duction began in 1979, and the Lem- ington mine, which commenced coal- ing in 1971. Coal & Allied merged the Howick and Hunter Valley mines in 2000 to create Hunter Valley Operations
and included Lemington when it was acquired in 2001. The company will approximately produce between 10.5 and 13.5 Mt/y
.
In addition to the Hunter Valley Ope- rations, the Coal & Allied portfolio in- cludes the quite new Bengalla strip mine 4 km west of Muswellbrook and the integrated Mount Thorley Warkworth open cut mines 15 km southwest of Singleton.
Purchase factors
Dale Radnidge explained that there had been various reasons why Coal & Allied (C&A) wanted to buy the Pit Viper 275. For one thing, it would be fitted with the Cummins QSK 19 Tier 2 compliant en- gine that will meet the relevant Austra- lian environmental impact regulations for some time to come. C&A had good previous experience with the Pit Viper’s predecessor rig, the DM-M2, which was bought in 1995. This has always been a very cost effective machine for the company, with very good life cycle costs – despite the fact that the rig has had to operate for periods in
ambient temperatures of over 50° C. Dale had also had positive feedback from Pit Viper owners concerning the steps taken by Atlas Copco Drilling Solutions to improve features that had been weak points on the older rigs.
At the crunch, Atlas Copco quoted a competitive purchase price and the com- ponent life cycle costs were acceptable. Atlas Copco also offered to pro- vide a maintenance technician for 12 months: previously an Ingersoll-Rand Drilling Solutions rig owner himself, this technician has also helped the Atlas Copco team at Muswellbrook to iden- tify maintenance issues.
regulatory issues
However, life is not too simple for eq- uipment purchasers in Australia, espe- cially in New South Wales where the government guidelines on equipment specifications, primarily designed for machinery operating in coal mines, are the most stringent in Australia. Rio Tinto Coal Australia management also has very strict rules covering equipment specifications and it was necessary to
In the Hunter Valley, New South Wales, Coal and Allied Industries mines a multi-seam, multi-pit operation.
Coal mining in eastern Australia
hunter Valley
Shipping 260 million tonnes in 2008, Australia is the world’s larg- est exporter of black coal. Roughly one third comes from coalfields in New South Wales, two thirds from those in Queensland. Pit Viper 275 rigs are contributing to pro- duction from the Hunter Valley in New South Wales and the Bowen Basin in Queensland.
have the standard version of the PV-275 modified in a number of respects. Dale Radnidge, the maintenance electrician and maintenance fitters at HVO were involved and so was the unit’s produc- tion trainer.
The order was placed late in 2007, not too long after the AIMEX mining equipment show in Sydney, and Atlas Copco was able to deliver the PV-275 that had been displayed - in yellow and gray livery – to the Muswellbrook workshop.
C&A also ordered a new Atlas Copco DML rig that required rather more modification than the Pit Viper. Mr
Radnidge explained that a major aim of purchasing these two rigs was to start to create a unified fleet of different size drills with a common cabin design so that each operator can easily switch from one model to another when neces- sary. The DML rig has replaced an ex- isting competitor machine, whilst ano- ther elderly competitor machine had been put on stand-by when the PV-275 started work.
Modifications
The HVO maintenance team were able to inspect the Pit Viper at the Atlas Copco
workshop. They could therefore make recommendations as to the changes to be made in addition to those modifica- tions necessary for regulatory reasons. These additional alterations were in- tended to make it easier to maintain the PV-275.
Meeting NSW electrical equipment requirements necessitated taking out the whole electrical system and install- ing a different one. Some of the hydrau- lic system components also had to be changed.
operation
The mines presently use a walk meter and laser depth indicator in conjunction with mine survey data for drill positi- oning as the hardware needed to use the GPS system on the PV-275 is not in place yet. The DML has the Aquila sy- stem fitted for use with HVO’s Modular Mining Dispatch fleet management system. Dispatch is also being used to monitor the availabilities being achieved by the two new Atlas Copco drilling rigs. At the time of the visit, the Pit Viper was being used with five rods to drill 54 m holes in overburden for blasting and stripping by either dra- gline or shovel. However, the drilling requirements range from 10 – 60 m depth although the bulk of the benches are drilled with 30 – 40 m vertical holes. Hole size is 7⅞ in for coal and partings and 10⅝ in for overburden. Pre-split holes are drilled at either 10 m or 80 m spacing, in both cases at a 15° angle. Approximately 20 – 25% of drilling time is spent on the pre-splits. All nine drilling rigs working at HVO use Secoroc tools provided through a separate supply and service contract that has been in force for six years.
HVO has two Bucyrus International draglines (1 x 1370, 1 x 1570), six P&H electric shovels and a Terex-O&K RH70 hydraulic excavator. As well as the Atlas Copco drilling rigs there are six older ones from other manufacturers. Mr Radnidge explained that this mixed fleet was built up as a result of the merging of the mines that are now part of the Hunter Valley Operations. C&A has been using the maintenance plan- ning tools in the SAP software port- folio since May 2008.
The Coal and Allied Ltd Pit Viper 275 is fitted with a Cummins QSK 19 Tier 2 compliant engine. HVO Maintenance Supervisor Dale Radnidge (right) with Atlas Copco’s Rob Swan.
Summarizing, Dale Radnidge said that not only was the deal which Atlas Copco offered sound but the working relationship that C&A has established with the Atlas Copco team has been good too. C&A is comfortable with the purchase. Indeed, HVO had planned to buy two more rigs, which had been shipped to Australia. However, in the current economic climate this will not be possible during 2009.