M Redirect Traverse

[Steve Bullman]

Come on - get the grey matter working!

 

 

and for your information, mine happens to be more of a brownish colour, and slightly sludgy:001_tongue:

[Peter]

You should be able to rig a redi with the gear you carry on the harness in minutes. If the tree warrants a second climbing system, then you should have assessed it beforehand and have the gear ready to set it up.

The point of the redirect technique is not that it replaces the second climbing system technique, but supplements it.

The right tool for the right job.

[Laz]

I don't disagree with either of you on the points raised...except that you don't have brown sludge instead of grey matter, Steve. I just tire of doing others risk assessment legwork for them, so thought I'd go through the thought process on the whiteboard with y'all.

 

My point is, re-directs can fail on the extremities of branches, due to leverage, increased anchor forces and reduced safety factors of wood with poor H/D ratio. Particularly some species like Eucalyptus, poplar and willow, whose form often requires re-directs but whose strength is lacking where they are most usefully applied.

 

Anyway...

 

3. What happens if the re-direct anchor fails?

 

4. What happens if a secondary system anchor fails?

[Dean Lofthouse]

Big swings and or heavy loading on primary anchor point and equipment. ?

 

Brown stains in your undies

[Peter]

If a redi fails, you are quite likely to hit the deck, due to the amount of slack suddenly introduced into the climbing system.

 

If a secondary anchor fails, then big shock loading on the primary anchor.

 

Therefore a redi should only be used when the redi point is a suitable load bearing tie in point, taking into account loading angles and forces etc.

 

As I said, the right tool for the right job!

[ecolojim]

If a secondary anchor fails, then big shock loading on the primary anchor.

 

why is that? surely both primary and secondary anchors should have all slack taken out of their respective systems thus no shock loading at all.

 

bit of a nasty swing, inconvenience at best, for sure extra loading, but I cant see a case for shock loading

[D Mc]

I am sure you are all aware of the substantial side loads created by a redirect. If you are not familiar with this, just find a sling chart and look at the force multiple factors.

 

With that aside, the problem with the M redirect is that you wind up with a substantial amount of rope by running it through the pulley and a friction hitch on just one side. If either one of your TIPs fail, you are all of a sudden holding a bunch of useless slack as you are falling. With the standard double rope redirect, (with two seperate ropes or the tail end of your rope) if one of your TIPs fail you will going for a swing but not a fall.

 

Dave

[ecolojim]

Peter, if you were talking in terms of this M system, I get ya now, I was thinking in terms of standard use of a secondary TIP

[Laz]

I am sure you are all aware of the substantial side loads created by a redirect. If you are not familiar with this, just find a sling chart and look at the force multiple factors.

 

With that aside, the problem with the M redirect is that you wind up with a substantial amount of rope by running it through the pulley and a friction hitch on just one side. If either one of your TIPs fail, you are all of a sudden holding a bunch of useless slack as you are falling. With the standard double rope redirect, (with two seperate ropes or the tail end of your rope) if one of your TIPs fail you will going for a swing but not a fall.

 

Dave

 

You got it Dave! (of course!).

 

With a conventional re-direct or secondary system, there will be a swing but not a fall if either fail, and the primary anchor should remain intact.

 

The difference with the M technique, is if the second anchor fails, there will be likely so much slack in the system that a howler of a fall will result, plus the swing. Falling any distance on a doubled low stretch rope is likely to lead to injury, if it doesn't break out the primary TIP.

 

This type of fall would likely result in serious internal injury/death from high fall forces.

 

This risk compared to using a trad re-direct or secondary system, far out weighs any benefit.

 

It does worry me about the future of the industry if these techniques are being promoted without the serious limitations explained or understood.

 

Take care!

Laz

[Amelanchier]

It does worry me about the future of the industry if these techniques are being promoted without the serious limitations explained or understood.

 

Promoted? I saw an experienced, competant climber use a technique unknown to me in a appropriate situation. I thought I'd share my experience.

 

Promoted? Seriously?