Repowering a Hawaiian Tug: More Power, Better Air Quality

Photo of Kamaehu courtesy of Sause Bros. Inc.

Sause Brothers, based in Coos Bay Ore. also operate tugs out of Long Beach, California and Honolulu, Hawaii. They have been providing ocean towing between the mainland and the Hawaiian Islands since 1966. In more recent years they have also maintained three docking tugs in the islands. As many harbor operators can attest, the high visibility of docking tugs provides a unique opportunity to demonstrate a commitment to environmental protection. When the time came to repower Sause’s Z-drive ship assist tug Kamaehu (ex Koos Pilot) the importance of a low emissions and minimal exhaust smoke was a significant criteria in the selection of replacement engines. A pair of Cummins KTA38 M2 met these as well as horsepower requirements and the company ordered a pair for installation this coming December. Given the duty cycle in the ship assist role, the new engines will be able to operate at the intermittent rating of 1500 hp each at 2050 RPM. This will give the 72 x 25.5 x 9.5-ft. (21.9 x 83.6 x 31.1-m) tug a total of 3,000 hp turning the 78 x 69-in. props on her twin Schottel Z-drive units. The company expect that the tug’s bollard pull with the new engines will be in the 100,000-lb. range. The Kamaehu is equipped with a Knutson Diesel bow winch and two 60 kW gen sets. As a harbor boat she operates with a crew of two. She carries 9000 gallons of fuel as well as 400 gallons of water and 150 gallons of lube oil.