Shearex VM-65SV excavator mulcher

A head you specify the carrier around

The VM-65SV is the heaviest attachment in the Shearex VM excavator mulcher range and the only one that should never be treated as something added to an existing machine. At 1,681 kg, 193 to 344 L/min of continuous flow and a published minimum carrier power of 170 hp (127 kW), it presupposes a 25 to 40 tonne excavator ordered with a forestry hydraulic and cooling package from new. Buyers who fit it to a general-purpose earthmoving machine and then try to fix the shortfall afterwards spend more than they saved and still run the head in the bottom half of its range.

Below it, the VM-60SR serves 20 to 25 tonne carriers on a 40 cm target and a smaller flow window. There is nothing above it on the excavator side of the catalogue: the larger Shearex heads are the front-mount HM-90SV and HM-100SV2, which need dedicated carriers of their own.

Heat is the limiting factor, and this is where the family explains it

Every mulcher page on this site mentions cooling. This one carries the detail, because at 344 L/min there is no margin left anywhere else.

Hydraulic heat is simply the power that does not become work. Everything lost to pressure drop across hoses, valves and the return filter, everything absorbed in motor and pump inefficiency, and everything dumped over relief when the rotor stalls arrives in the oil as heat. On a digging machine that heat is intermittent, because slewing, dumping and repositioning give the system time to shed it. Mulching is continuous demand at high pressure with the fan drawing air through a cooler pack that is steadily filling with the fines the rotor throws. Those three things compound.

There are four questions to put to the carrier supplier in writing. First, what is the oil cooler’s rated capacity and has the machine ever been sold with the forestry cooling package? Second, how large is the tank, since tank volume is thermal buffer and small tanks heat quickly. Third, can the fan reverse, and how often will an operator need to run it in a fines-heavy environment? Fourth, at what oil temperature does the machine derate or alarm, and how far is that below the point where seal and hose life starts falling away. Hydraulic cooling and heat sets out what the answers should look like.

Return-line design deserves the same attention. A restrictive return path raises case pressure and turns the motor into a heater, so a large, short return to tank and a case drain that is genuinely a drain rather than a tee into the return line are both specification items. The VM range’s maximum operating pressure is published as up to approximately 410 bar, and the auxiliary relief setting has to be confirmed against it, not assumed.

165 cm, 50 cm and 1,681 kg

The 165 cm swath is the widest in the VM range and lets a 30 tonne boom take a corridor edge in very few passes. The published optimal target material diameter of 50 cm is a continuous production figure, but it is the figure most likely to be misread on this page: a 50 cm stem holds roughly six times the wood of a 20 cm stem, so a well-spaced stand of large trees can be genuine production work while a dense one of the same diameter is often cheaper to shear, extract and then mulch as residue. Maximum diameter versus production diameter sets out that arithmetic.

Mass at this scale interacts with boom configuration. On long-reach or heavy-lift setups, 1,681 kg plus bracket, hoses and options has to be read off the chart at the radius the work actually uses, and it should be part of the carrier order rather than a check performed after delivery.

Buying the carrier and the head as one package

Tonnage is the least useful number on this page. A 30 tonne excavator ordered for earthworks can quote an impressive pump total and still be unable to hold 300 L/min at pressure without derating, because the auxiliary circuit was never the design priority. What decides the pairing is the flow the carrier can dedicate under load, the pressure it holds at that flow, the return and drain arrangement, and the cooling described above. Run the measured figures through the hydraulic power calculator rather than reasoning from the 170 hp minimum, which is a floor and not an operating point; the worked example behind that sum is on the VM-50SR page. See also hydraulic matching. In practice the top of the 193 to 344 L/min window belongs to large forestry-configured carriers, and most 25 to 30 tonne machines will work in the lower half of it.

Campaign work, not job work

This head fits mining and pipeline corridors, powerline and transmission easements and plantation thinning and re-establishment where the leavings of earlier work, heavy trunks and pushed-up material alike, have to be broken down on site. Mobilising a 30 to 40 tonne machine with a 1.7 tonne head is a permit and float exercise every time, so the economics favour long campaigns on one corridor over a run of short jobs; transport and mobilisation covers what that costs. Where a contract is mostly flat traversable ground with continuous vegetation, a dedicated front-mount carrier will produce more per hour, as excavator mulcher versus skid steer mulcher explains. This head earns its place on slopes, around towers and wherever selective treatment matters. Step down to the VM-60SR if regular material is under 40 cm or the fleet runs 20 to 25 tonne carriers.

Tooling and housekeeping at industrial scale

Spoil, cuttings and windrows on corridor projects carry rock and buried debris, which is a carbide argument; blades stay the better choice only in clean green material. Blades versus carbide teeth sets out the comparison, and tooling at this scale should be budgeted per hectare rather than per set, with Australian stock confirmed by Machinery Specialist before signing. The consumables worth pricing are listed in wear parts to price before buying.

A head generating this much heat and this many fines makes housekeeping a safety item rather than a tidiness one. Daily blow-down of the belt housing and engine bay, bearing temperature checks and a leak inspection belong in the shift routine, particularly during fire season; see fire risk in clearing operations. The circuits required by the standard hydraulic door and the grapple, tilt and heel options are set out on the VM-25SK page, and at this scale they should be specified with the carrier’s forestry package rather than added to it.

Ordering the carrier: what a forestry package has to include

If the argument of this page is that the carrier is specified around the head, it is worth being concrete about what that specification contains. The items below are the ones that are expensive or impossible to add later, and they belong on the carrier order rather than on a variation.

• Auxiliary circuit sized for the head, not for a hammer. Continuous flow within the published window at working pressure, with the relief set against the range’s approximate 410 bar maximum and documented.
• Return and drain. A full-size return to tank and a separate case drain, both routed for minimum restriction rather than for convenience of assembly.
• Cooling. The largest cooler package offered for the machine, a reversing fan, and screens that can be cleaned from ground level.
• Guarding. Belly plates, cylinder guarding, hose protection along the boom and glass rated for thrown material, since a mulching head damages its own carrier in ways a bucket never does.
• Undercarriage and boom. Track configuration for the terrain and a boom and stick combination chosen for mass at radius rather than for maximum reach.
• Telemetry and gauges. Oil temperature visible to the operator, not buried in a menu, because temperature is the number that governs this machine’s day.

None of these is exotic and all of them are cheaper at order time. A machine assembled from an earthmoving specification plus a retrofit kit will usually work; it will simply work in the lower half of the head’s range and spend more of its life hot.

Campaign logistics and support at distance

Corridor projects at this scale are run as campaigns from a camp or a compound, and the support question changes shape accordingly. The important figure is not the price of a part but the time from failure to running, which on a remote corridor is dominated by freight and by whether the item is in Australia at all.

The practical response is to split consumables into three groups. Items that fail regularly and are cheap, such as teeth and holders, live on the truck in quantity. Items that fail occasionally and stop the machine, such as belts and hoses, are carried as one set per campaign. Items that rarely fail and have long lead times, such as rotor bearings or a motor, are the ones to discuss with Machinery Specialist before mobilisation so the position is known rather than discovered. A machine of this size idle on a corridor costs more per day than any of those spares.

Exclusion zones, conductors and other people’s assets

A 165 cm rotor working 50 cm timber throws material a long way, and on transmission and pipeline corridors the assets nearby belong to someone whose approval conditions govern the work. Exclusion zones need to account for thrown material as well as the machine’s slew envelope, and crews should work to applicable WHS procedures and the manufacturer’s instructions. Where live conductors are involved, approach distances, permits and isolation arrangements belong to the asset owner and are settled before the machine arrives, not negotiated at the gate. Clearing on projects of this type also commonly carries conditions under state and local vegetation rules, which are worth reading before the programme is priced; native vegetation approvals sets out what to check.

Commissioning and the first hundred hours

The failures that matter on a head like this cluster at the start rather than in the middle. Commissioning should include a measured flow and pressure check at the coupler with the head fitted, a full-load run with oil temperature logged, a belt tension check after the first shift and again after the first week, and a torque check on tooling holders after the first few hours of work.

Set a review at around a hundred hours to compare actual production against the rate the job was priced on, with oil temperature and any derate events noted alongside it. On industrial contracts that early comparison is what allows a rate to be corrected while the programme is still young, rather than defended at the end of it.

Confirm before ordering

• Whether the carrier is being ordered with a forestry hydraulic and cooling package, or retrofitted after the fact
• Cooler rating, tank volume, reversing fan and the derate temperature, all quoted for Australian summer conditions
• Flow the carrier dedicates under load within the 193 to 344 L/min window, and the pressure held at it
• Return line size and a case drain that runs to tank rather than teeing into the return
• Auxiliary relief setting against the range's approximate 410 bar maximum
• Head mass with options read off the chart for the intended boom configuration
• Permit and float arrangements for the carrier and head as a combination
• Tooling budgeted per hectare, with Australian stock for teeth, holders, belt and bearings
• Delivered price including bracket, hoses, commissioning and training

Frequently asked questions