Loaders - Types of Construction Machinery

Types of construction loaders

The basic classification depends on the undercarriage and the boom design. The figures below are approximate and vary by manufacturer and machine configuration.

• Compact wheel loaders – operating weight approx. 3–8 t, bucket approx. 0.5–1.5 m³. Municipal work, landscaping, small construction sites, farms.
• Medium wheel loaders – operating weight approx. 10–20 t, bucket approx. 2–4 m³. Aggregate loading, concrete plants, stockyards, earthworks.
• Large wheel loaders – operating weight over 20 t, bucket approx. 4–7 m³ (much more in mining). Aggregate quarries, loading haul trucks, stockpiles.
• Track loaders – operating weight approx. 10–40 t, bucket approx. 1–4 m³. Soft ground, demolition, quarries, work on slopes.
• Telescopic handlers (telehandlers) – lifting capacity approx. 2.5–6 t, lift height approx. 6–18 m. Building construction, agriculture, warehouses.
• Skid steer loaders (wheeled and tracked/compact track loaders) – rated operating capacity approx. 0.5–1.5 t. Confined spaces, work with a wide range of attachments.
• Backhoe loaders – operating weight approx. 7–10 t, front bucket approx. 1 m³ plus a rear backhoe arm. Utility networks, small excavations, municipal work.

Wheeled or tracked?

Wheel loaders perform best on level, firm ground. They are fast, can travel on public roads and move easily between jobs, which is what makes them so versatile. Track loaders offer better traction and lower ground pressure, so they excel in mud, on disturbed ground and in quarries. Their drawbacks are transport – every site change requires a low-loader – and higher undercarriage running costs.

Front loaders, swing loaders and side-tipping buckets

On a front loader the attachment works in a single plane – along the machine's axis, with the bucket moving up and down. This is by far the most common design. A swing loader has an upper structure that rotates relative to the undercarriage, so it can discharge material to the side without manoeuvring the whole machine. A side-tipping bucket is useful when loading along a wall or in narrow halls.

Articulated, telescopic and skid steer

Most modern wheel loaders are articulated loaders – the frame is split into front and rear sections connected by pins. Steering is done by articulating the frame with hydraulic cylinders, which gives a tight turning radius despite the machine's weight. A telescopic loader uses an extendable boom instead of conventional lift arms, increasing reach and lift height. A skid steer turns by varying the speed of the wheels on each side – it is highly manoeuvrable but causes heavy wear on tyres and the drivetrain.

The key parameter: tipping load

When selecting a loader, the critical figure is the tipping load – the load in the bucket at which the rear wheels lift off the ground. Rated operating capacity is usually taken as about half the tipping load at full articulation. For example: the compact Liebherr L504 Compact has a 0.7 m³ bucket and a tipping load of approx. 3,000 kg, the L508 – 1 m³ and approx. 3,900 kg, while the Volvo L30G with a 1 m³ bucket reaches approx. 5,500 kg. Bucket capacity must be matched to material density: the same machine needs a different bucket for sand than for wet rock.

Loader attachments

A quick coupler allows attachments to be changed in minutes, so one machine can handle a variety of tasks. The most common are:

• buckets – general purpose, light material (high capacity), rock buckets with teeth, high-tip, grapple (clamshell) buckets,
• pallet forks and grapples for timber, bales or scrap,
• snow ploughs and sweepers – road and yard maintenance,
• augers for drilling holes and cold planers for road surfaces – mainly on compact loaders.

With heavier attachments, remember that their weight reduces the permissible payload, and attachments requiring an auxiliary hydraulic circuit must be matched for flow and pressure.

Buying a used loader – what to check

1. Articulation joint and pins – play in the frame articulation and in the lift arm and bucket pins. Excessive play means replacing bushings and often build-up welding and line boring of the bores.
2. Frame and lift arms – cracks and signs of welding, especially around cylinder mounts.
3. Transmission – smooth gear changes, jerking, slipping under load (driving into a pile), oil temperature after extended work, controller fault codes.
4. Axles – leaks from hubs and final drives, noise when turning, brake performance, metal particles in the oil.
5. Hydraulics – full-bucket lift time, drift of the lift arms and bucket (leaking cylinders or control valve), hose condition.
6. Engine – cold start, smoke, crankcase blow-by, oil pressure, leaks.
7. Documentation – operating hours, service history and ideally a diagnostic readout of the fault memory.

Rebuild or replace?

For transmissions, axles, pumps and diesel engines, an overhaul is usually cost-effective if the housings are undamaged and only the wear parts are worn. Replacing with a used or new unit makes sense when downtime is critical or the damage is extensive. The decision is best made after disassembly and measurement.