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V-threads, or Abalakov threads (after the inventor Vitaly Abalakov), can be tricky to make (especially left handed in the dark...), but when you miss the mark on your first attempt, or second attempt, or third... at what point do you abandon your anchor and try again somewhere else? How far apart should v-threads be from other screw holes in good ice? I have a hard time trusting a v-thread unless I get it perfect the first time, I feel as if I'm compromising the integrity of the ice if I try to drill another hole to meet the first if my first attempt misses.

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At what point does an attempted v-thread become unsafe?

STW
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ShemSeger
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  • I would guess it's a it depends kind of answer. I'd guess this is an experience kind of thing. Not an ice climber so I'm not really sure though. –  Jan 15 '15 at 14:41
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    It really is a depends kind of thing, it depends on the ice, that's why I narrowed my question down to "good ice" so I can get a point of reference. I'm still new to ice climbing, I've never taken a fall and I've never had an anchor fail, and personally I'd rather not have the experience. – ShemSeger Jan 15 '15 at 16:12
  • Not falling on ice is a good mindset. For a discussion of why ice climbing is not rock climbing (and why you should really never fall), see this link: http://willgadd.com/ice-climbing-is-not-rock-climbing/. Will Gadd states that in 30 years of ice climbing he's never taken a lead fall. – Felix Jan 18 '15 at 16:59
  • As a side note, it's reasonable to prepare your v-thread before the last man goes so that somebody does test it having a good ice screw backup. Also you shouldn't get any big falls while rappelling (except if you are starting with your anchor below you, which is very dangerous). – Steed Feb 15 '15 at 21:13

1 Answers1

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Will Gadd's book Ice & Mixed Climbing states that if you mess up the first attempt at a V-thread, start over in clean ice. This includes if your screw holes intersect only partway down the hole, the two holes didn't intersect, or the distance between the holes isn't large enough. Practicing making V-threads on the ground is much better than trying to figure it out on rappel when it's cold, dark, and everyone is soaked.

A good rule of thumb for all anchors (but especially rappel anchors) is to make the best anchor possible with what you have available. Fortunately, on most ice climbs starting over means moving over a foot or two to solid ice.

In some cases, building a "textbook" anchor may not be possible. If you have to use an anchor that is less than optimal, make a backup anchor and clip the rope to this backup in case your V-thread fails. You want the backup to be relatively taught but all of the weight should be on the primary V-thread (just a little bit loose). The last person will remove the backup when they rappel. This Petzl video shows a good example of this (at 4 minutes).

Felix
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  • I read as far as, "Will Gadd's book..." Then went to amazon and immediately bought it. I don't know if there is anyone in the world more qualified to write a book on ice climbing. – ShemSeger Jan 18 '15 at 19:59
  • I actually watched that video a number of times before I started Ice climbing. – ShemSeger Jan 18 '15 at 20:03
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    @felix I'd change the wording about the loose back up anchor. As stated in the video the anchor must be equalized to reduce shock loading. – aaaaargZombies Jan 19 '15 at 00:42
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    @aaaaargZombies - I agree with an edit but disagree with your wording: if the backup is equalized then it's no longer a backup (it's now part of your rappel anchor). The video's exact words are "relatively taught to minimize shock loading" (5:14), and I'll add this to my answer. However, that is very different than equalized. – Felix Jan 19 '15 at 14:20
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    @felix Could you explain the merits of not equalizing the anchors, I was under the impression that any anchor that isn't equalized is at risk of shock-loading.

    I hope you don't think I'm being pedantic, I would genuinely like to know if I could make my anchors safer.

     – aaaaargZombies Jan 19 '15 at 14:36
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    That sounds like a great question in its own right :). Basically, there's a difference between equalization (all forces spread equally) and no-extension (if a piece fails, things don't move very much). – Felix Jan 19 '15 at 15:09
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    @Felix: this question was already asked and answered: https://outdoors.stackexchange.com/questions/5654/2410 – Benedikt Bauer Jan 19 '15 at 15:52
  • @aaaaargZombies - Rappel anchors and belay anchors are different. If you're shock-loading your rappel anchors then you are rappelling wrong. Belay anchors are meant to catch a fall, rappel anchors are only meant to hold body weight on a descent. – ShemSeger Jan 20 '15 at 18:44
  • @ShemSeger "If you're shock-loading your rappel anchors then you are rappelling wrong." very true, but these things do happen. The situation I imagine a piece of protection becoming shock loaded would be like the one above. You have a v-thread which is your rappel anchor and an ice screw which is a backup. Your v-thread fails for what ever reason and the load is suddenly transferred to the ice screw. – aaaaargZombies Jan 20 '15 at 23:09
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    @aaaaargZombies "These things happen" Once again, if they happen then you did something wrong, either you made your v-thread wrong, or you used poor judgement when selecting a piece of ice to make your anchor in. You are the author of your own fate when ice climbing. – ShemSeger Jan 20 '15 at 23:28
  • @ShemSeger I'm interested in what constitutes a good backup, not whether a back up is necessary or not. – aaaaargZombies Jan 21 '15 at 07:34
  • @aaaaargZombies - In this case, an ice screw with a relatively taught sling is a good back up. If you're really concerned about shock-loading your back up, then use a nylon sling with an overhand knot or two tied in it. It's been shown that knots in nylon slings can actually reduce impact forces in factor 1 falls (see 8:05 in this video. – ShemSeger Jan 21 '15 at 20:36