bitzer
******** Timber Expert
A pressure gauge can be a real eye opener. There's usually quite a bit of safety margin built in to the red line but age and normal deterioration can make the limit something of a guessing game. I've seen jacks blow out and I've had pressure gauges and pump lines rupture. If you're right up to the limits of the jack and that happens it gets real ugly real quick. If I'm going to be jacking trees that I know will test the limits of the jack I'll carry some shims with me. Another good trick is to wedge as you jack and wedge as much as possible the whole time. That way if your jack blows out or if the tree sets back hard on the jack you might have a better chance of getting out without tearing up expensive equipment.
Another caution about jacks, as long as I'm blabbing away, is to never ever assume a jack will solve all your problems with a bad leaner. Using a combination cut, like the Coos Bay, along with a little gentle jacking, will usually produce better results. And it might result in a lot less cussing, too. :smile2:
Thats some great info right there! I was thinking about that with the wedges. I stacked them and tried to keep them tight hoping my jack would hold. The hinge made me a little nervous too. Thanks Gologit!
Heres another one from the next day. Nevermind the cut farthest down. I kind of lost my mind on that one. Its kind of fun to watch, but hopefully I can get one of a better stump in the future. Each successive kerf should have been not as far back, kind of like steps and a chunk came out that was not supposed to. I also put a siswel in the far side for good measure. The tree started to grab my saw which delayed the motion a little I think. There was enough wood. My camera died as soon as the stem hit the ground. Oh well. Entertainment if anything else.
[video=youtube;WSa0osZs8Z0]http://www.youtube.com/watch?v=WSa0osZs8Z0[/video]