CATERPILLAR has claimed it has made a major breakthrough in excavator technology following the completion of long-term field trials of its Eco-Mate fuel-efficiency system for large excavators.
The trials confirmed Cat's forecasts of around 20 per cent fuel savings per hour, compared with standard machines.
The manufacturers said the development was especially significant at a time when the cost of fuel was rising faster than other machine costs.
Also, rather than impeding other machine functions, Cat engineers said they had managed to fine-tune the engine performance to give the machine 5 per cent faster cycle times.
The system, which uses accumulators to 'store'hydraulic pressure from boom movements, is only available as an option on Cat's 50-tonne 345B Series II excavator but the successful trial is set to see the technology rolled out to a wider range.
The Eco-Mate system works by means of high-pressure accumulators, which store the hydraulic pressure on each lowering of the excavator boom, then release it back into the hydraulic circuit as soon as the boom is lifted again.
This boost reduces the need for hydraulic flow from the excavator's main pumps, in turn reducing engine demand and thus fuel consumption.
Cat claimed this amounted to an increase in fuel efficiency of 25-30 per cent, which, when averaged out across all the excavator's activity, translates into fuel savings of around 20 per cent a year.
As well as the bonus of a faster cycle time, the system improves the durability of the hydraulic system by reducing the overall temperature and smoothing out pressure peaks.
The system is set to remain viable only for 30-tonne machines upwards, given the cost of the technology, but Cat says the initial outlay can be repaid in around 18 months, through the fuel saved.
Cat estimates that for a 60-tonne excavator the fuel use would be anywhere from 40-55 litres an hour. If a European excavator owner is running a machine for 2,0002,200 hours a year, it says the savings could be anywhere from £11,500 upwards per machine per year, depending on the application.
The only minor drawback appears to be that operators will have to learn to accommodate the smoother hydraulic action that results.
The manufacturer said: 'Customer feedback indicates that, once operators have become accustomed to the smoother hydraulic action and lower noise level, they will prefer to continue using machines equipped with the attachment.'