Canada: Class of Small, Tough BRAtt Workboats Produced
A new class of ultra-compact tugboat is turning heads and filling important industry niches. Originally conceived as a training vessel, the BRAtt has developed into a class of small but tough workboats.
Recent developments have produced not only a very cost-effective tug for training, but an ultra-compact workboat which can operate in small ports and perform specialized functions such as ship-handling, line-handling, yarding, boom deployment, etc. BRAtt designs are now available in a range of sizes, from 7 metres to 10 metres, in both aluminum and steel construction.
The BRAtt has all the functionality of a full sized tug – from a fully operational ship-handling winch to modern fully azimuthing Z-drives. This gives the operator the opportunity to train personnel in a realistic environment with all of the associated real world variables. Risks and costs are reduced significantly during training as no additional crew are required, and running costs are much less. Similarly, the BRAtt can perform everyday small tug duties in a fully functional manner, and it is this capability which has surprisingly attracted the most attention to this exciting “MicroTug” since its introduction.
The three BRAtt designs either built or in production to date are:
BRAtt 780-AE (7.8m Aluminum Escort)
BRAtt 880-SU (8.8m Steel Utility)
BRAtt 880-SL (8.8m Steel Line-handling)
Adrenalin Marine Ltd. of Delta, B.C. was chosen as the licensed builder for all BRAtts in North America and to date has built three of these innovative new vessels.
While the original BRAtt is of all-welded aluminum construction and has been classified as a BRAtt 780-AE, a recently built pair for Suncor Energy are constructed with a steel hull and aluminum house. These two new BRAtt 880-SU workboats are ice-strengthened utility vessels with the following particulars:
Length, overall – 9.40 metres
Length, moulded – 8.80 metres
Beam, overall – 4.65 metres
Beam, moulded – 4.32 metres
Depth, moulded – 1.87 metres
Draft, maximum, approximately – 1.70 metres
The BRAtt 880-SU has an all-welded steel hull with an all-welded aluminum alloy wheelhouse.
The propulsion machinery consists of two Cummins QSB5.9-230 HD diesel engines, each rated 168 Kw at 2,600 rpm., driving Olympic HD-3 drives through ZF reduction gearboxes.
The deck machinery comprises two hydraulic barge connecting winches with a maximum brake holding capacity of 7.1 tonnes (16,000 lbs.) each.
The fendering fitted to the new BRAtts includes:
– Hull side and stern fenders
– Schuyler modified model 114D solid laminated fenders
– Fenders on vessel side are removable for road transport
– Schuyler model 115 vertical push knee fenders
The electrical system consists of the following:
– Diesel Genset: 7kW, 120/240V AC
– 24 Volt DC: house batteries, starting batteries, engine-driven alternators
– Lighting: compact fluorescents and LED type
– 120V AC shore power connection
– Battery charger
On trials, the BRAtt 880-SU met or exceeded all performance expectations, with the following results:
– Bollard Pull, ahead – 3.0 tonnes (6,700 lbs)
– Free running speed, ahead – 8.3 knots
The BRAtt class has all the functionality of a full-size tug in a compact package, making it an ideal training tug or ultra-compact line-handler, utility or yarding tug for confined harbours or shallow water operations.
Shipbuilding Tribune Staff, January 14, 2013; Image: ral