m |
Macleod is classed by Bureau Veritas Class with the following notation:
BV 1 ✠ HULL, ✠ MACH, ✠ AUT-UMS, TUG, UNRESTRICTED NAVIGATION, AUT-UMS, IWS
Tank capacities are as follows:
| Fuel Oil: Fresh Water: Ballast: Z-drive Oil: Sludge: Oily Water: Main engine lube oil: Sewage: |
– 103 m³ – 36 m³ – 304 m³ – 1 m³ – 4 m³ – 6 m³ – 2 m³ – 4 m³ |
On trials, Macleod met or exceeded all performance expectations, with the following results:
| Bollard Pull, ahead: Bollard Pull, astern: Free Running speed, ahead: |
– 63 tonnes – 58.5 tonnes – 13.7 knots |
The vessel has been outfitted to the highest standards for a normal operating crew of four. Master’s and Chief Engineer’s cabins are located on the main deck, with two additional private crew cabins located on the lower accommodation deck. An additional two temporary crew can be accommodated in a double cabin, and four riggers can be carried on transit voyages. Also included are an exercise room and an office, also housed in the lower accommodations.
The deck machinery comprises a ship assist hawser winch on the bow, and two large mooring line reels on the aft deck, each with a capacity of 1325 m of 76 mm line. In addition, a tow pin/shark jaw set, capstan, three gob-eyes, and a tugger winch are installed on the aft deck to facilitate line handling operations. 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.
Main propulsion for each tug comprises a pair of CAT 3516C diesel engines, each rated 1920 kW at 1600 rpm, and each driving a Rolls- Royce, US 205 fixed pitch Z-drive unit, in ASD configuration.
The electrical plant comprises three (3) identical diesel gen-sets, each with a power output of 86 ekW.
Ship-handling fenders at the bow consist of one row of 800 x 400 cylindrical fender at the main deck lever, with 300 mm W fenders between the main deck and the knuckle. A 300 x 300 hollow “D” fender provides protection at the main and foc’sle deck sheer lines, and 300 mm “W” block type fendering is used at the stern.
For more information on the Macleod or any of the RAmparts 3000 Class tugs, or on any other vessel designs developed by Robert Allan Ltd., please contact us at design@ral.ca.