Comeau Marine’s 600t capacity railway, one of Nova Scotia’s oldest patent slips, operates year-round to maintain and service much of the inshore fishing fleet as well as the fishing fleet of parent company Comeau’s Sea Foods Ltd.
“The patent slip, or marine railroad, a cost-effective alternative to a conventional drydock or synchrolift, uses a large cradle on rolling stock to hoist ships out of the water on an inclined railroad,” said said Thom Hofmann, president of Avalon Marine, Nova Scotia-based distributor of Thordon Bearings.
“For the past 40 years the railroad has used all types of bearings including phenolics, bronze, Lubrite, but as far as I can tell the yard’s best success has been with ThorPlas-Blue. “
Thordon’s XL and SXL bearings were also used in this application, but in 2018 Comeau made the decision to install 110 mm (4.3 in) diameter ThorPlas-Blue bearings in critical areas of the wheels to high load of the ship’s cradle.
“After inspecting several wheels and examining the operation of the ship’s winch, we learned that two ships were regularly loaded at the same time,” Hofmann said. “This meant that all the load capacity was concentrated in a longitudinally central section of the cradle, which required the use of extreme performance bearing materials.
“Performance was further enhanced by the fact that the Marine Railway, which operates year-round, is located in the Bay of Fundy, an area of Nova Scotia’s southwest coast known for its extremely high tides. high. A large amount of abrasive sand and sediment frequently poured into the estuary and eventually coated the tracks and wheels.
Hofmann added: “While the first XL and SXL bearings performed as well as expected, the cradle needed something sturdier. We considered a number of Thordon options and after considering the business implications the owners chose to use ThorPlas-Blue material as it was the best option.
Avalon designed the bearings and supplied the material as raw cast tubes so the shipyard could quickly and easily machine and install the bearings between the dry docks.
Joe MacDougall, General Manager, Comeau Marine Railway, accompanied by his assistant, Brian Amirault, said: “We haven’t had any problems yet, everything is fine. ThorPlas-Blue has been in use for a few years and so far the material has not failed despite uneven loads, sand and debris. »
The success of the bearings is largely the result of Avalon’s initial engineering. Access to this superior bearing material has allowed Comeau to improve bearing wear rates and reduce maintenance time and costs, while dramatically improving yard performance.
Scott Groves, Vice President of Sales for Thordon Bearings, added, “It is not uncommon for Thordon’s proprietary polymer bearings to be used in this type of application and other ship repair yard installations, such as dock doors, water pumps and cranes, largely due to the material’s ability to withstand extreme loads and abrasion.
ThorPlas-Blue is a self-lubricating polymer bearing capable of withstanding operating pressures up to 45 MPa (6,527 psi) installed in a complete interference fit configuration. ThorPlas-Blue does not require lubrication to ensure proper operation. Lubricants formulated in the homogeneous polymer matrix ThorPlas-Blue guarantee a low and stable coefficient of friction, even when the bearing wears.