Category Archives: rock climbing

Helmet Design and Environment Interaction

I wanted a new helmet that offered some side-impact protection to replace my trusty Petzl Ecrin Roc, especially after a helmet-less Slovenian climber mocked me in Italy for wearing “such a heavy helmet” at a sport climbing crag.

I now own the Petzl Meteor, but after one trip discovered a strange design flaw.

Most helmets clip together the way carseats or backpack buckles clip together:
clip

The Petzl Meteor helmet has a similar clip, but also contains magnets that draw the buckle together. Here is how it should work:

I was climbing at Lover’s Leap in California, a granite cliff. Those of you who know your geology might guess what happens when you combine magnets and iron-rich granite. I put the helmet on the ground while sorting gear, put it back on and heard the buckle snap together. A few minutes later, I looked down (which put some strain on the helmet strap), the buckle popped open, and the helmet fell off my head.

When I examined the buckle, there was grit stuck to the magnet.

Iron grit on magnet
Iron grit on magnet

Wiping it off seemed to work, except that it moved some of it to the sides rather than just the top. My fingers weren’t small enough to wipe it from the sides. So, the next time I snapped it shut and checked to make sure it was locked, I couldn’t get it off. The grit on the side prevented the buckle from pinching enough to release. I was finally able to get it off the sides by using part of a strap to get into the crevices.

Iron grit on sides

I made some videos of the phenomenon. It was pretty easy to do, I just had to put my helmet on the ground for a moment and pick it up again. Attached grit was guaranteed – these are strong magnets!

I am not the only person to notice this:

In one review of another helmet with a similar closure:

The only issue I had with the buckle came after wearing the Sirocco while bolting and cleaning a granite sport route. Some of the swirling granite dust adhered to the magnets, obstructing the clips. It was easy enough to fix: I just wiped the magnets clean, and it has worked perfectly since.

and:

Helmet review from Outdoor Gear Lab

What we found in our tests of both the Meteor and the Sirocco was that the magnet did not always have enough oomph to click both small arms of the buckle completely closed. About one in four times, only one of the plastic arms would fasten and the buckle would need an extra squeeze to click the other arm in. Another thing our testers noticed was that the magnet would pick up tiny pebbles which would prevent the buckle from fully closing. The pebbles can be easily cleaned by brushing off the exposed part of the magnet, but it adds an extra step to applying the helmet. The bottom line is, we prefer the simplicity of the old plastic buckle. We think that the magnet is a gimmick which potentially makes a less safe helmet.

Safety gear shouldn’t add steps to be remembered, such as making sure the buckle is locked, even after getting auditory and tactile feedback when one connected it. Some people may never climb in an area with iron in the ground, but the use-case for a granite environment should have been considered. You know, for little climbing areas such as the granite cliffs of Yosemite.

Rock Climbing Human Factors – Harness attachment points

A friend of mine was recently rappelling from a climb, meaning that she had the rope through a device that was connected to her belay loop on her harness. As she rappelled, she yelled that her harness broke, and the waistband of the harness slid nearly to her armpits. Fortunately, she remained calm and collected, and was still able to rappell safely, if awkwardly, to the ground. On the ground, her partner saw that her waistband with belay loop had become disconnected from her leg loops. The leg loops were intact, though a keeper-strap that helps the leg loops stay centered was no longer connected.

So, what happened?

First, for the non-climbers, a primer. A climbing harness is composed of three major parts, attached to each other in various ways depending on the manufacturer. The first part is the waistband, which is load-bearing, meaning that it is meant to take the weight of a climber.

The second part of the harness is the belay loop, a load-bearing stitched circle that connects the waistband and leg loops and is also used to hold a belay device, to hold the climber’s weight when rappelling, and for anchoring to the ground or a wall when needed.

The last part of the harness is the leg loops, which are also load-bearing in the parts that connect to the belay loop and around the legs themselves.

Figure 1 shows the general composition of climbing harnesses, with these three parts diagrammed in the Base Concept.

harness_leg_loop_error
Figure 1. Simplified diagrams of climbing harnesses.

On most harnesses, the leg loops are kept connected to the belay loop by a “keeper strap.” This is usually a weak connection not meant to bear weight, but only to keep the leg loops centered on the harness (shown in blue in figure 1). In the case study that prompted this blog post, the keeper strap was connected through the belay loop, rather than the full-strength leg loops (figure 2.) When loaded, it came apart, separating the leg loops from the waistbelt. My own tests found that the keeper strap can be very strong, when it is loaded on the strap itself. But if the leg loops move so that the keeper buckle is loaded by the belay loop, it comes apart easily.

errorharness
Figure 2. Harness assembled with keeper strap bearing weight via the belay loop.

There are two ways to mis-attach leg loops to the belay loop of a harness. The first way is by connecting the leg loops back to the harness, after they were removed, using the keeper strap. The video below demonstrates this possibility. Once connected, the harness fits well and gives little indication the leg loops are not actually connected to bear weight.

The second (and I think more likely) way is by having the leg loops disconnected from the back of the harness, usually for a bathroom break or to get in and out of the harness. The leg loops are still connected in the front of the harness, but if a leg loop passes through the belay loop, suddenly the keeper strap is load bearing when the leg loops flip around. However, the harness does not fit differently nor does it look particularly different unless carefully inspected. Video below.

The non-load bearing parts of the harness are what determine the possibility for this error. In figure 1, some harnesses either do not allow disconnection of the leg loops in back or only allow their disconnection in tandem. When the leg loops are connected in this way, the front of the leg loops cannot be passed through the belay loop. Video demonstration below.

Back to figure 1, some harnesses allow the disconnection of leg loops for each leg. If these are disconnected, a loop may be passed through the front belay loop, resulting in the error in figure 2.

In sum, this error can be examined for likelihood and severity. It is not likely that the error occurs, however if it does occur it is likely it will go undiscovered until the keeper strap comes apart. For severity, the error could be lethal, although that is not likely. The waistbelt will hold the climber’s weight and having leg loops and a waistbelt is a (comfortable) redundancy. However, the sudden shock of suddenly losing support from the leg loops could cause loss of control, either for an un-backed-up rappell or while belaying another climber.

What are the alternatives?

  • Climbing is exploding, particularly climbing in gyms. The “gym” harnesses, with fewer components and gear loops (Figure 1), are a good option for most climbers now. However, there is little guidance about what harness one should buy for the gym vs. outdoor versatility so few probably know this harness is a good option.
  • Some harnesses are designed to be load-bearing at all points (i.e., “SafeTech” below). It is impossible to make an error in leg loop attachment.
  • safetech

  • Harnesses with permanently attached leg loops or loops that attach in the back with a single point are unlikely to result in the error.
  • Many climbers reading this are thinking “This would never happen to me” or “You’d have to be an idiot to put your harness together like that” or my usual favorite “If you wanted climbing to be perfectly safe, you shouldn’t even go.” Blaming the victim gives us a feeling of control over our own safety. However, there are other instances where gear was assembled or re-assembled incorrectly with tragic consequences. No one (or their child) deserves to pay with their life for a simple mistake that can be prevented through good design.

    Brilliant guard against accidents in indoor rock climbing

    For those who don’t follow news of climbing accidents as closely as I do, there has been a spate of accidents associated with the automatic belay devices (autobelays) installed at climbing gyms.

    These devices are handy to have around as they negate the need for a climbing partner, allowing one to exercise and train alone. The climber clips his or her harness into the device at the bottom of the wall, and it automatically retracts (like a seat belt) when you climb upward. At the top, you let go of the wall and the device lowers you slowly back to the ground. You are probably imagining that the accidents had to do with failures of the equipment – while that is not unheard of, the most recent issues have all been with climbers forgetting to clip into the system at all.

    The most recent tragedy occurred this past September, where an experienced climber died after a fall in a Texas gym, and it’s been listed as so common it happens at “every gym,” though not always resulting in a fall. Here is the facebook page with members of another gym discussing a similar accident.

    fb

    If you talk with climbers or read accident forums you will invariably be faced with a large contingent bent on blaming the victim. I’ll grant that it is hard to imagine forgetting to clip into a safety device and climb 30 feet up a wall, but that’s because I hardly ever do it. One characteristics these accidents share is that the victims were experienced and used the auto-belays frequently.

    When a procedure becomes automatic, it becomes more accurate and less effortful, but it also becomes less accessible to the conscious mind. When a step is skipped, but all other steps are unaffected, it’s especially hard to notice the skipped step in an automatic process. If caring more or working harder or “being more careful” could actually prevent this type of problem, we wouldn’t have any toddlers left in hot cars, perfectly good airplanes flown into the ground, or climbers falling because they didn’t clip into the autobelay.

    That brings me to the device I saw installed at a climbing gym last night.

    guardAbove: The guard in place, clipped to the wall and ready to go. Notice how it blocks the footholds of the climbs.

    photo 2Above: Nikki shows how to unclip the guard before attaching to her harness.

     

    photo 4Above: Clipped in and safely ready to go. Guard is on the ground and out of the way (it is ok to step on it!)

    Let me tell you why I think this is brilliant.

    • It’s highly visible.
    • It functions as a guard. This adheres to the hierarchy of safety: First, try to design out the hazard. Second, guard against the hazard. Last, warn. These are in order of effectiveness. Prior to this device, I had only seen signs on the wall saying “Clip in!” (And a year ago, even those didn’t exist.) This device physically blocks the start of the climbing routes, demanding interaction before one starts climbing.
    • Using it properly does not add any additional time or mess to climbing a route. If it weren’t there, the climber would still have to unclip the autobelay from an anchor close to the ground, etc. With it there, the climber does the same thing and once done, the guard becomes a flat mat that doesn’t get in anyone’s way.

    Is it perfect? No. You can also climb with a belayer on the same or nearby routes, and then it’s also blocking your way at the start of the climb. Some adaptation should be made by the route-setters at the gyms to minimize this. But overall, what a great and simple solution.

     

    The Human Factors of Rock Climbing – A matter of life and death

    A tragedy occurred last week in West Virginia where a rock climber died apparently due to a human factors issue with her gear. This text comes from a commenter on Rockclimbing.com:

    The climber was Karen Feher from Midlothian Va. She climbed to the anchor of Rico Suave and clipped in direct. Her setup: She had two thin dyneema slings girth hitched to her harness. At the end of each sling was a locking carabiner held in place with a rubber Petzl keeper…She clipped a locker to each bolt and probably called off belay. I’m unclear if she was going to rappel or lower. It doesn’t matter. She fell to the ground.

    The day after the accident a local climber named Craig (last name?) climbed to the anchor and found a locker on each bolt with a Petzl String still affixed to each one. Both Petzl strings were torn on the side.

    Let me give a little background on the gear so you can understand what seems to have happened:

    Climbers can affix themselves to the wall with equipment that has carabiners on both ends. This allows them to clip themselves to one side and clip the other to the wall. These can come in different varieties, and two types are illustrated below.

    The first type consists of a sewn sling between the two carabiners. It is sewn tightly in multiple places to make sure that it holds tightly to the two carabiners.

    A "quickdraw" with two carabiners
    Notice the larger and smaller holes in each end. One holds a carabiner loosely to the rock while the other holds a carabiner more tightly on the rope end.

    Notice on one side it is sewn so the carabiner hangs loosely and on the other side it is sewn tightly, so that it holds the carabiner almost immobile. The reason for this is to allow the side connected to the wall to swing freely as the rope moves, which keeps the rope movement from jarring or upsetting protection put into the rock. The other end that is connected to the rope keeps the carabiner from moving around and possibly turning sideways.

    The second type (below) consists of a nylon sling doubled over between the carabiners. The benefit of this kind of sling is that it can be changed in length – by doubling and tripling it, it can either be 4′ long, 2′ long, or just a foot long. However, notice both sides are the same. The benefit of having one loose side and one tight side does not exist here. Incidentally, this is the type of sling I use almost exclusively.

    A simple loop connects the two carabiners
    A simple loop connects the two carabiners
    The sling has now been doubled over to shorten it

    There is one way to turn the second type of sling into an approximation of the first type: a rubber band. Not only can you do this with a plain rubber band, there are some specifically sold for this purpose.

    The rubber band holds the rope end tight while allowing the other end to swing freely
    Again, rope holds one end, this time with sling not doubled over

    The problem with this solution lies in the changes to visibility and function that the rubber bands can have when the slings are doubled-over incorrectly.  Click here for a video explaining what can go wrong.

    Essentially, the sling can become almost invisibly connected ONLY by the rubber band. I am sure no one would like to think of hanging 100 feet from the ground by a grocery store rubber band.

    The additional component to the tragedy that prompted this post is that both of her slings were attached only by the rubber band. Climbers build redundancy into their systems to prevent accidents like this, but here both failed.