Guided rappel
From ropewiki.com
A guided rappel will be useful to allow rappelers overcome a dangerous hydraulic, a keeper hole or transfer a victim over a waterfall.
- Set blocked rope at top of drop to rappel down single line
- Rappel down and overcome the obstacle
- Make an anchor at the bottom of the drop to tie off the guide line (which will now also become the new rappel anchor)
- The blocked line the first person used for rappel is now the guide line. Tension it using any tension system (examples shown below)
- Throw down the rope bag to the person below (or zip line the rope bag down on the tensioned line), creating a second line from the top of the drop to the anchor at bottom
- Get people on guided rappel:
- Have them clip with a short tether directly to the tensioned guide line
- Have them rappel on the loose, bag side of the rope (make sure the bag reaches the bottom anchor and is securely fastened to the bottom anchor first)
- Once everyone is done, release the guide line from the bottom anchor
- Pull down the rope as usual
The simplest way to tension the line is often to use the Trucker hitch because it does not require any additional gear, it locks, and it is easy to release.
Trucker Hitch
- Option a) 3:1 mechanical advantage NON self-locking: DSC_8 to DSC9
- Option b) 5:1 mechanical advantage with self-locking: DSC_10 to DSC_13
Voodoo
Also called the Transport Hitch, PM Hitch, or Purely Magic Hitch, the Voodoo holds tension after pulling. It is difficult to analyze how it works of what the theoretical mechanical advantage is, but practically it has been measured to have a mechanical disadvantage of 0.5:1.
