Umbilicals “Not For Climbing Use”


While watching this video recently, I was struck both by the mechanism of the fall, which resembles a rag doll falling down a laundry heap, as well as by the failure of a piece of equipment which has recently regained popularity and widespread use among ice and alpine climbers. I’m referring of course to ice tool umbilicals.

The umbilical is an old idea which briefly fell out of style with the advent of the wrist loop for vertical ice climbing.  Old umbilicals would prevent dropping axes, but leashes offered a much more efficient resting position while climbing.  Recently,  as tools have developed steeper picks and larger pinky-hooks, umbilicals have regained popularity as a means of climbing longer and more committing routes without the risk of dropping a tool.  Though they create slightly more hassle and clutter, they are a clear choice compared to carrying a third tool.

But drop-protection is not the only way that they’re used.  There is an implicit understanding among climbers who use umbilicals that they function as a sort of moving belay.  Or at least, we would hope so.  As the video shows at 00:45, the leader’s umbilical fails under the sudden load of his weight. This illustrates a fundamental deficiency in the design of ice umbilicals which should be fixed.

There are three leashes in widespread use in the US today, from Black Diamond, Blue Ice, and Grivel.  All of these manufacturers publicly disavow their leashes for hanging or fall-protection. Their leashes are rated to loads of 2kN, 5kN, and 200 kg (!) respectively. In addition to these paltry loads, black diamond and Grivel use puny carabiners for attachment which are unrated, or in Grivel’s case, rated to “750kg and must never be used instead of normal carabiners when climbing or belaying”.

The Black Diamond Spinner Leash, Blue Ice Boa Leash, and Grivel Double Spring Leash
The Black Diamond Spinner Leash, Blue Ice Boa Leash, and Grivel Double Spring Leash

There are two main arguments against building full strength leashes:

First, an ice tool is a relatively insecure point of anchoring, compared to a deliberately placed ice screw or intentionally constructed belay.  Thinking of a leash as a point of protection may create a false sense of security.

Second, even short falls in static systems can generate large forces, much as one would do falling onto a belay using a daisy chain.  These forces can be high enough to injure a climber if his anchor holds.

The attached video, however, provides some evidence against these objections.  First, in both falls shown, the leader’s tool or tools remain placed in the ice, including the tool which was initially attached to the first leader’s leash.  It is a mantra among ice climbers that each tool should be a good placement and an effective self-belay. In this instance, the leash failed before the tool broke free.

Additionally, regarding the second objection that such falls generate dangerous forces, this video shows that that may apply to vertical ice, but doesn’t apply to falls on WI4 or less than vertical alpine ice.  These falls are rag-dolling, bouncing affairs which are further cushioned by the stretch of the umbilical leash.

The obvious shortcomings in umbilical design are likely in place out concern for liability, which is unfortunate.  As our sports grow more mainstream, and an industry develops around them, our culture of accepting personal risk and responsibility will inevitably erode.  But as always, the few companies which build functional tools for core users will ignore that trend, and ice climbing will be the better for it.

Here’s how I would design a set of umbilicals from scratch:

The ideal umbilical will be constructed out of a semi-dynamic nylon and won’t have carabiners used for attachment but will instead connect through the full-strength loops in tools which are becoming more common by the use of a simple girth hitch. Per preference, if it does include a swivel to prevent tangles, this will be rated to the excess of the strength of the webbing.  Ideally, the stretch of the umbilical would become much stiffer at the outer limit of its range to distribute the force of a fall over time.  (Similar to what Mammut did with their dynamic cordalette 7mm cord.) It should not be challenging to produce a leash which is rated to 22kN. Nor should it be challenging to provide intermediate points of attachment for attaching oneself to an anchor, or for use as a cow’s tail while repelling.

Perfection has never been the standard for innovation in climbing gear. I suspect that once one company has the courage to make such changes, all will soon follow because a full-strength leash is what climbers are looking for.  Always, we want redundancy in our systems, and those who choose to rely on only leashes will have to understand their limitations, but they’ll be better than what we have today: elastic webbing belts with trivial attachments. You might as well grab that little carabiner off your sunscreen bottle.  Yeah, the one that says ‘not for climbing use’.  That should be fine, right?

Thanks to Alex Ragus, admiral of mechanistic recollections, for input on this article.

Note: Climbing is a dangerous sport which even when practiced safely can result in serious injury, disability, or death.  Seek professional instruction and supervision before traveling independently in the mountains.  Any information contained herein is for informational purposes only, and is not intended as a substitute for concrete experience and informed judgment obtained under the guidance of a professional instructor or guide.  I am not a professional; use this information at your own risk.

Category: Gear & Reviews



  1. I disagree. Especially to you calling umbilicals terrible in your Tweet. Umbilicals function as they should, ie not as a weight bearing tool. They are designed to keep you from dropping a tool. If you want to hang use a leash. But hanging from the waist, off your tools, mid lead, is a bad idea because you will end up popping your tools as your weight shits and pulls the bottom of the tool sideways, creating a levering force, pulling the pick sideways. Ice climbing is not rock climbing. It is hard. It is dangerous. The climbers in the video above were in way over their heads. I’ve built my own full strength umbilicals and found them less useful than the commercial non full strength ones.

    1. Keese,

      Thanks for your comment. I still disagree, though I understand your objection that my criticisms are directed towards uses for which they’re not designed. What I don’t understand is why it would be anything but beneficial for the leash to be stronger.

      I agree that they are poorly suited to mid-lead rests. Ice screws are better for that as umbilicals will be well out of reach if weighted. I’m suggesting that if they were stronger they could act to stop short falls, thus providing added security, especially when used while climbing unroped on moderate terrain.

      The climbers are certainly well over their heads, and they’re lucky that they only bruised their egos. But I still contest that had the leader’s (black diamond?) leash not failed, he wouldn’t have taken a bouncing fall. Clearly his ice tool placement held the 2 kN force required for leash failure.

      I call leashes terrible because none of them are well designed. All have some great flaw (though I have no experience with the camp ones, they look essentially the same as Grivel/BD models). Why not use real carabiners? Why not provide more just-in-case strength?

      Other devices which were used outside of their original intent have now been modified for and endorsed for their previously clandestine uses. Take for example the use of certain ascenders for top-rope soloing. I am suggesting that the umbilical has the potential to be much more useful and safe than it now is, and I can’t see a reasonable objection to that. I’ll be floored if manufacturers don’t come around to this eventually.


  2. Thanks for writing this post. I don’t ice climb and have never used an umbilical before, but I see them used all the time and have been a bit perplexed about the extent of protection they are intended to provide. Clearly stated here. Thanks.

  3. I see some flaws in your arguments. I know of no experienced climbers who implicitly or otherwise view umbilicals as a moving belay. They are simply used to keep from dropping a leashless tool. I guess some climbers might hope they would arrest a fall, but I doubt any experienced ice climbers would count on it.

    Third tools were carried as a hedge against broken picks more often then for a dropped tool. While pick manufacturing techniques and materials have made broken picks rare, the design of picks have not changed at all, i.e become ‘steeper’ between leashed tools and leashless tools.

    Umbillicals are generally considered to cause less hassle, especially while when placing screws, the most difficult part of ice climbing.

    Redesigning umbilicals to hold falls is kind of like redesigning cam hooks to hold falls. Neither will ever work as fall protection with any level of reliability and both work perfectly for the applications they were designed for. Why design full strength umbilicals when a well placed ice tool in good ice will only reliably hold body weight?

    1. If what you say is true, then why do climbers build their own full-strength umbilicals? Why is it always a consideration in their design that should the climber fall, he not be out of reach of the tools?

      “The current commercial umbilicals are not designed to hold a leader fall. But everyone knows that is how they are being used. And have been now for decades. Insurance for the leader to avoid a potential fall and security so a tool isn’t dropped.” Cold Thistle and more from him.

      Of course no one with a brain will “count on” a tool placement to not fail in a fall scenario. My argument is simply that there is no harm in building stronger umbilicals to provide a bigger margin of potential safety.

      “Why design full strength umbilicals when a well placed ice tool in good ice will only reliably hold body weight?”

      Why do you think that a well-placed tool in good ice will only hold body weight? I suspect that with an appropriate direction of pull (ie one which does not lever out the placement) that such a tool would hold several thousand pounds. Unfortunately, I can’t seem to find any data on the matter. While ice screws have been studied, no studies of tools are public to my quick search.

      The comparison with a cam hook is a good one, except that the ice tool remains in place when not weighted. Further, would you accept the use of cordage on your cam hook which is rated only to a few hundred pounds? Of course not. All that we use is overbuilt so that the load capacity of the cord or webbing is much larger than the anticipated forces. You could say that this is because the world often serves us with unanticipated scenarios.

      I appreciate your critical look at my argument, but I have yet to hear a good reason why they should not be built to full strength. If they happened to catch 1 fall out of 5, I would accept that added margin of safety. There would be almost no weight change in a full-strength build, so there is no inherent downside to this design.

  4. This is an old thread but the debate is still relevant. Having been saved by a old style blue ice tether when attached to another axe which ripped I entirely agree. I would estimate I fell about a foot before arrest. Long enough to think this is going to hurt. But the leash went taught and the nightmare ended as quickly as it started. Had I been on weaker leashes I would have broken ankles at the very least. The stopping force wasnt that jaring, i guess the axe moved a bit. So I agree entirely that stronger tethers should be standard because should your axe actually hold only for your leash to break…. and an ntegrated screamer or give would only increase your chances.

    1. Steve,
      Thanks for weighing in. I wager that the first company to see that the benefit in technology like this outweighs the liability will capture the (admittedly small) market for umbilicals. Until then, we’ll have to wait or make our own. Have a good season!

      1. I am not sure that full strength thethers are a good idea.
        Yes, even if it only holds 1/4 of the time, that’s better than nothing.
        The problem is when it fails, you no have a spring loaded icetool launched at you.
        That’s very different from a micronut failing.

        If you really want it though, these tethers do exist: full stretch, load absorber and all.
        They are called Via Ferrata kits.

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