A WESTERN District contractor has given new meaning to the term tree-trimmer, reports MARK SAUNDERS
Birregurra's Neal Dunnill describes himself as an educator of trees.
And in Neal's classroom you'll find among other things, a 2.4m diameter circular saw blade attached to a 280kW articulated tractor.
The massive machine, used for trimming and shaping trees up to 30m tall, took Neal three years to complete and represents about 20 years of accumulated tree-care knowledge.
"It's the ninth version of a tree trimmer I have built and it is by far the best," Neal said.
At the heart of Neal's monster trimmer is a Case IH 9370 tracked tractor.
Known as a quadtrack, the Case IH is articulated and has four tracks instead of wheels.
Neal chose the Case IH for the job because of its strong gearbox and ability to move across a variety of surfaces.
"The quadtrack is a fantastic machine," Neal said.
"The tracks provide excellent stability and the increased size of the footprint allows the machine, which weighs about 28 tonnes all up, to get around in wet conditions."
Neal said the 12 forward and three reverse-gear transmission of the Case IH allowed further flexibility.
"The three reverse gears are ideal as I can go at a creeper speed backwards or quite quickly, which is well suited to the tree pruning, where there can be a lot of backward and forward movement."
The quadtrack has been modified to cater for the 2.4m saw, which is made from 10mm-thick steel and sits at the end a series of hydraulically-controlled boom arms.
The arms can be extended or retracted and the saw can be moved to virtually any position.
The boom arm is attached at the rear of the tractor via a large turntable, underneath which sits a heavy-duty, three-stage hydraulic motor that can move 650 litres of hydraulic oil a minute.
The oil tank for the system that drives the saw and controls the movement of the boom arms has a whopping 1000-litre capacity.
And like most of the modifications on the monster pruner, Neal has engineered and made all the fittings, couplings, arms and controls in his workshop at Birregurra.
The cabin of the tractor has also been modified, including extending the size of the operator area, adding an overhead window, removing curved glass and replacing it with straight panels and covering the side closest to the saw in a steel-mesh cage.
The possibility of the tractor being struck by falling branches or debris also led Neal to strengthen the tractor's bonnet.
Not one to beat around the bush, Neal completely rebuilt the engine cover in 6mm-thick steel, using a frame made of 75mm by 50mm box steel.
"On such a large tractor, that makes the bonnet quite heavy, so I've made a hydraulic system for it so you can open and close it from the tractor cab," Neal said.
Born in New Zealand, Neal and his wife, Pat, moved to Birregurra about 25 years ago.
A certified engineer, he said he believed moving to Australia would maximise opportunities to build machinery.
"I had built and sold machinery in New Zealand but always wanted to come to Australia and check it out," Neal said.
"I also had many years of experience working on tree pruners in New Zealand and when we moved to Birregurra I could not believe the amount of cypress-pine trees planted as wind-breaks.
"If not managed properly, the pines will eventually begin to fall apart and can be dangerous but if pruned, or educated, the trees can provide an excellent source of shelter for a long time.
"And with the manoeuvrability of the tree trimmer, I can shape the trees right down to ground level if required."
The trimmer can prune to the ground, thanks to three large, removable steel flails, which can be attached to the outer edge of the saw blade.
Each flail acts like a conventional lawn-mower blade and protrudes about 250mm from the edge of the saw.
If the flail hits the ground, it deflects away and does not damage the saw's teeth.
In good conditions, the saw needs to be sharpened every second or third day.
Sharpening requires a 230mm diameter, hand-held grinder and takes about an hour and-a-half.
Neal has a customer base of several thousand clients and said he is finding more work in native trees as well as the cypress pines.
"The flexibility of the pruner really gives you the opportunity to be able to manage trees," he said.
" I have trees which have been pruned for about 20 years and they will be going strong for many years to come."