The ladder pump shaft, with a Vesconite Hilube bearing with round grooves visible. (Photo courtesy of Vesconite)

After Field Trial, Vesconite Hilube Bearings To Be Installed On Dredge

Vesconite Hilube no-swell, lubrication-free bearings will be installed as the ladder pump bearings on a dredge that is currently undergoing a major maintenance overhaul, the company announced recently.

This follows a field trial where the dredge owner installed the Vesconite Hilube bearings side-by-side with a competing elastomeric bearing material. The test started in May 2022, and the bearings were inspected in May 2023. It was found that Vesconite Hilube offers the same wear performance at a more affordable price.

The ladder pump bearings support the shaft that runs along the length of the ladder and drives the ladder pump. The ladder is the component that is lowered into the water and, at the end of it, sits the dredge cutter head, the piece of equipment that cuts into the sediment or rock. The ladder pump sits a little higher up, and the purpose of the ladder pump is to transport the sediment to the main dredge pumps, which are huge pumps that can move the sediment miles away.

Following the test, five large, double-flanged Vesconite Hilube split bearings will be fitted to support both 6-inch ladder pump shafts during this docking, the company said.

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“The dredging company tries not to take any dredge out of service for maintenance and repairs so, if the dredge is not on a job, the company replaces everything that would require replacement before the next maintenance interval instead of risking a failure during operation,” said Vesconite marine application engineer Monique Potgieter, noting that the bearings that were previously installed had to be replaced once a year and sometimes twice or three times a year when they were working in areas with heavy sand.

“Most of the bushings that support the ladder pump shaft operate submerged when the dredge is running except for the bearing closest to the motor (since it sits too high up on the ladder to be submerged),” she said.

“Each bearing has a flushing line that forces clean water through the bearings. Furthermore, these bearings operate in freshwater, seawater and wherever they have a job. Being fitted on a dredge, the Vesconite Hilube ladder bearings can be exposed to dirt and grit and suspended solids in the water, but the clean flushing water helps to limit the amount of dirt that gets into the bearings.”

As a next step in the dredging market, Vesconite Bearings plans to test the performance of a bearing material known as Hitemp150, which has proven to fare well in pump applications with abrasive mediums, in applications like cutter head bearings.