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Extraction

Skidders

Drags stems to the landing — the workhorse of full-tree and tree-length systems.

1 benchmark machines7 buying criteria2 buying traps

A skidder drags stems or logs to a landing rather than carrying them. That makes it faster and simpler than a forwarder in the right conditions, at the cost of more soil disturbance and more contamination of the wood.

Skidders remain highly relevant to tree-length and full-tree harvesting, particularly where a feller buncher is producing large bunches and a landing has the processing and loading capacity to keep up.

What it does

  • Travels to the felled bunch
  • Grips the bunch with a grapple, or winches it with a cable
  • Drags the stems to the landing
  • Releases the bunch for the processor or loader

Who profitably buys one

  • Full-tree harvesting contractors
  • Tree-length contractors
  • Biomass contractors recovering whole stems
  • Large land-clearing operations

Market context

The skidders market in Australia

Skidders remain central to full-tree and tree-length harvesting in Australia, where a feller buncher produces bunches and a processor works at the landing. Their appeal is speed and simplicity; their cost is soil disturbance and wood contamination.

Skidder sizing is the clearest example of the bottleneck principle in practice. Extraction capacity converts to revenue only if the landing can process and load what arrives. Where it cannot, a larger skidder simply builds a bigger pile.

Configuration choice — four-wheel grapple, six-wheel, cable, swing-boom or clambunk — follows terrain and extraction distance rather than preference. Six-wheel machines dominate where distances are long and flotation matters.

Variants

Main configurations

Four-wheel grapple skidder

Best for

  • Conventional plantation extraction
  • Moderate distances
  • Lower capital cost

Six-wheel skidder

Best for

  • High-volume extraction
  • Longer distances
  • Soft ground and flotation
  • Larger bunches

Cable skidder

Best for

  • Selective extraction
  • Scattered stems
  • Terrain where the machine cannot reach the stem

Swing-boom skidder

Best for

  • Constrained trails
  • Working from the trail without turning the machine

Clambunk extraction

Best for

  • Very long extraction distances
  • High-volume tree-length systems

Published specifications

Benchmark machines in the Australian market

Indicative published manufacturer and distributor figures. Confirm every specification, lift chart and hydraulic requirement with the manufacturer or authorised dealer before purchase.

A six-wheel skidder representing the high-production end, positioned for high-volume and longer-distance extraction.

Power~212 kW
Operating weight~25.1 t
Grapple optionsup to ~2.32 m²
Maximum grapple opening3.835 m
Top speed23 km/h
Ground clearance~710 mm

Model pages

Specific machines in this class

Full published specifications, commercial fit, and what to verify before signing — for each machine.

Measurement

How this machine should be judged

These are the numbers that determine whether the purchase works. Specification sheets rarely contain any of them.

Tonnes per turn
Bunch size is set upstream by the feller buncher, not by the skidder.
Turns per productive hour
Dominated by skid distance and trail quality.
Tonnes per productive machine hour
The number that must match processor capacity at the landing.
Fuel per tonne
Rises sharply on poor trails and adverse grades.

Before you request quotes

Buying criteria

Assemble every one of these before contacting a supplier. Any line you cannot answer is where your commercial risk sits.

  • Average and maximum skid distance
  • Bunch size the feller buncher actually produces
  • Trail gradient, surface and wet-weather trafficability
  • Landing processing and loading capacity
  • Grapple area matched to stem size and bunch geometry
  • Tyre specification and chain requirements
  • Ground clearance for stump height and slash depth

What goes wrong

Buying traps

Each of these is a documented pattern, not a hypothetical.

Ownership

Consumables and wear items

Cost drivers

  • Tyres and chains — often the largest single consumable
  • Transmission and axle wear
  • Grapple and boom maintenance
  • Fuel on adverse grades
  • Trail construction and maintenance

What it actually costs

Cost structure and the variables that move it

Purchase price is the smallest part of most forestry equipment decisions. These are the variables that decide what the machine costs per unit of saleable production.

Tyres and chains are typically the largest single consumable on a skidder, and trail condition drives them harder than hours do. Fuel follows gradient and trail quality more than machine specification.

The hidden cost is trail construction and maintenance, which rarely appears in machine comparisons but materially affects both productivity and compliance.

Cost drivers, their effect, and what you can do about them
Cost driverEffect on your economicsHow to control it
Tyres and chainsUsually the dominant consumable, accelerated by rocky or rutted trails.Specify tyre and chain packages for your ground and track cost per tonne extracted.
Skid distance and gradientSets turns per hour and drives fuel burn on adverse grades.Measure real average and maximum skid distance before sizing.
Bunch size upstreamTonnes per turn is set by the feller buncher, not by the skidder's grapple rating.Match grapple area to the bunches actually produced, not the maximum quoted.
Landing capacityExtraction beyond landing throughput becomes inventory, not revenue.Model landing processing and loading capacity before adding extraction capacity.
Wet-weather operationDragging stems in wet conditions creates rutting, contamination and compliance exposure.Plan seasonal operating windows and trail drainage as part of the cost.

Model these against your own contracted hours rather than accepting a generic hourly rate — the machine cost calculator works the arithmetic with your figures, and the bottleneck analyser shows whether the machine is the constraint at all.

Worked situations

Three buyers, three different right answers

The same machine class suits very different businesses in very different configurations. These are the situations that recur.

1

High-volume clearfell with long skid distances

The situation
Large bunches, reasonable trails and a landing with processing capacity to spare.
What usually works
A six-wheel machine in the high-production class. Travel speed converts directly into turns per hour when distances are long.
The trade-off
Higher capital and machine mass, with more exposure in wet conditions.
Ask the supplier
What tonnes per hour can the landing process and load, sustained?
2

Selective extraction on broken ground

The situation
Scattered stems the machine cannot always reach directly, on variable terrain.
What usually works
A cable or swing-boom configuration, which extends reach without requiring the machine to travel to every stem.
The trade-off
Lower throughput per turn than a grapple machine in clean bunched conditions.
Ask the supplier
What proportion of stems can be reached from the trail, realistically?
3

Contractor weighing a larger skidder against an extra truck

The situation
Extraction appears to be the constraint, but roadside stock is building up rather than depleting.
What usually works
Building stock at roadside means extraction is not the bottleneck — haulage or processing is. Additional extraction capacity would compound the problem.
The trade-off
Resisting the obvious purchase requires modelling the whole chain rather than the visible symptom.
Ask the supplier
What is the sustained hourly capacity of every stage, and which is genuinely smallest?

Local conditions

Australian considerations

Specification sheets are written for global markets. These are the factors that change the answer here.

Soil disturbance and harvest plan compliance

Dragging stems across soil is the defining characteristic of this class. In regions with restricted harvest plans, rutting and contamination limits can constrain operating windows more tightly than machine capability does.

Trail construction is part of the system

Trail gradient, surface and drainage determine both turns per hour and wet-weather trafficability. Budget trail work as a production input, not overhead.

Contamination and mill acceptance

Where wood is destined for pulp or a mill with contamination limits, the soil picked up during skidding has a commercial consequence. That is part of the reason cut-to-length dominates in some Australian regions despite higher machine complexity.

Warning signs

Red flags in the sales conversation

None of these are proof of a bad supplier. All of them are reasons to keep asking.

  • Grapple area compared without reference to the bunch size your feller buncher actually produces
  • No discussion of landing processing capacity during the sales conversation
  • Tyre and chain costs not quoted
  • A production figure quoted without stating the skid distance it was achieved over
  • Wet-weather operating limitations not raised in a high-rainfall region

Before you sign

Skidder buyer checklist

Any line you cannot answer is where your commercial risk sits. Take this to the supplier meeting.

  • Average and maximum skid distance
  • Bunch size the feller buncher actually produces
  • Trail gradient, surface and wet-weather trafficability
  • Landing processing and loading capacity in tonnes per hour
  • Grapple area matched to stem size and bunch geometry
  • Tyre specification, chain requirements and cost per tonne
  • Ground clearance for stump height and slash depth
  • Seasonal operating window given soil and rainfall
  • Contamination limits at the receiving mill

For the full procurement sequence, see the commercial procurement checklist and what a dealer quote should include.

Common questions

Frequently asked questions

What is the difference between a skidder and a forwarder?

A skidder drags stems or logs along the ground to a landing. A forwarder carries them completely off the ground in a load bunk. Skidding is faster and simpler; forwarding produces cleaner wood with less soil disturbance and better assortment control. They belong to different production systems — full-tree and cut-to-length respectively.

How do I know what size skidder to buy?

Work backwards from the landing. A bigger skidder pays when large bunches, reasonable trails, high feller-buncher output, sufficient landing capacity and sufficient processor capacity are all present together. If any one of those is missing, extra extraction capacity creates inventory rather than revenue.

Four-wheel or six-wheel?

Six-wheel machines suit longer distances, larger bunches, soft ground and situations where flotation matters. Four-wheel machines carry lower capital cost and suit moderate distances on reasonable ground. Distance and soil decide it more than volume does.

What is the main running cost on a skidder?

Tyres and chains, usually by a clear margin, followed by fuel and transmission or axle wear. Trail condition drives tyre cost harder than hours do, which is why trail construction and drainage should be treated as a production input rather than overhead.

Can a skidder work in wet conditions?

It can, but at a cost that is often not worth paying. Dragging stems in wet soil creates rutting, contamination and potential compliance problems under a restricted harvest plan. In high-rainfall regions the practical answer is a seasonal operating window plus trail drainage, rather than a machine specification.

Elsewhere on this site

Where this class comes up

The comparisons, buyer profiles and fleet packages that turn on this machine.

See also

Related machine classes