![CamionFermont](https://upload.wikimedia.org/wikipedia/commons/5/5c/CamionFermont.png)
Haul trucks are off-highway, rigid
dump truck
A dump truck, known also as a dumping truck, dump trailer, dumper trailer, dump lorry or dumper lorry or a dumper for short, is used for transporting materials (such as dirt, gravel, or demolition waste) for construction as well as coal. A t ...
s specifically engineered for use in high-production mining and heavy-duty construction environments. Haul trucks are also used for transporting construction equipment from job site to job site. Some are multi-axle in order to support the equipment that is being hauled.
Description
Most haul trucks have a two-axle design, but two well-known models from the 1970s, the 350T
Terex Titan
Terex Corporation is an American worldwide manufacturer of lifting and material-handling plant for a variety of industries including construction, infrastructure, quarrying, recycling, energy, mining, shipping, transportation, refining and ut ...
and 235T Wabco 3200/B, had three axles. Haul truck capacities range from to .
Large quarry-sized trucks range from . A good example of this is the Caterpillar 775 (rated at ).
Quarry
A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to reduce their envir ...
operations are typically smaller than, say, a
gold/copper mine, and require smaller trucks.
Ultra class
![Liebherr t282 1](https://upload.wikimedia.org/wikipedia/commons/0/0c/Liebherr_t282_1.jpg)
The largest, highest-payload-capacity haul trucks are referred to as ''ultra class'' trucks. The ultra class includes all haul trucks with a payload capacity of or greater. , the
BelAZ 75710
The BelAZ 75710 is an ultra class haul truck manufactured in Belarus by BelAZ. As of 2013, it was the world's largest, highest payload capacity haul truck.
Design
The BelAZ 75710 has a conventional two-axle setup but the wheels are doubled, one ...
has the highest payload capacity, .
Rear-eject
![Komatsu HM400-2 RE rear](https://upload.wikimedia.org/wikipedia/commons/3/3f/Komatsu_HM400-2_RE_rear.jpg)
A rear-eject configuration is an alternative haul truck body style. Instead of lifting the bed vertically, the
hydraulic cylinder
A hydraulic cylinder (also called a linear hydraulic motor) is a mechanical actuator that is used to give a unidirectional force through a unidirectional stroke. It has many applications, notably in construction equipment ( engineering vehicles ...
pushes a ram-face horizontally through the body to eject the hauled load.
Rear-eject dump vehicles were first introduced in the 1980s by LeRoy Hagenbuch, P.E. of Philippi-Hagenbuch, Inc., for a refuse hauling application in New York City. They were designed to work on Volvo BM truck chassis. While the functionality of the ejector bodies worked well, they were prone to maintenance issues and not replicated until the 1990s. The next documented ejector bodies were developed by DDT, a UK truck manufacturer. A variation using steel chains instead of a hydraulic ram was introduced by
Bell
A bell is a directly struck idiophone percussion instrument. Most bells have the shape of a hollow cup that when struck vibrates in a single strong strike tone, with its sides forming an efficient resonator. The strike may be made by an inte ...
, but did not become popular.
Caterpillar Inc.
Caterpillar Inc. (stock symbol CAT) is an American ''Fortune'' 500 corporation and the world's largest construction-equipment manufacturer.
In 2018, Caterpillar was ranked number 65 on the ''Fortune'' 500 list and number 238 on the Global ''Fo ...
began offering a rear-eject option using technology originally designed for its scrapers after one of its contractors successfully converted a few CAT D400 models. The new design, installed on the company's D400E model, was less likely to jam in cold weather.
CAT later began manufacturing a standard R.E. body for its 730, 740, and 740B articulating haul-truck series.
Philippi-Hagenbuch, a company specializing in truck body design, developed its own mechanism for its rear-eject bodies, and has patented its design in the US, Europe and Australia.
The company customizes Rear-Eject bodies or trailers for several manufacturers' off-highway vehicles; including both rigid and articulating varieties.
As of 2014
Caterpillar Inc.
Caterpillar Inc. (stock symbol CAT) is an American ''Fortune'' 500 corporation and the world's largest construction-equipment manufacturer.
In 2018, Caterpillar was ranked number 65 on the ''Fortune'' 500 list and number 238 on the Global ''Fo ...
and Philippi-Hagenbuch, Inc. are continuing to manufacture Rear-Eject bodies for off-highway applications,
each using its own design of mechanism.
Rear-eject vs. end-dump
Because rear-eject bodies do not lift, or move externally in any way, they maintain a lower
center of gravity
In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force ma ...
. This means more stability on uneven terrain where the truck might tip over during the dump process. The truck can also be driven while dumping is in progress; this reduces subsequent time and effort spent on
grading the dumped material.
Rear-ejects are typically better suited to completely eject sticky material, preventing "carry-back."
A rear-eject truck can deliver a load in an area with a low overhead barrier.
[Moore, Paul]
"Material Progress"
''InfoMining''.
Notable examples
See also
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Articulated hauler
An articulated hauler, articulated dump truck (ADT), or sometimes a dump hauler, is a very large heavy-duty type of dump truck used to transport loads over rough terrain, and occasionally on public roads. The vehicle usually has all-wheel drive and ...
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Dumper
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Haul road A haul video is a video recording, posted to the Internet, in which a person discusses items that they recently purchased, sometimes going into detail about their experiences during the purchase and the cost of the items they bought. The posting of ...
*
Rear-eject haul truck bodies
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Unit Rig
Notes
References
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{{Mining equipment
ru:Самосвал#Внедорожные (карьерные) самосвалы