NEWMAN, WESTERN AUSTRALIA
IF there were any man-made structure that could begin to capture the atmosphere of the Grand Canyon, the Newman mine in northeastern Australia would probably be it. Against a flat landscape of parched bush, the sides of the deep open-cut mine rise up in giant steps to form steep red-brown terracing, like the walls of some huge ziggurat. Each terrace is 15 metres deep and dwarfs the steady stream of dump trucks crawling past, each one bearing more than 200 tonnes of iron ore away towards the stockpiles. The trucks in turn dwarf the few humans that wander the site 鈥 the vehicle tyres alone are more than 2 metres tall. In the distance the long terraced lines of the mine curve around, following the contours of the surrounding hills, and disappear.
All of the statistics for this mine are incomparable. From this one site comes 3.5 per cent of the whole world鈥檚 production of iron ore. The richest deposit is 5 kilometres long, 2 kilometres wide and several hundred metres thick 鈥 to exploit it all, the main pit will eventually be sunk around 370 metres. And there are many more deposits besides this one 鈥 close to 40 at the last count 鈥 in a surrounding 300 square kilometres.
BHP, the company that owns the mine, says that there is an insatiable demand for its iron ore. The year to the end of May set a new record: Newman produced 35.3 million tonnes of ore. But the most astonishing thing about this mine is not immediately obvious 鈥 every last tonne of its ore must be shipped out to the coast, 400 kilometres away as the crow flies, across inhospitable, sparsely inhabited terrain.
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鈥淭oo far from the coast,鈥 said the mining companies when the ore was discovered in the early 1960s. Eventually, however, the lure of one of the world鈥檚 richest iron ore deposits proved too great. The company鈥檚 426 kilometres of standard-gauge track, linking Newman with Port Hedland on the north coast, was completed within 8 months by January 1969, the longest privately owned railway in Australia.
Now, the line carries 150 000 tonnes of ore to the coast every day. The line has to be open at all times: even a day鈥檚 closure could cost A$5 million in lost revenue. The job of making sure that the trains never have to stop falls to a team of troubleshooters. One of them is Phil Stewart, and a ride with him to see the line is something special.
His Toyota Landcruiser looks much like any other of the 200 road vehicles that serve the Newman mine. But looks deceive, as Stewart soon demonstrates. He drives onto the level crossing, aligns the Toyota鈥檚 wheels with the tracks, and presses a switch next to the driver鈥檚 seat. Underneath the car a hydraulic arm unfolds a steel frame carrying a set of mini train wheels. They descend onto the track, ahead of the vehicle鈥檚 two front tyres, and the Landcruiser is off down the line, moving at 80 kilometres an hour through the bush. Termite mounds line the track, emus stand watching, and young kangaroos race the car. It鈥檚 a thrilling sensation, riding a road vehicle on a railway through the vast open spaces of the bush 鈥 even when there is no trouble to shoot.
But often enough, there鈥檚 plenty. In the semi-arid territory the heat can be intense. Marble Bar, about halfway between Newman and Port Hedland, is one of the world鈥檚 hottest places 鈥 the town has recorded a temperature of more than 38 掳C on 162 consecutive days. Stewart has endless tales to tell of buckled track and derailed trains, of long days and spoiled dinners.
Long haul
The trains are on a scale that makes the 8.20 to Waterloo look like a toy tram. Each train is 2.6 kilometres long, made up of 240 trucks or 鈥渙re cars鈥 carrying more than 100 tonnes of ore apiece. Four huge 4000-horsepower diesel- electric locomotives are needed to haul them 鈥 that鈥檚 a combined power of 12 megawatts, enough to supply a small town. Such massive traction and braking power has to be distributed along the train. Two locos are harnessed as a set or 鈥渃onsist鈥 at the front, with the other two in the middle. It鈥檚 important that the two consists perform in unison, accelerating and braking together, to minimise wear and tear of the trucks between them.
To achieve this, the consists are equipped with computers that monitor and control their operations, feeding instructions by radio from the lead consist at the front of the train to the 鈥渟lave鈥 consist in the middle. 鈥淭hey鈥檙e extremely smart locos,鈥 explains Mal Roberts, a senior engineer for the railway. He foresees the day when there鈥檒l be no humans on the train at all.
On a good day, the journey to Port Hedland with 25 000 tonnes of ore aboard takes just six and a half hours. On a bad one, much longer. BHP鈥檚 contingency plans allow for a cyclone to knock out the railway system for a fortnight. Delays of an hour or two are more common, when buckled tracks throw a few wheels off the line. The alarm is raised automatically. As displaced ore cars are dragged along by the train鈥檚 momentum they smash soft iron bars jutting out from the track, breaking electrical circuits.
Preventive care is the philosophy, however. Maintenance crews spend their days travelling the line, checking on the condition of the sleepers, tamping the ballast and grinding the track back into shape. Infrared detectors in the track monitor the temperature of the ore cars wheels as they pass, to check whether they鈥檙e running smoothly. To avoid such problems as far as possible, the wheels are regularly reprofiled in the workshop at Port Hedland. 鈥淭hey鈥檒l come back for turning eight or nine times,鈥 says Bill Walker, the railroad manager. Turning them on a lathe eventually reduces their diameter from 960 millimetres to a minimum of 885 millimetres, giving them a working life of about 1.5 million kilometres, the equivalent of almost 1800 return trips to Newman.
But preventive care can do little to contain the natural intruders that hamper the railway鈥檚 operations. Kangaroos and cattle often stray too close, and carcasses litter the line. 鈥淪chool holidays can be a worrying time,鈥 says Stewart. Newman has become a thriving tourist centre. As many as 30 000 visitors a year drive off the Great Northern Highway, attracted by the chance to take a coach trip round the mine.
The mine works 24 hours a day, seven days a week. Once every couple of days an explosion blasts a slice from the opencast pit to yield around 2 million tonnes of spoil for the shovels and dump trucks to clear up. Trains returning empty from Port Hedland run under chutes that fill 13 ore cars at a time.
Rich reserves
All but 30 kilometres of the trip are downhill and, according to BHP, the route has been chosen to run near other untapped iron ore deposits. The region, known as the Pilbara, is estimated to hold nearly 40 billion tonnes of iron ore. The principal deposit at Newman, Mount Whaleback, has been mined for 25 years. It鈥檚 a bluey-brown ore known as Brockman, which contains a high ratio of iron, 63.5 per cent on average.
More than 850 million tonnes of Brockman are still waiting to be dug out from Mount Whaleback, making the site good for another 30 years according, to Mal Kneeshaw, BHP鈥檚 chief geologist. Kneeshaw鈥檚 first job on arriving in Australia in 1966 as an immigrant from England was to confirm whether the deposit was worth exploiting. He hasn鈥檛 looked back since. Lower-grade ore from 鈥渟atellite鈥 deposits around Mount Whaleback are mix-and-matched with the richer material to produce an overall grade that meets a client鈥檚 specification.
Much of the mixing is done at Newman. Further crushing and screening take place at Port Hedland, where BHP staff are responsible for the final quality control. The 300-hectare site at Nelson Point is a dense network of conveyor belts carrying ore from below the tipping shed 鈥 where ore cars are unloaded three at a time by being turned upside down 鈥 to the stockpiles of different grades.
From there the ore is loaded into bulk carriers, ships that typically carry 150 000 tonnes and take 36 hours to load. The largest vessel ever to dock at Nelson Point left with 255 000 tonnes of ore. Before the vessel was loaded at the dockside, recalls one worker, 鈥渋t was like looking up at a wall of steel.鈥
The biggest customers are the steelmakers of Japan. But more and more Korean and Chinese manufacturers are looking to the Pilbara for their raw material. And many come to see for themselves the slender steel lifeline that keeps the operation running.
OLYMPIC DAM, SOUTH AUSTRALIA
SITTING alone in the changing room, it can all seem a little extreme. You must strip stark naked before going down the mine, they insist, and put on clean overalls. When you come back up, you must go straight into the shower. Then it鈥檚 time for a quick check with the Geiger counter, handily placed next to the mirror, so that you can be sure you鈥檝e washed away every particle of radioactive dust.
This is Olympic Dam, an oasis in the outback of South Australia, about 560 kilometres northwest of Adelaide. The incongruous name came from the pioneering owner of a local sheep station who drilled the first borehole for water in 1956, the year the Olympics came to Melbourne. Now it鈥檚 home to one of Australia鈥檚 most unusual, and controversial, mines.
Unusual, because of the composition and size of the deposit. There are rich reserves of uranium, copper, gold and silver, enough to keep the mine in business for 200 years: 鈥淏ut we don鈥檛 fully understand why these four metals have formed together,鈥 says Rob Smith, chief geologist on site for Western Mining, which owns the mine. And controversial, because the most abundant metal is uranium; there鈥檚 so much of it that the site鈥檚 reserves are reckoned to be the largest in the world. Mining uranium can be a dangerous business 鈥 which is why the showers provide Geiger counters.
Jim Hondros manages a team of 35 people responsible for the health and safety of the site鈥檚 850 employees and its surrounding environment. Underground, he says, the main problem is the particles of radioactive dust. On the surface, they have to worry about exhaust from the mine鈥檚 huge ventilation shafts and about the material left over after the ore has been processed, both of which are contaminated with radioactive particles. Much of the waste can go back underground, but the remainder, mostly in the form of an ugly black slurry, is stored on site.
Every month, more than a thousand air samples from fifty or so monitoring points above and below ground provide a measure of the radiation levels. Regular training sessions are designed to educate the workforce about the hazards. 鈥淲e鈥檙e very open with information,鈥 says Hondros, 鈥渂ut we can鈥檛 give everyone a three-year degree in nuclear science.鈥
Recovering the ore has set technical challenges for the project鈥檚 engineers too. The reserves lie more than 350 metres below the ground, and are distributed over an area covering around 15 square kilometres. There鈥檚 at least 500 million tonnes of ore to bring out 鈥 possibly four times that amount. Miners work on 30 or 40 headings 鈥 drilling and blasting their way into six huge masses of rock at any one time. These stopes, as they are known, can be as big as 40-storey tower blocks.
To reach them, you drive into the mouth of the mine and down an access tunnel with a steep 1 in 9 gradient. Four kilometres down the road, with lay- bys every 100 metres or so for passing traffic, you鈥檙e below the sedimentary rock and into the ore reserves. The main road now branches into an intricate network of tunnels providing more than 70 kilometres of access way to the headings for drilling rigs and dump trucks, and for the crews of miners.
The underground workings are immediately impressive, but the mine鈥檚 most remarkable feature takes a practised eye to spot. Back above ground and only a few minutes ride from the mine entrance, stacks of pure copper sheets lie glinting in the sun. Pure metal is not actually what you expect to see at a mine. At Olympic Dam, however, an entire processing plant has been built to sit at the mine entrance. Grinding mills in huge revolving tubs lie alongside giant vats covered with a frothy black scum of copper sulphide or leaking a green liquor containing uranium particles into collection trays. Large pipes skirt the walkways feeding steel sheds housing filters, furnaces and electrochemical plant for extracting the last ounce of metal from the ore, and purifying it.
Not even Australia鈥檚 biggest copper producer, the giant Mount Isa mine in northwest Queensland, boasts its own on-site copper smelter and refinery. Processing the ore at Olympic Dam begins immediately, at an average rate of 320 tonnes an hour, 24 hours a day. The metallurgical production line is set up so that silver, gold and uranium oxide are extracted at different stages of the process. But it is only copper that is left out on display; the silver and gold recovered during the electrorefining of the copper are purified behind closed doors, and it鈥檚 not easy to get close to the final processing plant for uranium.
KIMBERLEY, NORTHERN TERRITORY
THEY call it the world鈥檚 longest commute. That鈥檚 the 4500-kilometre return trip from Perth to Argyle, a remote spot in the hills of the Kimberley region of northern Western Australia. It鈥檚 a way of life for more than 600 people working on the world鈥檚 largest diamond mine. Every fortnight, two shifts switch over.
Argyle Diamonds, the company which runs the mine, also has around 60 staff in Kununurra, the town nearest to the mine. For them the daily commute is a mere 110 kllometres in a small plane that takes them across some of Australia鈥檚 most spectacular scenery. The company鈥檚 flight costs are staggering 鈥 it charters around 40 000 seats a year between Kununurra and the mine, and another 18 000 seats between the mine and Perth. Why rely on commuting? 鈥淲e didn鈥檛 want to build any mining towns,鈥 explains John McGagh, Argyle Diamonds鈥 principal business adviser. 鈥淵ou tend to end up with a range of social problems.鈥 Alcoholism, of course, is the one everyone talks about.
The mine itself is tucked in a ridge of the Kimberley region. Its 鈥渟outhern tail鈥 is a giant amphitheatre that opens out into the 鈥渘orthern bowl鈥 at the other end. Bucket loaders hog the action, scooping up material loosened by blasting, and filling a train of dump trucks. Slowly, full trucks move towards a terminal where they tip their material into the funnel of the site鈥檚 first crushing plant, which feeds a conveyor belt carrying the broken spoil to a huge stockpile below.
Since the mine opened in 1985, the annual production of diamonds has risen to more than 40 million carats (8 tonnes), or around a third of the world鈥檚 supply of natural diamonds. But the treasure is hard won. To retrieve those 8 tonnes, Argyle Diamonds must excavate more than 40 million tonnes of material, and then process at least 8 million tonnes of diamond-bearing ore buried in that spoil. Over the 20 years of the mine鈥檚 expected working life, McGagh explains, the company will retrieve about 120 tonnes of diamonds, of which 6 tonnes will have provided half the revenue.
To succeed in the treasure hunt, you have to increase the ratio of diamond to ore in the mixture until you鈥檙e left with only precious stones. Material is run on conveyor belts through a mechanical network of crushers and scrubbers, filter screens and centrifugal separators, X-ray sorters and chemical cleaners. The sorters make the final choice, and their detailed design is a closely guarded industrial secret, says Bill Hutton, the mine鈥檚 senior metallurgist. They consist of a fast-moving conveyor belt that accepts a stream of the material at one end, and runs it under three separate devices at the other end: an X-ray beam, a light meter and a tube for blowing air through. The X-ray beam causes only diamonds in the stream to fluoresce; when this happens, the light meter detects it and turns on the air blower. Instead of flying off the end of the conveyor belt into a waste bin with the rubbish, the diamonds are blown into another collection tray.
With all this effort, you might expect to see stockpiles of glittering diamonds on site or, at the every least, the odd diamond glinting from processed ore. But there鈥檚 none of that. Just huge mounds of brown lamproite, the igneous ore, waiting to be processed. It鈥檚 not until the material arrives at the X-ray sorters and chemical cleaners that anything approaching the appearance of a diamond might be evident. But that equipment is locked away and shielded from view in steel sheds. Only selected personnel can enter these domains, and even they must be accompanied by a security guard, or two.
Security conscious
Security is a serious matter on site 鈥 the guard in the fortified gatehouse makes that absolutely clear before letting you through in the first place. He warns that he may want to strip-search you before you leave, and he鈥檚 not kidding. There鈥檚 a special act of Parliament enshrining these exceptional powers. He also advises you to have a chaperon on site at all times 鈥 staff are told 鈥渘ever work alone鈥. And don鈥檛 even consider picking up anything from the ground, he says; just being seen bending over and peering at one spot for too long could well raise the alarm. If you think you鈥檝e found a wayward diamond, simply mark the spot and call a guard.
Why then do you see so many people wearing gemstones set in rings on their fingers or as studs through their ears? That turns out to be because staff get the chance to buy cut and polished diamonds at a 50 per cent discount on shop prices. A reward no doubt well earned: shifts last 12 hours a day, seven days a week, and often there鈥檚 only time for 鈥渨orking, eating and sleeping鈥, says McGagh.
His principal mission on site is to find ways of streamlining the operation so that, one day, the mine can be run with many fewer people. Soon anyone who doesn鈥檛 need to be on site to do their job or, as McGagh puts it, 鈥渨ho doesn鈥檛 pass the muddy-boot test,鈥 will be shifted to the company鈥檚 head office in Perth. 鈥淲e could run our processing plant from a PC in Perth,鈥 he suggests. In five years, he predicts, the dump trucks won鈥檛 use human drivers, they鈥檒l be robotic And that may be the end of commuter mining.
