In reply to Trangia:
Seems to be quite a lot of theoretical discussion going on here...
I'm a big fan of practicing ice axe arrests, I try to make sure I do a session every year. It's easy enough to find an area of steep neve with a safe run-out below. I have also tried arresting with a pole, and with no tools at all. I have found:
- With no tool (i.e. fists and toes), it is only possible to stop in fairly soft snow, though relatively steep angles are possible.
- If a foot doesn't penetrate at least a couple of cm into the snow, this technique is completely ineffective, even at very low slope angles.
- A pole can be useful in arresting the very early stages of a slip, the best way is to press the tip into the snow as you fall, and grip the shaft low down. This is preventing a slip becoming a slide, rather than arresting.
- Using a pole to arrest is awkward, especially if wrist straps are worn. If anyone does fancy experimenting, I would strongly advise removing wrist straps to prevent arm and shoulder injuries if you roll over the pole.
- On soft/medium snow, the pole tip gives better purchase than the no-tool case, and can make an arrest possible where it wouldn't be otherwise.
- The gap where a pole makes an arrest possible but a no-tools arrest isn't possible is really quite narrow.
- An ice axe, used sloppily, is far far better than a pole.
- An ice axe, used well, is far better than one used sloppily. Technique matters more on harder snow types. It also matters more with a climbing pick; walking picks are more forgiving.
- On hard neve, even if only 20 degrees, speed builds up very fast. An arrest is easiest and quickest if started immediately.
- An arrest with an axe and good technique will ultimately be successful on most snow types up to about 40 degrees, and on some snow types up to much steeper. It may take some distance though, further reinforcing the need to
start immediately and get it right first time.
I use poles almost all the time, for my sore knees, but I change over to my ice axe anywhere that I don't think I could do a no-tools arrest. I do store my axe between my pack and back, but I cannot draw it fast enough to satisfy me that it would be any use in an arrest, especially if sliding over lumpy ground or head first. I do think that a longer axe (~65cm) reduces the risk of a slip, without impairing my ability to arrest, and I use one whenever I don't need a shorter pair for climbing.
Post edited at 17:18