Grupo Servicios Maritimos, an Argentinian company with maritime, inland waterways and port activity operations, found excessive tailshaft wear was being experienced on some vessels operating conventional rubber bearings in a mix of sea, brackish, muddy, and fresh waters.
The company, which operates a fleet of 10 tugs, two container feeders and six pilot/service launches, as well as barges, looked for an alternative solution. In October 2020, it contacted Thordon Bearings’ authorized distributor in Argentina, Marine Logistics SA, with a request to install Thordon’s robust, low maintenance water-lubricated RiverTough tailshaft bearings to the 1975-built push boat Candela S.
The Tandanor Shipyard in Buenos Aries completed the work to the 44.7 meter (147 foot) long, vessel in December 2020.
“Being an old boat, this did not appear to be a simple installation,” says Marine Logistics’ Hernan Lopez. “The 303-mm (12-inch) diameter tailshaft and rubber bearing were both showing considerable wear, along with excessive bearing clearances. Another problem was that the shaft liner was a different diameter from that shown on the drawings.
“Fortunately, Thordon materials can be easily machined to adapt to multiple shaft and housing sizes, whereas conventional materials would encounter difficulties when faced with this issue. The RiverTough tailshaft bearings were installed successfully—and quickly!”
Impressed by the attention to detail shown by Marine Logistics and Egnard Bernal, Thordon’s Business Development Manager for Latin America, Grupo Servicios Maritimos decided to include Thordon SXL rudder bearings and Thordon Pucker Seals on the purchase order.
“The owner will save money in the long run because the Thordon material can be machined to suit multiple shaft diameter sizes,” says Bernal. “This makes ordering and the installation much simpler. Additionally, the long lifecycle of the Thordon material reduces the need for frequent drydockings for bearing and seal replacement, which reduces the operating costs considerably for the vessel owner.”
RiverTough tailshaft bearings, run in combination with hard coated nickel-chrome-boron (NCB) shaft sleeves, routinely outlast rubber bearings by a factor of two or more in the abrasive water conditions encountered on South American waterways.
“The elastomeric polymer material pioneered by Thordon offers increased resilience compared to rubber bearings, resulting in easier alignment and less edge loading,” says Bernal. “For repair applications where the housing bore condition may be less than ideal, water lubricated RiverTough bearings can be bonded in place using an approved adhesive.”
Thordon SXL rudder bearings, meanwhile, operate without grease, above and below the waterline. SXL offers high abrasion resistance and can also withstand high shock loads, improving the wear life of the bearing.
Similarly, the Thordon Pucker Seal, is manufactured from a tough self-lubricating polymer, designed to keep out abrasives such as sand and grit from the rudder trunk.