'Shelf' might cut foot ferry wake
June 11, 2008 · Updated 10:58 AM
"Fuel consumption has emerged as a costly consideration for Kitsap Transit officials and members of the Kitsap Connections committee seeking to find foot ferry alternatives.Because larger vessels consume more fuel than smaller ones, transit officials are focusing on a program based on running a large number of smaller boats so during off hours you're not running 50 people and burning 350 gallons of fuel, Kitsap Transit executive director Dick Hayes said.Smaller boats use between 100 and 150 gallons an hour, which makes running fewer people during off-hours more economical.An extra 200 gallons per hour is a couple hundred bucks an hour, Hayes said.The Washington State Ferries' Wave Action Committee will continue to monitor wake energy levels since an interceptor was installed onto the Chinook's stern. The interceptor, a shelf that lifts the stern out of the water as the ferry runs, appears to be cutting down on wakes. The shelf at the stern has worked, and it's proven it worked ... In theory, if you improve the wake, the energy consumption goes down, he said, thereby burning 100 gallons of fuel per 50 people rather than 300 gallons of fuel per 50 people.Officials tested the St. Nicholas, a former Mosquito Fleet whale watching ship, and found it to have a low wake at fast speeds. Eith the interceptor, the Chinook also exceeds the WSF's wake energy standard.Now, with the shelf, it gets under the state standard earlier and farther. With the shelf, we're much better off having the Chinook go 40 knots, Hayes said. Commissioner Charlotte Garrido, chairwoman of Kitsap Connections, said the reduced wake energy is really good news, though not conclusive in determing which direction the committee will go.I think while we've got information on the table, we should dissect it and see if it's either/or or and/or. We're looking at whatever produces lower wake, she said."