Stump Systems

Stump grinders

Stump grinding is a specialised removal business rather than conventional logging. A high-speed cutter wheel reduces the stump to chips.

Applications include arboriculture, commercial development, road construction, utility work, parks, council contracts, landscaping and plantation roads.

Vermeer SC70TX

Australian published specifications include:

• approximately 1,769 kg
• 67 hp / 50 kW diesel
• 584 mm cutter wheel
• 30 teeth
• approximately 13.6 L/h stated maximum fuel consumption

It represents an upper-commercial arboriculture machine rather than an industrial plantation stump-removal system.

Vermeer SC1052

The larger SC1052 includes:

• approximately 2,023 kg machine weight
• 115 hp / 85.8 kW engine
• 660 mm cutter wheel
• 33 teeth
• approximately 787 mm above-ground cut
• approximately 635 mm below-ground cut

Vermeer specifically positions it for contractors regularly handling larger or multiple stumps.

Stump grinder economics

Do not quote stump work purely by visible stump diameter. Consider:

Stump diameter
×
root flare
×
required depth
×
species hardness
×
access difficulty
×
soil contamination
×
cleanup requirement

A 700 mm eucalyptus stump surrounded by rocks may take longer than a much larger softwood stump in clean soil.

Commercial tracking should include:

• minutes per stump
• teeth consumed per 100 stumps
• fuel/stump
• setup time
• chip-removal time
• mobilisation

Teeth per 100 stumps is the metric that exposes soil contamination, and it is the one most contractors do not record.

Stump cutters, planers and drills

The term "stump grinder" covers several technologies. Industrial options include the horizontal cutter wheel, vertical disc cutter, screw planer, auger grinder, forestry tiller and stump shear. They produce different site outcomes.

FAE stump cutters

FAE's Australian catalogue spans:

The largest special-vehicle cutter can work down to approximately one metre.

OMEF stump planers

Australian distributor examples include:

SPV2 Plus 510 — 5.5-8 tonne excavator, 285 kg, stated maximum stump diameter around 1,000 mm, 6,440 Nm torque, 60-75 L/min.

SPV3 Plus — 14-25 tonne excavator, 770 kg, stated maximum stump diameter around 2,000 mm, 20,000 Nm, 150-200 L/min.

These slow-speed systems can be attractive where conventional high-speed chip projection is undesirable — near buildings, traffic, glazing or livestock.

Stump shears

A stump shear does not grind the stump. It:

1. penetrates
2. splits
3. loosens
4. extracts
5. handles

the stump.

For large-scale land conversion this may be commercially superior because the root mass is removed rather than left in place — and because the extracted material becomes a potential biomass stream.

OMEF ST90 and ST140

ST90 — 12-20 tonne carrier, 1,600 kg, 900 mm opening, up to 70 tonnes cylinder force.

ST140 — 20-35 tonne carrier, 2,500 kg, 1,400 mm opening, up to 90 tonnes cylinder force.

Randalls specifically identifies large-scale clearing, biomass and plantation preparation as applications.

Commercial stump-system comparison

Read that table by starting from the objective, not from the machine. The question is never "which stump machine is best" — it is "what does this site have to look like when I leave, and how many stumps are there per hectare".

Three problems that look like one

"Stump removal" describes at least three commercially different jobs, and the equipment that suits one is wrong for the others.

Finishing an individual stump in an accessible setting, where the ground has to be usable afterwards — turf, paving, planting. This is grinding work, on an arboriculture-class stump cutter, and the specification that matters is below-ground cutting depth rather than stump diameter.

Clearing stump density across an area for site preparation or conversion. This is a shearing or tilling problem on a carrier an order of magnitude larger, and the constraint is hectares completed within a window rather than minutes per stump. Grinding individual stumps one at a time does not scale into it.

Recovering stump material where it has a biomass outlet. This is a shearing and handling problem with a contamination constraint attached, because stumps carry soil and soil affects both wear rates and specification compliance.

Establishing which of the three you are actually being paid for is the first decision, and it determines everything after it.

Sizing a shear

Two measurements govern, and both are commonly taken wrong.

Stump diameter at ground level, not at breast height and not from the standing tree. Stumps flare at the base, so a measurement taken anywhere else understates what the shear has to engage. Take it across representative ground rather than at the largest example — if most stumps fall inside a smaller opening, size to the distribution and handle exceptions another way.

The carrier's lift chart with the attachment fitted, at the reach and slew angle the work actually uses. A published carrier class is a guide; the chart is the check. Stump shears are heavy attachments, and their mass reduces lifting capability everywhere on the chart before any material is engaged.

Cylinder force is the third specification and the hardest to judge from a sheet. Opening determines whether the shear can engage the stump; force determines whether it can split it once engaged, and on dense, well-rooted material that is where attachments separate. It is worth witnessing on your material rather than comparing on paper.

Grinder economics

Stump grinding is priced per stump or per hour, and both are dominated by factors other than grinding rate.

Access governs. In urban and semi-rural work, travel, setup and getting the machine to the stump consume most of the day. A machine that fits through the gate completes jobs a faster machine has to decline, which is why sizing to access rather than to stump diameter is the recurring advice in this class.

Mobilisation recurs. Where grinding follows a removal, completing it in the same visit avoids a second mobilisation. Where access forces a return trip, that trip is a real cost and should be priced rather than absorbed into the stump rate.

Tooth cost varies with the site, not the machine. Urban and semi-rural stumps carry buried rubble, gravel and grit, and tooth consumption responds sharply to all three. Track cost per stump rather than per hour — it is the clearest early signal of both ground conditions and operator technique.

Below-ground depth decides whether the job is finished. The client is buying what happens next. A machine that cannot reach the required depth in one pass turns one job into two visits or leaves a finish the client will query.

Own or subcontract

The test is the same as for any specialist capability: how many days a year would the machine actually work?

Own a grinder when stump work follows enough of your removals that subcontracting adds a scheduling dependency and a margin you are giving away. Subcontract when stumps are occasional, or when access at your typical sites would require a size you could not otherwise justify. The deciding number is frequency of use, not frequency of stumps existing.

For area-scale stump work the same logic applies with larger numbers attached, and the answer more often favours hire or subcontract — because conversion campaigns are episodic and a heavy shear or cutter used in one campaign a year carries twelve months of fixed cost against a few weeks of revenue.

See stump grinder versus stump shear for the direct comparison, and stump removal costs for what drives the price of the work.

What is underground

Stump work is the one category in this guide where the main hazard is invisible, and it is worth stating plainly because the cost of getting it wrong is not commercial.

Stumps sit in ground that may contain services — electricity, gas, water, telecommunications, irrigation — and in urban, roadside and infrastructure settings that possibility is the default rather than the exception. Before any below-ground work, the location of services has to be established through the appropriate enquiry process for the site and confirmed on the ground, not assumed from a plan.

The commercial consequence sits alongside the safety one: a service strike stops the job, carries rectification cost and liability, and on a client site it affects whether you are asked back. Time spent establishing what is underground is not overhead on stump work — it is part of the work.

What happens to the arisings

Every stump system produces material, and where it goes is a cost that quotes routinely omit.

Grinding produces a mix of chip and soil. It is usually left on site and levelled, which is cheap — but where the client wants it removed, or wants clean fill in its place, that is a separate operation with its own truck movements.

Shearing and extraction produce whole stumps, which are bulky, heavy and carry soil. They have to be stockpiled, processed or carted, and soil contamination limits what a biomass buyer will accept.

Tilling incorporates residue into the soil, which is the point of the operation — so the arisings question is answered by the method rather than after it.

Establish which of these the client expects before pricing. A stump quote that assumes the material stays and a client who expects it gone are separated by a cost neither party has discussed.

Regrowth and what follows

A stump removed and a stump killed are different outcomes, and clients do not always distinguish between them when specifying work.

Grinding to a shallow depth removes the visible stump and leaves root material that can reshoot in species that sucker. Grinding deeper, or removing the stump entirely, reduces that but costs more and disturbs more ground. Where regrowth control is actually the client's objective, the treatment specification should say so, because it changes the depth, the method and the price.

This matters most on species that regenerate readily from roots and lignotubers, which covers a substantial part of Australian vegetation. It is worth asking directly: is the objective a level surface, or is the objective that it does not come back? Those are different jobs.

Access decides more than capability

In urban, semi-rural and roadside stump work, the machine that reaches the stump completes the job and the machine that cannot has no production figure worth discussing.

Gate widths, driveway crossings, surface load limits, overhead services and the route from the street to the stump determine which machines are viable on a given site — and across a client base, they determine how much of your enquiry flow you can actually service. A larger cutter excluded from half your sites earns less per year than a smaller one that fits, however much faster it is when it gets there.

Size against the access your work actually has, then check that grinding rate is adequate. Doing it the other way round produces a machine that is impressive on the jobs it can reach and absent from the rest.