Modern laker Mark W. Barker features Thordon RiverTough bearings

Mark W. Barker is believed to be the first ship for U.S. Great Lakes service built on the Great Lakes since 1983. [Photo: Interlake Steamship Company]

Like other vessels in the Interlake Steamship fleet, Mark W. Barker, the first new U.S flagged Great Lakes bulker in almost 40 years, is fitted with oil-free propeller shaft bearings from Thordon Bearings.

Thordon’s scope of supply for the vessel includes a water lubricated RiverTough bearing, nickel-chromium-boron (NCB) alloy liner for a propeller shaft diameter of 445 mm (17.5 inches), and two Thordon Water Quality Packages.

Thordon’s authorized distributor in Ohio, Advanced Sealing Technology, worked with the ship owner to get the RiverTough package specified.

Built by Fincantieri Bay Shipbuilding and designed to transport salt, iron ore, stone, and other bulk cargoes throughout some of the narrowest rivers in North America’s Great Lakes region, including the tight bends of the Cuyahoga River, the single screw Mark W. Barker is the sixth Interlake Steamship vessel on which Thordon’s proprietary polymer bearings have been installed.

“Interlake has had a lot of success with our propeller shaft bearings,” said Jason Perry, Thordon’s regional manager, North America. “Their vessels operate in some of the region’s narrowest, shallowest waterways which means vessels are unable to turn and instead must reverse using bow and tunnel thrusters. When operating at lower shaft speeds, the RiverTough polymer formulation reduces friction and bearing wear. The material can also withstand operations in highly abrasive, very sandy environments.”

Thordon says that wear rates for RiverTough are typically less than half that of rubber bearings, based on ship owner feedback. Offering increased resilience, easier shaft alignment and less edge loading, lubricants in the polymer material reduce friction levels during nearly-dry starts, significantly eliminating stick-slip and vibration at low shaft speeds. Results from shipowners have shown wear rates of 0.075 mm to 0.100 mm (0.003 inches to 0.004 inches) in 6,000 to 7,000 hours of annual use.

“From the outset, Thordon always responds quickly to our requirements with its bearing expertise, technical know-how and customer service,” said Ian Sharp, Interlake’s Director of Fleet Projects. “Having multiple RiverTough bearings in operation with proven reliability made it a very simple decision to choose the same Thordon bearing for our new ship.”

“Mark W. Barker is truly a milestone ship for Interlake and we are proud to be associated with what is arguably one of the most advanced, energy efficient self-unloading bulkers to operate on the Great Lakes,” said Craig Carter, vice president business development at Thordon. “Our relationship with Interlake Steamship and Bay Shipbuilding dates back to 1998 when we installed propeller shaft bearings to the 25,000 dwt Kaye E. Barker. Since then, we have enjoyed a very productive, collaborative relationship with both owner and shipyard and look forward to working together on future projects.”