Michele Foss: Foss Maritime's First Arctic Class Tug
The Michele Foss, the first of three 132-foot tugs being built at the Foss Rainier, Oregon Shipyard, was christened in April at the Foss Waterway Seaport in Tacoma, Washington. This new vessel is the first tug in the western hemisphere built specifically to operate in the harsh arctic environment. The design combines the best features of traditional towboat design with advanced engineering concepts to meet the highest standards of safety and efficiency. Its first assignment will be a sealift this summer of oil field modules from South Korea to the Alaskan arctic.
Michele Foss complies with all SOLAS rules and is classed American Bureau of Shipping (ABS) A1 Towing to enable it to work internationally, and meet the latest ecological and navigation safety standards demanded by the oil and gas industry. It is powered by twin 3,634-HP Caterpillar diesels giving a bollard pull of more than 100 tons, and has sufficient fuel capacity for a 30-day/3,000-mile operation. That's the top standard for operating these vessels," said Tim Beyer, vice president for project sales in the Pacific. "Foss has a long history in Alaska, and the arctic tugs represent part of the company's new commitment to Alaska's future," he added.
Ice Class and Zero Discharge
Foss chose Seattle naval architects Glosten Associates to provide detail design services, specifying that the class must be engineered for zero-discharge of Ballast Water, fuel or sewage. The hull has no ballast tanks, thereby eliminating the chance of introducing invasive species to arctic waters. Instead, it will adjust trim by transferring fuel between several inter-connected fuel tanks. During fueling, an innovative piping system allows diesel oil storage tanks to cascade to port and starboard overflow tanks as an additional level of environmental protection.
To qualify for ABS Ice Class D0 and reduce the chances of a fuel spill, the hull was built with heavy steel plating. The topsides, which are vulnerable to ice damage, are 3/8-inch with an inner skin creating a void space three feet wide to protect against impacts. Along the hull's 1/2-inch bottom, this void protects the engine room and is used for additional fuel storage. The bow is reinforced by closely-spaced frames and 1/2-inch plate, with a 1-inch thick band extending along the deckline – all protected by Schuyler's high-absorption fendering.
To cope with extreme cold, the decks are heated and the bulwarks have been boxed in to reduce ice build-up. The engine coolers are housed in sea chests, which are equipped with heaters to prevent ice from blocking them. Other green features include holding tanks for black and gray water to permit operations in "no discharge zones," hydraulic systems compatible with biodegradable oil and energy-efficient LED lighting. The tug also qualifies for the Green Passport designation, which requires an inventory of hazardous materials.
The builder is the small Foss yard on the Columbia River midway between Astoria and Portland that previously built all ten of the 80-foot Dolphin class ship-handling tugs. For these 132-foot craft with a beam of 41 feet and a maximum draft of 18 feet, the yard was expanded by 10,000 square feet to create more space for assembly and launching. "It's the biggest and most complex boat we've built here," said Shipyard director Don Nugent. Work is now underway on the second arctic class, the Denise Foss.
Powertrain by Caterpillar, Reintjes and Nautican
Power comes from twin Tier 2 Caterpillar C280-8 diesels with a combined continuous rating of 7,268 HP at 1,000 rpm. The Reintjes WAFF 3455 reduction gears, flexible coupling and drive shaft are oversized to withstand the shock of ice operations. The exhaust and silencer are also designed to reduce the engine noise. Fuel capacity is 122,000 gallons.
The stern gear is of particular importance since it must be capable of withstanding broken ice, along with maneuvering barges and drilling rigs in difficult weather conditions. To handle such challenges, Foss selected Nautican Research and Development's Integrated Propulsion Unit (IPU) – built in Vancouver, B.C. The IPU combines the company's high-efficiency nozzle with pre-swirl stators, a 126-inch diameter propeller and linked triple rudders.
Nautican explained the whole unit was custom-built to "Ice-class" standards; the five-blade, Kaplan-style stainless steel propeller has thicker leading and trailing edges. The nozzle is assembled with a large head box that slots into a recess in the stern, anchoring it firmly into the hull. "This Nautican unit will offer increased bollard pull, greater maneuvering and efficiency through ice and rough sea conditions. We're excited to see what the tugs will do once they are in service," said Elizabeth Boyd, Nautican owner.
The gen-sets – a pair of Tier 2 Cat C9-2, 215kW, 480 VAC – are installed in a separate space aft of the engine room. The generator room also houses a John Deere 4,045 99 kW engine set athwartships below the Markey tow winch and turning it via a drive chain inside a heavy chain case. (The size and height of the engine spaces with extensive piping, overhead wire runs and sub-panels to meet SOLAS standards resembles a small ship rather than a typical offshore tug.)
Designed for Towing in arctic Weather
"We designed the boat around the winch and the towing mission," said Jay Edgar, president of Glosten. It is protected from the weather by an extension from the house open only at the aft end. Foss chose a direct-drive Markey double-drum TDSD-40 model with a line pull of 91 metric tons. Each drum carries 3,000 feet of 2.5-inch under-wound wire that is controlled by Smith Berger shark jaws and towing pins that retract flush with the deck and exit through the cutaway in the stern bulwark. "This keeps the crews as safe as possible," explained Scott Kreis, Markey Machinery's vice president of sales.
There are also two smart electronic systems that monitor the towline. The pneumatic band brake on each drum can apply 230 metric tons of resistance and is supplemented by a water-cooled slip brake in the drive train that can be set to release wire in response to surges in the towline in rough weather. Alternatively, the skipper can set the band brake and check the tension via a tension monitoring system.
Markey offers a wide range of options, Kreis explained, and Foss also specified a horizontal warping head on the port side and a pennant drum on the starboard, which are driven by a separate 40HP electric drive. The John Deere is backed up by a 15-HP electric drive that will take over if the diesel fails to start. Hatches atop this house can be opened to allow crew in the pilothouse to monitor the winch. The towing bridle is assembled from 3-inch chain. The bow winch is a Markey WEWD-22, with a single hawser drum, anchor windlass, and warping heads port and starboard.
Accommodation Designed for the Long Haul
The wheelhouse layout was worked out by consulting the crews who will man the tug for many weeks at a time. A 3D model of the wheelhouse resulted in the inclusion of a large chart table behind the helm station, where steering is by jog sticks. The angled sides of the deckhouse give the men on watch clear sight lines around the entire main deck from the interior and the external walkway. The accommodation consists of seven staterooms - four doubles and three singles – all above the main deck.
Particular attention has been paid to insulation throughout the vessel, to reduce noise and vibration, ensuring the crew can maintain awareness on watch, relax off-watch, and sleep well. The galley is equipped with a Lang range and Cospolich refrigerator, with spacious walk-in reefer, freezer and dry good storage filling the space forward to the collision bulkhead.
After the first sea trials, Gary Faber, senior vice president at Foss, expressed the company's satisfaction with the boat. "Our project teams invested countless hours to design and build a boat that would meet our vision. It is particularly gratifying to now see the boat meet or beat all the performance standards that went in to the design. As always, as we work the boat we will see opportunities to improve the design to meet the demands of the projects at hand and in the future."