Hi Dave,
Yes I possess and use a Silky high pruning saw. I use this mainly on softwood trees and tend to remove only dead branches to a height of about 16 - 18 ft. Above this height the saw becomes very whippy and the angle of cut steepens such that one has to stand too close to the tree trunk and therefore within the target drop zone of the falling branches. You will also need to wear eye and head protection. Sawdust raining down is a major nuisance and I have found that wearing a baseball type hat is ideal.
I cleaned all of my softwoods about 10 years ago when they were in the 30 - 40" BHG region and really I should have done this a bit earlier. I would caution against removing large live branches on softwoods since this can result in large amounts of resin weepage and in some species the formation of bulbous callouses e.g. especially Norwegian spruce. I have had good clean results from Douglas Fir, Cedar and Larch which have healed over real quick. Ideally branches should be no larger than 1 - 2" and removal of live branches of this size and greater runs the risk of allowing pathogens to enter the tree.
The downside to this practice is that the woodland floor becomes littered with branches which makes negotiation through the woodlot more difficult and increases the prospect of foot & leg wounds and tyre punctures so I tend to gather and stack fallen branches in heaps to provide better access and also to provide wild life refuge habitat and encourage rotting down. I have found that a major safety benefit to high pruning softwoods is that there is no longer a danger of getting a poke in the eye from a sharp stick and owls seem to frequent the wood more being able to fly unimpeded through the trees. It becomes much easier to look up into the canopy and make better decisions about which trees should be selectively removed and there are also less incidents due to hang up on branches as a tree is felled.
I have not had good luck with high pruning deciduous trees like oak, ash, etc. The saw can bind in the kerf as the branch sags as the cut proceeds and care needs to be taken on live branches to make 2 pruning cuts - one to drop the branch and one to remove the branch peg. This is because deciduous branches have a nasty habit of tearing the bark back along the underside of the branch.
In medieval times commoners were allowed and indeed most probably encouraged to remove deciduous tree branches to a height of about 16 feet for cutting up and stacking into firewood bundles (faggotts [from the Latin fagisti]) and this process gave rise to the right of gathering firewood in some woodlands however this had to be done "by hook or by crook" and so it was not a right to cut down trees. Most medieval buildings are 16 - 17 feet wide and this timber length fits rather nicely with high pruning practice.
The major downside of high pruning is that it results in a major crick in the neck and is thus best tackled in easy stages.
Regards
Ken Hume
