Warning: Invalid argument supplied for foreach() in /home/planet/public_html/classes/class.basket.php on line 577
planetFear - Articles - Crevasse Rescue Techniques

Crevasse Rescue Techniques

Article by Barry Roberts
Monday 12th April 2010

It's something we've all thought about: you're travelling across a remote glacier and your partner suddenly disappears into a slot in the ice. Do you really know what to do next? Fortunately, the method for getting someone out of a crevasse is relatively straightforward, provided that certain key procedures are used, as mountain guide Barry Roberts explains.  

 

A sea of crevasses on the Geant Glacier, Mont Blanc, Chamonix: travelling safely in such heavily-crevassed terrain requires proper knowledge of rescue techniques. Photo: copyright David Pickford / www.davidpickford.com

1. Anchor the rope

As discussed in the section on Steep Ground the single most critical element of a good rescue system is a solid anchor. If the anchor fails you can make the situation even worse than it is, so it must be solid. Choose an anchor position 5 metres back from the edge of the crevasse and in line with where the victim went over (set to one side there is a risk that the victim will pendulum on the rope). There are then two options for the anchor:

  • On snow use a ski anchor: this requires 2 skis, 2 slings, 1 screwgate karrabiner, a rope and 1 ropeman. Bury the first ski up to its bindings with the base of the ski pointing towards the crevasse and with the ski pointing away from the crevasse at a 45 degree angle. Bury the second ski at the same angle one foot behind the first in a straight line towards the victim. Press the front ski towards the back ski and while holding the tension tie a sling between the skis. This should run at 90 degrees to the skis and wrap round the back ski at the snowline. Next wrap a second sling around the front ski when it hits the snowline and clip on a screwgate karribiner. Done right in reasonably firm snow, this is a completely bomb proof anchor. 
  • On ice use an ice screw ski anchor: this requires 2 ice screws, 1 sling, 3 screwgate karribiners, a rope and 1 ropeman. First clear away all the loose snow and ice from the anchor position down to the hard part of the glacier. You may find it helpful to use an ice axe to do this. Screw the first ice screw vertically into the ice making sure that it goes all the way down to the head, and that the head points towards the victim. Screw in the second ice screw around two feet back from the first and one foot apart or as close to this as the angle of ground and quality of ice permits. Again make sure it goes in all the way to the head and that the head points towards the victim. Clip a screwgate karribiner into each ice screw, clip a long sling into each screwgate. Pull the middle of the sling into the direction of the victim, tie an overhand knot, and pass a third screwgate through the overhand knot. This ensure that the force is evenly distributed between the two anchors, and if one fails the full force will come evenly onto the other with no shockloading. Again, in good ice, this is a bomb proof backed up anchor system.

2. Check the victim and attach the rope

Once the anchor is secure, the next stage is to get a rope down to the victim. To do this, first clip a ropeman onto the screwgate at the anchor, run the rope through and screw up all the gates. You now have a secure rope with the ropeman acting as a solid one-way ratchet (i.e. the rope can be pulled through but can’t slip back). Take hold of the end that can’t slip back (the “live” end) and tie a figure of eight knot in the live end of the rope. Secure yourself to the rope with a prussic loop then walk towards the victim staying well back from the edge of the crevasse and shout down to ask how they are. When you hear the victim is ok , throw the rope tell and tell them to clip on and walk back to the anchor. As soon the victim is clipped in, pull the slack rope through the ropeman until it becomes taught. You now have the victim attached to the rope and secured so that they cannot slip any further into the crevasse.

3. Prepare lip

As you haul the victim out the rope can cut deeply into the lip of the crevasse, particularly if there is a snow cornice. This can make it very difficult for the victim to get out as they will be pulled vertically up into the overhanging cornice roof . You therefore need to prepare the crevasse lip. To do this, send one person with an ice axe forward secured with a prussic loop tied to the rope and attached to their harness. This provides security in case they slip or in case the cornice collapses. Use the axe to clear away as much loose snow as possible (remembering to warn the victim about the debris coming down). Then embed the axe with the adze pointing down firmly into the snow so that the edge of the rope runs over the shaft of the axe and should not cut so deeply into the crevasse edge. Retreat back safely to the anchor position.

4. Set up the pulley system

With a large enough group of people on the surface you can simply haul on the rope to pull the victim out. In practice, the friction in the system means that you will almost always have to set up a pulley system to increase the leverage . With the ropeman set-up, this is simple to do. First tie a prussik onto the live rope about 3 metres in front of the anchor point, and clip a snap gate through the end. Clip the dead end of the rope through the snap gate and you have completed the system. When you haul on the dead end of the rope, the prussic grips allowing the rope to slide through the ropeman ratchet and slip over the snap link giving the desired 3:1 mechanical advantage.

5. Haul out

You are now ready to perform the rescue. Simply haul on the dead end of the rope to gradually pull the victim up out of the crevasse. As you do so, the prussik will move towards the anchor, so you will need to have one person directing operations and watching the knot carefully. As it gets close to the anchor the co-ordinator should stop the hauling and slide the prussik 3 metres back up the rope towards the victim. Haul slowly and carefully, being particularly careful as the victim nears the cornice and may have to make a heroic effort to haul themselves safely out and over.

Glacier skiing through a heavily-crevassed section: confidence with rescue techniques is vital in such terrain. Photo: copyright David Pickford / www.davidpickford.com

So to summarise, the sequence is:

  • Set up the anchor,
  • Secure yourself then check the victim and attach the rope,
  • Prepare the lip,
  • Set up the pulley, and
  • Haul out.

This is the complete rescue technique. The only major variation you need to learn is if the victim falls in already attached to the rope. This is a much simpler and safer situation. All you have to do is:

  • Hold the fall and walk backwards – hopefully the victim will emerge!
  • Failing that, set up the anchor as usual,
  • Clip in the rope and escape the system.

Crevasse rescue is not difficult but it is one of the more complex and technical processes you need to learn and it is easy to make mistakes if you get confused. A few simple tips are worth bearing in mind:

  • Practice, practice, practice: although less technical than transceiver search, crevasse rescue is still a complex process and you want to get it right. The last thing you want to do is to stand there struggling to remember how to set up part of the system while your friend is freezing or bleeding at the bottom of a slot. At least once or twice a season, it’s worth finding a safe crevasse or even just a steep piece of ground to practice the technique – using a rucksack or a willing volunteer. You can even set up and practice crevasse rescue in the comfort of your own home during the quiet summer months (although we suggest you tie the anchor to the furniture rather than drilling ice screws into the floor!).
  • Be methodical: speed matters – certainly until you’ve attached a rope to prevent the victim from falling further, but much less so than in transceiver rescue where the risk is suffocation. Dropping your victim further into the crevasse because of a fault in setting up the rescue system is far worse than leaving them there for a couple of extra minutes while you check the set up. A slow and safe rescue will always be better than a rushed one which leads to mistakes.
  • Appoint a leader: too many cooks certainly spoil the broth if you’re all trying to do different things at the same time. Get one person to take overall responsibility for directing operations and checking the set up at each stage of the process. The leader should be the person who goes to check on the victim and watches the prussic loop and victim during the haul out.
  • Take care when nearing the lip: despite your best efforts to prepare the lip, the most difficult part of the rescue is often when the victim approaches the lip and may have to haul themselves over an overhang. Don’t rush, instead give them plenty of time to get organised. Pulling too hard can trap the victim under the cornice lip and make their job much harder. In one tragic case in the US, a victim who would probably otherwise have survived, was killed when she became trapped under the lip. The rescuers pulled so hard that her harness snapped and she fell to her death. Take your time!

 


PlanetFear media is funded by our online store. Consider shopping with us for your latest outdoor gear, and check out our latest sale items at great prices: visit the planetFear shop here.

 

Bookmark: Add to Favourites Add to Google Bookamrks Add to Delicious Digg this Add to Myspace Add to Facebook Add to furl Add to Yahoo Review on StumbeUpon Add to reddit Add to Newsvine Add to Windows Live Favourites
Subscribe to RSS Feed Add to Technorati Add to Twitter Add to Yahoo Bookmarks Add to Aol Favourites Add to Ask Add to FARK Add to Slashdot Add to Mixx Add to Multiply Add to Simpy Add to Blogmarks

Comments

There are currently no comments on this article.

Add a Comment

Title
Comment
Security Code:


Please enter the security code in the text box below.