UK company Finning accomplished two major firsts for a Caterpillar dealer when it was called in to help its customer Westminster Dredging: the first hydraulic system overhaul in Europe…and the first mounted on a dredger.
While the rebuild of a machine, or a powertrain, is popular among Cat dealers worldwide (under its Cat Certified Rebuild and the Cat Certified Powertrain programmes), a hydraulic system overhaul had never been attempted in Europe.
Under the new Cat Certified Hydraulic Rebuild (CHR) programme, Finning carried out the work on a Cat 330 medium-size hydraulic excavator that is permanently mounted on a dredging ship working off the coast of the UK.
The excavator’s undercarriage has been removed and its slew tower directly mounted on the Norstone, a trailing suction hopper dredger. The Norstone works for Northwood Gravels, a subsidiary of Westminster Dredging, part of the Royal Boskalis Westminster Group which runs more than maintains a fleet of 1,000 dredgers globally.
Delivered in 2006, the converted Cat 330 hydraulic excavator had clocked up 4,335 hours of operation when the rebuild commenced.
While that might not seem like a large number of hours for an excavator, the machine is working constantly in salt water, which takes its toll on hydraulic and electrical components. However it was not the machine that prompted the rebuild, but the fact that the ship itself was being removed from the water for its regular special survey, and would be in dry dock for some time.
Westminster’s technical superintendent Peter Tudor opted to carry out the Cat Certified Hydraulic Rebuild at the same time to prevent downtime in the future.
“We’d had a few niggling faults developing and it seemed like the perfect time to carry out the work,” he said.
As the machine has no track motors or lower hydraulic components, Finning developed a specific CHR programme for Westminster. The machine was removed from the ship and transported to Finning’s workshop. As parts were being delivered regularly over a six-week period, Caterpillar said it was essential to ensure contamination control in the rebuild environment, which would not have been possible on board the ship.
The dealer rebuilt the engine and complete hydraulic system, using the most cost-effective combination of new, remanufactured and reconditioned sub-components. For instance, for the engine the firm opted for remanufactured fuel injectors, cylinder head and turbo, reconditioned sub-components and new gaskets and seals. Product updates were also included to bring the Cat 330 up to date with the latest machines.
Although the excavator is used to discharge dredged materials from the ship, rather than actually digging below the waterline, there was corrosion on the rams that required more complex repair work to be carried out.
According to Cat, the rebuild totaled just 40 percent of the cost of a replacement machine, and “that’s without taking into account the lack of demand for a Cat 330 without an undercarriage on the used equipment market”.
In addition Finning was able to complete the work and refit the excavator on the ship within the time frame that the vessel was out of the water. Ordering a replacement excavator would have required a longer lead time, due to the unusual machine specification.
With the rebuild completed the excavator has now gone back to work, explained Tudor.
“The decision to have a complete hydraulic rebuild has proven the most cost-effective option for us,” said Tudor. “At the moment the machine is operating perfectly.”
