John Paul Sanborn
Above average climber
If this is the Paolo I've met, he's got some working gray matter. If he does not chime in, I'm sure Dunlap will. They are as good of friends as any 2 people living on oposet sides of the world can be.
I too have seriouse reservations on trusting lags with that kind of loading.
Using a kerfs to set your hitch and and marl sounds much more reasonble.
My rough math gives me ~450# for a 1x3 chunk of oak. I'm not going to huck that chunk too far from the base of the tree, and I'm not a little fellah.
I'd not be comfortable with a metal spring in the rigging, Tenex slings have enough flex for me. If the spring failed it could take your head off.
As for truely huge trees (Not all that many in our metro area) I have a list of people they can call for competative bids. They are not worth it to me any more. If it's a big nastyand one of my sub'ing clients needs help, I'll recomend Sean or Bryan. Though I Sean seems to be thinking of scaling back.
I too have seriouse reservations on trusting lags with that kind of loading.
Using a kerfs to set your hitch and and marl sounds much more reasonble.
My rough math gives me ~450# for a 1x3 chunk of oak. I'm not going to huck that chunk too far from the base of the tree, and I'm not a little fellah.
I'd not be comfortable with a metal spring in the rigging, Tenex slings have enough flex for me. If the spring failed it could take your head off.
As for truely huge trees (Not all that many in our metro area) I have a list of people they can call for competative bids. They are not worth it to me any more. If it's a big nastyand one of my sub'ing clients needs help, I'll recomend Sean or Bryan. Though I Sean seems to be thinking of scaling back.