Cost of rebuilding the machine was 40% of the cost of replacement.
The excavator is permanently mounted on a dredging ship working off the coast. The excavator’s undercarriage has been removed and its slew tower is directly mounted on the Norstone, a trailing suction hopper dredger. The Norstone works for Northwood Gravels, a subsidiary of Westminster Dredging, itself part of the Royal Boskalis Westminster Group.
Delivered in 2006, the Cat 330 hydraulic excavator had clocked up 4,335 hours of operation when the rebuild began. 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. The machine was removed from the ship and transported to Finning’s Halstead workshop in Essex to ensure no contamination in the rebuild environment.
For the engine, Finning opted for remanufactured fuel injectors, cylinder head and turbo, reconditioned sub-components and new gaskets and seals. Product updates were 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.
“The decision to have a complete hydraulic rebuild has proven the most cost-effective option for us,” says Mr Tudor. “At the moment the machine is operating perfectly.” What’s more, the company has the benefit of an as-new excavator for a fraction of the cost of a replacement.”
Although this was the first hydraulic rebuild Cat dealers worldwide have for years been offering Cat Certified Rebuild (CCR) and Cat Certified Powertrain (CPT) programs.
Finning usually carries out around 20 machine rebuilds each year, of which two thirds are dealer rebuilds and one third are Cat Certified Rebuilds. However, with the downturn in the industry in the UK, more customers have been opting to extend the life of their equipment to second life. This has led to Finning carrying out 14 Cat Certified Rebuilds in 2010, along with 16 dealer rebuilds.
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