MA in negative rigging?

[Fulcrum Tree Felling]

I had a situation come up in which my apprentice suggested that we insert a 3/1 MA system behind the porta-wrap to help control a large section we were negative rigging.
I didn't do it but I found afterwards that I couldn't exactly explain why it wouldn't work (or at least help slow it down)
Has anyone tried this?
There's nothing about it in any book I've read or video I've seen.
I'm happy to answer any questions about the situation.

 

[Del_]

How do you plan on stabilizing the Port-a-Wrap when slack develops during the short period of free fall?

Sudden slack in Port-a-Wrap rigging can fool with the wraps on a Port-a-Wrap.

 

[beastmaster]

I had a situation come up in which my apprentice suggested that we insert a 3/1 MA system behind the porta-wrap to help control a large section we were negative rigging.
I didn't do it but I found afterwards that I couldn't exactly explain why it wouldn't work (or at least help slow it down)
Has anyone tried this?
There's nothing about it in any book I've read or video I've seen.
I'm happy to answer any questions about the situation.

I don’t understand why you would need it, unless you needed to lift the cut piece after the fact. If that was the case you could safely add it after you stopped it on the portawrap. Or I’m I missing something?

 

[telecasterfool]

Please clarify the "behind the port a wrap" statement. show a picture or diagram. I'm interested in any new thinking, but I don't understand the proposed setup.

 

[Del_]

Please clarify the "behind the port a wrap" statement. show a picture or diagram. I'm interested in any new thinking, but I don't understand the proposed setup.

Meaning the MA is between the anchor point and the Port-a-Wrap.

 

[TheJollyLogger]

Yeah, this one doesn't make sense to me either. You must be taking some monster picks for him to have max wraps on a porty and he still wants more help.

 

[Fulcrum Tree Felling]

The idea was to put a z-rig between the porta-wrap and another tree to give the groundsman more control with the porta-wrap.
Its completely impractical, just a thought experiment.

 

[Del_]

The idea was to put a z-rig between the porta-wrap and another tree to give the groundsman more control with the porta-wrap.
Its completely impractical, just a thought experiment.

It's not impractial at all and is a great way to pre tension a Port-a-Wrap. Important too is reducing 'shock loading of the rigging system' by allowing some slippage of the rope on the Port-a-Wrap. This 'slipping' is an advanced skill and to be taken quite seriously.

It just isn't a good idea if slack can develop in the rigging system as in negative rigging, for the reasons I mentioned earlier.

 

[pdqdl]

If you are trying to gain control, consider putting a 2:1 mechanical advantage by adding a block/pulley to the chunk being lowered, then back up to the rigging point. This distributes the shock load on all the points involved, and reduces the strain on the porty and the rope.

Of course, you'll need twice as many pulleys and twice as long a rope.