Thordon’s water-lubricated shaft bearings selected for bulk carrier refit

Thordon Bearings has delivered COMPAC water-lubricated propeller shaft and SXL rudder bearings to replace oil and grease-lubricated bearings onboard McKeil Marine’s bulk carrier Northern Venture as part of a major refurbishment project.

Established in 1956, Canada-based McKeil Marine provides marine transportation along the St. Lawrence Seaway, the East Coast, and Canadian Arctic with its diversified fleet of tugs, barges, workboats and vessels, including bunkers, cement carriers, and tankers.

The shipowner acquired the 155m (508.5ft), 19,651dwt Northern Venture in 2022. The self-discharging River Class vessel has a forward mounted discharge boom and a single point loading system which allows all four holds to be loaded via shuttle conveyors from a single deck-mounted hopper.

The conversion to water-lubricated propeller shaft and grease-free rudder bearings was made to ensure the vessel does not discharge oil or grease into the Great Lakes, said Andy Vary, Director of Technical Operations at McKeil Marine. “It’s part of our continuous commitment to our people, our customers and the communities in which we operate.”

The retrofit included COMPAC bearings for the vessel’s 409mm (16.1in) diameter propeller shaft along Thordon’s Water Quality Package to ensure a clean water supply to the bearings. Thordon grease-free SXL rudder bearings were also supplied for the bulker. This installation was undertaken in summer 2023 at COSCO’s Nantong Shipyard in China, with the vessel operational on the Great Lakes in December 2023.

McKeil Marine is a returning customer for Thordon Bearings. The world’s first Thordon water-lubricated propeller shaft bearing was installed on a Great Lakes tug owned by McKeil Marine in the late 1970s.

Following this conversion, many other Great Lakes operating vessels converted to Thordon, helping to raise the profile of the Burlington, Ontario-headquartered company across the global shipping industry.

Thordon’s COMPAC propeller shaft bearing is constructed from a cross-linked polymer alloy that offers a low breakaway friction resulting in quiet and smooth operation. The material’s abrasive resistance is much greater than traditional laminated materials. The visco-elastic nature of the material also improves the hydrodynamic performance of the bearing leading to longer wear life, and as the material is homogenous, it provides consistent low wear and friction properties.

To promote early formation of a hydrodynamic film between the propeller shaft and bearing, the lower (loaded) portion of the bearing is smooth, while the upper half of the bearing incorporates grooves to allow water lubricant/coolant to flow. A key benefit of the water-lubricated propeller shaft system is that it negates the need for a damage-prone aft seal.

José Duarte, Marine Business Development Manager - North America, Thordon Bearings, said: “As an added environmental benefit, Thordon’s COMPAC system has been shown to lead to fuel savings and reduced emissions. Compared to oil-lubricated bearings, at rated shaft speeds viscous friction is lower with water.”

The Thordon Water Quality Package is designed to supply sea or lake water to the propeller shaft bearings for lubrication and cooling and to condition the water by removing suspended solids.

Thordon’s SXL rudder bearings operate without grease above and below the waterline, offer high abrasion resistance and can also withstand high shock loads, improving the wear life of the bearing.

Thordon has been actively supporting shipowners such as McKeil Marine, Algoma Central, American Steamship, CSL, Lower Lakes Towing and Interlake Steamship for over three decades. More than 120 vessels sailing the Great Lakes have Thordon’s water-lubricated components.