January 20, 2011
For more than fifteen years Robert Allan Ltd. has enjoyed remarkable success having tugs built to their designs by a cadre of very capable Turkish shipyards. In that 15 years there have been almost one new tug delivery every month to a Robert Allan Ltd. design in Turkey. To date more than 150 tugs have been Turkish-built, and even in a slightly reduced market this year, compared to the heady days of 2008–2009, there are at least 15 Robert Allan Ltd. designs under construction there today. Our first Turkish Client was the very successful tug-Owner/Shipbuilder Sanmar Denizcilik Ltd. and they lead the pack with 80 RAL tugs built to date, a significant milestone serendipitously achieved during the celebration of Robert Allan Ltd.’s 80th year of business in 2010.
These Turkish-built tugs have been delivered to Owners around the world, but the majority of these now operate in the Mediterranean, Western Europe, the Middle East, and in the Black Sea. It is noteworthy therefore that on January 4th the first Turkish-built tug for Canada arrived in Vancouver, the birthplace of its design. Seaspan International Ltd., of North Vancouver took delivery of the new RAstar 2800 Class tug Seaspan Raven, the first of four powerful new tugs destined to reshape harbour towage and tanker escort operations in the environs of the largest port in Western North America.
Particulars of this RAstar 2800 Class tug, illustrated on the accompanying General Arrangement drawing and photographs, are as follows:
Operating Draft, Maximum
Potable water capacity
|– 28.20 metres
– 12.60 metres
– 5.30 metres
– 5.10 metres
– 119.3 m³
– 12.9 m³
The Seaspan Raven is classed for both harbour and coastal towing, and escort duties. The tug was built to ABS Class notation ✠ A1, E, AMS, ABCU, Towing Vessel, Escort Support, Fi-Fi 1.
Propulsion comprises a pair of CAT 3516B marine diesel engines, each rated 1840 kW at 1600 rpm, and each driving a Rolls-Royce model US 205 CP azimuthing Z-drive unit with a 2400 mm diameter propeller, through a Cardan shafting system. This combination delivered a Bollard Pull of 71.2 tonnes on trials conducted in late October, 2010. A free running speed of 13 knots was recorded.
In common with all the RAstar series designs, this new tug will out-perform its typical wall-sided competition, offering far superior escort towing performance, and reducing roll motions by at least 50%. The RAstar hull form is also far more energy-efficient, as the reduced waterline beam reduces free-running resistance considerably in comparison to old style tugs of similar overall proportions.
The Seaspan Raven is outfitted for a crew of six (6) persons, in modern and well-equipped, air-conditioned accommodations.
The main hawser winch is a single drum, hydraulic winch supplied by Rolls-Royce. The aft deck is equipped for harbour towage with a Rolls-Royce towing winch.
Electrical power is provided by a pair of MAN gen-sets, each rated 120 ekW.
The tug has a full Fi-Fi 1 rating of 2,400 m³/hr in accordance with the ABS Class notation requirements. The fire pumps are driven from the front end of the main engines through a Kumera gearbox, which also drives the main hydraulic pumps, powering the winches.
The second tug of this class is expected to arrive in BC within a few months.
For further information on the RAstar 2800 Class or any other high-performance tug designs, please contact us.
 Compact Tugs: Their Evolution, and Recent Developments, R.G. Allan, P. Eng., ITS 2002 Conference, Bilbao, Spain, May 13-17, 2002