PORT TOWNSEND — State ferries system officials hope to know next week just how long the inaugural sailing of the new 64-car ferry Chetzemoka on the Port Townsend-Coupeville route will be delayed after excessive propeller drivetrain vibrations were discovered during sea trials last week.
The launch originally was set Sunday, Aug. 29, with both Port Townsend and Whidbey Island planning to celebrate getting the new boat on the route that has not had a permanent ferry since November 2007.
The launch has been delayed for a yet-to-be determined amount of time.
“We’ll know by the middle of next week what we need to do and when we will have the celebration,” state Deputy Transportation Secretary David Moseley said Wednesday night.
The vibrations in the new boat, the state’s first in 12 years, found last week were apparent at the vessel’s highest rate of speed.
Moseley said there is a possibility the Chetzemoka may still operate soundly at a lower but normal cruising speed along the often-treacherous Admiralty Inlet route.
Sea trials — which began in late July in Possession Sound and were expected to end today — were halted Friday while state ferries engineers analyzed the source of the vibrations over the weekend.
Trials will resume today, Moseley said.
“The purpose of sea trials [today] are to see if we can power the boat appropriately to positively serve the Port Townsend-Keystone route,” Moseley said.
Vibrations were discovered when both diesel engines powering the vessel were pushed to the highest rate of speed — 16 knots — during crash testing.
Capt. George Capacci, who this week was named deputy chief of operations and construction with the ferries division of the state Department of Transportation, said the vibrations were coming from two shafts to the propeller.
“There’s a lot of moving parts,” Capacci said. “Maybe if we don’t need 16 knots, then we could set computer system” to limit the vessel’s speed.
Capacci said the initial results were that the top speed was not necessary.
“Those vibrations were only recorded at highest power setting — over 16 knots,” he said.
He said the vessel will be tested at 10, 12 and 14 knots today to determine at what speed it can run to meet scheduled times and maneuver safely into the Keystone landing on Whidbey Island near Coupeville.
“It’s a tricky little space to get into,” Capacci said, confirming what ferry captains have said for years.
Normal speeds are 12-14 knots, depending on sea conditions, tides and currents, Capacci said.
“We don’t need 16 knots to carry out the schedule.”
Moseley said the vibrations could affect the vessel’s machinery over the long term, so engineers hope the vessel can run at reduced speeds.
“We are also trying to determine what the long-term fix to the vibration would be,” Moseley said.
He added that he spoke to Port Townsend Mayor Michelle Sandoval on Wednesday and expressed his disappointment about the delay.
The hull of the second ferry for the Port Townsend-Coupeville route is under construction at Todd Pacific Shipyard in Seattle, Moseley said.
Cappachi said the second and third boats have a different propulsion systems, with engines that are used in the state fleet’s 144-car ferries.
The Chetzemoka, budgeted at $76.5 million, and a second ferry, the Salish, will replace the 80-year-old Steel Electric ferries that Transportation Secretary Paula Hammond pulled out of service in late November 2007, saying the vessels were unsafe.
The 50-car ferry Steilacoom II, which the state leased from Pierce County, has sailed the route since then. The Salish is expected to ply the route in spring 2011.
For more information about the Chetzemoka, see www.wsdot.wa.gov/ProjectsFerries/64CarFerries.