Tuesday, August 17, 2010

Fast Ferries

By Chris Philips, Managing Editor

Alaska is not for the faint-hearted. Everyday life has unusual challenges, from 20 hours a day of darkness in the winter, to flocks of mosquitoes in the summer and crazy hormonal bull moose in the fall. Alaskans exposed to these challenges seem to thrive on the extraordinary, which explains the participants in the Iditarod and the Bering Sea Opilio crab fishery.

Another extraordinary Alaskan is the recently launched, 95-foot by 60-foot ferry M/V Susitna, for Alaska’s Matanuska-Susitna borough on Cook Inlet.

“We’re pretty proud of her,” says Doug Ward, director of shipyard development for Alaska Ship and Drydock (ASD), in Ketchikan, Alaska. “She’s an extremely unique ship.”

Built by ASD to a design by Seattle Naval Architecture firm Guido Perla and Associates, with guidance by the US Navy’s Office of Naval Research (ONR), the unusual ferry will connect Anchorage to Port MacKenzie in the Mat-Su Borough on a 3-mile route that will turn a 2½-hour drive into a 15-minute boat trip. The borough, known as Mat-Su, will own and operate the passenger-vehicle ferry and give the Navy data on its operation as a possible ship-to-shore transport vessel.

Susitna is powered by four MTU 12V 4000 diesel engines, driving four specially designed waterjets as well as two azimuthing thrusters. The ro/pax vessel has a capacity of 100 passengers and 20 vehicles.

What makes the Susitna so unique is its dual-purpose hull, which combines the speed and seakeeping capabilities of a SWATH (Small Waterplane Twin-Hull) vessel with the versatility of a landing craft. Where a conventional catamaran has a main deck, Susitna’s is missing. Instead the craft has two demi-hulls with fore and aft crossmembers, and an empty space where the deck should be. “It’s like a big open donut,” says Ward. The hole is filled with a cargo deck that can be raised or lowered to fit the needs of the boat. Raised, the cargo deck is out of the water, the demi-hulls submerge to their 12-foot design depth and the vessel operates like a SWATH- in other words, with the seakeeping capabilities of a much larger vessel. The buoyancy of the hulls remains under the water’s surface, offering a surprisingly smooth ride. In SWATH mode the vessel has a 12-foot draft.

Stop the ferry and lower the cargo deck – an operation accomplished via a carefully calibrated hydraulic system – and the draft is reduced to 4 feet. In this mode, the vessel can be driven up on the beach with her hull-mounted waterjets and cargo can be offloaded via a ramp like a conventional landing craft.

The Navy has invested more than $1 million in the integrated science package, which includes sensors to monitor the stresses and strains on the hull.

During the builder’s trials, which begin this month, the vessel is expected to reach 20 knots and produce a service speed of 17 knots.

Ward says that in spite of the fact the vessel is a testbed for the Navy, the Susitna was designed to be a ferry. Terminals on each side of the ferry’s route will allow her to stay in deep-draft mode, using her sharpened demi-hulls to full advantage. Because Cook Inlet freezes in the winter, the ferry also has ice cutting capability.

“The lower hull leading edge is 2-inch-thick high strength steel,” says Ward. The builder calls the concept an “ice knife.”

“The rounded bow goes under first tier sea ice up to two feet thick,” he says. The leading edge of the hull then lifts the ice and cuts it. “As far as we know the Susitna is the first ice strengthened twin hull vessel.”

One of the biggest challenges for the shipyard was the diverse material that went into the hulls of the boat. For example, the bottom of the demi-hulls is reinforced, and has five different grades of steel in seven different thicknesses. While the demi-hulls are steel, the cargo deck is aluminum, and was built by Latitude Marine Services in La Conner, Washington, along with the passenger compartments. Alaska Ship & Drydock, Inc. built the aluminum pilothouse.

Alaska Ship and Drydock is an independent corporation owned by the Alaska Industrial Development and Export Authority and supported by the local borough and city. Susitna is the yard’s third newbuild, following a 120-foot ro/ro ferry, Oral Freeman, built in 2001, and the Chevron Legacy, a floating fuel dock and grocery store built for the 2010 winter Olympics in Vancouver, BC.

Low Emissions
In the lower 48, Kvichak Marine Industries and Nichols Brothers Boat Builders have delivered M/V Taurus, their fourth high-speed, environmentally friendly ferry to the Water Emergency Transportation Authority (WETA) located in San Francisco.

WETA has mandated that their new passenger ferries integrate as much green technology as possible and that emissions be 85 percent cleaner than the current EPA emission standards for Tier II (2007) marine engines. They started with a sleek, low wake 118-foot catamaran hull, designed by Incat Crowther of Australia, to minimize shore erosion from wake and reduce fuel consumption.

The vessels are powered by a pair of Tier II-compliant, MTU 16V2000, 1,410 HP Diesel engines with Selective Catalytic Reduction (SCR) systems from Engine, Fuel & Emissions Engineering of California. SCR injects urea into the exhaust before it passes through a precious-metal catalyst, converting nitrogen oxide into harmless nitrogen and water.

In addition to minimal shore impact and low emissions, the passenger ferries showcase several additional green features, including custom exhaust systems minimize noise pollution on ship and shore, solar panels to augment the electrical system and a sonar system that allows the captain to detect and avoid whales and debris.

Taurus is the final boat of the four-boat contract.

On Whidbey Island, Washington, Ice Floe, LLC, (dba Nichols Brothers Boat Builders) recently completed a repower of the M/V Del Norte, for Golden Gate Ferries. Four new Tier 2-compliant MTU 12V4000M60 series engines and new main driveline components were installed, while the four MJP waterjets were rebuilt by Seattle-based Sound Propeller.

Following the refurbishment of the Del Norte, Nichols Bros. will address the refurbishment of two ferries purchased by Golden Gate from the State of Washington. Golden Gate Ferries purchased the two boats, originally built at Dakota Creek Industries in the late 1990s as the M/V Chinook and M/V Snohomish, in January 2009. The engines to be installed in the two boats will have emissions that are 20 percent cleaner than the required Tier 2 marine engines. Additionally, Golden Gate Ferries, in partnership with MTU/Detroit Diesel, will be conducting a bio-diesel pilot project with the two boats.

In addition to new propulsion systems, the interiors and exteriors of the vessels will be fully refurbished to like-new condition.

The Chinook will be completed first, and work on the M/V Napa (ex- Snohomish) will begin when work on the first vessel is complete. The work is expected to take approximately six months per vessel and a little more than a year in total.

Fifth Ferry Boat for USS Arizona Memorial
The US Navy accepted delivery of the fifth USS Arizona Memorial passenger ferry boat from Modutech Marine Inc. of Tacoma, Washington in late June. This vessel is one of six boats being procured to replace the existing ferries that have reached the end of their service life. The boats, procured for the National Park Service by the US Navy’s Program Executive Office (PEO) Ships, serve as a ferry service to shuttle visitors to and from the memorial, and continue to support the US Navy’s commitment to the National Park Service, as they tell the compelling stories of the Dec. 7, 1941, attack on Pearl Harbor.

The new 78-foot vessels are constructed of fiberglass and can accommodate up to 149 passengers and three crew members. The boats use a combination of clean fuel technology propulsion systems, including EPA Tier 2 compliant marine diesel engines, exhaust and fuel system treatments, and biodiesel fuel. This will significantly reduce the “carbon footprint” of the passenger service provided at the national memorial. The ferries also comply with applicable Federal Passenger Vessel Accessibility Guidelines, improving accessibility.

Golden Gate Ferries 40-Year Mark
Sunday, August 15th marks the 40th Anniversary of the Golden Gate Ferries. The service was inaugurated by the Golden Gate Bridge, Highway and Transportation District, which purchased the twin-engine, diesel-powered ferry M/V Point Loma, reconditioned and rechristened her the M/V Golden Gate and began service on August 15th, 1970.

Between 1972 and 1977, the District built three new gas turbine-powered aluminum ferries, each capable of carrying 715 passengers, designed by renowned Seattle Naval architects Philip F. Spaulding and Associates. The new boats were built by San Diego-based Campbell Industries, with the first of the series, the G/T Marin, beginning service between Larkspur and San Francisco on December 11, 1976.

Former PMM California editor, Wes Starratt, says Kaiser Aluminum provided the aluminum and developed the aluminum welding techniques that made the fast aluminum ferries possible.

In June of 2007, Bay Ship & Yacht completed a $6.5 million refitting of the Marin, including a complete remodeling of the boat. Structural modifications were required for new passenger seating, along with new interior bulkhead linings, carpet, and vinyl flooring, as well as overhead ceilings, ventilation, lighting, and exterior windows, plus new fresh water and sanitary systems, new generators and electrical systems, and a complete repainting of the vessel. New safety features included new fire boundary bulkheads on both decks, and new fire doors.