|Washington State Ferries intends to build four of these 144-vehicle, 1,500-passenger ferries. The first of them is expected to go into service by early 2011. The double-ended boats will be 362 feet long and have a beam of 83 feet.
Guido Perla & Associates Inc., the Seattle naval architecture firm, has been chosen to design a new class of 144-car ferries for Washington State Ferries.
“Once built, these four boats will be available for most of the ferry system’s routes except the Townsend-Keystone route,” said Steve Gleaves, the project manager at Guido Perla & Associates.
The design contract was awarded to Guido Perla in March. The ferries are to be built by Todd Pacific Shipyard Corp. and J.M. Martinac Shipbuilding Corp. The first of the new vessels is expected to be in service by early 2011.
The new double-ended boats will be approximately 362 feet long with a beam of 83 feet and a draft of about 16.5 feet. They will have a carrying capacity of 144 standard autos and 1,500 passengers.
“For stability purposes the boat is designed as a two-compartment vessel,” Gleaves said.
The engineers’ operating control station is located midships with an engine room fore and aft of it. One engine room will have an EMD diesel, a reduction gear and two diesel generators. The other engine room will have an EMD diesel, a reduction gear, one diesel generator and heating boilers. Each of the two propulsion systems will use a 3,000-hp EMD 12-710G7C Tier 2 marine diesel with Falk reduction gears connected to Rolls-Royce main shafting driving a single controllable-pitch propeller at each end.
Rudder control will be provided by a Tenfjord rotary vane-type mechanism. This compact unit has just one hydraulic mechanism. That sets it apart from the ram-yoke designs commonly used on other ferries, with their exposed push rods that can corrode or seals that could leak, Gleaves explained.
The rudders, for the first time on WSF vessels, will use a flap-rudder design to improve maneuverability, according to Gleaves.
To achieve a high level of operating efficiency, “WSF had design consultants do a complete computer analysis of the hull form. Even though these boats will nominally look like other WSF boats, under the waterline the contours are substantially different. A lot of time was spent to make it just right for the most efficient form possible both going through the water and the water going through the propellers. Efficiency is a big criterion for these boats’ designs — how much fuel will they use,” he said.
Hotel power will be supplied by three Series 60 engines by Detroit Diesel with Stamford Newage alternators rated at 300 kw each. A fourth 300-kw diesel generator will be designated for emergency use. Gleaves noted that efficiency goals include recovery of waste engine heat for interior heating purposes.
Safety is another high priority. “One big difference of these boats compared to the others of the fleet is the passenger evacuation slides for the 1,500 passengers will be on the passenger deck. Previous boats evacuated from the car deck,” said Gleaves.
Liferaft Systems Australia will supply the SOLAS-certified life-raft system and slides. Sets of additional rafts will be located on the sun deck.