Transit has high hopes for low ferry wake

A prototype vessel plies Rich Passage in a 2005 wake test. - Review file photo
A prototype vessel plies Rich Passage in a 2005 wake test.
— image credit: Review file photo

A new fast ferry could be in service by 2008, researchers say.

Scientists testing a new low-wake passenger ferry in Rich Passage reported “some promising results” this week.

“We’re seeing indicators that show we’re on the right track,” said principal researcher and project manager Phil Osborne of Pacific International Engineering.

Recent posted results show the prototype M/V Spirit’s highest wake at about 20 inches, while more traditional foot ferry models generated wakes of up to 27 inches.

Results also showed that the force of wakes from the Spirit’s test runs hit the shore with less than half the power of common foot ferries.

PI Engineering will likely continue tests for another year before revamping the vessel’s design for another series of tests. If all goes well, Osborne predicted, a low-wake ferry could be racing through Rich Passage by 2008.

The Federal Transit Admini­stration commissioned the study in 2004 to find a way for a passenger ferry to cover the distance between Bremerton and Seattle in 30 minutes while reducing wake damage to the shoreline along the island’s south end.

Kitsap Transit is assisting in the administration of the low-wake vessel study in the hopes of “restarting this service in a sustainable way,” said Dick Hayes, the transportation agency’s director.

Faster ferries servicing the runs from Bremerton and Kingston to Seattle could “reduce pressure on the Bainbridge ferry and on State Route 305 as well,” Hayes said.

Properties along Point White and Pleasant Beach suffered from years of beach erosion and bulkhead damage from high speed vessels, including the sleek M/V Chinook foot ferry that began servicing the Bremerton-Seattle run in 1998. The faster Washington State Ferries vessel, which traveled at 34 knots, cut the usual hour-long travel time in half, but turned beaches into “moonscapes,” some south shore residents contended.

About 15 islanders joined almost 100 other shore residents from Manchester and the west side of Port Orchard Bay in suing the state for damages and a speed reduction.

WSF and the claimants settled in 2002, with the state paying almost $5 million to Rich Passage residents and reducing speeds to 16 knots.

Osborne and his team plan to “nourish” damaged beaches with imported sand and gravel at a few areas along Point White and the shoreline north of Fort Ward State Park.

The replacement materials will be brought in by barge over a two-week period in the coming months.

“The amount will be equivalent to the historic losses,” he said, adding that up to 4,000 cubic yards of sediment could be introduced.

Scientists will monitor the imported sediments’ movement with laser scanning technology, computer-assisted beach mapping and by monitoring tagged beach rocks.

Continued tests on tidal circulation and marine habitats are also planned, Osborne said.

Most of the south shore’s beaches have recovered naturally, with many areas now “relatively stable and relatively healthy,” he said.

Despite the Spirit’s cutting-edge design, Osborne hopes to further improve the vessel’s hull for even less wake.

The 72-foot catamaran was designed by Teknicraft New Zealand and built by All American Marine in Bellingham. Its design was based on the M/V Condor Express, which has set new standards for low wake generation in fast passenger-only ferries.

According to PI Engineering, longitudinal chines inside the Spirit’s hull tunnel and wide chines on the outer hull deflect water and reduce the vessel’s resistance. Other design features cut wave interference, which further reduces drag.

“The conbined effect is a hull with the potential for low resistace, low vertical accelerations, low wake wash and therefore excellent performance,” according to PI Engineering’s website.

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