Caterpillar 797
When a new 797 is delivered, it arrives in pieces aboard 12 semis, including an 850 gallon (or optional 1800 gallon) fuel tank.
With a full load, the 797 can move as fast as 40 mph on level ground. Behind each wheel is a pack of 42-inch brake discs ... 10 each in front, 15 per corner in the back. Dissipating that energy is a computer controlled brake-cooling system that pumps oil -- up to 1160 gallons of it per minute -- through multiple coolers and then through the discs. These brakes work!
The truck uses fuel in huge amounts ... an average of 65 gallons/hr ... with a fuel economy rating of 0.3 mpg. With such huge costs involved, the vehicle is usually run 24 hours per day, 365 days per year, stopping only for regularly scheduled maintenance.
For maximum efficiency, mining truck volume must be a multiple of mining shovel capacity. Cat built the 360 ton capacity 797 specifically to handle the 90-ton loads carried by the industry's biggest shovels; four scoops and the truck is full. But P&H Mining Equipment of Milwaukee recently debuted a "dipper" capable of snatching ore in 100-ton bites, which creates a problem in filling the 360-ton-capacity pickup. New models are in the works!