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Articulated tug-barge Aveogan-Oliver Leavitt: unique integrated design
Tug Aveogan has Azimuthing drives to enhance manoeuvrability, and an Intercon C-series coupling system with a first-of-its-kind lightering helmet.
Unique integrated design
CROWLEY FUELS HAS TAKEN DELIVERY OF ITS NEW ALASKA CLASS 100,000-BARREL ARTICULATED TUG-BARGE (ATB), WHICH WILL BE USED TO TRANSPORT MULTIPLE CLEAN PETROLEUM PRODUCTS FOR THE ALASKA MARKET.
ALL IMAGES COURTESY OF CROWLEY.
Aveogan is equipped with a fire monitor and foam proportioner, providing off-ship firefighting capabilities to the barge.
The articulated tug-barge (ATB) is the first in Crowley’s fleet to be dedicated to the Alaska market. Crowley will operate the 147m ATB for Alaska-based Petro Star, a whollyowned subsidiary of Arctic Slope Regional Corporation (ASRC) under a long-term charter. The agreement extends Crowley’s longstanding partnership with ASRC and Petro Star, which dates back four decades to ASRC’s earliest days. The barge is named Oliver Leavitt, in honour of ASRC’s former chairman and current member of the corporation’s board of directors. The tug has been named Aveogan, Mr Leavitt’s Iñupiat name. “We are pleased to take delivery of this high-performance Aveogan-Oliver Leavitt ATB and look forward to getting her up to Alaska to begin serving our partners at Petro Star,” says Rocky Smith, Senior Vice President and General Manager at Crowley Fuels.
Ice Class and Polar Class The 100,000-barrel ATB was constructed at the Bollinger Marine Fabricators facility in Amelia, Louisiana, with on-site construction management by Crowley Shipping that designs and manages the construction and operation of diverse vessel types, including tank vessels. Jensen Maritime, Crowley Shipping’s Seattle-based naval architecture and marine engineering subsidiary, designed the ATB to meet Ice Class and Polar Code requirements, which includes increased structural framing and shell plating and extended zero discharge endurance. The double-hulled design also features a barge form factor to achieve high-cargo capacity on minimal draught. “The Alaska Class articulated tug-barge Aveogan-Oliver Leavitt is a great example of Crowley’s uniquely integrated design >>
Crowley’s new Alaska Class 100,000-barrel articulated tug-barge (ATB), which will be used to transport multiple clean petroleum products for the Alaska market.
development capabilities, leveraging the internal resource of the Jensen team with the company’s ship operations experience to construct an innovative, high-performing ATB”, explains Jay Edgar, Vice President Engineering for Crowley and Jensen Maritime.
Special features Some of the notable features include design specifications that meet Ice Class and Polar Class requirements, allowing extendedseason access to remote Alaskan destinations including the Arctic and Aleutian Islands. To minimise discharge, the ATB has a patent-pending, internal ballast transfer system, hull heat exchangers, and effluent storage supporting extended zero discharge endurance. Both the tug and barge are fully double-hulled to reduce risk of oil outflows. The hull form has been optimised using Computational Fluid Dynamics (CFD) for low resistance and fuel efficiency at design speed. The vessel has a highly capable mooring system, with six constant tension winches and optimised line arrangements, and transfer capabilities that allow the ATB to lighter offshore, instead of only at terminals, to meet the long-term needs of Petro Star. “In total, this Jensen design meets the needs for service in Arctic and Western Alaska regions, southeast Alaska and the Pacific Northwest”, states Mr Edgar. “The benefit of Jensen and Crowley’s integration is that our vessel design team can refine performance specifications and designs based not just on our professional expertise, but on years of ATB experience, as Crowley operates and manages the largest US-flag petroleum and chemical tank vessel fleet in the country. Furthermore, we have
SPECS
Vessel Name: Oliver Leavitt
Length 121.91m Beam 25.91m Depth 9.75m Maximum Draught 6.71m Ship’s Service Power 3x 300kW John Deere 6135, EPA Tier 3, IMO Tier II Speed Approx. 11 knots with Tug Hull Construction Steel, Scantlings designed to Ice Class D0 Deadweight Tonnage (OSVs) 14,600LT
Ancillary Equipment/Systems:
• Twelve Marflex MDPD-200 Electric Motor-Driven
Cargo Pumps • Two Panasia, USCG Type-Approved Ballast Water
Treatment Systems, each with a 350m 3 capacity • Bergan Tank Level Indication and Monitoring System • Spill Response Equipment, including 2000-feet of
Inflatable Spill Boom that can be deployed from a hydraulic-operated reel • Vacuum Stripping System • Maritime Protection – Inert Gas Generator • Three 5.5m x 2.5m Yokahama-style pneumatic fenders for lightering
Vessel Name: Aveogan
Length 39.0m Beam 12.80m Depth 5,84m Maximum Draught 5.64m Main Propulsion Two General Electric 8L250MDC, Each 3384 HP at 1,000 RPM, EPA Tier 4, IMO Tier III Z-Drive Two Schottel SRP-560 with Carbon Fiber Shafts Bollard Pull 97 Short Tons Propellers/Waterjets Two 2,800mm Dia. Stainless-Steel, Ice Class Propellers Steering System/Controls Schottel Speed Approx. 11 knots Hull Construction Steel, Scantlings designed to Ice Class D0 Crew/Passenger Capacity 11
experienced engineers and on-site shipyard construction managers to help us effectively drive the concept into a sophisticated, robust vessel that is complete and ready to support harsh Alaskan operating conditions.”
Enhanced manoeuvrability The ATB was designed under the Safety of Life at Sea (SOLAS) Convention and will be classed with the American Bureau of Shipping (ABS). The vessel was built with enhanced features to benefit the crew, including 45-degree sloped staircases, interior sound deadening, and dedicated heads in each cabin. Tug Aveogan has Azimuthing drives to enhance manoeuvrability, and an Intercon C-series coupling system with a first-of-itskind lightering helmet. The tug is fitted with two GE 8L250 main engines that meet US Environmental Protection Agency’s Tier IV emissions standards. The generators on the tug and barge meet EPA Tier III and IMO Tier II emissions standards. In addition, the ATB features a patentpending closed-loop, freshwater ballast system whereby the tug’s ballast will be transferred to-and-from a retention tank on the barge to account for fuel burn. The design has been approved by the USCG and will eliminate the need to discharge tug ballast water into the sea. The tug is equipped with a fire monitor and foam proportioner, providing off-ship firefighting capabilities to the barge. The barge is also outfitted with spill response gear and a hydraulic boom reel with 2,000 linear feet of inflatable boom to support spill response efforts. “The new vessel’s advanced design and environmental protection features mark a new era for fuel transportation services in Alaska,” comments Rick Meidel, Vice President and General Manager, Crowley Fuels Alaska. “She will provide many years of safe and reliable service for our valued customer Petro Star.” Alaska’s fuel wholesaler Crowley operates and manages the largest US-flag petroleum and chemical tank vessel fleet in the country, including 40 other Jones Act qualified large petroleum transportation vessels that carried nearly 590 million barrels of product with more than 6,200 transfers in 2019. Crowley Fuels is a leader in Alaska’s fuel industry, providing transportation, distribution, and sales of petroleum products to more than 280 communities across the state. The company is the state’s largest wholesaler of quality fuel products, including diesel, heating fuel, propane, gasoline, aviation fuels, marine fuels, and packaged petroleum products. Crowley has eighteen petroleum terminals across the state with a combined 76 million gallons of storage capacity. The company utilises its diverse distribution channels, on land, over water and occasionally via air, to deliver the fuel Alaskans need to live, work, and play throughout the state.
