Moutain knowledge | Crevasse rescue Part III - Anchor construction

Crack rescue is one of the topics that most tourers, ski mountaineers and freeriders find very complex. However, the basic principles are actually quite simple and the tools are not rocket science either. Once you have understood both, you are actually equipped for all situations on the glacier. Today we will give you an introduction to the construction of anchor points.

For crevasse rescue, you can use a variety of anchors to create fixed points (points at which the rope safety chain is anchored to the terrain), but as a rule you will not find any rock within easy reach, so you will have to create an anchor in snow or ice. Depending on the strength and compactness of the frozen water base, the different anchor types have different holding forces, which is why you have to choose the anchor type accordingly.

Different anchor types are used in the different phases of crevasse rescue and the construction of the respective anchors can often be more time-consuming and complex overall than the construction of the pulley and the actual rescue. Crevasse rescue is much more than just mastering a pulley system, and creating snow anchors in soft snow in particular requires experience and should therefore be practiced whenever possible. In principle, the necessary anchors can be divided into three classes.

Holding a fall

Holding a fall in particular cannot be taught with theory alone and should therefore definitely be practiced outdoors under controlled conditions and under realistic circumstances when everyone involved is additionally secured. Especially in winter alpinism with skis (splitboards can essentially be used in the same way and are therefore not discussed in detail here, if you are on snowshoes and the board on your back, some of the techniques explained here will not work) on your feet, arresting a fall - whether on the ascent or descent - is relatively difficult

SKIES AND STOCKS Once the skis are on your feet, it becomes more difficult, especially in quite hard conditions. In ascent mode with touring bindings, it may not be easy to get the skis under control and build up pressure. For support, it is advisable to grab the poles directly below the grips, turn them around and ram the grips into the snow to stop the fall. Skis, on the other hand, are very helpful for holding the person who has fallen, whether you build up pressure over the edges or even ram the whole end of the ski into the snow, with skis on your feet you can apply a lot of force.

Temporary anchoring

In order to give the whole thing as much support as possible as quickly as possible and to relieve the load on the holding rope team members so that a reliable anchor can then be set up as a fixed point, a temporary anchoring is usually created first. This is usually not able to withstand the loads of a pulley, let alone further falls (deeper snow bridge collapses or similar), but creates enough free space so that at least one of the rope team members can set up a permanent anchor.

In most cases, the task of setting up a temporary anchor falls to the rope team member closest to the crevasse and the person who has fallen, i.e. usually the second rope member. In large groups or if the person who has fallen is easy to hold, the temporary anchor can also be omitted. If a rope team member has fallen from the middle of the rope team, it is usually a rope team member below the crevasse who creates the temporary anchor. The permanent anchor can then usually be set up above, but depending on the situation, also below the crevasse.

Depending on the condition of the glacier surface, loose snow, firn, rotten ice, etc. should be scraped away as quickly as possible before setting up the anchor for any type of anchorage.

Snow You are most likely to encounter relatively soft snow of the same year when touring on the glacier. To create a temporary anchorage here, it is best to ram at least one ski with the end at least up to the binding through the hand strap into the snow (twintips, heavily rockered skis and splitboards are clearly at a disadvantage here) so that the hand strap transfers the load directly to the snow surface (or below). Ideally, the ski should be rammed in at a slight angle to the rear with the edges pointing in the direction of the load so that they do not cut into the cord. Gloves, a hat or similar can provide additional protection from the edge. Hold the ski tips with your hands behind you for the entire duration of the load or kneel in front of the ski and lean against it with your shoulder to prevent it from slipping out of the snow.

This type of ski anchor can be reinforced by ramming or burying another ski into the snow crosswise in front of the inserted ski.

HARD FIRN The technique of the inserted pick is suitable for setting up a temporary anchor in hard firn conditions, which are particularly common in summer. This involves ramming the shaft of the ice axe through the hand strap into the snow cover and then kneeling on the pick to hold it down. It is best to look away from the crevasse, as this allows you to counteract the pull better with your feet and you are better positioned if the temporary anchor breaks out.

Ice In the unlikely event that you find bare ice, you can hammer the ice axe into the ice with the pick and clip the hand loop into the eyelet at the end of the shaft.

IN THE SNOW No matter how soft or hard, compact or loose the snow cover is, if there is no bare ice, there is actually only one anchor that is useful: the T-anchor.

This anchor, also known as the "Dead Man", takes its name from its T-shaped form and is created by burying an object at right angles to the load direction and tying it in the middle with a webbing sling or cord (at least 8 mm in diameter or several thinner ones), into which a large carabiner is hooked as a central point.

If the snow is sufficiently hard (e.g. well-set old snow), an ice axe is usually buried; in softer snow, a pair of skis is used (a single ski is also possible, but then the sling should be lined with gloves, a hat or similar to protect the sling from the steel edges). To do this, a slot is dug at right angles to the direction of loading, whereby the front wall should overhang slightly and you should avoid trampling uncontrollably on the snow in front of the slot.

This creates instability in the snowpack. The situation is different if the entire area in front of the slot is compacted over a large area, which can certainly increase the stability of a T-slot. In compact snow, the slot is scraped out more with the pickaxe shovel than dug, otherwise the avalanche shovel is used. The depth of the slot depends on the nature of the snowpack, a rather shallow slot that lies in a compressed old snowpack may be more stable if, for example, loose floating snow threatens underneath.

Now tie the object serving as an anchor with an anchor stitch (better with a Prusik knot for smooth ice axe shafts, ski poles, etc.) and place it in the slot (tip: if necessary, the slot can be narrower than the ski or ice axe. You can ram the ends of the skis or the shaft of the ice axe sideways into the snow from the hole). If the snow is hard, you may need to scrape out a guide channel for the sling. The excavated snow is now poured back into the hole and tamped down. Caution! A T-anchor may only be loaded perpendicular to the buried object!

If you are concerned about the snow being too soft, especially if you have buried an ice axe or smaller object, you can reinforce the anchor with a second T-anchor above it by tying off and burying a backpack, for example, and then bringing the loops of the anchors together at the central point and cutting them to length.

Another way to reinforce a T-anchor is to simply place two skis, poles or something similar vertically in the snow in front of the transverse anchor and turn the anchor into an H-anchor.

In ice It is relatively easy to create a definitive anchor when there is bare ice. In most cases, simply screw in two ice screws diagonally offset from each other and tie them off using a compensating anchor or fixed triangle of forces. If there are not enough ice screws available or the quality of the ice is not beyond doubt, you can - assuming you have an Abalakov anchors in your pack - tie a fixed point together from several ice anchors.

Securing the rope shaft

The rope is then attached to the central point of the definitive anchor that has now been created using Microtraxion, Ropeman, Prohaska, Prusik or similar and the anchor is put under tension. After carefully transferring the load by releasing the temporary anchor, the rope is secured with a mast throw in a separate carabiner for safety.

Once the entire rope team has been secured in this way, the actual rescue can begin.

In Part IV: Rescue methods