TREE FALLING

Story: Hayley Leibowitz W ORKING IN HARVESTING CREWS on the East Coast for over 32 years, doing predominantly tall tower difficult terrain logging, Tairawhiti Timber Training’s Alan Paulson would often come across edge trees that were difficult to fall. “Five years ago, myself and my wife started our own business training, auditing, mentoring and doing specialised tree falling. This was at a time where I was looking forward to giving back to an industry that I had enjoyed so much. I saw a need for purpose-built tree jacks as a jack is a very safe way of falling difficult trees, requires minimal effort compared to pounding on wedges with a big hammer, and saves cost, especially for a cable crew who do not have to stop yarding as all their edge trees are already on the ground.

Above: A big old crop recently jacked over on a farm. Left: The 53-tonne Borntrager tree jack on an average edge tree.

Alan started “playing around” trying bottle jacks that “weren’t that successful” and, before long, imported a 28-tonne Borntrager tree jack from the United States which “worked really well but didn’t quite have the capacity for a lot of the work I was doing”.

After discussions with Andy Costello at Hikurangi Forest Farms (now Aratu Forests), a forest owner Alan was working with, who had a number of archaeological sites in a coastal forest that needed to be preserved, Alan “took a punt” on purposebuilt tree jacks and imported the 100-tonne Borntrager tree jack – made up of two 50-tonne cylinders that could be operated individually or together.

“This ended up working extremely well as we felled a lot of trees while keeping the sites one hundred percent preserved with no soil disturbance. Then we moved onto jacking edge trees along fence lines, keeping the fences preserved and, again, this worked well with big cost benefits to the forest owner and contractor who didn’t have to stop logging and back-pull these trees.

Plenty of pluses Tree jacking is “actually pretty simple” says Alan, but you must be a very confident and competent faller.

He explains: “Generally if you have the likes of an edge tree that is heavily branched on the back side and there is no way you can fall it by wedging it over, you will just make a conventional quarter cut and scarf. Accurately measure a box to cut out of the back of the tree for the jack, seat the jack and apply some pressure and take the weight, then finish the last quarter cut and continue pumping the handle and jack the tree over.”

The advantages of jacking over wedging include: • Safety: Jacking edge trees is very safe as the faller is in total control and not relying on a third party in a machine. • Cost: If a logging crew can have all their trees on the ground before logging and

not have to stop and back-pull a tree, it is a big saving. • Minimal effort: Compared to stacking up wedges to get a tree over. • Well-suited to edge trees and marginal trees on the fence line: The average edge tree is straight up and down with heavy branching at the back and hard to wedge over – but easy with a jack. • Suited to challenging topography: “On the East Coast we get a lot of steep ridge tops the falling machine can’t get to and then these jacks come into their own,” says Alan. • Less fatigue: Pounding on wedges gets

“pretty tiring”.

Asked about disadvantages, Alan has to think: “To be honest I don’t see any disadvantages. The jacks are high-capacity but designed to be carried easily – it is a two-person job. One person pumps the jack handle and the other keeps an eye on the canopy above, as generally there are interlocked branches that can break and dislodge.

“The Borntrager jacks are very safe to use. I have only ever had a mechanical linkage break on the 100-tonne which was no big deal and to date the hydraulics have been faultless.”

As for training, he says, “I guess I have learnt a lot over the last five years having jacked in excess of 5000 trees and there are a few things that I have learnt that make the process a lot easier. I have worked with some fallers that pick this up straightaway and some that don’t.

“When falling any tree, being aware of your surroundings is a big thing and when falling edge trees, interlocked branches are always a risk to watch for. A real benefit of using the purpose-built jacks is that they have a built-in pressure gauge that tells you a lot about what the tree is doing, especially on a day when you might have a bit of wind, where you can watch the gauge when the pressure comes on, stop pumping and as the tree sways and pressure comes off, start pumping again.”

Fit for purpose As to how widespread the practise is in New Zealand, he says, “People have been Above: 100-tonne Borntrager tree jacks positioned in the back of a tree. Opposite top: Blue from Lloyd Logging using the 100-tonne Borntrager jacks in Northland, jacking edge trees away from a fence line. These were road edge trees jacked on different days with no machine access. Opposite bottom: Alan Paulson jacking a tree.

jacking trees for years here in New Zealand and overseas but at present I believe that Borntrager is the only company that makes a purpose-built tree jack in different sizes. The purpose-built jacks are designed just for jacking trees as they are made out of aluminium to keep the weight down and if you nick the top plate with your saw no damage is done. The 53-tonne jack which I use the most only weighs 15kg with the swivelling top plate as opposed to a 50-tonne bottle jack weighing 30kg or more with no top plate.”

While the jacks come in different sizes from 28-tonne to 100-tonne, Alan says the 53-tonne is the most commonly used in New Zealand, being aluminium and fairly easy to carry around. These work well on Pine, Redwood and Douglas fir, he adds.

“If I’m jacking a Eucalyptus I will secure the base of the tree with chain as they tend to want to split. The jacks are designed with a square plate on the bottom which forms the base of the jack and the square top is on a cone so it can move as the tree is going over. I have both the 100-tonne and the 53-tonne jacks and have found on the occasional big old tree I can utilise both jacks together and get 150-tonne of lift which hasn’t been often but is handy.

He says there are a few New Zealand contractors who have bought jacks: “Recently I spent a little bit of time with Isaac Lloyd’s brother, Blue, who does his falling in Northland for Lloyd Logging. I spoke to Isaac recently and he said he wished they had been using the jack years ago as now they aren’t working weekends back-pulling edge trees, they don’t have to walk a machine from another job, and they don’t have to stop the yarder, so it has worked out to be very cost-effective.”

Alan is also working on a project with Rob Prebble and Forest Growers Research where the aim is to remote control the jack and take the man well away from the tree. “Unfortunately COVID has delayed this a fair bit,” he says.

A video of the tree jacking process can be viewed on the Safetree website. NZL

Top: A large edge tree needing both the 100-tonne and 53-tonne jacks which gives 150-tonne maximum lift. This was along a fence line with no machine access. Right: Alan Paulson jacking some difficult trees in the Waikato for A&D Logging's Ryan Donnelly.