Tractor & Construction Plant Wiki

Liebherr T282B at Kaltim Prima Coal mine. Sangatta East Kalimantan, Indonesia

A Dump truck is usually the term used in the UK to referred to an off road truck / lorry used in Quarrying and mining fitted with a tipping body. The road going version is more usually called a Tipper Truck or Lorry. The road going tipper truck, or lorry is used for hauling crushed aggregate material such as sand, gravel, or hot asphalt for use in construction, concrete manufacture, road building and coal from surface mining applications to the processing point or the customers directly.


Manual (Gravity) tipping

The earliest versions of trailer and lorry mounted dump bodies relied on the principle of gravity for dumping (emptying the load). The very first versions of a dump truck used to haul and dump material was nothing more than a simple dump body style cart drawn by horses. It would have consisted of a two-wheeled cart hinged to the axle with the centre of gravity, when loaded, just behind the axle. The loaded front body was hooked, and when unlatched, would dump. When loaded, the dump body’s centre of gravity would shift, thus it would tend to tip up and discharge the contents or Dump them on the floor. The dump body, when empty, remained locked in a the lowered (horizontal) position. These carts were used in open mines and pulled by horses along a railway track.

After 1900, a four-wheeled horse-drawn flatbed wagon with a rectangular body lifted with a hand operated hoist mechanism at the front was employed. Some of the first trucks with dump bodies designed on this principle appeared as early as 1904 when the Mann gravity dump was built in England.[1]

Early mechanically dumped bodies

The first mechanical mechanism was the use of a threaded rood (screw) and Nut mounted on the body operated by a hand crank. This allowed less rear overhang and a better weight distribution, to the front axle. This was known as the Bristol dump body raised by a continuous screw in 1905. The first product built by JC Bamford founder of JCB was a simple tipping trailer built from war surplus components, with screw tipping, and the second had a hydraulic tipping mechanism.

Hydraulically operated Dumper bodies

Hydraulics were being incorporated into truck mounted dump bodies relatively early on (cira 1900). Records show that one of the first hydraulic dump bodies was the Robertson Steam Wagon with a hydraulic hoist that received power from the truck’s engine or an independent steam engine. Alley & McLellan of Glasgow developed another early hydraulic dump body in 1907 that was power-driven by steam.[2]

Alternative bodies

A conventional dump body is mounted on a truck chassis and has an open body hydraulically operated and hinged at the rear of the truck usually by one or more hydraulic rams that raise the dump budy to unload contents at a delivery site,with off highway trucks rarely have tailgates unless moving saturated sand or sludge that will flow out on an incline.

The hydraulic tipping rams are either front mounted on the head board or underbody mounted and are driven from a gear box power take-off. with hydraulic rams mounted under the body the capability of the body to tip in a three-way basis, either to the left or right side or to the rear is possible by use of four pivot points in place of the usual two.

Dump truck bodies come in various sizes from four-wheelers for two to three tons payload on alight truck chassis to large, heavy-duty articulated and drawbar outfits grossing 30-ton payload capacities for on highway work. The type of dump truck body used will depend on the types of construction or mining material to be carried. For Muck away and demolition waste rugged steel lined bodies are prefered for durability, were as for Coal and grain lightweight "Bulker" bodies are used due to the lower density a much bigger body is required for a given payload.

Off-road Dump Trucks

These modern mammoth sized ( bigger than a house in some cases) dump trucks are “heavy-duty” dump trucks used in open cast mining operations and large-scale earthmoving jobs such as bulk excavation work for cuttings on new roads. In the mining industry, these extra large sized dump trucks are often called “haul” trucks. Loads can be dumped from the side or bottom of the truck in some versions, but usually from the back.

Early manufacturers

Articulated Dump Trucks

CAT 740 ADT at Kaltim Prima Coal mine. East Kalimantan, Indonesia

Articulated Dump Trucks or more usually called just an ADT have a Pivot point (hinge) arrangement between the cab and the rear chassis section/Dump body that was used to steer and on later models allows for twisting by incorporating a vertically mounted rotary bearing. What also makes the articulated dump truck unique is the cab is a permanent fixture and not a separate vehicle (earlier versions used farm tractors fro the power unit with removable trailers fitted with dump bodies. The steering on an articulated dump truck is by hydraulic ram(s) that pivot the complete cab rather than rack-and-pinion steering in the front axle (thus a simpler fixed axle can be used without swivel joints aon

Volvo A35E at Kaltim Prima Coal mine. East Kalimantan, Indonesia

All wheel drive versions). Used mainly on rough terrain applications and able to haul long distances, the articulated dump truck is versatile and has often replaced the motor scraper due to its versatility.

Major manufacturers

Off road articulated trucks (ADT's)
Off-road rigid trucks;
Modern Mine Haulers
Road going trucks (UK)

See also

References Sources

  1. Dumper Trucks by D. F. Wood
  2. Dump Trucks by Donald F. Wood, published by MBI, ISBN 0-7603-0867-5
  • 500 Years of Earth Moving by Hienz-Herbert Cohrs
  • Ultra Haulers (book) by Mike Woof
  • Dump Trucks (book) by Donald F. Wood

External links