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.
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.
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.
The ability to refurbish the roller bearings while the vessel was afloat saved time and money for the client, according to OPI.
“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,” said Malcolm Barratt, Thordon’s Regional Manager – Southern Europe & Gulf Med.
