Haul truck

Haul trucks are off-road, heavy-duty dump trucks specifically engineered for use in high-production mining and exceptionally demanding construction environments. Most are dual axle; at least two examples of tri-axles were made in the 1970s. Haul trucks are denominated by their payload weight capacity.

Description

Most haul trucks have a two-axle design, but two well-known models from the 1970s, the 350T Terex Titan and 235T WABCO 3200/B, had three axles. Haul truck capacities range from to nearly.
An example on the smaller end is the Caterpillar 775. Quarry operations typically employ smaller trucks than mining operations.
Haul trucks can generally be distinguished from standard dump trucks by:

Being far too large to travel legally on public roads
Having a dump body made of exceptionally strong steel plate that extends over the cab to protect it, angled upright at its end to aid in dumping; some are heated by exhaust gases to prevent loads from sticking or freezing to the bed;
Having a driver's cab narrower than its body;
No axle suspension;
Limited speed and operating range;
Special off-road only tires;
A ratio of dead weight to payload not exceeding 1:1.6

Most large haul trucks use some form of traction motors coupled to regenerative braking for power, braking, or both.
Haul trucks are classified by:

Type of unloading ;
Direction of discharge ;
Type of body.

Ultra class

The largest haul trucks, with a payload capacity of or greater, are referred to as ultra class trucks., the BelAZ 75710 is the truck with the highest payload capacity,.