Thordon Bearings - Experts & Thought Leaders

Bronze bearings in the stern roller of the Anchor Handling Tug Supply (AHTS) Vessel ES Kestrel have been replaced with grease-free SXL bearings from Thordon Bearings while the vessel remained afloat and operational. The replacement was undertaken in May 2024 by Thordon’s Dubai-based distributor Ocean Power International (OPI) for the AHTS owner Echo Cargo & Shipping of U.A.E. While typically checked during routine drydocking, the vessel’s stern roller was experiencing turning issues during operation. On inspection, it was found that the existing bronze stern roller bearings were seized and worn, mostly due to failed grease lubrication. Harsh sea conditions Stern rollers are a key feature of anchor handlers and other offshore support vessels that need to deploy and retrieve anchor chains and wires. These vessels often operate in harsh sea conditions with high bearing loads. These vessels often operate in harsh sea conditions with high bearing loads ES Kestrel was built in 2011 and has mostly operated in the shallow coastal waters of the Persian Gulf region. Thordon SXL bearings operate without oil or grease above and below the waterline and are approved for pressures up to 12 MPa (1740 psi). The SXL material offers high abrasion resistance and can also withstand high shock loads, improving the wear life of the bearing. High abrasion resistance Rafid Qureshi, President of OPI, said off-the-shelf availability and his team’s ability to undertake the engineering and installation were key to the success of the project. His team worked with the vessel’s owner and the shipyard to design, machine and install the 360mm (14.2in) long bearings that were interference fit into split housings. The top half of the bearing housing needed to be lifted to remove the worn bushes and install the new ones. Axial installation was not possible, and the bearings had to be placed over the pin prior to positioning the stern roller. The ability to refurbish the roller bearings while the vessel was afloat saved time and money for the client. Sustainability of stern rollers Thordon’s Regional Manager – Southern Europe & Gulf Med, Malcolm Barratt, said, "Thordon’s bearings enhance the performance and sustainability of stern rollers on AHTS vessels." “Our polymers feature exceptionally long wear life and offer the best combination of strength and stiffness with flexibility and elasticity, along with high abrasion resistance. Their use in this project demonstrates the shipowner’s commitment to innovation, environmental friendliness, and cost effectiveness. This upgrade was a noteworthy achievement that showcases OPI’s engineering capabilities and dedication to efficiency.” Small machining errors Thordon has previously supplied rudder and tail shaft bearings to other Echo Cargo & Shipping vessels Thordon SXL bearings are easy to machine and produce no dust. In comparison, other non-metallic materials require dust extraction and tight machining tolerances that may result in product rejection or repair delays.  With Thordon SXL, machining tolerance is less critical, and because of the relatively large interference on the bearings, it is usually possible to adjust dimensions to compensate for small machining errors. Thordon Bearings has more than 70 distributors in 100 countries who carry extensive inventories of Thordon’s common bearing sizes. This is backed up by large regional and head office inventories. Thordon has previously supplied rudder and tail shaft bearings to other Echo Cargo & Shipping vessels and now expects to refurbish the roller bearings on two more vessels. To date, more than 80 AHTS vessels worldwide have been fitted with Thordon SXL bearings in stern roller applications.

Representing a breakthrough in the evolution of a ship’s propeller shaft line, Canada’s Thordon Bearings has unveiled the Thordon-Blue Ocean Stern Space (T-BOSS), a new solution designed to meet the propeller shaft requirements of the sterntubeless ship design proposed by the Blue Ocean Alliance. Introduced to the global maritime industry at the SMM trade fair in Hamburg, Germany, the new T-BOSS propeller shaft arrangement includes Thordon’s award-winning COMPAC polymer bearing with tapered key set, Thordon Bearing Condition Monitoring system, a Wärtsilä Enviroguard shaft seal, and Thordon’s Water Quality Package. Significant OPEX savings Thordon’s Technical Director Anthony Hamilton said: “T-BOSS has been designed as a sterntubeless ship solution, which will replace the traditional sterntube system with a dry chamber, that will allow for the full range of inspection and maintenance activities for a seawater-lubricated single bearing and seal arrangement. These activities can be done while the vessel is afloat, thus avoiding the need for shaft withdrawal or drydocking. This has never before been possible.” “By creating an opening in the engine room bulkhead, adjusting stiffeners, shortening the intermediate shaft (allowing the main engine to be moved further aft), eliminating the sterntube, forward sterntube bearing and aft seal and installing the T-BOSS solution, shipbuilders can take advantage of reductions in material and labor costs, while ship operators benefit from significant OPEX savings. It is the most significant ship design intervention in more than a century.” Cargo carrying capacity The arrangement also reduces the risk of environmental fines related to sterntube oil pollution to zero Aside from immediate savings in lubricating oil and elimination of the aft seal, shipowners opting for a T-BOSS sterntubeless ship could save more than US$1 million in through-life operational costs. This is based on reduced fuel consumption, reduced drydocking and maintenance costs, and associated loss of earnings; shaft alignment optimisation, lower bearing wear rates, better EEDI; and a potential increase in cargo carrying capacity. The arrangement also reduces the risk of environmental fines related to sterntube oil pollution to zero. Speaking during the T-BOSS launch at SMM, Dr. Chris Leontopoulos, Vice-President, Technology, EMEA, at ABS, a Blue Ocean Alliance partner, said that a T-BOSS ship’s simplicity of the arrangement, its maintenance, robustness and reduced environmental footprint, are astonishing. The design is fully ABS Rule compliant. Reduced fuel consumption “An order for the first T-BOSS ship design could be close. Speaking at SMM, Craig Carter, Thordon Bearings’ VP Business Development, revealed it has submitted quotes for T-BOSS to major shipbuilders in China and South Korea, for boxships and gas carriers.” “Yards have been quick to see the commercial, operational and environmental advantages of a sterntubeless ship, compared to a design with a traditional oil-lubricated shaft line,” he said. “We have been asked to submit quotes for a number of newbuilds and anticipate orders soon.” Optimising energy efficiency Dr. Chen Kang of SDARI (Shanghai Merchant Ship Design and Research Institute, CSSC), the naval architect firm that is part of the Blue Ocean Alliance, stated: “Since 2022 when ABS granted Approval in Principle (AiP) for our sterntubeless container ship, there has been considerable market interest in the concept.” “We cannot underplay the importance of this concept in the maritime industry’s goal of reducing emissions. It offers naval architects, builders and ship managers greater freedom and flexibility for optimising energy efficiency.” In June 2024, ABS published guidelines for the Requirements for Sterntubeless Vessels with Water-Lubricated Bearings and introduced the ABS STBLess-W Notation.

Thordon Bearings’ brake cups are being supplied to Hydro-Québec, the largest hydropower company in Canada, as part of a decade-long turbine brake system overhaul program. The Burlington-based bearing and seal specialist is providing the brake cups to its Canadian distributor RMH Industries, an integrated company specialising in mechanical and hydraulic repair and machining of oversized parts. RMH Industries has been manufacturing and repairing brake blocks for Hydro-Québec since 2020. Repairing brake blocks Forty-eight Thorseal brake cups will be delivered for installation to the Manic-2 station (the Jean-Lesage generating station) in Québec, after previously supplying them to the Churchill Falls, NL station. While Manic-2 deliveries continue, Thordon is also supplying the first cups for the Bersimis-2 station. Each brake block is generally made up of two to four pistons, depending on the size of the power plant One hydro-turbine typically has 8-12 brake blocks. Each brake block is generally made up of two to four pistons, depending on the size of the power plant. The cups are a critical component of the pneumatic/hydraulic braking system, because they ensure a seal is maintained for the pistons that are used to slow and stop the turbines. Potentially catastrophic failure The hydro-turbines typically weigh hundreds of tons and if the braking system were to fail, the thrust bearing could be subject to excessive load, leading to wiping and potentially catastrophic failure. The brake blocks are also used to lift the turbine, and if low quality seals result in significant leakage, this operation cannot be performed. The brakes are located under the turbine, making them difficult to access. The dimensions of the cups can vary considerably. For the Manic-2 power station, the Thorseal self-lubricating polymer lip seals are 152mm (6in) in diameter with 177-203mm (7-8in) lip. Oil-lubricated alternatives Thordon’s Thorseal brake cups are made from a proprietary elastomer that has no shelf life Ryan Edmonds, Business Development Manager for Hydro Power at Thordon Bearings, notes that unlike slightly cheaper rubber cups, Thordon’s Thorseal brake cups are made from a proprietary elastomer that has no shelf life or degradation of properties over time. “The Thorseal material will not crack, so it eliminates the risk of slow wind down that can damage fragile babbitt sleeve bearings,” he said. Thorseal brake cups provide long wear life with no need for periodic replacement due to their internal lubricant that reduces drag more effectively than oil-lubricated alternatives.  Operating mechanism bearings Operators of many other hydro facilities around the world are considering brake system refurbishment programs, said Edmonds. “Saving a few thousand dollars on low-quality cups is not a wise investment when the catastrophic consequences of failure could result in extensive downtime and tens of millions of dollars in repairs.” Thordon Bearings designs and manufactures a complete range of high-performance, long-lasting hydro-turbine bearing system designs that require no oil or grease, including turbine guide bearings, wicket gate and operating mechanism bearings, and radial or axial shaft seals.