Trevi Benne WR15 tree shear

The WR15 is the WR model that most Australian clearing contractors will end up comparing, because the 17 to 22 tonne excavator it is indicatively matched to is the machine most of them already own. Per-model sizing on this page comes from regional dealer literature and is indicative; the factory publishes the WR family as three models spanning 1,250 to 2,225 kg, 11 to 35 tonne carriers and roughly 400 to 550 mm trunk capacity.

Where the WR15 sits in the range

The WR15 is the middle of the heavy family, between the WR10 for 12 to 16 tonne carriers at a nominal 400 mm and the WR20 for 23 to 30 tonne carriers at around 550 mm. Unlike the WR10, it has no WL competitor in its carrier band; the largest WL Series head tops out around 21 tonnes and 450 mm, and a 20 tonne machine that regularly cuts hardwood above 300 mm is better served by the twin-blade WR15. The range-level comparison is in the tree shear buying guide.

What the published figures mean on site

The nominal 500 mm class matters less for what it lets you cut than for what it implies about everything below it. A head with 500 mm of headroom cuts a 250 mm hardwood stem in one clean stroke without the blades labouring, which is where cycle time and blade life are actually won. Treat 500 mm as the occasional-stem limit and price the job on the sample distribution, as the maximum diameter versus production diameter guide describes. The twin-blade Hardox system penetrates from both sides so the cut face on merchantable timber is closer to a saw cut than a single-blade shear produces, which matters when logs are being sold rather than chipped. Because the WR15 sits mid-family, a configured head with rotation and bracket is likely to land in the upper half of the 1,250 to 2,225 kg span; the exact figure belongs on the quotation.

Carrier matching

A 20 tonne class excavator has the reach to make the lift chart the real constraint. Illustratively, assume a 20 tonne machine rated at 3,800 kg over the side at seven metres and a configured attachment of 1,900 kg with rotation, bracket and hitch: 1,900 kg remains for the tree. A 500 mm green hardwood stem of 20 metres will exceed that, so at seven metres the operator should be cutting well below the nominal class or cutting closer in. Reduce the radius to five metres and the same chart might allow 5,500 kg, which changes the answer entirely. That sensitivity to radius is the whole point of the lift chart and attachment mass guide. Hydraulically, a 20 tonne machine normally carries auxiliary flow to spare for the cutting cylinders, but the rotation circuit, return pressure and case drain still need matching against the current data sheet; the hydraulic matching guide lists the figures to give the dealer.

Typical work and production considerations

The WR15 fits subdivision and civil clearing, solar and wind farm site preparation, mining and pipeline corridors and biomass harvesting, which are the jobs where a 20 tonne excavator is already on site for earthworks. A typical remnant-woodland block might have a third of stems below 200 mm, a third between 200 and 350 mm and a third above, and the WR15 is the first WR model that handles that top third as routine work. Cycle logic changes with stem size: on the large stems the cut and the controlled lay-down dominate; on the small ones the accumulator and the placement pattern for the grapple or chipper crew dominate. Rotation earns its keep on solar sites where stems must be laid in windrows for a forestry grapple to feed a chipper. In dense eucalypt, expect blade loading and cycle times well above European brochure conditions and run a timed trial before committing per-hectare rates.

Limitations and when to step up or down a size

Step up to the WR20 when the carrier is 23 tonnes or more, when stems above 500 mm are routine, or when the fork tower is needed to handle large stems on a regular basis. Step down to the WR10 when the carrier is under 17 tonnes or transport weight is the constraint. If most stems are below 250 mm, step across to a WL with an accumulator rather than paying for WR mass you will rarely load.

Options and configuration to settle at quotation

The option list is the family’s, as set out on the WR10 page, but two decisions bite harder on a 20 tonne class machine. The first is counterweight: ask whether the manufacturer recommends a change for your carrier in the ordered configuration. The second is the fork tower, which adds mass at the worst possible place for the lift chart and should be ordered only if large stems are routine. Confirm which options are offered on the WR15 specifically rather than on the family, and get the total configured weight in writing.

Wear parts and support

The consumables are the same as the rest of the family, and the wear parts guide lists them. What changes at this size is blade economics: a head used at the top of its class in eucalypt goes through edges faster than the same head used mostly in 200 mm regrowth, so ask for the replacement threshold and price blades and a pin and bush kit at quotation rather than treating them as a later problem.

Confirm before ordering

• That the 17 to 22 tonne and 500 mm figures are indicative and the quotation carries the current factory data sheet
• Configured weight with rotation, accumulator, fork tower, pedestal, bracket and hitch
• Over-side lift-chart values at five and seven metres with that weight and a representative large hardwood stem
• Flow, pressure, rotation circuit, return pressure and case drain against the data sheet
• Rotation type matched to windrow or corridor placement needs
• Fork tower and pedestal only if large stems and steep ground are routine
• Blade, pin and bush pricing and Australian stock location
• A timed trial in representative eucalypt before per-hectare or per-stem rates are set
• Any counterweight recommendation for the carrier in the ordered configuration

Frequently asked questions