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Port Security Conference

April 9, 2003

Hulls were fabricated in China

Vancouver yard completing tugs
Vancouver B.C. based Seaspan International is having an interesting pair of new tugs finished up at its Vancouver Shipyard division.

The hulls were fabricated in China and shipped across the Pacific by barge.

When the two 64 by 23-foot tugs are completed with the addition of machinery and deckhouses, they will be the result of several years design and planning that included significant input from the operations end of the towing company.

Over the past twenty years, Canadian tonnage regulations have created a generation of beamy 50-footers in British Columbia. These new boats have gone beyond this limit to define a new generation of tug with a fine longer double-chined hull. The hull has a molded depth held to 10.4-feet to facilitate working some of the shallower areas of the lower Fraser River while providing good water flow to the propellers. This fine hull form, combined with a smooth "slipper" stern will reduce wake wash and lessen the need for the tug to make a "slow-bell" past riverside moorings.

The boats will be towing big, boxy wood chip scows. They have been designed so that the aft bulwarks are the same height as the deck of a loaded chip barge while the bow matches the height of an empty barge.

Bulwarks are set two feet back from the hull side so that crew can move safely between barge and boat. A total of 17 tons of rubber in soft loop, laminated and D-form will protect the already heavily built hulls from the wear and tear of barge work.

Main engines will be a pair of Cummins KTA38 M0 diesels. The engines will be operated at reduced speed to deliver 600 hp each rather than their full continuous rating of 800 hp each, although in times of high river this can be adjusted upward.

The main engines will turn into TwinDisc 540 marine gears with 5.19:1 rations. The 72x62-inch propellers will turn in Harrington Kort19 A nozzles. The Twin Disc gears will provide for counter rotating propellers to give maximum efficiency in handling and in drawing water flow.

The four Cummins main engines were installed in the boats in late March with plans for the new tugs to be in operation by summer.

Outboard profile of completed tug
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