rcwild
04-11-2004, 09:35 PM
You heard the longest rappel in the canyon is less than 70 feet, so you took along your 50 meter rope. Half-way through the canyon, standing at the top of a 90-foot drop, you realize the beta you received is not very accurate. What do you do?
The simplest way to deal with the situation is to set up a block on your rope. Run your 50 meter rope through the rappel rings and feed out enough of it so the end reaches the ground. This will be your rappel strand. On the back side of the rappel rings, tie a figure eight on a bight. This knot will jam up against the rappel rings, keeping your rappel strand from pulling through.
Your 50 meter rope is approximately 164 feet long. You need an additional 16+ feet of pull cord (90 feet x 2 - 164). Scrounge around in your pack and you will probably find more than enough accessory cord, webbing, shoe laces, etc. that you can attach to the back end of your rope to extend your pull cord.
Because the knots are in the "pull cord" portion of your ropes, you will not have to pass it while on rappel.
A few notes:
(1) It should be obvious that the rappel rings, rapide or whatever, need to be smaller than the figure eight knot so it can't slip through.
(2) The knot is adequate to block the rope, but may be difficult to untie after retrieval if heavily loaded. For this reason, some people insert a carabiner through the body of the knot. After retrieval, the smooth 'biner is fairly easy to remove and the knot is much easier to untie.
(3) Another option for a block is to use a carabiner directly. On the back side of the rappel rings, make a clove hitch in the rope and place it on the backbone of the carabiner. With this set-up, the carabiner itself comes to rest against the back side of the rappel rings.
(4) I always carry a river rescue throw bag while canyoneering. Mine contains 60 feet of 1/4 inch polypro rope. Comes in handy for situations like this one and is very compact to carry.
Have fun. Be safe.
Rich
The simplest way to deal with the situation is to set up a block on your rope. Run your 50 meter rope through the rappel rings and feed out enough of it so the end reaches the ground. This will be your rappel strand. On the back side of the rappel rings, tie a figure eight on a bight. This knot will jam up against the rappel rings, keeping your rappel strand from pulling through.
Your 50 meter rope is approximately 164 feet long. You need an additional 16+ feet of pull cord (90 feet x 2 - 164). Scrounge around in your pack and you will probably find more than enough accessory cord, webbing, shoe laces, etc. that you can attach to the back end of your rope to extend your pull cord.
Because the knots are in the "pull cord" portion of your ropes, you will not have to pass it while on rappel.
A few notes:
(1) It should be obvious that the rappel rings, rapide or whatever, need to be smaller than the figure eight knot so it can't slip through.
(2) The knot is adequate to block the rope, but may be difficult to untie after retrieval if heavily loaded. For this reason, some people insert a carabiner through the body of the knot. After retrieval, the smooth 'biner is fairly easy to remove and the knot is much easier to untie.
(3) Another option for a block is to use a carabiner directly. On the back side of the rappel rings, make a clove hitch in the rope and place it on the backbone of the carabiner. With this set-up, the carabiner itself comes to rest against the back side of the rappel rings.
(4) I always carry a river rescue throw bag while canyoneering. Mine contains 60 feet of 1/4 inch polypro rope. Comes in handy for situations like this one and is very compact to carry.
Have fun. Be safe.
Rich