Longliner/pot boat prepares for sea trials

02 May 2013
Josh Trosvig with the new longliner. Credit: Haig-Brown/Cummins

Josh Trosvig with the new longliner. Credit: Haig-Brown/Cummins

Alaskan fisherman Josh Trosvig’s new longliner/pot boat is preparing for sea trials in June.

The boat was designed by naval architect Hal Hockema, who designed Mr Trosvig’s previous boat, the 58x27ft Cynosure that was built and launched in 2009.

“That boat has been very successful so we made very few changes when we decided to build this one,” explained Mr Trosvig, who has skippered the Cynosure longlining black cod and halibut and pot fishing Alaskan cod.

Construction of the new vessel started in May 2012.

The new boat will have two fish holds with a total of 3,300ft3 as well as a 350 ft3 bait hold. A 40-ton refrigeration system will be support the frozen bait and the refrigerated saltwater fish holds.

Two Cummins QSB7-DM powered 200kW Stamford generators will support the electrical requirements of the refrigeration as well as the vessel’s hydraulics. These QSB7-DM engines are newly developed six-cylinder diesels employing high-pressure common rail injection and other refinements to offer highly efficient Tier 3 compliant engines.

The new boat will have the same Cummins QSK19-M main engine delivering 660HP through a Twin Disc gear to a 70 by 57-inch propeller as they have on the Cynosure. This has proven a capable and reliable propulsion package. The gensets and refrigeration are a significant upgrade.

“The Cynosure had a 30 ton refrigeration system with 100,65 and 30kW gensets. We have upgraded this boat to the 40-ton and the two 200kW gensets, as well as a 40kW hotel set,” explained Mr Trosvig.

This will allow the same RSW system as well as coil freezer capacity should they decide to freeze onboard. There will also be a 10-ton per day ice machine for making slush ice.

From the engine room to the auto baiting longline system in the fully covered working deck and to the wheelhouse, the emphasis on this boat is on redundancy, reliability and best available technology.

“We have pretty much the same electronics as the big factory trawlers,” says Mr Trosvig. “In addition to a Simrad ES70 split beam sounder we are using a multi-beam sonar. We had the third New Zealand made multi-beam WASSP sonar on the coast three years ago. Now there are 25 on the west coast.”

The combination of the two technologies allows Mr Trosvig to identify the type of bottom and fish by species.

“We can spot a 24-inch cod at depths of 850m,” he said with pride.

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