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The Caterpillar 797 series trucks employ mechanical drive powertrains in contrast to the diesel-electric powertrains of similar haul trucks offered by competitors.[4] During initial development in 1997, a diesel-electric powertrain was considered for the 797, but this powertrain configuration was not developed because Caterpillar considered a mechanical drive powertrain more appropriate for market conditions at that time.

The 797 series haul trucks are equipped with a rear-axle-mounted, computer-controlled, seven-speed planetary transmission with a separate lock-up torque converter. Both transmission and torque converter use a common powertrain oil.

The BelAZ 75710 has a conventional two-banana setup but the wheels are doubled, one to an axle, like a scaled-up International Payhauler 350. For this reason it needs two 59/80R63 tires.[1] It also has four-wheel drive and four-wheel hydraulic steering which is unusual. It has a turning radius of about 31 m (102 ft).

The 75710 can carry a 450-tonne (440-long-ton; 500-short-ton) load.[2] With an empty weight of 360 tonnes (350 long tons; 400 short tons), it is much more heavily built than the previous largest model, the BelAZ series 7560, which weighed 240 tonnes (240 long tons; 260 short tons) when empty.[3] [4] It is 20.6 m (67 ft 7 in) long, 8.16 m (26 ft 9 1⁄4 in) high, and 9.87 m (32 ft 4 5⁄8 in) wide. The bed is relatively shallow, limiting the volume of material that can be carried.

Instead of a single engine, the Siemens MMT 600 drive system is powered by two MTU 65-litre (4,000 cu in) 16-cylinder four stroke diesel engines, each with 2,300 horsepower (1,700 kW). These are coupled to two AC alternators and four AC traction motors (two in each axle.[5] Fuel consumption (according to company data) is 198 g/kWh (1.94 oz/MJ) per engine, with option to run on only one if carrying less than capacity loads. Maximum speed is 64 km/h (40 mph), and economy maximum speed (when fully loaded and on a 10% gradient) is 40 km/h (25 mph).[6]

Here's a series hybrid truck.