Monday, July 7, 2008

Crevasse Rescue Review

The following crevasse rescue description is based on the course work provided by American Alpine Institute field guides. This systematic description will make the most sense to those students who have worked with AAI in the field on crevasse rescue systems.

This two person crevasse rescue description is broken into three parts. The first part is entitled Anchor; the second, Z-Pulley and the third, C on Z.
Most students obtain the best results when they think of this as a dynamic three part system. Students have problems and get lost when they lose sight of their objective. Any time one gets lost while working through the system they should step back and think clearly about what they are trying to do in that part of the rescue.

  1. Self-arrest and place your foot over the rope. Be sure to kick your feet in firmly to hold the weight.
  2. Place a piece of snow or ice protection and attach it to a locking carabiner. This locking carabiner will thus be designated the "master carabiner." This first piece of snow protection must be extremely good. If it is not, both the victim and the rescuer will be in serious danger.
  3. Attach your foot prussiks to the master carabiner. Lock the carabiner and NEVER OPEN THE MASTER CARABINER AGAIN!
  4. Keeping your ice-axe handy, slowly allow the victim's body to weight the anchor. Be sure to keep your ice-axe within reach until the anchor is complete. If that first piece of protection blows out, you will need to arrest again.
  5. Take the rescue coils off of your shoulder and slowly unwrap them. Be sure not to panic as the mountaineers coil is easily tangled.
  6. Estimate the distance up to the master carabiner, then estimate the distance from the carabiner to the crevasse. Add these two figures together and then tie a figure-eight knot in the rope at this length. If there is a large amount of crevasse danger in the area, you may have to tie this knot significantly closer to yourself in order to protect yourself.
  7. Clear one of the two locking carabiners that you are tied into the rope with of all items. Clip the new figure-eight knot into this carabiner. Clear the second carabiner of everything. Leave your waist prussik on the rope.
  8. Work your way up to the master carabiner. Tie a figure-eight knot into the rope that is being held by your foot prussik. Using a locking carabiner, clip this into the master carabiner and lock it. This will back-up the prussik which is currently holding the victim's weight.
  9. Step nine is where you will back-up the first piece of protection. It is important not to disturb this piece of protection while placing the second piece or all will be lost. Measure the distance from the master carabiner to your second placement. Be sure that when you place the second piece, you consider the length of the sling or cordellete with the carabiners on them. You want this second piece to be as equalized as possible. Beginner level students will stretch a sling as tightly as possible from the master carabiner to the second piece, where advanced students may use the block and tackle with a cordellete. Once you complete this, the Anchor is finished.
  1. Take your pack-prussik or a shoulder-length sling and girth-hitch it to your waist prussik which is still on the tensioned rope. If you are wearing crampons, be very careful not to step on the rope. Clip this extension to the unused locking carabiner at the tie-in point on your harness.
  2. Work your way toward the crevasse while probing for additional crevasses with your ice-axe. You may have to re-tie your safety knot to reach the crevasse. Re-tie this knot whenever it is necessary.
  3. Once you reach the lip, confirm that your partner is conscious and needs to be pulled out of the crevasse. If he or she does not answer, you will have to rappel down into the crevasse to see what is wrong. To climb back out of the crevasse it is possible to use your partner's prussik cords. Pad and clear the lip before rappelling.
  4. If your partner answers and says that he or she needs to be pulled out, clear the lip of all snow. Warn your partner before you start to kick snow down on top of them. The entire rope should be visible at the lip of the crevasse before you are finished.
  5. Slide your ice-axe under the rope at the lip in order to pad it. Place the pick into the snow in order to secure it. Clip the axe to the rope so that it does not fall down into the hole.
  6. Unclip the extension attached to your harness. Take the pack prussik off of your waist prussik. You should still be relatively close to the lip of the crevasse when this takes place.
  7. Clip a pulley to the waist prussik. Run the rope coming from the master carabiner through this pulley. The waist prussik may also be reffered to as the "tractor."
  8. Walk back up to the master carabiner. Clip a second pulley into the master carabiner and run the rope that is clipped to the locking carabiner on the master carabiner through the pulley. It doesn't matter which side of the knot you attach the pulley too.
  9. Untie the knot next to the pulley, but leave the locking carabiner attached to the master carabiner.
  10. Pull on the line that you are tied too. Haul the vicitm up approximately a foot.
  11. Untie the knot between the pulley attached to the master carabiner and the foot prussik. The foot prussik may be reffered to as the "ratchet."
  12. You may now haul the victim on a 3:1 system. Remeber to mind the foot prussik (ratchet) while hauling, and be aware that for every three feet you pull, the victim will only rise one foot. You have now completed the Z-Pulley.
C-Z Pulley System
  1. "To add the C, I must tie the end of the rope into the anchor!" This is usually chanted during some guides trainings for a reason. If you remember this, the rest will make more sense. Tie a figure-eight knot into the end of the rope and clip it into the locking carabiner that is still attached to the master carabiner.
  2. Tie a knot next to the pulley nearest the crevasse lip and clip a carabiner into it. This knot may be a clove-hitch or a figure-eight. Advanced students may place the pack prussik on the haul line here with a non-locker clipped to it. This carabiner may also have an additional pulley on it if you have one.
  3. Clip the line that you just clipped into the locking carabiner into the new carabiner down by the pulley nearest the lip. This is your new haul line.
  4. You now have a 6:1 hauling system. It is important to realize that you must haul six feet for every foot that the victim rises. You have completed the C-Z Pulley system.
The photo to the left shows a completed anchor. The red carabiner is the master carabiner. Note that there are two pieces of gear. The first piece placed was a snow fluke. The back-up piece was a picket buried in a t-slot. The blue carabiner is the backup line.

This photo shows a completed Z-Pulley anchor. There will be one more step for the rescuer in this picture. He will have to release the figure-eight knot from the blue locking carabiner before the rescue can continue. The blue locking carabiner should stay in place for later use.

This photo shows a completed Z-Pulley system. The rescuer need only to pull on the "haul line" in order to get his partner out of the crevasse.

This photo shows a climber hauling her partner out of a crevasse with a completed 6:1 pulley system. We often refer to this as a C-Z Pulley system.

Other Consi
  1. Always pull away from the crevasse.
  2. If the victim suddenly becomes more difficult to pull-out check the victim. Do not crush the victim in the lip of the crevasse.
  3. Make sure the victim keeps his hands from behind the rope as it cuts through the lip.
  4. Lock all carabiners. You only need two locking carabiners aside from the two on your harness to complete this rescue.
  5. If you can haul the person out on a 3:1, then do it. It will be faster.
  6. Once you understand the system, experiment with short-cuts. Do not experiment until you have a concrete understanding of the whole system.

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