In the early 1960s exploration teams in the Hamersley Ranges depended upon pedal radio via the Royal Flying Doctor network for communications. At the start of construction in 1965 HF radio was used between Dampier, Mount Tom Price and Perth with a full time operator required at each location. Later automatic PABX systems provided a company network with restricted and oft times difficult access via two VHF radio links to the public telephone network. This was superseded by the extension to Dampier of the Perth/Carnarvon co-axial cable which in addition to improved telex and telephone services brought national TV to the town. A tropospheric scatter system connected Mount Tom Price (and Paraburdoo) to the national network. Later with the advent of microwave technology communications between the minesites and the coast were further upgraded.

With the increasing demand for data transmission between all sites and head office, PABX obsolescence and improving technology, the latest in communications systems viz. digital SPC (stored program controlled) PABX units which can switch both voice and data were installed in the Hamersley operation in 1987. Together with Telecom's expanding national digital network the Hamersley facility will provide one of the largest and most modern company systems capable of providing efficient and flexible communications into the foreseeable future.

The example of changes in haul truck technology is no less impressive. The major haul units at the Mount Tom Price mine in 1965 were the largest and latest 'state of the art' 100 short ton articulated 3-axle, ten wheeled mechanical drive 700 HP (520 kW) diesel engined trucks -behemoths of the day! The latest trucks introduced to the Paraburdoo fleet in late 1986 are 212 short ton, 2-axle, six wheeled, 2000 HP (1500 kW) diesel electric (electric wheel) units.

Restrictions on size of the early trucks included

tyre technology

engine capacity

structural integrity and

user acceptance of large units

Tyre technology improved at a rapid rate and as early as 1972 manufacturers were offering 200 short ton units mounted on six tyres. The development has continued to ensure that tyre life is no longer compromised by heat build up in the high ambient temperature and rigorous haulage conditions experienced in the Pilbara.

The use of 'electric wheel' transmission, increased capacity dynamic braking systems, solid state circuitry and an on-board computer to monitor loads, log general performance factors and provide maintenance diagnostic information, have all resulted from improved and new technology and result in easier maintenance, more efficient and better controlled, lower cost operations. The latest trucks in the Hamersley fleet are effectively custom made for the local conditions and applications.

Similar developments are evident in other major pit equipment including drills (i.e. change from 230 mm down hole hammer drills in the 1960s to 380 mm rotary percussion units virtually capable of automatic operation), shovels (diesel electric in 1966 to all electric modern units in the 1980s), front end loaders, graders, bulldozers and so on.

The use of high speed cameras to photograph blasting operations to enable the analysis of blast dynamics has led to more efficient use of explosives, drill hole spacings and better rock fragmentation. Modern explosive emulsions enhance the effects of the simple ANFO (ammonium nitrate/fuel oil) mixtures.

Australian Academy of Technological Sciences and Engineering