Tuesday, August 13, 2013

Felling with the Tifor winches

Felling a Leaning Spruce.

Spruce can be notorious for suffing from root plate lift in strong winds, this one was no exception. This Spruce was located in a small stand of trees, on a slope near the gable end of a house. There are power lines running between the house and the trees. The tree was leaning in the direction of the house and lines. As it happens this tree is being supported by the surrounding trees and they are stopping it from going over. How do you tackle something like this? This is the approach we chose to take!

Firstly closely inspect the tree to make sure that it can be dealt with safely in the way that we want to deal with it. 

Climb the tree removing the limbs from the direction it is going to be felled; remove the limbs from the ground up to a point where they are in contact with the surrounding trees, these will be under tension! Having these limbs removed allowed us a space to attach winch wires to the stem so that they have a clear line towards our anchored winches. Two winch wires are attached to the stem, one about two thirds the way up this 60-70ft tree, the second about 6ft below the first. Why two winch wires? The first and highest is the one that will be used to pull the tree over it being high up the stem gives maximum leverage. The direction of fell is across the slope. The problem is trying to control a tree like this with a compromised root plate. There is a chance that as the tree is being pulled to the vertical that it might start to veer downslope; fall along the fence line damaging the fence landing in a position that would be difficult to deal with. A second winch was therefore to be used, it being placed up-slope 45 degrees from the line of fell. The theory being as the tree is pulled to the vertical on the first winch the second winch is kept tensioned so the tree can not head downslope. Once the tree is beyond vertical and heading in the line of pull towards the first winch, also guided by the direction of the felling cut, the second winch wire looses tension but would still restrict the tree falling downslope.  The result was a tree safely on the ground. All that remains would be to tidy up.


Leaning tree with cleaned stem, 2nd wire visible.                Second Tirfor winch.

Posted by James on 13/08 at 08:10 PM
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