Ferry COHO Gets a Repower

Elliott Bay Design Group (EBDG) announced the successful completion of sea trials, following the repower of the M/V COHO. Vessel owner and operator - Black Ball Transport Inc., retained EBDG to design and engineer the repower, and also to provide owner's representation during the yard period at Todd Pacific Shipyard.

The successful yard period and sea trials culminated over eight months of effort by various EBDG personnel, spanning the disciplines of Naval Architecture, Marine, Mechanical, and Electrical Engineering. EBDG also provided the vessel owners with comprehensive project management support, which included detailed contract specifications, project cost estimate, regulatory and vendor liaison, technical specifications for the purchase of all machinery and equipment, and owner's representation during the project's construction and testing phases. A key element to the ultimate success of the project was the high level of active participation of the COHO crew. As no one knows this vessel better then those who operate her, beginning with the planning phase, they played an integral role in supporting the entire design and construction effort.

In addition to the repower, regularly scheduled maintenance and regulatory inspections (USCG and ABS) – were all completed inside a nine week time period. Extensive project pre-planning, advanced equipment selection and purchasing, and pre-fabrication of the new machinery foundations, shaft line modifications, and numerous sections of engine room piping, were required in order to meet the owner's nine week delivery schedule.

At the heart of the project, the vessel's 1958 vintage, direct reversing Cooper-Bessemer main engines (2000 BHP at 300 rpm) were replaced with EMD 12-645 F7B turbocharged engines, producing 2550 BHP at 900 rpm, delivering power through new Falk 3485 MRV marine reverse reduction gears. Through sound engineering, experience, and diligent attention to detail, EBDG's engineers were able to utilize and build on several of the vessels' existing system designs, thus minimizing time and overall project costs. New propellers are to be designed by EBDG and installed aboard the vessel sometime later this year, in order to take advantage of the EMDs' increased HP and efficiency.

The RORO passenger ferry M/V COHO was originally designed and built in 1957-58 by the prominent Seattle naval architecture firm Philip F. Spaulding and Associates. Philip F. Spaulding and Associates later became Nickum and Spaulding Associates, which evolved over time into Elliott Bay Design Group. It was therefore quite fitting, that during sea trials in Puget Sound, the vessel's original designer, Mr. Spaulding himself, was seen in his front yard waving the American flag in salute to the gallant old lady, who has served the communities of the Olympic peninsula, Washington State, and British Columbia so well for all these years.

The sea trials and delivery went off without a hitch and the COHO returned to her normal service between Port Angeles, Washington and Victoria, British Columbia on March 12.