Tigercat · Skidder

Tigercat 635H

Name: Tigercat 635H
Brand: Tigercat

Six-wheel skidder at the high-production end — 25.1 t, 23 km/h, grapple to ~2.32 m².

6 published specificationsAustralian representation: Onetrak

Positioning

Where this machine sits

The 635H sits at the high-production end of skidding — a six-wheel machine at roughly 25.1 tonnes, 212 kW, a top speed of 23 km/h and grapple options to about 2.32 m². Every one of those figures points at long snig distances and high volume rather than at gentle work in a residual stand.

The six-wheel configuration is the defining choice. It spreads weight, improves flotation and traction on soft or broken ground, and it costs manoeuvrability and capital against a four-wheel machine. Where extraction distance is long and ground is difficult, that trade is usually worth making.

Published figures

Specifications

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

Power	~212 kW
Operating weight	~25.1 t
Grapple options	up to ~2.32 m²
Maximum grapple opening	3.835 m
Top speed	23 km/h
Ground clearance	~710 mm

Interpretation

What the published figures actually constrain

A specification table tells you what the machine is. This is what each of those numbers means for the work you would put it to.

Published figure	What it means commercially
23 km/h top speed	Travel speed is what turns a long snig into a viable cycle. On short hauls it is largely irrelevant; as distance grows it becomes the dominant productivity specification.
Grapple options to ~2.32 m², opening 3.835 m	Larger grapple area means more stems per turn, which shortens the cycle at long distance. It also means more weight at the rear and a larger hydraulic demand.
~25.1 t operating weight on six wheels	Weight spread across six wheels rather than four, which is what delivers traction and flotation on soft ground. Ground pressure is better than the operating weight alone suggests.
~710 mm ground clearance	Clearance over stumps and debris, which determines what ground the machine can cross without damage. On clearfell sites with high stump density this is a practical constraint rather than a specification detail.

Design intent

Built for long snigs at volume

~25.1 t on six wheels, 23 km/h top speed and grapple options to ~2.32 m² describe a machine aimed at long extraction distances and high volume rather than gentle work in a residual stand.

Sustained duty it is built around

Long snig distances where travel dominates the cycle
Soft or broken ground needing flotation and traction
Large grapple loads per turn
Full-tree chains at production volume

Commercial fit

Where this machine earns its cost

Right machine when

Large bunches, reasonable skid trails and high feller-buncher output — all three together
Longer extraction distances where travel speed converts directly into turns per hour
A landing with the processing and loading capacity to absorb the extra wood

Wrong machine when

The landing is already the bottleneck — bigger skidding capacity then just creates a larger pile
Short skid distances where the top speed never gets used
Wet conditions where dragging stems creates rutting and contamination problems

Before you sign

Verify these for this specific model

Beyond the standard buying criteria for the class, these are the questions this machine in particular raises.

Bunch size the feller buncher actually produces, against the grapple area quoted
Landing processing capacity in tonnes per hour
Tyre and chain specification and cost — usually the largest single consumable

Running cost

What drives the cost of owning this machine

Skidder economics are cycle-time economics, and cycle time is travel plus loading. Travel speed and grapple capacity both attack it, which is why this machine's specification is weighted toward both — and why neither matters much on short hauls.

Tyres and chains are the recurring cost that varies most with terrain. Rocky or abrasive ground consumes them quickly, and the specification that suits one estate can be expensive on another.

In a full-tree chain the skidder stage is frequently the constraint, because extraction cycle time scales with distance while felling does not. Sizing the skidder fleet against the longest haul rather than the average is what keeps the chain balanced.

In practice

Ownership considerations in Australian conditions

Match grapple area to the stems, not the maximum

A larger grapple shortens the cycle only if it is filled. On smaller stems a machine's turn is limited by what can be gathered, not by grapple area, and the extra capacity is weight carried empty.

Six wheels earn on specific ground

The configuration pays on soft, broken or steep terrain where traction and flotation limit the machine. On firm, level ground a four-wheel machine will usually be more manoeuvrable and cheaper.

Plan the snig tracks before sizing the fleet

Extraction distance is partly a planning decision. Landing placement and track layout can change the required skidder capacity more cheaply than adding a machine can.

Questions

Common questions about this machine

When does a six-wheel skidder justify itself over four?

On soft, broken or steep ground where traction and flotation limit what the machine can do. Six wheels spread weight and improve grip, which converts directly into turns completed in conditions a four-wheel machine struggles in. On firm, level terrain the advantage narrows and the manoeuvrability and capital cost of the four-wheel machine usually win.

How many skidders does one feller buncher need?

Enough to clear the buncher's sustained output at the coupe's longest snig distance, not its average. Two is the common answer in full-tree chains because extraction cycle time scales with distance while felling does not — a ratio that balances at 200 metres can leave the buncher waiting at 600. Measure the actual hauls before assuming the default.

Is top speed really a useful specification?

It becomes one as haul distance grows. On short snigs, loading and positioning dominate the cycle and travel speed changes little. On long extraction, travel is most of the cycle and speed is close to a direct multiplier on turns per shift. Like most specifications, its value depends on which part of the cycle is actually consuming your time.

In service

Fleet packages that use this class

Package A

High-production pine clearfell

The highest-volume softwood configuration, and the one with the greatest exposure to bottleneck mismatch. Either a full-tree chain or a cut-to-length pair, depending on terrain, mill requirements and contamination tolerance.

Package H

Biomass and wood-waste contractor

The one package where the offtake agreement must precede the fleet decision. Chip specification, moisture limits and contamination tolerance determine whether the correct machine is a chipper or a grinder.