Because… Science!!

There are fanciful stories about pretty much every aspect of humanity, and sometimes truth is stranger than fiction. For example, George Washington’s dentures were not made from wood. They were, in fact “made from gold, ivory, lead, human and animal teeth (horse and donkey teeth were common components)” according to a forensic anthropological study conducted in conjunction with the Smithsonian.

Myths and misconceptions abound in the realm of climbing, especially in regard to the reliability and deployment of gear. This is due in part to the piecemeal education by which many of its aficionados achieve competency (or an approximation thereof). Despite often having been debunked by scientific studies, many of these gear myths remain steadfast in the vaguely nefarious realm we call “common knowledge”.

Today, we’ll take a look at few of the most persistent myths (in no particular order), as well as the reasons that they just ain’t so. Heads up… Knowledge bombs, Danger Close.

  1. Micro-Cracks
    The Myth:
    Dropping a carabiner can result in micro cracks, undetectable to the human eye. These micro cracks degrade the strength of the metal and may propagate on use. The carabiner should be retired immediately.

The Reality:
Micro cracks are indeed a thing, however they form as a result of metal fatigue, not impact. There is plenty of scientific literature on this if you are so inclined, as it has huge impacts on the industrial and aviation sectors.

For our purposes, however, it is reassuring to know that a dropped carabiner is good to go as long as it has no visible defects. There have been several tests conducted on this issue, all with varying degrees of scientific legitimacy, but the most commonly quoted study is that conducted by Steve Nagode, a Quality Assurance Lab testing manager for Recreational Equipment Inc. If you think that signifies a conflict of interest, bear in mind that REI has nothing to gain from dissuading consumers to retire carabiners at the first possible juncture.

After dropping 30 carabiner bodies, both D’s and Ovals, six times each from a height of 33ft/10m, the carabiners showed no loss of strength in comparison to the control samples.

The Take Away:
Only 10 metres, I hear you cry! What about greater heights? Other tests in which carabiners were dropped from great heights (over 100 feet for example) showed catastrophic failures of the equipment, namely snapped bodies and broken gates. These were obviously identified on visual inspection.

As always, it behooves us to look after our gear. Inspect carabiners regularly for wear and defects, including notches, burrs and gate operation.

  1. Metal on Metal
    The Myth:
    You can’t connect metal gear with metal gear, such as linking carabiners. It’s bad juju.

The Reality:
I’m really not sure where this one came from, but you’ll often be told whilst building an anchor that you shouldn’t connect metal to metal. This is espoused by the same people who just climbed a sport route by means of clipping a quick draw into a bolt. The evidence, therefore, is both anecdotal and empirical – if metal on metal was bad, we’d all be dead by now.

It’s a similar story for soft goods, however you need to factor in movement. Fabric can be linked to other fabric (otherwise you wouldn’t be able to tie into a harness) but should only be employed if the interfacing materials are static. If there will be movement (such as a rope being pulled), the introduction of friction and heat can be catastrophic, especially in the instance of materials with low melting points like Dyneema or Spectra.

The Take Away:
Once again, visual inspection is the key. If metal goods develop burrs or snags, they should be retired.

  1. Knot Dressing
    The Myth:

A dressed knot is a strong knot. Poorly dressed knots are significantly weaker.

The Reality:
Nope. There is simply no evidence, scientific or otherwise, to substantiate this claim. The weakness of a knot is directly proportional to the severity of curves in the cordage, specifically the first curve which bears almost 100% of the load. The dressing of a knot does little to change the degree of bend in any knot.

The Take Away:
So, should we even bother dressing knots? My word, yes.

There are other benefits to a well-dressed knot, the most substantial of which is that it provides climbers and guides with an ability to quickly and accurately inspect knots. A well-dressed figure of eight, for example, is immediately identifiable by an experienced operator with nothing more than a simple glance. This alone makes them worth tying, both in a professional and casual scenario.

  1. Equalisation
    The Myth:
    This is less of a myth than an examination of the common methodology of anchor equalisation. For the lion’s share of anchor set ups, it would be fair to say that the individual strands appear to take an equal load by virtue of the fact that they are of equal tension when not under load.

    The Reality:
    For the sake of argument, let’s take a look at the following example featured on the left. Whilst it may appear equalised, with equal tension given to each strand, the anchor performs differently under load than you may suspect. The presence of a knot on the left strand will tighten under load, and thereby lengthen that strand. This in turn places a greater portion of the force on the right strand.

The students on our Rock 402 course earlier this year undertook a Rigging For Rescue course, the presenters of which are responsible for some interesting studies on anchor equalisation. Their conclusion was that it is very difficult, if not impossible, to achieve a perfectly equalised system. There are many factors that can contribute to disparity of force on each piece, including knots, material types, direction of pull and terrain considerations.

The Take Away:
So, how would this effect our practical anchor construction? Sport climbing? Not such a big deal. Trad climbing? Ice Climbing? It might pay to take some notice, assuming you’re into the whole “living” thing.

Don’t assume that your anchor is equalised just because the strands are of equal length. Think critically and make adjustments should you need to favour a stronger piece or allow for knots, etc.

  1. Stepping on Rope

    The Myth:
    You’ve all heard it before. “DON’T STEP ON THE ROPE! YOU’LL KILL US!”

The Reality:
Climbing rope is much sturdier than you’re often led to believe, however there’s certainly nothing wrong with a little bit of respect and healthy fear regarding the main piece of gear that will save your life.

The following are two studies that I found courtesy of On Rope 1, a climbing equipment store near Chattanooga, TN. The first states that:

“Jim Kovach, in an exhaustive 8 month study in Ohio, and reported to/by ITRS (International Technical Rescue Symposium) including using rope as a doormat for months, and then driving over the same rope while it lay on beds of broken shards of bricks and a glazer’s pile of broken glass. Then the rope was pull tested! Although the kernmantle showed minor signs of wear, in testing no loss of strength was seen. There is no evidence that stepping on a rope will grind dirt past the kernmantle into the core.”

The second study related to the common belief that almost any foreign substance, from gasoline to climber’s tears after failing a redpoint, will cause the rope to degrade:

“In other testing done by CMC out of California, rope were immersed in various substances for long periods of time and then tested. Some of these included paint, tar, sap, gasoline, oil and vomit. Most of the test items, including gasoline and oil, did not cause strength problems (although an oily rope is tough to use, it did not weaken the rope). Acidic materials, like vomit and animal urine, can cause a 30 percent or more strength reduction.”

The Take Away:
By all means, take good care of your rope. But don’t have an aneurism if someone accidentally treads on it at the crag. You should do your best to keep your crampons away from your rope. They don’t make good bedfellows. And don’t pee or vomit on your rope…

I’m sure you’ve heard some or all of these before, and probably more than once. What they highlight is that you can never know too much. Look after you gear. Learn the best methods for its use. Above all, ask questions and think critically. Your life literally depends on it.

Ryan Siacci, Esq.
Originally published in October 2015

0 Replies to “Because… Science!!”

Thoughts? Opinions? Cries of dissent?