Article on testing of damage to synthetic fibres

At the Climbers’ Forum in Augsburg Angela Sipos from Teufelberger presented some preliminary results of on-going testing that they are doing regarding various types of damage to synthetic fibres, such as abrasion, heat, exposure to various chemicals, UV exposure etc.

Rope failure due to overload
Rope failure due to overload

Here is a summary of the findings that she and her colleague presented.

Obviously, it’s in German, but Angela will be attending the NZ arb conference in Rotorua in October and will be presenting these results there.

As I understand it, these tests were intended to establish a baseline in quite general terms, the plan is to continue these tests and taylor the types of damage to be more specific to what might be encountered in tree care.

Final day of testing

Today concludes a week of rigging testing in the Highlands – and what a week it was!

As I wrote earlier this week, it’s much to early to even consider communicating any conclusions or wisdom in regards to what we were testing, however these days have certainly given us much to think about and discuss – not to mention 120GB of video and photo footage.

I would like to use this opportunity to mention how thoroughly annoying GoPros can be. Not just because of the weeks worth of wobbly, uncut helmet cam footage (that always makes me feel rather nauseous and bores me  to tears after about fifteen seconds) we are bombarded with via Youtube  and the likes, but mainly because they are soooo temperamental, which is not ideal if you have four cams dotted around the site fifteen meters up trees. Still, minimum one was working all the time.

We feel strongly that it is essential to continue building on the insights gained through research such as the HSE and Forestry Commission Rigging Research, or work done by people such as Andreas Detter or Peter Donzelli to increase our understanding  in regards to the ways in which we work and techniques that we employ, and where possible to identify ways in which we can make them safer, more ergonomic and/ or more efficient. Hopefully in the future weeks and days such as this past one will contribute something towards these goals.

We had the privilege of having a fantastic team working with us, as that is always the thing that makes or breaks this kind of enterprise. So big thanks to Jon Turnbull, Henk Morgans and Georg Schwenteck for helping to work through a really very demanding schedule – and of course to Chris for making this all happen in the first place.

Day three of testing

Day three, what can I say?

Fantastic weather and big forces sums it up. Best explained with some pictures…

Make your life easier

Yesterday during a break we were discussing how sometimes it’s all very well to decide to do something in a certain way, but if the correct tool to do it with is missing – you won’t do it… until the right tool comes along.

A classic example for me to illustrate this is the throw line on a spool or in an old paint bucket. You won’t use it, because the line off the spool is all twisted and really annoying to wind on and off and the paint bucket is just not handy… along comes the folding cube, and hey presto, suddenly your life gets much easier, you use the throw line more – and become more proficient by doing so. Well, most of the time anyways, unless you happen to be having a throw line meltdown day.

Another use of a throw line
Another use of a throw line

The example we were discussing yesterday was securing the load on the back of the vans.

The authorities in Switzerland have become much more restrictive in this matter over the last couple of years – probably rightly so. When we first got a net to cover the brush we got wide mesh nets, with the result that they were really annoying to use as the branches would always get stuck in them, it was hard to install and to remove. The result? Often as not they were not used. Then we found very fine-meshed material – I think that originally the fabric is used to shade green houses – , really tough but still easy to handle. One person can easily cover the load area on the back of a van with it and it’s easy to remove as the branches don’t pass through the mesh.

So, because it’s easy to do so, it gets used.

This got me thinking about lanyards: I think lanyards are a fantastic tool right there on our harness that can be used in many versatile ways. I find it frustrating to see people thinking no further than side D-ring to side D-ring. But often as not, this is because in people’s perception a lanyard is something that’s inconvenient and burdensome.

So, I say, let’s make it easy.

For instance, you might consider how you stow the lanyard. I dislike nothing more than returning from a limb walk to find my feet tangling in the lanyard hanging down behind the adjuster… this will provoke very un-Zen like states in my mind! So you could use a shorter lanyard to prevent this from happening, which seems a pity as you lose versatility – or stow it in multiple loops, so that when you’re not using it, it’s out of the way – and when you do need some extra length, it’s there for taking.

Over the years we used different ways to do this, small prusic loops of accessory cord, short bits of hose – but all of these methods didn’t feed very well.

Gabriele Dovier from Formazione3t in Italy came up with a very elegant solution: Scuba clips. These are used for scuba diving to hold the air hoses. They have two or three open clips that will take a line from 10 to about 11.5mm. If you give the line a tug it’ll pull out, if you pull it steadily, it’ll feed nicely.

Scuba clip
Scuba clip

So, you just attach it below you lanyard adjuster, stow the lanyard in two loops – and you’re sorted. Most models even have an integrated swivel, which is handy.

With this simple, compact and light solution, that’ll cost you maybe a couple of Euros, you have uncluttered your harness and tidied up your lanyard and by doing so made your life easier. This means you don’t have to focus on messing around with your lanyard, but can rather focus on the climb. Which is a good thing.

Testing stuff

Heath Robinson's rope test
Heath Robinson’s rope test

Got a week of testing coming up next week in Scotland, which I’m looking forwards to, good crew to spend time with, in the Highlands, which is always beautiful – and let’s not talk about the weather forecast. I’ll be writing about it on the blog as we progress…

Thinking about this got me pondering testing.

Testing implies something that is complex and somehow mysterious. It’s not – or at least it needn’t be. As a kid I loved Heath Robinson’s drawings (see above) – still do, come to that – where he would develop a solution to a seemingly easy task by means of some ridiculously complex contraption held together by bits of string, nails and springs (I suppose the modern-day equivalent to that would be zip-ties and Duck tape). This is one way to do you testing, but there is a different approach, which – as in any systems design – is to keep it as simple as possible.

First off you want to decide what you want to find out about: maybe it was a question that came up during a lunch break and that lead to a heated debate. One way to resolve this is to define a test set- up and to run some tests. An example? One year I finished off a presentation with a slide with a picture of a compact steel karabiner choked onto a lanyard. The discussion that year had been on configuration of connectors and one of the summaries was a suggestion or a question whether it might be an idea to use a compact steel connector in certain applications. Thinking about this, observing my own use of karabiners and discussing it with Chris raised further questions, so we decided to do some testing on choked karabiners.

We defined a test methodology, met in our yard on a Saturday, set up and got going… The test set-up involved a mechanical advantage system, three steel drums of different diameters to simulate a range of branch diameters, a load cell and a Dyneema line.

Test set-up
Test set-up

We defined a three minute 15kN pull on three different diameters of “branch” and documented each sample. This resulted either in a pass or fail. The summary was that all karabiners struggled on the small diameter, with one complete failure (karabiner broke), whilst on the larger diameters, the shorter the karabiner, the better it handled this unusual loading – unusual in the sense that the connectors are not designed for this. No manufacturer would ok this kind of loading, the design merely foresees loads along major and minor axis and with the gate open. Still, we felt this was a configuration used fairly frequently in tree care and we weren’t able to find any answers to our questions, so by doing this testing we improved our knowledge – and were actually able to back up a gut feeling with facts.

The other testing I mentioned in a post a while ago was the continuous long descents testing. For this we went to the Musical Theatre here in Basel, as that offered a height of 20m plus, sufficient to do the testing in. Next problem was measuring the descent speed, 1, 2 and 3m/second. The way we sorted this was by building a rig consisting of a wooden base that we could load with weights and a small 20″ kid’s bike wheel with a speedometer on it. The line ran round this and gave us the speed km/ h speed that we converted into m/ sec. Obviously not super-accurate, but good enough to get the descent speeds roughly right.

Not brilliant quality image, sorry about that, lighting left something to be desired… still, gets the point across. Actually looks quite Heath Robinson-ish, come to think of it.

The point I’m getting to here is that if you have a question about a technical issue, go beyond a web search on Wikipedia, Youtube and the forums, get together with some friends, work out a replicable test methodology and go for it. Don’t let yourself be intimidated, testing is not something reserved for boffins in labs in white coats, it can be hands-on, exciting and can expand your comprehension of tools and systems you are working with.

It doesn’t even have to look very sexy, as long as it does the trick! Just look at the Russian space program – basically tractors sitting atop big rockets, but they get the job done.