Articulated tug and barge goes airborne

But seeing them built in a warehouse, lifted over a railroad track and onto a single barge before being floated out to the port for the initial splash was quite unusual.

Using a 900-tonne barge crane to take two 384-tonne tugs from dry land, loading and then launching them at the Port of Vancouver was a delicate and meticulously planned event. The owners, Island Tug, had the two Cummins KTA38-powered ATBs built at their Annacis Island warehouse across a railroad track and steep embankment on the Fraser River.

It took the creative use of self-propelled modular transports to get the tugs onto the Dynamic Beast barge, with Mammoet and Dynamic Heavy Lift assigned to handle the roll-on and lift-off over the weekend in preparation for a Monday launch.

Weight distribution is critical when executing any kind of lift – and it took the precise positioning of three spreader bars and four slings to support Island Raider, the first tug to go. Raising the ATB up 6 m in the air, it easily cleared equipment on the barge deck and was gently lowered into the waters of the Burrard inlet. The successful launch was then duplicated for its twin, ITB Resolution.

These ATBs are 25 m in length with a 12.5 m beam. The draft when fully loaded is just 3.2 m. These two tugs were designed in conjunction with the renowned naval architects and marine engineers at Robert Allen Ltd who researched the hull design, engines and propeller options – recommending Z-drive propulsion units, a first for Island Tug and Barge. Twin Cummins KTA38 engines power Rolls-Royce azimuthing thrusters, generating a top vessel speed of 9 knots and bollard pull of 21 tonnes.

Get the full story behind this launch by viewing the case study or visit cummins.com for more information on Cummins power solutions for marine applications including our IMO Tier III offerings for propulsion and electrics.