science

Load, haul, dump machine

Load, haul, dump machine is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Load, haul, dump machine rather than just read about it. In short: LHD (load, haul, dump) loaders are similar to conventional front end loaders but developed for the toughest of hard rock mining applications, keeping overall production economy, safety, and reliability in consideration. They are extremely rugged, highly maneuverable, and exceptionally productive.

Key takeaways

Load, haul, dump machine belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Load, haul, dump machine to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Load, haul, dump machine from memory before moving on to harder problems.

Reference excerpt

LHD (load, haul, dump) loaders are similar to conventional front end loaders but developed for the toughest of hard rock mining applications, keeping overall production economy, safety, and reliability in consideration. They are extremely rugged, highly maneuverable, and exceptionally productive. More than 75% of the world's underground metal mines use LHD for handling the muck of their excavations.

Constructional details LHDs have powerful prime movers, advanced drive train technology, heavy planetary axles, four-wheel drive, articulated steering, and ergonomic controls. Their narrower, longer, and lower profile make them most suitable for underground applications where height and width are limited. As the length is not a limitation in a tunnel and decline, LHD loaders are designed with sufficient length. The length improves axial weight distribution and bucket capacity can be enhanced. The two-part construction with central articulation helps in tracking and maneuverability. In mining, there is a limitation for shifting heavy equipment, and sometimes, an LHD has to be shifted through a shaft while dismantled.

Capacity An LHD tramming capacity varies from 1 to 17-25 tonne. Their bucket size varies from 0.8 to 10 m3. Bucket height ranges from 1.8 to 2.5 m.

Drives LHDs are available in both diesel and electric versions. The diesel version is easily transportable from one location to another and has diesel engines with a power drive of 75 to 150 HP or more. Engines are either water- or air-cooled. LHD with electric motors as drives have a general capacity of 75 to 150 HP. These are operative at a medium voltage of 380 to 550 volts. Flexible trailing cables are provided with a reeling/unreeling facility to feed power. These drives operate hydraulic pumps and hydraulic motors for further operation of the various movements of buckets and vehicle traction and steering. The speed of the vehicle is controlled mechanically. The transmission is controlled by a hydrostatic drive; in hydrostatic transmission, the motor drives a variable displacement pump hydraulically connected to a hydro-motor driving the axle via a gearbox. The speed is controlled by changing the displacement volume of the axial pump. The power train consists of a closed-loop hydraulic transmission, parking brakes, a two-stage gearbox, and drive lines.

Safety provisions Service, emergency, and parking brakes with fire-resistant hydraulic fluid are used. Headlights, audible warning signals, backup alarms, and portable fire extinguishers are provided. A special cabin is also provided for the safety of the operator. A safety device is provided to shut off the engine if exhaust gases exceed a temperature of 85 °C (or as per the set value). For electric shock safety, these LHDs' power source (gate end box) is equipped with earth conductivity protection using pilot core in electric trailing cable, which isolates complete power when earth continuity is broken.

Latest developments Most LHDs come equipped with remote control capabilities, which are crucial for clearing materials in areas where the stope lacks top protection, preventing loose muck from falling off. Some LHD models offer remote tramming functionality, enabling them to handle a daily ore capacity of 8000 tons. Two LHD OEM's (Caterpillar and Sandvik) have developed commercial auto-tramming systems - called Minegem and Automine respectively.

See also Adit Gold mining Mining Shaft Mining Mining Act of 1872 Stoping

Footnotes

Further reading Surface and Underground Excavations, 2nd Edition: Methods, Techniques and ..., By Ratan Raj Tatiya, Brown, Ronald C. Hard-Rock Miners: The Intermountain West, 1860-1920 (2000) De la Vergne, Jack.Hard Rock Miner's Handbook (2003) Tempe/North Bay: McIntosh Engineering. pp. 2. ISBN 0-9687006-1-6. McElfish Jr., James M. Hard Rock Mining: State Approaches to Environmental Protection (1996) Wyman, Mark. Hard Rock Epic: Western Miners and the Industrial Revolution, 1860-1910 (1989)

Illustrations

Worked examples

Example 1 — a first encounter with Load, haul, dump machine

Start with the simplest possible case. Write down what Load, haul, dump machine claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Load, haul, dump machine before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Load, haul, dump machine ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Load, haul, dump machine

In research: Load, haul, dump machine appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Load, haul, dump machine in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Load, haul, dump machine is common in secondary-school and first-year university syllabi. It links to neighbouring topics Mining equipment, Underground mining, so understanding it makes those chapters shorter.
In everyday life: Look for Load, haul, dump machine outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Load, haul, dump machine” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Load, haul, dump machine in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Load, haul, dump machine means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Load, haul, dump machine out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Load, haul, dump machine in simple terms?

Why does Load, haul, dump machine matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Load, haul, dump machine?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Load, haul, dump machine.