A typical dump truck is equipped with an open-box bed, which is hinged at the rear and equipped with hydraulic rams to lift the front, allowing the material in the bed to be deposited ("dumped") on the ground behind the truck at the site of delivery.
The dump truck is thought to have been first conceived in the farms of late 19th century western Europe.
[1] The first motorized dump trucks in the United States were developed by small equipment companies such as The Fruehauf Trailer Corporation, Galion Buggy Co. and Lauth-Juergens among many others around 1910.
August Fruehauf had obtained military contracts for his semi-trailer, invented in 1914 and later created the partner vehicle, the semi-truck for use in World War I.
[3][4][5] Companies like Galion Buggy Co. continued to grow after the war by manufacturing a number of express bodies and some smaller dump bodies that could be easily installed on either stock or converted (heavy-duty suspension and drivetrain) Model T chassis prior to 1920.
The lifting device was a winch attached to a cable that fed over sheave (pulley) mounted on a mast behind the cab.
The cable was connected to the lower front end of the wooden dump box which was attached by a pivot at the back of the truck frame.
[10] Today, virtually all dump trucks operate by hydraulics and they come in a variety of configurations each designed to accomplish a specific task in the construction material supply chain.
The bed is raised by a vertical hydraulic ram mounted under the front of the body (known as a front post hoist configuration), or a horizontal hydraulic ram and lever arrangement between the frame rails (known as an underbody hoist configuration), and the back of the bed is hinged at the back of the truck.
The tailgate (sometimes referred to as an end gate) can be configured to swing up on top hinges (and sometimes also to fold down on lower hinges)[11] or it can be configured in the "High Lift Tailgate" format wherein pneumatic or hydraulic rams lift the gate open and up above the dump body.
Some bodies, typically for hauling grain, have swing-out doors for entering the box and a metering gate/chute in the center for a more controlled dumping.
[15] The largest of the standard European dump trucks is commonly called a "centipede" and has seven axles.
A semi end dump is a tractor-trailer combination wherein the trailer itself contains the hydraulic hoist.
A transfer dump truck is a standard dump truck pulling a separate trailer with a movable cargo container, which can also be loaded with construction aggregate, gravel, sand, asphalt, klinkers, snow, wood chips, triple mix, etc.
It rolls on small wheels, riding on rails from the trailer's frame into the empty main dump container ("A" box).
Transfer dump trucks are typically seen in the western United States due to the peculiar weight restrictions on highways there.
Depending on the axle arrangement, a triple transfer can haul up to 129,000 kilograms (284,000 pounds) with a special permit in certain American states.
When the truck is empty or ready to offload, the trailing axle toggles up off the road surface on two hydraulic arms to clear the rear of the vehicle.
The key advantage of a semi bottom dump is its ability to lay material in a windrow, a linear heap.
In addition, a semi bottom dump is maneuverable in reverse, unlike the double and triple trailer configurations described below.
Because of that, this type of truck is frequently configured to take advantage of local weight limitations to maximize the cargo.
They offer the perfect solution for a variety of applications, including roofing, rock and mulch delivery, general contractors, skid steer grading, trash out, and recycling.
The key advantages of the side dump are that it allows rapid unloading and can carry more weight in the western United States.
Bigger off-highway dump trucks are used strictly off-road for mining and heavy dirt hauling jobs.
The term "dump" truck is not generally used by the mining industry, or by the manufacturers that build these machines.
Other major manufacturers of haul trucks include SANY, XCMG, Hitachi, Komatsu, DAC, Terex, and BelAZ.
It has a hinge between the cab and the dump box but is distinct from a semi-trailer truck in that the power unit is a permanent fixture, not a separable vehicle.
The disadvantage is that in a collision with a standard car, the entire motor section or luggage compartment goes under the truck.
Several countries have made rules that new trucks should have bumpers approximately 40 cm (16 in) above ground in order to protect other drivers.
Because of their size and the difficulty of maintaining visual contact with on-foot workers, dump trucks can be a threat, especially when backing up.