Francis Bartley studied electrical engineering at Oklahoma State University, but by 1968 he had given up his early work on special purpose batteries and was working in big trucks for Terex. Three or four jobs later, he is now with Liebherr, one of Terex鈥檚 major competitors. He says that his brother is still transfixed by the scale of the trucks he works on, but the rest of his family have become more blas茅. Hunting and fishing in the Virginia countryside help him switch off, but he still sometimes wakes up at night fretting over an engineering detail. A model of the T 282B will be available later in the year from
Just how big is this truck?
Well, empty it weighs in at 224 tons (203 tonnes), it鈥檚 24 foot 3 inches (7.4 metres) tall over the canopy, 47 feet 6 inches (14.5 metres) long with a wheelbase of 21 foot 6 inches (6.6 metres). And it can carry loads of 400 tons (365 tonnes). So that鈥檚 an overall weight when loaded of 624 tons (568 tonnes).
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How similar is it to an ordinary truck you would see on the highway?
It鈥檚 quite different from what you might expect. For a start there isn鈥檛 one huge engine powering the wheels, as you would get in a regular truck. Instead, a 3650-horsepower (2723-kilowatt) diesel engine generates power for two electric motors in the rear axles. So it鈥檚 more like a huge electric railroad locomotive than a conventional truck. Older giant trucks used a DC electrical drive system but this one uses AC, which is more efficient.
It must cost a fortune鈥�
In the US, $3million. In the over-300-ton range there are probably 50 to 75 trucks sold each year worldwide. Our big trucks end up used in coal mines in Wyoming and Australia, copper mines in Chile, in iron extraction in South Africa and in gold mines in Nevada.
What鈥檚 it like to drive?
It鈥檚 like driving a house. After you鈥檝e been around a lot, it鈥檚 not as exciting as if suddenly someone said: 鈥淲ould you like to drive one?鈥� You鈥檇 go crazy in that case! It鈥檚 not hard to drive, basically like driving an automatic shift car.
Isn鈥檛 it so big you could roll over a car without noticing?
That鈥檚 basically true. The first time I was in it at a mine, the driver started to drive away and actually ran into the back of a service truck. It seems we mashed it down to the ground. I saw someone yelling, but we didn鈥檛 feel a thing.
Like a mangled insect.
Yes.
But you are not having lots of accidents.
The mining industry, open-pit mining particularly, has improved safety continuously over the past few years. It鈥檚 safer than farming now.
This is the kind of job that men and boys dream about. How did you get into it?
My degree is electrical engineering, and I started out building batteries. I didn鈥檛 like it and it didn鈥檛 like me, so I started looking for another job. I found this truck manufacturer building these funny diesel-electric trucks. I thought, it鈥檚 outrageous what they鈥檙e doing 鈥� so I went to work for them. I鈥檝e been building trucks ever since.
And this is your biggest baby ever.
Yes, and it鈥檚 the biggest anyone has built. We are just a touch ahead of our nearest rival, Caterpillar.
What has the reaction been like?
It鈥檚 鈥淲ow, that鈥檚 big.鈥� And it really is. When I first got into this truck business seriously, I thought it鈥檇 be neat some day to design the biggest truck in the world. And one day when we were about three-quarters of the way through this truck, we found ourselves saying: 鈥淭his will be the biggest truck in world.鈥� Caterpillar kind of messed it up because they came on at the same time we did. Our truck was out and working before theirs, but both trucks were completed in the same month, the first ones.
But you鈥檝e got the edge at the moment?
Yes, our truck is lighter and so we鈥檙e doing a little bit better. They鈥檙e selling their truck technically at 380 tons and we鈥檙e selling ours up to 400 tons.
How come these trucks are so big?
Mines are constantly looking for more economical transportation of material. And one of the ways to increase efficiency is to increase size.
So how have you done it?
We work with a lot of other people. There鈥檚 four major components of the truck: tyres, engine, drive system, and then structure. To have a good truck all four of those have to match. So we had to have somebody to build an engine for us. That鈥檚 been Detroit Diesel MTU (DDC/MTU) and Cummins. Siemens has designed the drive system, the electrical control and electric motors and so on. The tyres were developed by Michelin and Bridgestone.
Have there been any big leaps?
Yes, in the drive system. The older trucks used DC motors, which had to be high performance, but relatively low-weight. There鈥檚 only so far you can go with that concept in a DC motor. So we switched to AC, allowing us to increase the size of the drive system. That had been a limitation of this size truck.
How on earth do you stop these great beasts? Surely not with ordinary brakes.
That is a real problem. We have electric retarding, we can generate up to 6000 horsepower of retarding effort using the electric motors. And that鈥檚 a primary speed control going down hill. In an emergency we have this brake, similar to what you have on your car, only bigger. And you can overheat them and destroy them in a hurry.
Supposing your tyre goes?
The trucks are supposed to be driven at no more than 40 miles per hour. That is relatively slow, so if a tyre blows out it鈥檚 not going to cause an accident in most cases.
A blow-out can damage vehicles close-by because the tyre is holding so much air and just the force of that鈥� Drivers have actually been killed by tyre explosions, but not on our trucks, thank goodness.
What happens if it falls over?
The driver usually says ouch!
But seriously, are there circumstances in which it might tip?
It鈥檚 not an everyday occurrence but it does happen. The driver can make a mistake and miss a turn and run up on a bank and fall over.
Or he could start downhill and get going too fast and try to make a turn and miss it. So there are things that cause the trucks to turn over.
If they do, then to get them back up, you need really big, big cranes.
What is the next breakthrough you would like to see in your working life?
The biggest thing I see down the road is the fuel cell. Right now we have an engine driving a generator making electricity to drive a truck. A fuel cell would replace the engine and generator both, so right off we have bigger savings than in the general automotive industry. And the tyre manufacturers are really pushing the limits at the moment. We鈥檝e talked to them about bigger tyres and it鈥檚 very difficult to make another major step up in size. They are reaching some limits in the technology. They know today that to increase the tyre capacity 50 per cent you have to double the size of the tyre, and that鈥檚 not good. Eventually we鈥檒l see a sudden leap in tyre capacity.
Could you use these giant trucks for other work outside mines?
No, the problem is you can鈥檛 drive these down the highway. There鈥檚 too much ground pressure and it cracks it up.
But aren鈥檛 there applications we haven鈥檛 thought of? Like under the sea?
There鈥檚 been talk for a long time, because there鈥檚 a lot of material down there, and some day equipment will work down there.
What about robot-controlled vehicles? It would cut out a lot of the health and safety problems?
You鈥檙e right, and the technology is only just now available with GPS. With GPS the trucks can be set to control themselves and stay in specific paths and locations, and probably could be programmed to back under the shovel accurately. But it is a tremendous programming challenge.
Surely every company would want one?
They do, but they need to justify it. One of the mines in Chile is at about 16,000 feet (almost 5000 metres) altitude. Not everyone can work at that altitude. A location like that really has a need for such a truck. And there鈥檚 another mine somewhere in the world where they have a lot of fog so it鈥檚 impossible for the driver to see to drive, and they鈥檝e been asking for autonomous trucks for 10 years. No one had a system until GPS, but even GPS has problems in some of these pits, which can be thousands of feet deep. But it will come.