Matt is very adept at sidestepping my attempts to mildly troll him
Heh heh
I try David but you're bloody good!
OK Andrew I'll fill you in mate. This is actually documented in "some" forestry manuals and the forestry courses I've done didn't talk about this technique. A number of arborists I've dealt with know about it though. I've made references and shown photos of it before in my Today's Job thread.
Basically if you are pushing or towing a tree off it's stump, you can sometimes actually pull the butt of the trunk off the FRONT of the stump. This can end in disaster and is a real risk with heavy leaners and a low push/tow where the bulk of the weight is still above your pull/push point. I have had this happen to me twice. The first one was an over exuberant relative in a 120HP New Holland 4WD tractor who put his foot into it (after telling him to go GENTLY) and tore a heavy leaning 4' gum straight off the front of the stump - end result was a tree that pulled straight off the stump, dug in, then went sideways swinging around on the cable. It crushed an old grain silo/tank. No biggy.
Ahem...
The other one was when my brother and I were towing over a smaller dead gum and he stalled the ute mid pull and didn't get on the brakes quick enough. Result was a tree that pulled forward off the stump, dug in, then fell straight back, taking the Rodeo with it, but luckily fell straight down the middle of an orange row with no damage done.
By bringing the back cut in lower it is basically impossible to tear the trunk off the front of the stump and lose control of the tree. This was the reason why I cracked the sh*ts with the corporate farm I was working for as their dopey worker decided to get an excavator in and play Mr Forestry for a day (while borrowing my 390XP and 32" bar to just "cut some stumps"!). I came back and he'd had an excavator push all these heavy leaners I'd left while doing incorrect cuts with MY saw - interestingly the week after a fellow AS member and qualified arborist came over from Mildura to buy my 5100-S. Wayne (gmax) was up for a chainsaw trip so was with me. The first thing that this guy commented on when I said this peanut was pushing them over with an excavator was that "his cuts are wrong and he'll have a tree come back over on the excavator using that technique". Wayne will back this up.
Remember though the taller the tree, the heavier the lean, and how far the excavator/tow cable can go up the tree all have an influence but it's a good, safe technique to use. If you've got a heavy leaning 100 footer and you're pushing/towing it over from 20 foot up you might want to get your will sorted
In the photo below both went to the right...
I hope you can see what I mean mate and being an engineer I reckon you'll be able to see what I'm saying
Good work too and I wasn't trying to be critical but somehow the above technique as useful as it is seems to be basically unheard of. Even the guys at the forestry course hadn't seen or heard of it before but I first saw it in an NSW Forestry Manual.