Often to speed up your climb, it is possible to advance through easier snowy terrain without a rope belay. If you’re not belayed with rope, self-arrest is the only way of stopping a fall in the snow. But even if you start belaying with the rope, you still practice self-arrest in case of a fall so that you can at least reduce the subsequent catching impact on the rope. You therefore have two objectives with self-arrest: 1) if possible, to stop a fall, 2) to slow a fall. The actual braking is accomplished either with hands and feet, or with an object. The standard and most ideal aid for self-arrest in snow is an ice axe, but if you don’t have one available you can less effectively use telescoping hiking poles, for example, or in emergencies it is also possible to reach for the handle of an avalanche shovel, snow picket, longer snow piton, or in the absolute greatest emergency it is better than nothing to use a suitably shaped sharp rock.
Self-arrest without an ice axe
Braking a fall with empty hands is no joke, particularly on a firn slope, and it can happen that you will be unable to stop yourself. For this reason it is fitting to warn that movement on snow slopes without an ice axe or any other self-arrest device is not appropriate, and it is always necessary to consider well whether the conditions (the grade of the slope, its length, the character of the slope landing and the path to it) are such that the given approach is justifiable. Without an ice axe you should move only along slight slopes with potentially safe landings.
The actual self-arrest can be carried out by digging your hands and feet into the snow. In order for them to dig in strongly enough, they must be applied in a direction leading into the snow layer, which can be accomplished by raising the body above the surface of the snow (as if performing a pushup). Tip: bring gloves with you; that is, have them ready even in summer and put them on when entering a firn slope.
Otherwise, it would be a mistake to remain with your body lying on the ground, as the hands and feet are then oriented parallel to the surface, and therefore slide along it and do not dig into the snow adequately.
Self-arrest with ice axe
A classic hiking ice axe (approx. 70 cm long) with a head and adze is sufficient for self-arrest. A short ice axe can also be used well for self-arrest, which actually holds better and can be better handled when braking a fall. In firn snow the head of the ice axe should be used for self-arrest; in soft snow the adze should be used. Of course, if there is a layer of hard snow under the layer of soft snow which you will dig through to when braking a fall, then it is essential to brake with the head of the ice axe. When moving through snow, always have your gloves on! Very hard firn snow in particular is like sandpaper and when trying to brake on it can cut your bare hands to ribbons, even to the bone.
After falling in snow you will begin to slide downward. The speed of your fall of course depends on the grade of the slope, the characteristics of the snow, and your clothing and gear. On slopes with hard snow (firn) and inclined more than 40° the speed of your fall will be considerable after only a few metres, almost approaching the speed of a freefall. If you are wearing smooth clothing made of artificial fibres (warmups and windbreakers), there will be less friction between your clothing and the snow, and the speed of your fall will be greater. Certain apparel manufacturers make the surface of the top layers slightly grooved, for the very purpose of increasing friction against snow in the event of a fall on a snowy slope. This self-arrest effect is none too significant, however… it can slow the fall far more if you are wearing a harness (seat harness, chest harness, or full-body harness). The webbing of the harness grind against the snow rather well, but they also cannot stop the fall on their own. But even so it is recommended to wear a harness for climbing a snowy slope, even with a few carabiners or quickdraws attached to it. At least this will slow your fall in more moderate situations. It is necessary, however, that the quickdraws, etc. hanging off you are short and do not get tangled up in your legs; take particular caution when walking that the points of your crampons do not get tangled in the material hanging off of your harness! If you were to resign yourself and give up any attempt at self-arrest, for example during a simple fall along a 45° slope 20 m long on hard snow, you can reach speeds of up to 70 km/h. If you run into any obstacle at the bottom of the slope (a boulder, serac, crag, etc.), then the effect is as if you were sitting on the hood of a car doing seventy when it crashes into a wall. So how will that work out for you?
It is important for effective self-arrest in snow that you hold the ice axe properly. The ice axe should be held at the head with the end you will use for self-arrest set in the opposite direction from your field of view. This applies during ascent, descent, and traverse. The ice axe must also be fastened to your hand by the lanyard! A proper grip on the ice axe will enable you to have one hand continually holding the head of the ice axe (both before and during a fall) and it will then suffice to grip the handle of the axe with your other hand. This is without question the fastest method for grabbing the ice axe by both hands while at the same time having the bottom pike oriented set toward the ground. Some consider this unnatural, and instinctively tend to switch hands; that is, to shift the hand from the head to the haft, and use the free hand to grasp the head. Most likely because they wish to have their more dominant hand (e.g. the right for right-handers) on the bottom end of the shaft near the pike so they can handle the ice axe better. And yet this is a mistake: if you have to switch hands during a fall you can lose your ice axe by having it yanked from your hand as it drags against the snow, and what’s more it can cost you valuable time – a fall rapidly accumulates speed and every second counts.
More in e-book.
Mountaineering Methodology – Part 5 – Snow and Ice
Available for download from Apple iTunes (in the Books section).
For example U.S. store – link
Another countries – look on the page Download
Another possibility is Google Play. This version is a simplified (as PDF).
Mountaineering Methodology – Part 5 – Snow and Ice
Available for download from Google Play