Andrew Miles plays with his trucks.
I was five years old that Christmas when the bright yellow truck arrived – chunky tyres, opening doors and that tipper truck action – get me to a sand pit, now! Tonka toys were large, usually painted bright yellow and virtually indestructible. Since that time my interest into the real-life enormous dump truck has never waned.
Think electric power is the preserve of cars future? Think again…
The Erzberg open cast mine, near the Austrian town of Eisenerz, is roughly forty miles northwest of Graz. They found stuff to mine here 1,300 years ago but of course it was by pick, shovel and hard, manual labour. Today sees twelve millions tons of stone mined every year to extract three million tons of siderite iron ore. That’s substantial shifting, leading to equipment of real life Tonka toy dimensions.
Diesel was the de facto engine choice for years. Huge torque, decent reliability but with lots of power sapping gear changes and questionable ethics which have only grown larger over time. Being over a thousand metres above sea level and constantly seeking better profitability, efficiency and reduced costs, German engineers, Liebherr used Erzberg as a testing ground for diesel-electric motion in their T236 100 tonne capacity dump truck.
Producing 1,200 hp (895 kW) means this truck with payload now weighing in at 180 tons can climb the six kilometres to the stone crushing station in around ten to twelve minutes, weather permitting. That’s some going and conducted with smooth, gear change free, constant speed, keep your foot down and avoid the tiny cars somewhere down there – easy.
Blasting the rock occurs twice a day. Four shifts work constantly around the clock, the ceaseless greed of the crusher forever hungry for more. The T236 (does the T denote Tonka?) has only been operational about eighteen months now, the remainder of the fleet, for now still on pure diesel power. But changes and improvements are ongoing.
Shifting this amount of weight by these means means the T236 is a European first. Constant power driving the rear axle and extremely smooth initial starts lead to those all important factors of less wear and tear, less breakdowns, maintenance and therefore lower costs. Manna from heaven for the giant mine’s operators.
Once those one hundred tons of rock payload are gone, another load has to be collected. Downhill and empty, you still have eighty tons of truck to slow down and stop – once more, electricity plays it’s part. Pressing the brake pedal draws on the electric motor. With assistance from the deceleration effect of the diesel engine, fuss free and virtually fuel free braking can be had. The truck also has huge, oil cooled multiple disc brakes to facilitate manoeuvring when positioning to the excavator and reversing toward the crushing area.
Should this heavy lifting become all too much for you, the Erzberg mine can offer more soothing ways for the tourist. One can ride in a tourist- modified (diesel) truck of old and overtake a full laden machine. You can even watch them blasting the rock from a safe distance: Vienna, presumably. And get up close and personal with the Tonka truck excavators. Should the weather turn foul, perhaps a trip into the mine will satiate your needs? Travelling in a former crew katl rail based carriage, you can delve 1.5 kilometres underground where a local brewer has found these to be ideal conditions for his lager to settle and mature. Tasting is encouraged.
For those with more energy than the dump trucks can produce, the mine also holds sporting adventure days. Motor crossing, climbing, abseiling and marathons around the zig-zag courses are held in the summer, hopefully nowhere near live mining operations.
Back to the trucks and that endless pursuit of lowering those Total Costs of Ownership, the clever folk at Liebherr have looked to other forms of powering their trucks. And their search led to trolley buses.
From November last year, an experimental truck along with 800 metres of overhead wiring has been operating on the mines roadways. The trolley poles are raised or lowered automatically with radar control. The supply is rated at 900volts DC. The pantographs have to be fitted to the trucks front on a large A frame but apparently causes little in the way of obstruction. Should these experiments prove successful, plans are afoot to fit an overhead network of 20km’s length.
And it’s not just in Austria where trolley bus style pantograph mechanisms are being used in mining operations. A uranium mine in Namibia has this very same set up along with a copper mine in Zambia. Those machine are bigger too. Liebherr can offer the T264 whose payload of 240 tons means a gross vehicle weight of 416; not big enough? Then the T284 is the one for you. This beast has a 363 ton payload making a heavyweight total of 600 tons full laden. None of these trucks are suitable for narrow lanes, bridges or trips to the supermarket. And you’ll still need plenty of diesel to run them.
Tonka toys then are alive and well and positively thriving on their diet of electricity. My only concern being why the Erzberg truck is mainly white over a splash of yellow? I ordered yellow. I demand a refund; look, my boy has this big sand pit and…