Sanmar Shipyards has delivered two Robert Allan Ltd (RAL)-designed terminal support/escort tugs to Orkney Island Council Marine Services, which had ordered the new duo to replace two of its older workhorses. Built to the specs of RAL’s RAstar 3200-SX design, Odin of Scapa and Thor of Scapa each feature an overall length of 32m, a moulded breadth of 13m and a depth of 5.35m. RAL says the pair were purposely designed “with a shallower draught than comparable high-performance escort tugs”, resulting in a maximum draught of 5.5m. The tugs were developed for a crew of six and sufficient onboard tankage to cover 162,000litres of fuel oil, 20,000litres of potable water, 1,000litres of lube oil and 9,000litres of sewage.
Each 497gt tug is powered by two Caterpillar 3516C diesels, rated 2,350bkW at 1,800rpm apiece. These drive twin Rolls-Royce US255 controllable-pitch Z-drives with 2.8m-diameter propellers. In sea trials, this arrangement enabled a free running speed of 14.3knots and a bollard pull capacity of 78tonnes ahead. Caterpillar also equipped each newbuild with three C4.4 diesel gensets.
The tugs feature a DMT escort winch at the bow, for escorting and ship-handling operations, and a DMT towing winch and MacGregor towing pins at the stern, for towing purposes. The towing process has been simplified by granting each vessel a rounded transom. Each of the vessels can also store up to 9,800litres of foam for firefighting purposes.
Crew are accommodated in two twin-berth cabins and two single officer cabins. RAL explains: “The wheelhouse is designed with a single split control station which provides maximum all-round visibility and exceptional visibility to bow and side fendering.” Both newbuilds have been classed by RINA.