NO BREAKS. NO WORRIES.
Fixed felling head fixes breakage issues
THERE’S NOTHING MORE FRUSTRATING THAN watching an impressive 35-metre tall Radiata pine topple to the ground and then shatter into two or more pieces. That stem has now not only lost a chunk of its value, it has also become harder to get those fractured pieces back up to the landing or skid site, compared to a wholly intact tree.
Unfortunately, this is a sight that is all too familiar in logging operations throughout New Zealand forests, with some estimates putting breakages as high as 75% – that’s three quarters of the crop! Amazingly, it’s accepted as normal practice by forest companies and contractors alike.
But now something is being done about it.
An old, yet simple idea is making a timely comeback and it’s set to play a significant role in the way our trees are felled, particularly on steep slopes.
It’s a new take on the venerable fixed head feller-buncher. And interestingly, a bunch of Australians have been driving the trend in this part of the world.
Hardly surprising. Fixed head feller-bunchers have been popular in ground-based Eucalyptus forests across the Tasman for many years, notably the US-style disc saw and shear head models that can cut and accumulate multiple stems and place them accurately and, most importantly, gently on the ground. This results in better bunching for the skidder and virtually no breakages.
It didn’t take long for astute Aussies to figure that pine trees could be felled in a similar fashion. But disc saws don’t work so well with large diameter pines, which led to fixed head chainsaw models being developed and becoming mandatory in some Australian forests, particularly those under the management of HVP Plantations in the state of Victoria.
A Kiwi was involved in the HVP decision (it wouldn’t be right for the Australians to take all the credit, would it) and on moving back to New Zealand, Ian Wilson has become the catalyst for a similar change that is now taking place here.
That change can be precisely pinpointed to a discussion that Ian, now Director of Operations with ForestPHD (the company that owns the STICKS harvesting software), had with two Nelson contractors, which set things in motion.
The pair, Nathan Taylor and Hamish Matthews, had recently established Mechanised Cable Harvesting (MCH) in partnership with their old boss, Ross Wood. Ian knew both men from visiting Wood Contracting over the years to update himself on the winch-assist technology developments spearheaded by Ross, which included bringing Australian contractors over from HVP to see tethered harvesting in action.
Like Ross Wood, Nathan and Hamish are fervent believers in using mechanisation to create a safer working environment, along with making the most of technology to enable their operations to become more efficient and more productive.
That led to talks with Ian about using the data from their harvesting equipment via the STICKS cloud-based software programme to understand what they are doing and how they could make good use of the information gleaned from the machines. Ian has been involved in the utilisation of harvesting machinery data for many years and sits on the StanForD committee that’s run out of Sweden, so he knows his stuff.
His knowledge and experiences led Nathan and Hamish down the path to putting a fixed felling head with lateral rotation onto a new levelling felling machine for their Nelson operation – the first of its type in New Zealand – and discovering what a huge difference this style of machine can make to minimising felling breakages and improving the way they extract trees on steep terrain.
This is hardly news to Aussie contractors. People like Andrew Mahnken, from Mountain Logging in Gippsland, Victoria had discovered the benefits of using fixed felling heads to harvest full stems long ago, says Ian.
And HVP became aware of it when the company decided to take a more holistic approach to their value recovery programme around 2003, rather than just focusing on the log making phase.
“Our mantra was that ‘operational value recovery’ starts at the tree felling phase and goes all the way through the whole production chain, right to the delivery and if we want to capture the value that we have worked so hard to create over the last 30 years growing the tree, we have to get every step in that process correct,” says Ian.
“Otherwise, we can do a great job on log making but we could have already lost 20% of the value of the trees through breakages”.
As the HVP team looked more closely, they discovered that significant value was indeed being lost through felling breakage in full stem operations – but not all of them. Using the available harvester/processor optimisation data, they could clearly identify which contractors were using fixed felling heads and those who were using dangle heads.
“We were able to look at like-for-like operations, with the same tree sizes, same species, same conditions, same slope and see what the differences were (between fixed and dangle felling heads),” says Ian.
“There were contractors who already had fixed heads on their feller bunchers, like Andrew Mahnken and he was very much aware of what could be done – he’s an incredibly knowledgeable guy in steep slope tree length logging and, in my opinion, he’d be the leader in the Southern Hemisphere when it comes to felling heads.”
The fixed felling heads being used at that time included the US-built Timbco 33” bar-saw, and a suite of Aussie designed and built heads such as VHLC LogMate and PulpMate, Rosin Developments’ CF750 and CF800 and Waratah’s FL235 via its purchase of Unicon from Dennis Smith. The LogMate, PulpMate, CF750, CF800 and FL235 had the added advantage that they had full lateral rotation, so could shovel, load trucks and put in extraction tracks if needed, turning the feller buncher into a real multi-purpose machine.
In addition to dramatically reducing the amount of felling breakage, other benefits were recognised in the HVP study, such as lower stump heights, increased utilisation of the harvesters ‘Find End’ function and no slabbing or splitting of the stems. The other major plus was in the presentation of the wood – with full control of the tree as it is brought down to the ground, the feller buncher operator can precisely place the stem neatly into a bunch ready for a yarder grapple to grab or for a skidder to collect. This made extraction easier and much faster, which delivered a productivity gain for the contractor.
Ian says HVP took a very commendable approach to this gain, saying: “We didn’t go into it for productivity gains. We said the value for us is in the tree crop and if there’s gains for the contractor in productivity, let them have it.”
That approach helped win over contractors when HVP went on to make fixed felling heads mandatory in its tree-length harvesting operations, much as it did when the use of harvester optimisation became non-negotiable a couple of years earlier.
Ian says the goal was for zero tree felling breakage, i.e. eliminate it altogether, but the realism is that you’ll likely never ever eliminate it and instead, stem breakage minimisation would be a better description…but there’s no harm in shooting for the moon!
“Like all forest companies, we had a felling breaking equation in our business model, so we knew for every 1% increase in felling breakage what it was ultimately costing us,” he says. “We changed our thinking around from saying ‘felling breakage is something we just have to live with’ to ‘what processes or systems do we have to change to prevent it from occurring and get a more positive outcome for our investors’.”
And that’s the way it’s been in HVP Plantations’ tree-length harvesting operations for the last 15 years.
So, when the discussion with Mechanised Cable Harvesting’s Nathan Taylor and Hamish Matthews about how to capitalise on the information that STICKS had shown took place, which wasn’t long after Ian had returned to New Zealand, he used the opportunity to update the Nelson pair on his experiences in Australia, including the topic of fixed felling heads.
“I floated the concept of what Andrew Mahnken was doing and showed them some photos of all the stems nicely laid out on the hill and with minimal felling breakage, and Nathan said ‘that’s impressive, we should be doing something like that here’, which really got the ball rolling,” says Ian.