Thordon Bearings Unveils New Water-lubricated Shaft Seal

Thordon Bearings has debuted a new propeller shaft seal for the commercial shipping industry featuring a unique Safe Return to Port (SRTP) design.

Completing the COMPAC open seawater lubricated propeller shaft bearing system, Thordon's new BlueWater Seal is described by the manufacturer as a cost effective, commercial grade axial lip seal specifically designed for merchant shipping fleets. It incorporates Thordon’s emergency SRTP capability, first used in the company’s TG100 and SeaThigor – designed for the workboat and specialized naval vessel markets respectively – representing the first SRTP seal designed for the merchant fleet.

“At first glance the Thordon BlueWater Seal may look like any other axial lip face seal out there,” said Thordon Bearings’ technical director, Anthony Hamilton. “But what makes this seal unique is its SRTP capability and revolutionary RENFORM main seal ring.”

This technology, developed in-house by chief research engineer Gary Ren, allows the facing elements of the seal to operate almost without any friction. In practical terms, it means the seal is much better suited to variable and low draught conditions, Thordon said.

According to Hamilton, “The BlueWater Seal meets growing market demand for a complete propeller shaft line solution from a single source. Although we can offer the seal as an individual component, it forms a fundamental part of the Thordon COMPAC open seawater lubricated propeller shaft bearing system.”

The COMPAC system includes Thordon’s proprietary seawater lubricated COMPAC bearings, shaft liners, ThorShield anti-corrosion shaft coating, a Thordon Water Quality Package, a Thordon Bearing Condition Monitoring System, and, now, the new BlueWater Seal.

The seal can be installed to all vessels with shaft diameters between 300mm to 1000mm (11.8in to 39.4in) and is simple to install, operate and maintain.

Having received class approvals from ABS, LR, DNV, BV and CCS, Thordon Bearings is now actively marketing the Thordon COMPAC system and BlueWater Seal in all commercial marine sectors.

During comparative trials on Thordon’s full-scale test rig in Burlington, Ontario, Canada, the seal operated without friction spikes and considerably less friction than similar seals leading to reduced wear, longer life and less maintenance.

“This seal minimizes water leakage and dramatically improves hydrodynamic and lubrication efficiency,” Hamilton said. “The development is a real boon to those ship owners and operators looking to adopt an open seawater lubricated shaft line arrangement as the entire propeller shaft line system can now be sourced from one company.”

Thordon’s SRTP technology, Scott Groves, Thordon Bearings’ VP Sales, said, “The introduction of our innovative seal technology to the wider shipping fleet means a seawater lubricated propeller shaft is not only environmentally cleaner but even safer for ship and crew. The seal incorporates a secondary Safe Return to Port emergency seal. This inflates in the event of damage to the, primary seal, allowing the shaft to continue to turn, allowing the vessel and crew to return safely to the nearest port. I believe the merchant fleet has never before had this capability.”

Craig Carter, VP Business Development, Thordon Bearings, said, “Although seawater lubrication is not a new technology, the BlueWater Seal very much is and fits perfectly with the International Maritime Organizations’ World Maritime theme for 2022: “new technologies for greener shipping”. It has also been designed in accordance with United Nations Sustainability Goal #14. Everything we do here at Thordon Bearings is geared to creating a zero-emission ship below the water line and ensuring our oceans are clean, free of any oil and grease.”