Here are some selected excerpts from the intervew with Francis Bartley.
Here are some selected excerpts from the intervew with Francis Bartley.
Q: Just how big is this truck?
A: Well, empty it weighs in at 224 tons (203 tonnes), it's 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's an overall weight when loaded of 624 tons (568 tonnes).
How similar is it to an ordinary truck you would see on the highway?
A: It's quite different from what you might expect. For a start there isn't 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's 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.
Q: It must cost a fortune...
A: 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.
Q: What's it like to drive?
A: It's like driving a house. After you've been around a lot, it's not as exciting as if suddenly someone said: "Would you like to drive one?" You'd go crazy in that case! It's not hard to drive, basically like driving an automatic shift car.
Here are some technical details about the truck.
Q: So how have you done it?
A: We work with a lot of other people. There's 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's 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.
Q: How on earth do you stop these great beasts? Surely not with ordinary brakes.
A: 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's 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.
