Cost per tonne deal for tyres

Investing in new tyres is an expensive business but an offer of a guaranteed cost per tonne of operation convinced Stoneycombe Quarry to part with its cash. Claire Symes reports

While the time it takes to procure new tyres in Europe may no longer be an issue now the tyre shortage of recent years has been resolved, the high cost of replacement remains. Nonetheless, most quarries know that buying a quality tyre will provide better results in terms of not just traction and productivity on the quarry floor but also when it comes to service life.

Guarantees from the manufacturer of the higher performance available from upgrading tyres are not something that is common across the quarry industry. But it was exactly this promise that gave 3734 Bardon Aggregates' Stoneycombe Quarry in Devon, UK the confidence to invest.

Earlier this year the quarry had 449 Michelin's latest XHA2 tyres fitted all round to its 395 Caterpillar 972 wheeled loader which plays a key role in loading material directly from the screening operations.

The old tyres delivered 5000 hours of service and Wiltshire was pleased with that. The new XHA2 tyres were fitted to the loader in April and have now delivered several hundred hours of service and the operator has reported that they provide a better level of comfort with less vibration.

Stoneycombe Quarry is a busy site located in Newton Abbott and extracts around 280,000tonnes of Devonian Limestone for the construction market each year. There are records of a quarry at the site dating back to the 1850s but it was in the 1920s and 30s that quarrying activity there became established when the site was connected to the main railway network and used to produce rail ballast. Today concrete and asphalt are the main industries which use material from Stoneycombe.

The limestone is extracted by drill and blast techniques and crushed and screened in the quarry by a fleet of mobile crushing and screening equipment.

"We achieve a blasting ratio of 6tonnes per kilogram and the raw material is loaded at the face by a 436 Komatsu WA500 wheeled loader which feeds a Metso Minerals Lokotrack LT14, which is fitted with an S-module to provide pre-screening of the products," explained Bardon Aggregates quarry manager Brian Wiltshire. "The feed material is reduced to 40mm down by this stage." Screened material is moved by a Caterpillar 972 wheeled loader and this is the machine that is benefitting from Michelin's price promise. "The old tyres had worn and the advice from Michelin was to use the new XHA2 tyres on this machine rather than replace them with the same Michelin tyres that it had previously," said Wiltshire. "The company guaranteed that the tyres would offer a lower cost per tonne than the previous ones which gave us the confidence to trial them." The old tyres delivered 5000 hours of service and Wiltshire was pleased with that. The new XHA2 tyres were fitted to the loader in April and have now delivered several hundred hours of service and the operator has reported that they provide a better level of comfort with less vibration.

"So far the wear appears to be as good as - if not better - than the previous tyres," said Wiltshire. "The ground conditions here are not as challenging as some quarrying applications but we are pleased with the results so far." According to Wiltshire, the quarry had used Michelin tyres in the past but this is the first time the company has needed to invest in all-round replacement of tyres as most of the machines are still relatively new. "The support from Michelin has been good," he said. "The local rep worked closely with us and the operator to make sure we get the best from the investment.

"Our Cat 972 operator is experienced and this is clear from having managed to get 5000 hours of operation from the last set of tyres - this comes partly from the design but also from how the machine is used day in, day out."