The Mark W. Barker, the first new U.S flagged Great Lakes bulker in almost 40 years, has successfully completed sea trials and will now begin trading throughout the freshwater lakes and river networks with oil-free propeller shaft bearings from Thordon Bearings.

Built in Sturgeon Bay, Wisconsin, by Fincantieri Bay Shipbuilding for The Interlake Steamship Company, Thordon’s scope of supply includes a water lubricated RiverTough bearing, Nickel-Chromium-Boron (NCB) alloy liner for a propeller shaft diameter of 445mm (17.5in), 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.

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 6th Interlake Steamship vessel that 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 mean 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.”

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 0.075mm to 0.100mm (0.003 to 0.004-in.) in 6000 to 7000 hours of annual use.

Commenting on Interlake’s long-term relationship with Thordon, Ian Sharp, Interlake’s Director of Fleet Projects, said: “From the outset, Thordon always responds quickly to our requirements with its bearing expertise, technical know-how and customer service. 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.”

With a hull optimized for energy efficiency, the 28,000dwt River-class bulker is powered by a pair of 400HP main engines driving a single controllable pitch propeller through twin-input, single out-put reduction gearbox. It is the first ship to operate on the Great Lakes with engines that meet EPA Tier 4 emissions standards.

EPA Tier 4 standards entered into force in January 2017, requiring marine engines rated at 600kW and above to be fitted with technologies capable of significantly reducing nitrogen oxide (NOx), sulfur dioxide (SOx), and particulate matter (PM).

Craig Carter, Vice President of Business Development added: “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.

“Our relationship with Interlake Steamship and Bay Shipbuilding dates back to 1998 when we installed propeller shaft bearings to the 25,000dwt Kaye E. Barker. Since then, we have enjoyed a very productive, collaborative relationship with both owner and yard and look forward to working together on future projects.”