Big Boys, Big Toys and Big Holes

Today was all about Newman, and Newman is all about mining iron ore. And mining iron ore is all about digging big holes in the ground and getting the stuff out as quickly as possible.

So if you are in a hurry, you do things on a big scale, and the scale does not come much bigger than iron ore mining around Newman. The iron ore comes from Mount Whaleback. Except that Mt Whaleback is not the mountain it used to be, and by the time they have finished it will be a big hole filled with water. But they won’t have finished digging the hole for another 60 years or so.

  The official mine tour is the only way to see the mine, and really it is just a trip to the lookout overlooking the mine, with a bit of a guided commentary along the way. You need to use your imagination a little bit, because the lookout is the highest thing around, and when they started, Mt Whaleback, named because it was long like the back of a humpback whale, was 150m or so higher than where you stand at the lookout. From there you look down into a pit 250m metres deep. By the time they have finished, the pit will be 1km wider and over 200m deeper than it is now. There is a little bit of overburden, but as our guide said, the ore is such a high grade that there are many mines in the world that would be happy to have our overburden as ore.

Each one of the 15m high steps seen in the photo below is created by grilling a grid pattern of holes 15m deep, and backfilling with ANFO (ammonium nitrate and fuel oil, or diesel made famous by the Oklahoma bomber if I remember correctly), before lighting the blue touch paper and running. All that is left then is to clean up the mess with loaders and trucks and take the product away to the crushers. The drill hole is seen in the photo above.

So we are talking a hole in the ground currently 5km long, 1.5 wide and around 250m deep, which will probably double in every dimension over the next 60 years. Since they are already below the water table, pumping is a continuous operation, and when mining ceases, the filling of the pit will take place naturally from the artesian aquifer.That is the big hole.

The big toys came early in the day. The visitor centre in Newman is easily spotted by one of the original ore trucks. There were only 30 of these built in the world, and 22 of them came to Newman where they ran for about 20 years. They have 6 wheels, each rated at 60 tonnes, costing $30000 each. They last for around 9-12 months. Each truck works continuously at two, 12 hour shifts per day, every day of the year, travelling about 1000km a day, consuming around 4000 litres of diesel. When fully loaded each truck weighs around 100 tons more than the takeoff weight of a 747, and lumbers along at a maximum speed of 60km/h. They are a cross between a lawn mower and a locomotive in the powertrain, having a 12 cylinder, 128litre two stroke diesel engine delivering around 2500hp to a DC traction engine, which can also provide braking.

Next time I complain about the cost of feeding my Pajero, I’ll stop to consider this beast. It takes 908 litres of engine oil (vs my 8) and 700l of coolant. It takes about 4 litres to drive 1km. However, like my Pajero, it is fitted with tubeless Bridgestone tyres. The suspension setup is similar, with springs and hydraulic dampers, and power steering, although at around a 12m turning circle, my Pajero clearly beats its 50m! However, loading and unloading has been significantly optimised, able to disgourge it’s 200tonne payload in the blink of an eye with its hydraulic tipper.

The trucks are not the only big toys. Newman is connected to Port Hedland, the export terminal, by 450km of privately-owned railway, the largest in the southern hemisphere. They hold the record for the longest train and largest payload, at around 6.8km, and some ridiculous tonnage. Each train has only one driver for the up to 8 locomotives which may be coupled into the train. The train takes 3km to stop from its average speed of about 65km/h. Trains vary in size depending on demand, and we waited at a level crossing for a small train with 3 locomotives and 231 wagons.

The Mount Whaleback mine is one of 8 BHP Billiton mines in the area. They are not the only iron ore miner in the Pilbara. The train we waited for was badged Rio Tinto. BHP blends the ore mined at all sites to achieve the specified export grade of just over 65% (% of what was never stated). The Mt Whaleback mine produces ore at 70%, so it needs to be diluted significantly by lower grades before export.

Only 4% of the ore is processed in Australia. The remainder goes primarily to Asia.

And the big boy? That would be Elliot at the head of this entry.