Jump to content

Log in or register to remove this advert

Climber Down


Darrin Turnbull
 Share

Recommended Posts

Log in or register to remove this advert

1 minute ago, Mick Dempsey said:

Don’t get it, sorry.

It's basically because if you use a cambium saver you tie into the cambium saver and you hang off a branch so it is only your weight on the branch i.e a top anchor. In this format you're climbing with the same forces as a DDRT system, all of your weight only on the branch. If you base anchor then it's like having a pulley on the branch. Your weight of say 80kg is on one end of the line then the other end has to balance your weight so the anchor is basically weighing or pulling 80kg too. In total you have now loaded the branch with 160kg (your weight on one side of the line and the anchor pulling your weight again on the other acting as a 2:1 pulley system. 

 

Now, let's say you climb above your anchor point without using redirects. The "safety factor" when doing rigging if my mind is remembering correctly is 11x. You slip and fall 2/3 meters. Your shock loading (especially as you are using a static line) can be up to 880kg. Now, because of the basal anchor and the 2:1 system you have created your loading on the limb is now 1760kg of force in the worst case scenario.

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

33 minutes ago, Tommy_B said:

Because the other end is not anchored off statically. It is moving you

Correct in DDRT but not so in SRT (which was what was being referred to).

Great post Paddy, but I think you are confused (or I’ve interpreted it wrong) in saying that the cambium saver removes the double loading from the branch/anchor point. It doesn’t. 

  • Thanks 2
Link to comment
Share on other sites

Apologies, the post above mine came as I wrote.

If you tie a stopper knot into the cambium saver (which I now think you mean) then yes, you only load the branch with the climber’s weight. You can subsequently tie off a very long tail as a base anchor and that won’t apply any additional significant load into the cambium saver (and therefore anchor point) unless the anchor point fails and the ‘redundant’ tail then becomes hung up and catches the climber.

If (as I thought you meant) you simply base-tie your climbing rope after running it through a cambium saver you are in no way reducing the actual loading imposed on the anchor point - it will be double. 

Link to comment
Share on other sites

Sorry, bad explanation on my behalf. I usually tie an alpine butterfly and stick a carabiner through it and pull that up onto the the small ring side of the cambium saver. The knot side which is now unloaded goes over other branches and gets basal tied, if my cambium saver branch snaps then the loading changes to the basal anchor and hopefully the branches below. Worst case scenario the top snapping branches on the way down would hopefully slow my decent a little ?

  • Like 1
Link to comment
Share on other sites

5 minutes ago, Mick Dempsey said:

Right, gotcha, not using a base anchor.

 

 

Edit. No, still don’t get it. 
 

if you’re using a base anchor then there’s the same pressure on your top anchor point when ascending, cambium saver or not. 

The base anchor is tied but not loaded - the loading is taken up by a stopper-knot on the base-anchor side of the cambium saver. 
Clever system, I like that idea!

Link to comment
Share on other sites

Anyway, back on topic. I didn't mean this to be a "mines better than yours" "I'm better than you" thing...  Just explaining how I SRT when I'm unsure of anchor and how I feel it's safer than DDRT as we were discussing the dangers of srt. 

 

At least this seems like a clean cut case of climber error... 

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share


  •  

  • Featured Adverts

About

Arbtalk.co.uk is a hub for the arboriculture industry in the UK.  
If you're just starting out and you need business, equipment, tech or training support you're in the right place.  If you've done it, made it, got a van load of oily t-shirts and have decided to give something back by sharing your knowledge or wisdom,  then you're welcome too.
If you would like to contribute to making this industry more effective and safe then welcome.
Just like a living tree, it'll always be a work in progress.
Please have a look around, sign up, share and contribute the best you have.

See you inside.

The Arbtalk Team

Follow us

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.