Rigging? Maybe not.

[tockmal]

 

One thing I was taught to do on a tree I think might be unstable is to start from the top, or at least try to remove 2 times my body weight, then tie in and work off that stem.

I rarely see this done by other climbers though.

 

I've worked with guys that like that approach, starting by taking the top out first, I only do it if I'm working in a single stemmed conifer and its very windy.

 

The main problem I have with the top down approach is the branches dropping onto the branches lower down and creating shockloading on the stem especially if they are bigger scaffold limbs, its unlikely that this would cause a tree to fail but I don't like increasing the probability of this happening.

 

I would never rule it out though as you have to be adaptable to all circumstances and all trees in an infinite number of different situations.

[tockmal]

Would you consider rigging using two pulleys, one on either stem?

 

When the system was loaded (providing good rigging angles) it would share the force and reduce load on the weak union (by pulling it together)

 

I do this a lot pete, it really helps to give you a feeling of having more control over the forces being exerted on the tree. I like the way the forces are dissipated through the stems creating a safer rigging option.

 

The only thing with the Walnut was the obvious structural defect at the stem union, we didn't want to do any rigging at all. With a tree like that Walnut I think there is a slight chance when using the two pulley system (one in each stem) that the stems may separate due to the seesaw effect of the forces pulling and releasing on the stems when they are loaded.

[Pete Mctree]

With a tree like that Walnut I think there is a slight chance when using the two pulley system (one in each stem) that the stems may separate due to the seesaw effect of the forces pulling and releasing on the stems when they are loaded.

 

If the piece is not being locked off, and of suitable size, i do not consider this much of an issue. However when mis aligned the rotational effect does often worry me.

[tockmal]

If the piece is not being locked off, and of suitable size, i do not consider this much of an issue. However when mis aligned the rotational effect does often worry me.

 

Its the oscillaing de-limbed stem I fear, the wood has never moved in that way in its life, one of the most unpredictable aspects of our work.