Rigging point failure

[Winch]

I pretension the Hobbs to take some stretch out of the rope, and to lessen the shock-load on the system. Small limbs I usually just get the groundie to pull tight with a wrap. Large limbs, like this one, get 2-3 wraps and some ratcheting with the pole.

It's pretty standard to pretension top-rigged (i.e. not butt-hitched) limbs - exactly like telling the crane op to put 2000 lbs of lift on the cable. You wouldn't just hook the crane cable to the limb and cut, then tension later.

 

[Tom Dunlap]

Why use a dynamic rope like polydyne and then use the Hobbs to take the stretch out. That seems like a cancellation.

My rigging scenario for lifting or tensioning is to use a low stretch line like a double braid. Having stretch in a rigging scenario adds a variable that is hard to adjust for.

 

[Winch]

Tom, you are absolutely correct. I will switch out ropes on occasion. This was not one of those occasions. There was both positive and negative rigging happening in this tree, as there is in most removals.

Polydyne is not a one-size fits all rope after all. That is, if it contributed to the failure. If it didn't, I think it's a rope that's good for both, maybe not ideal for lifting, but it works.

I may just switch out in the future, but who am I kidding? The rigging point was 30' above me (but not over me)and it would take a good 5 minutes to switch it out, and then possibly back again - that's why I didn't switch it for better or for worse.

 

[brushbandit]

You also have to remember that once the piece is cut off you have twice the weight of the piece at the rigging point.