Reflections after a gear check

Don’t worry, not running out of topics to write about here, just energy to do so. Have I mentioned that there must be easier ways to make a living than tree work, some days you just end up shattered. Mind you, having said that, I can’t think of any better way of earning a living.

Swiss comps over the weekend, which took place in one of my favorite parks, Margarethen Park, here in Basel, an English landscape park with a population of beautiful, big trees. Once again, a big thank you to all volunteers, congratulations to all climbers and, finally, congratulations to Florim and Anja for winning it. Hopefully we’ll be seeing them compete at ITCC and ETCC later this year.

I was reflecting – once again – upon some of the gear that I came across during the pre-comp gear inspection. Let me explain…

What are your safety margins?
What are your safety margins?

I have to admit that I am sometimes surprised by how varied people’s approach to their equipment can be. Especially in regards to what kind of safety you incorporate into your system design. Safety factors are ubiquitous in the world of engineering and describe the margin integrated into the design between the Safe Working Load (or Working Load Limit) and the Minimum Breaking Strain (MBS). This relates primarily to lifting equipment, the MBS quoted by the manufacturer on an item of PPE (Personal Protective Equipment) is just that, but there also, it is necessary to consider safety margins.

One of the things safety factors takes into account are wear and tear and the resulting degradation that equipment is exposed to.

This is especially relevant when incorporating low diameter lines and high-modulus fibres into systems.

Of course on paper, these may all look just fine, considered from a MBS-centric point of view. However, other factors come into play also, such as tolerances or intolerances of specific materials. Add in a splice, for example, or abrasion and prolonged exposure to UV and the picture can change considerably. For example: a home-made pulley saver, made from 10mm Beeline, spliced into a hollow ART ring for the big eye, using a 6mm Edelrid Aramid stitched sling to attach a Cocoon pulley. New, this may be ok for all I know, but over time one does have to question how it is going to age: according to the Yale Cordage website the mantle of Beeline is a 75%/ 25 % Technora/ Polyester cover braid. Teijin, who manufacture Technora, state on their website:  The strength of Technora can be lowered to a half when exposed to sunlight for about 3 months. Umm. That then does beg the question of how well this cordage is going to age when used over a longer period of time, as it will be in a false crotch (unlike in a friction hitch, where life cycles are shorter). And as an anchor point it will also be exposed to UV. Of course, you could argue there is still the Vectran core, but the point remains that due to choices of materials, in this case environmental factors have radically changed the properties of a central element of this assembly. Don’t get me wrong, I am neither pointing fingers here, nor knocking a specific product, in the right place, Technora is fantastic  stuff, but the point I am trying to get to is that it is necessary to consider a wider range of factors than merely the MBS in mint condition when configuring systems and assemblies

And that is just one example. The exponential use of Dyneema is another worry. 6mm Dyneema is super-strong, no question. But one does have to wonder when a whole ascent systems is based around it – what kind of tolerances does this system incorporate? What would happen if heat were inadvertently applied to the cordage? How will the use of mechanical devices on such cordage affect its performance?

In my books, safety factors are a good idea. Imagine, if Boeing or Airbus removed say 50% of the rivets from their planes, just because when new this would work – not taking into account that their planes do not only fly when they are brand-spanking new, but also when they are older. I’m not sure I would be one very relaxed passenger.

A number of high-profile recalls the past year in the field of fall prevention PPE also fall into the category of light-weight designs rather than ones that incorporate somewhat more material, but with sufficient safety margins. Or with a focus on design rather than resilience and wear-resistance. This is a worrying development, especially when discussing class three PPE and the serious consequences a failure might have.

Ergonomic, light-weight gear is all very well, but it should never become a trade off for safety.