Forestry Mulchers Australia

Mulch in place, or recover the timber

A forestry mulcher is a production attachment that feeds woody vegetation into a high-speed rotor fitted with blades or carbide tools and leaves the result distributed across the site. Commercially, that makes sense where the objective is to treat vegetation on site rather than recover whole stems. A conventional clearing chain of fell, stack, load, haul and process can collapse to mulch and leave.

That is why mulchers dominate road reserves, rail corridors, transmission easements, pipelines, solar farms, mine sites, plantation maintenance, invasive woody vegetation, firebreak construction, bushfire fuel reduction, council programs, agricultural reclamation and private land clearing. It is also why the buying metric is rarely “largest tree diameter”. The professional question is: how many hectares can this machine complete to the client’s specified finish, at what fuel and tooling cost?

If the timber has value, or the client wants material removed, a tree shear or grapple saw may be the better front end, with the mulcher following for what remains. The mulcher versus tree shear comparison sets out that hybrid workflow.

Shearex and the Australian market

Shearex, a Canadian manufacturer, builds hydraulic forestry mulchers for excavators (the VM range) and for skid steers, compact track loaders and dedicated front-mount carriers (the HM range). Machinery Specialist markets Shearex in Australia; see the Shearex brand page.

What makes the Shearex factory data unusually useful is that it publishes carrier class, minimum carrier power, cutting width, attachment weight, minimum and maximum continuous flow, operating pressure, rotor speed and, most importantly, an optimal target material diameter for every model. That last figure avoids the industry’s most common mistake of presenting an occasional maximum cut as a normal production diameter.

Shearex VM excavator mulchers

Six VM models span excavators from 5 to 40 tonnes. Maximum operating pressure across the range is listed at up to approximately 410 bar, and the continuous flow requirements are serious hydraulic loads that push carrier selection well beyond tonne class.

VM-25SK and VM-35SK: compact and crossover

The VM-25SK puts 70 cm of cutting width on a 5 to 8 tonne excavator. It is not a high-acreage flat-ground machine; its value is that a compact carrier can reach over drains and banks and into locations a dedicated mulching tractor cannot enter, for narrow road reserves, council work, small firebreaks and selective clearing. The VM-35SK on 8 to 12 tonne carriers is the crossover class for mixed civil and vegetation contractors: 95 cm of width and a 15 cm target diameter on a machine that still travels economically and carries other attachments.

VM-40SL and VM-50SR: commercial clearing heads

The VM-40SL for 12 to 15 tonne excavators is a genuine land-clearing head at 107 cm width and a 20 cm target. If most work is flat and continuous, a front-mount carrier may produce more area per hour; if it is selective, sloped or around infrastructure, the excavator wins. The VM-50SR changes the carrier conversation entirely: at 159 to 238 L/min of continuous flow, the buyer needs to know how much flow the 15 to 20 tonne excavator can dedicate, whether it can sustain it, what pressure is available at the same time, the oil temperature after an hour and the allowable return pressure.

VM-60SR and VM-65SV: heavy and industrial

The VM-60SR on 20 to 25 tonne carriers with a 130 hp minimum, 149 cm width and a 40 cm target diameter is where a contractor should model whether an excavator head remains more economical than a dedicated mulching carrier. If the excavator digs most of the year and mulches for a few hundred hours, the attachment is very attractive; if mulching is the business for thousands of hours a year, purpose-built carrier economics deserve comparison. The VM-65SV for 25 to 40 tonne excavators, with 165 cm of width, a 50 cm target and up to 344 L/min, is industrial vegetation clearing equipment for major right-of-way, transmission, pipeline and forestry rehabilitation projects.

VM standard features and options

Shearex lists a hydraulic door as standard across VM models, carbide or blade tooling, Hardox 500 bolt-on liners and skid shoes, the CONVEX DX protection system, G2.0 rotor balancing, oil cooling through a flushing line, a Poly-Chain carbon transmission belt, and optional grapple, tilt and heel on most models. The options change the hydraulic requirement. Factory guidance is that the door uses pressure and return plus case drain with electrical control for the diverter, tilt is better served by a second double auxiliary line, and tilt plus grapple wants two double auxiliary circuits plus case drain. That is precisely why nobody should order the attachment and solve the hydraulics later.

Shearex HM front-mount mulchers

The HM family covers skid steers and compact track loaders at the light end through very high-output dedicated carriers at the top.

The HM-60 and HM-70 are each offered in SR and heavier DR variants. The HM-70SV, HM-88LV and HM-90SV move into 125 to 170 hp territory, and the HM-100SV2 is an extreme 254 cm head with a 60 cm target diameter and dual-motor high-flow drive for 250 hp and above carriers. It should not be compared casually with ordinary skid-steer forestry heads. The skid steer and track loader page covers front-mount carrier selection.

Excavator versus front-mount

Site geometry decides this, not brand or model. The excavator head wins wherever reach is the constraint: steep banks and drains, treatment over a barrier or below road level, selective work around retained trees, and positioning away from a drop-off. The front-mount wins wherever the ground is traversable and the contract is simply hectares per hour, because forward travel and a wider head produce more area. The full comparison includes the hydraulic questions specific to each.

Optimal diameter versus maximum capability

Suppose a head has a target diameter of 400 mm. That does not mean every hectare of 400 mm trees is economical. Wood volume rises roughly with cross-sectional area, so a 400 mm stem contains far more wood than a 200 mm stem, and production drops quickly as material volume rises. A site with 400 mm stems at wide spacing may be fine; dense 400 mm timber may make another method cheaper.

A real site contains grass, scrub, 50 mm regrowth, 150 mm timber and the occasional 300 mm tree, and the distribution of that material controls production. If a head is optimised around 150 mm, a tender should not assume every tree is 150 mm. The maximum diameter versus production diameter guide explains how to sample.

Hydraulic power: the sanity check

Theoretical hydraulic power in kilowatts is roughly flow in L/min multiplied by pressure in bar, divided by 600. At 238 L/min and 350 bar that is about 139 kW before losses, and the power that actually reaches the rotor is lower. The calculation exposes unrealistic pairings quickly: an excavator that quotes a high pump maximum but cannot deliver continuous auxiliary flow at pressure is not a mulcher carrier, whatever its tonne class. The hydraulic power calculator and the hydraulic matching guide cover flow, pressure, back pressure and case drain.

Cooling is a buying issue

Forestry mulching is unusually hard on hydraulic systems because the attachment demands high power continuously. Excavation has natural pauses as the machine slews, dumps and repositions; a mulcher can stay under load for long periods. In Australian summer conditions, confirm hydraulic oil cooler size, fan performance, carrier derating strategy, acceptable oil temperature, cleanliness of the cooling pack and whether additional cooling is required. A 20 tonne excavator with inadequate auxiliary hydraulics and cooling is not a better mulcher carrier than a properly configured 16 tonne machine. See hydraulic cooling and heat.

Blades versus carbide teeth

Blades cut clean wood efficiently and produce a finer particle, but they are vulnerable to rock and ground contact and need sharpening or replacement. Carbide tolerates impact and abrasive, dirty ground at a different cut quality, tooth cost and power demand. For Australian road and infrastructure clearing, rock exposure should be part of the tooling choice from the start. Walk the site, inspect road cuttings, check previous land use and ask about buried debris before tendering, because a rocky site can completely change tooling economics. The blades versus carbide comparison goes deeper.

Bite limiting and rotor design

A rotor can only absorb a certain amount of material before engine or hydraulic power falls away. Shearex uses a bite-limiting rotor design intended to control how much material reaches each tool, which helps reduce severe stalls, deep uncontrolled bites, abrupt rotor slowdown and holder stress. The objective is smoother use of the available power rather than a higher headline number.

What to measure on a paid demonstration

Record net hectares treated, productive hours, fuel used, tooth or blade condition before and after, number of passes, average vegetation diameter, the largest regular material, travel speed, final particle size and the amount of material needing another method. Then calculate hectares per productive hour, litres per hectare, tooling cost per hectare and total machine cost per hectare. Photograph before and after. That block becomes your tender benchmark.

Finish classes and passes

A contract should define finish. Rough knockdown leaves vegetation reduced enough for access. Standard mulch has material reduced and distributed. Fine finish needs extra passes for a smaller particle size. Ground incorporation may need different machinery entirely. A machine can double its time per hectare if the client moves from rough knockdown to fine finish, so track first and second pass separately. Illustratively, a first pass at 0.8 ha per hour and a second at 0.5 ha per hour gives roughly 0.31 effective hectares per hour to finish, not 0.8. Never quote from first-pass production alone if the specification requires two.

Soil contact and operator technique

An operator tempted to lower the head for a cleaner finish increases tooth wear, fuel, dust and rock impact. Agree the finish standard before work starts. Productivity also depends heavily on technique: sweeping, top-down processing of larger stems, using gravity on banks, controlling bite, using the hydraulic door and pre-positioning large material. A good operator materially outperforms a poor one on the same head.

Fire risk

Mulching produces dry fines, dust, heat and constant contact with combustible material. Inspect engine bay cleaning access, hydraulic leaks, bearing temperature, extinguishers and suppression systems, and plan for fire-danger days. The fire risk guide covers housekeeping and suppression strategy.

Wear cost

Track blade or tooth cost, holder replacement, rotor bearings, belts, liners and skid shoes. A head that is faster but consumes substantially more tooling can lose its advantage per hectare. The wear parts guide lists what to price.

Other brands to benchmark

Professional Australian buyers should also compare FAE, Fecon, Seppi, Tigercat dedicated carriers and other locally supported heads, and compare the entire support proposition, not only rotor design.

Buying used

Inspect rotor straightness and vibration, rotor bearing play, missing tools, holder cracking, wear liners, skid shoes, drive belt, hydraulic motor leakage, door, grapple, tilt pivots and weld repairs. Run the head at full speed and check vibration. See inspecting used forestry attachments.

Red flags

Be cautious when only maximum diameter is discussed, when the supplier does not ask about continuous flow, when the carrier pump maximum is confused with auxiliary flow, when oil cooling is ignored, when tooling cost is unavailable, when quoted head mass excludes options, when the demonstration vegetation is much lighter than the intended job, or when nobody mentions a case drain.

Confirm in writing before ordering a mulcher

• Which VM or HM model fits the exact carrier, and the current factory data sheet
• Continuous auxiliary flow and pressure available at working temperature, and whether the carrier can sustain it
• Case drain requirement, door control setup, and the extra circuits needed for tilt and grapple options
• Hydraulic oil cooling capacity and any additional cooling required for Australian summer duty
• Blade versus carbide recommendation for your ground conditions, with tool, holder, belt and rotor bearing prices
• Complete head mass including fitted options
• Australian stocking level for rotor tooling, holders, liners and belts
• A demonstration on vegetation representative of the intended contracts, recorded as hectares per hour and litres per hectare

Frequently asked questions