BRAtt: Burchett Robert Allan training tug

Cummins Vessel Reference #591

If you put one of the world’s leading designers of escort tugs together with a premier aluminum boat builder you will get an exceptional aluminum escort tug. This is a distinctly different vessel from the big Robert Allan Ltd. designed docking and escort tugs that fill the pages of marine publications worldwide. The BRAtt project evolved from the successes of Ron Burchett’s training programs for tug operators using radio-remote controlled scale models. “Why not build a ‘model’ that is large enough for the operator and instructor to ride on, and then always be working in the same space frame of reference as the boat?” went the reasoning.

The result is the niftiest little vessel to be constructed so far this year. At 7.8 metres (25.59 feet) by 3.6 meters (11.81 feet), the bright aluminum hull displays the distinctive Robert Allan double-chine hull form. Under the counter of the broad stern the hull tucks in quickly providing good water flow over the twin azimuthing drives located aft in the ASD manner. Forward, a relatively deep bow is augmented by a skeg that makes this an escort capable tug.

When completed later this spring the little tug will be able to provide real water training to aspiring assist and docking tug masters with out taking an expensive full-size ASD tugs off the job. The boat will be fitted with a fully operational Braden hawser winch forward with the tow line passing through a polished stainless-steel staple.

The propulsion system on the BRAtt (the name is derived from the initials of Burchett and Robert Allan) is scaled to proportionately represent the full size tugs. It begins with a pair of Cummins QSB5.9-230 HD engines, each delivering 225 HP at 2600 RPM into engine mounted ZF280.1 gears with 1:1 ratios. To allow for further reduction below the engines’ 600 RPM idle, the gears have slipping clutches. Flexible Centa torsional couplings are installed between the engines and their gears. Additional flexible couplings are at either end of the drive shafts to reduce vibration and to accommodate any movement in the flexibly mounted engines. The Z-drives are Olympic Model HD3 with 2:1 reduction. The propellers are 25 3/4 inch stainless in stainless nozzles. Both the engines and the Z-drives are mounted with a five-degree angle upward to the stern. The 450 HP twin-engined tug is anticipated to deliver an 8000-pound bollard pull.

Robert Allan Ltd.’s project manager Michael Burgess explained that, “We have tried to stay all aluminum for the piping and fittings. Where that is not practical, such as the staple on the bow, we have used stainless. The engine is isolated from the aluminum with stainless shims.”

Among the many interesting and innovative features of the BRAtt are the four bollards built to also serve as lifting points for the 16-metric ton vessel. The wheelhouse will be fitted on resilient mounts to provide a lower ambient noise level in the training area. In operation there will be room for at most three people on the boat, but ideally just two. In addition to its training functions, the BRAtt can serve effectively as a “real” tug, doing smaller towing, docking and line-handling duties, and other harbour tasks such as boom deployment, The BRAtt will be unveiled at the International Tug & Salvage Conference in Vancouver in May, where it will be a showcase of excellence in design and fabrication.

For further information contact:

Robert G. Allan P, Eng
Executive Chairman
Robert Allan Ltd.
230-1630 West 2nd Ave.
Vancouver, BC
V6J 1H3, Canada
Phone: 604 736 9466
Fax: 604 736 9483
E-mail: rgallan@ral.ca
Web: www.ral.ca

Peter Mitchell
President
Adrenalin Marine Ltd.
7811 Vantage Way,
Delta, B.C.
Canada, V4G 1A6
Phone: 604 940 3897
Fax: 604 940 1227
E-mail: info@adrenalinmarine.ca
Web: www.adrenalinmarine.ca

Geoff Conrad
General Manager
Cummins Marine (World Wide)
4500 Leeds Ave.
Suit 301,
Charleston, SC 29405-8521
USA
Phone: 843 745 1585
Fax: 843 745 1549
E-mail: geoff.Conrad@cummins.com
Web: www.cummins.com