Tahmoor colliery in the New South Wales Hunter Valley will be the first Australian mine to switch to complete dependence on battery haulers instead of shuttle cars. Mine manager Peter Wyne said conveyors of short length and limited life were found to be no longer viable.
"An alternative was sought to enable the driving of relatively short development panels without the need to install a conveyor. Diesel coal haulers were initially trialed. These performed well enabling a panel over 600m long to be driven without a conveyor and at rates as good as previously achieved with cable shuttle cars," Wyne said.
Management and workforce concerns over emissions and increased maintenance however, were the impetus behind the decision to trial battery haulage.
"Experiences at some other mines had indicated that battery life and tyrefloor problems may be an issue so Long-Airdox Un-A-Haulers were hired for a six month assessment," Wyne said. "The trial proved highly successful with the haulers ultimately reaching to 850m from the conveyor, yet still achieving advance rates in excess of those of previous adjacent development panels. No problems with battery life or tyrefloor eventuated."
Wyne said the reasons for this were thought to be a combination of favourable Tahmoor mining conditions and improvements implemented by Long-Airdox as a result of previous experiences at other sites.
First introduced at AIMEX in 1996, Long-Airdox Australia has fully Australianised its basic US model CHA818 Un-A-Hauler for local conditions said Ray Chadwick, director - sales & marketing. Special revisions include wider tyres to cope with more rugged Australian conditions, electrical control system refinements and task-specific mechanical and hydraulic changes to meet particular applications.
"As we developed modifications to the machine these have been implemented on most of the existing machines in the field and on all subsequent machines supplied," Chadwick said.
Tahmoor has bought two CHA 818 Un-A-Haulers and will hire a further two, taking the number of operating Long-Airdox battery haulers in Australia to eleven. Other mines which are using the CHA818 are Cooranbong Colliery with three machines, and Newstan Colliery and Moonee Colliery each with two machines.
Adapting the vehicle for Australian mines has been a difficult process Chadwick said but was based on experience rather than conjecture or theory. Some of the advantages offered by the Un-A-Hauler are an increased carrying capacity and much greater flexibility and versatility with the elimination of trailing cables. Features of the CHA818 include full shift operation between battery changes and LA 2000 solid state control system.
Chadwick said the machines have proven to be extremely reliable in some of the most arduous roadway conditions to be found in the Australian coal mining industry. Availability consistently exceeds 98% in a wide range of operating conditions.
"Where mines have successfully experienced cable-less coal haulage systems they are reluctant to consider the traditional shuttle car with a trailing cable again," Chadwick said, but added that battery coal haulage systems are somewhat limited by the severity of roadway grades that they can handle although localised grades do not cause problems.
Wyne said principal benefits to date were the elimination of downtime and costs due to car cable faults, damages and changeouts; and elimination of the need to install a costly drivehead for a relatively short panel. Several shifts per week had been gained which were previously spent advancing the panel conveyor.
Long-Airdox Asia meanwhile has been successful in winning an order for the Chinese marketplace to provide twelve CHA 818 Un-A-Haulers, five 488 Un-A-Trac Scoops and three MFB feeder breakers as part of a comprehensive package of roadway development equipment. This order also includes one Full Dimension Continuous Haulage System, which will be the first continuous haulage system ever to be installed in China. The equipment will be manufactured and supplied from Long-Airdox's US factory at Pulaski, Virginia.