BHP Billiton Illawarra Coal awarded Joy Mining Machinery the contract for the new longwall mining system for delivery in December 2003 to West Cliff Colliery, located in the Southern Coal Field.
The Joy system was chosen based on a reduction in seam height from 3m to 2.7m. The mine also aimed to increase longwall capacity to 3 million tonnes per annum with the ability to produce at 2,500 tonnes per hour at an average of 2,000tph. The panel width will also be increased to 300m, from 250m, when the face gets up and running, expected to be in June/July 2004.
Prior to being shipped to Australia, the equipment underwent compatibility trials at Joy's UK facility and was recently delivered to the mine site for a mini-build and operator training.
The total Joy package includes 170 two-leg 1,000t supports, 1.75m wide with a minimum closed height of 1800mm and a maximum extension of 3300mm. Working range is between 2.4m to 3m.
The armored face conveyor is driven by an L1000 BP gearbox on the tailgate and an L1000 EP gearbox on the maingate for a combined continuous rating of 1710kW and a capacity of 2,945tph. The AFC features Turbo Transmission Technology (TTT) soft start drainable couplings. The pans are 1756mm width 1100mm raceway, the chain is Parsons 48mm twin centre strand, and Joy forged flight bars are used.
The beam stage loader is rated at 3,522tph with a continuous rating of 375kW and fitted with a 34mm chain. The 3,000tph rotary impact crusher has a continuous rating of 375kW.
The mine's existing 4LS5 shearer has been upgraded to 3300 volt JNA headgate control system, J525 ranging arms, and Ultratrack 2000 haulage. It will operate alternately with the original Joy 4LS5 exchange machine.
Joy Australia managing director, Mark Finlay said the mini-build had gone very well: "The Joy Global project management team, involved from the early stages of the bid process, have been instrumental in taking this project from the mandatory drawing stage right through to the Minibuild. The joint BHPB Illawarra Coal and Joy project teams have ensured that when over 5000T of equipment arrived at Westcliff, the minibuild has come together very well.”
Colin Merriman, Joy business manager – longwalls, said the system would give the mine consistent production and improved roof control. At present the West Cliff face has several types of roof supports all rated differently, making management of the roof challenging.
"This is the highest capacity face at 1000t, the longest at 300m, has the highest installed power at 2 x 855kw on the AFC, and 48mm chain. It's certainly the biggest and bravest on the south coast," Merriman said.
