Imagine the versatility of a compact Cat® dozer matched with the power of a purpose-built mulching head and dedicated auxiliary pump, making it ideal for traditional site preparation together with rough terrain land management needs.
NSW dealer WesTrac Cat has taken a decisive step into dedicated vegetation management with its first Cat D1 tractor/dozer configured as a purpose-built mulcher, design-matched to the Cat HM518 mulching head.
Built on the Caterpillar® small-dozer platform but engineered specifically for forestry and fuel-load reduction, the D1 Mulcher combination pairs a 77.6kW (104hp) Cat C3.6 engine with a high-efficiency, closed-loop hydraulic circuit to keep drum speed steady in heavy material.
On each pass, the HM518 clears a 72-inch (1882mm) swath — ideal for firebreaks, right-of-way work, site development and tree/brush management across a variety of Australian conditions.
With this machine on site, there’s no need to use separate dozers and mulchers for various land clearing purposes.
Caterpillar Product Expert Robbie Southerland was in Australia recently to support dealer training on the Cat D1 to D3 tractor range, and took Earthmoving Equipment Magazine on a detailed inspection of the D1 Mulcher and its features.
“Across Australia, land managers face tighter timeframes for fire mitigation and corridor maintenance,” Robbie said.
“Compact Track Loaders are the product of choice for mulching, however they have their limitations, particularly on steep or rocky terrain. At the same time, conventional dozers aren’t optimised to process standing vegetation into a safe, uniform mulch.
“The D1 Mulcher bridges that gap, with a balanced steel track undercarriage for traction, strength and stability, plus a factory-matched mulching system that turns mixed scrub and saplings into fine mulch in one controlled pass.
“The result is faster, cleaner lines with less rework and improved operator protection, all on a compact footprint that still transports easily between jobs.”
Robbie said a key feature that made the D1 mulcher model unique was the closed circuit hydraulic system operating the mulcher.
“You don’t see a dozer blade on this machine. But it can be swapped out for added versatility. This D1 has the HM518 mulcher with its own separate hydraulic pump that drives the mulcher separate to the machine hydraulics, and this is going to give you superior mulching results without slowing the mulcher,” he said.
“You’re not sacrificing hydraulic power when you move the machine. It’s all focused here on the mulcher.”
The HM518 also comes with a hydraulic push bar on the top.
“That helps push those pesky trees over, and we’ve got a lift gate that can be closed to get a smaller mulch,” he said.
“The rotating drum has full carbide teeth to help guard against hard material, so if you happen to get into the rocks, you don’t have to worry quite as much about any damage to the mulcher.”
Robbie then moved on to the machine’s design which lets operators clean and maintain the attachment when faced with high debris.
“We’ve got a hinged, swing-out grill, which is important. When you’re in the forest and you’re mulching, you’re getting all that debris,” he said.
“Where is it going to go? It’s going to settle in on the cooling pack. So every day you’re going to need to open this up and clean it out.
“With this set-up, you can do that with ease on a daily maintenance schedule. This machine also has larger fence spacing on the cooling pack, which allows small debris to pass through easily.
“Combine that with an automatic reversing fan and we’ve got a cooling pack that’s going to keep this machine at optimum working temperature while it’s in the woods doing work.”
Away from the mulching unit, Robbie was effusive about operator safety and comfort features.
“The D1 has unique screens and sweeps,” he said.
“This machine is going to spend a lot of time in the forest dodging sticks and limbs and trees. The sweeps will keep those from damaging the windows.
“Meanwhile, the windows on this machine come with optional polyglass that is shatterproof.
“And as with all of our Cat dozers — D1 to D3 — we have what we believe is the best-in-class operator station.
“This is the operator’s office so we want them to be as comfortable as possible as they’re spending their entire work shift sitting here in the cab.
“Some of the comfort controls include the air-ride suspension seat, which can be moved forward and back, or up and down, and there are seat-mounted controls that move with the seat, offering superior ergonomic and lumbar control.
“There’s even a footrest here for operators to use and relax while working. So they are constantly moving around and are going to be super comfortable in this cab when sitting in it for their eight-hour shift.”
Robbie also pointed out the visibility down to the mulcher with extra large windows on the front and sides.
“A sloped hood and redesigned sight lines give operators a clear view to the work tool — critical when threading along fence lines or manoeuvring around stumps,” he said.
Back on the ground, Robbie highlighted the importance of the tractor’s undercarriage.
“The undercarriage is one of the most important things that you put on any dozer. This D1 has our heavy duty undercarriage on it. We also have an optional abrasion undercarriage for those super abrasive conditions,” he said.
“This machine uses our XL track, which is our standard size. They are also available with a low ground pressure track as well, for more swampy or adverse underfoot conditions.”
Robbie said that ultimately, the D1 Mulcher arrangement was ideal for civil and utilities contractors for land management tasks such as:
- Firebreaks and mitigation: The 72-inch cut and stable D1 tractor platform help crews open up mineral earth lines and reduce ladder fuels quickly before the high-risk season.
- Utility and road easements: Consistent drum speed and controlled chip size reduce cleanup along verges and under powerlines.
- Site development and asset protection zones: One-pass processing turns mixed regrowth into mulch for erosion control and easier access for follow-on earthworks.
Robbie added that until now, Australian contractors typically pieced together dozer-mulcher solutions separately or used compact track loaders with mulcher heads for lighter work.
“WesTrac bringing the factory-engineered D1 Mulcher combo into its range means one-stop specification, integrated guarding/cooling, and local support for parts and service under a single umbrella — important for contractors looking for uptime in bushfire preparation season or tight civil schedules,” he said.
In summary
The Cat D1 Mulcher has:
• Improved visibility
A lower sloping hood line provides improved peripheral vision to the mulching head, allowing the operator to better assess the jobsite.
• Seat-mounted controls
Mounted on the air suspension seats, these controls isolate the machine vibration from the operator, reducing operator fatigue.
• Intuitive operator interface
Primary display is a 254mm (10″) touchscreen colour monitor with backup camera.
• Pressurised cab
Heated and air-conditioned cab offers comfortable working environment resulting in less operator fatigue and improved productivity.
• Hinged radiator grill
Allows for easy clean out of radiator without the need for tools.
• Tractor platform
Balanced and rugged for operating in rough terrain and soft underfoot conditions. Optional blade to provide machine application versatility.
• Long-life mulching head
New Cat® hm518 mulcher frame is designed for longer life using cladding material in high wear areas.
• Hydraulically controlled
Mulcher conveniently operates with a hydraulically operated front door and adjustable push bar.
• Closed loop hydrostatic circuit
Delivers efficient, high performance power to the mulcher head, using less pump flow.
• Reversible drum
Easier operation and improved productivity.
• Drum speed bar indicator
In-cab indicator, aids operator in managing ground speed and overall mulching productivity.
• Engine
Cat c3.6 diesel engine meets US EPA tier 4 final/EU Stage V emission standards.
• Undercarriage
Cat heavy duty (hd) track with 406mm (16in) or 635mm (25in) track shoes provides superior flotation and stability.
• Reversing fan
Auto reversing fan changes air flow direction to purge debris from radiator and enclosures.
• Turbine pre-cleaner
Improves engine air filter life by removing large debris particles.
• Improved fuel economy
The D1 has improved fuel consumption over the previous model with the same great performance you’ve come to expect from Caterpillar.
