Mexican Navy contracts Thordon Bearings to reduce waterjet impeller cavitation damage

Canada’s Thordon Bearings has secured a second major Mexican Navy contract for the supply of its water-lubricated SXL wear rings for retrofit installation to the waterjet propulsion nozzles on 25 interceptor patrol vessels.

The contract follows the success of extensive trials in which the SXL material replaced the use of other anti-corrosive coatings in waterjet impeller housings, resulting in increased resistance to cavitation-induced corrosion.

Rotary Parts, Thordon’s authorized distributor in Mexico, is supplying the housings for 25 Polaris and Polaris II fast patrol boats.

The scope of supply is for 440mm (15.8in) outside diameter, 160mm (6.3in) long SXL wear rings for each impeller housing. Installation is taking place during routine drydocking at various Mexican Navy sites along both the Pacific and Gulf coasts.

“We received an initial contract in May 2023 for 50 SXL wear rings and this has now been followed by a second contract for another 75 units,” said William Lugardo, Thordon Specialist at Rotary Parts.

“As soon as the main contract was confirmed, we began with the impeller housing repairs to ensure the optimum surface area prior to machining Thordon SXL material. We have completed the first batch of SXL wear ring installations and now working on the second.”

Lugardo explained Rotary Parts recommended the use of the SXL material to replace the coating system of the impeller housing to better protect the surface area against corrosion and propeller cavitation. Typically, the inner housing of a waterjet impeller needs a re-coat every three months to maintain propulsion efficiency.

“They tried using different types of coatings but without success,” he said.

Tests carried out before contract signing demonstrated the longevity of Thordon’s water-lubricated polymer technology, Lugardo furthered.

“The Thordon material did not show any wear or damage. And a year after the first tests, it is still resisting cavitation and has improved waterjet efficiency for these vessels. The material better protects not only the propeller housing but also propeller blades and tips, potentially reducing the overall waterjet maintenance spend.”

“Thordon Bearings is a major supplier of advanced polymer solutions to the Mexican Navy but this is the first time our advanced SXL material has been used to replace costly anti-corrosion coatings in waterjet vessels. We were delighted the trials have been successful. Winning this order is confirmation of Naval Secretariat SEMAR’s continued confidence in Thordon Bearings’ proprietary technology,” Jeffrey Butt, Thordon Bearings’ Business Development Manager, Navy & Coast Guard, said.

The contract is to date Thordon Bearings’ largest marine contract in Mexico in 2023 and the Canadian company is hopeful of securing further orders for the same application in 2024.