Recommended Reads #1

Right, so I decided to do Recommended Reads posts when I come across books that I think are especially noteworthy (which is of course strictly subjective), because… well, books are cool.

As the first of a numbers of books that have stuck in my mind I would like to mention Atul Gawande’s 2009 book Checklist Manifesto. Atul Gawande is an American surgeon, writer and public health researcher. He practices general and endocrine surgery at Brigham and Women’s Hospital in Boston, Massachusetts. His previously published Better and Complications are also well worth reading, by the way.

In this highly readable book Gawande discusses a wide range of topics linked to the subject of getting thing right, such as  our propensity for different types of error and why we fall prey to them, or finding the sweet spot between specialization and efficiency vs. a generalized skill set. Looking to other industries, – apart from emergency medicine and hospital organizations – for instance to the aviation industry and the crew resource management programs employed there, Gawande illustrates in a very clear and coherent fashion how the behavior of people working under pressure or stress can be optimized by creating clear guidelines to ensure the best possible performance, for instance by defining checklists. This is especially (but by far not only) true of complex systems and procedures.

Many of the points he raises had me vigorously nodding and rang very true, as there were very clear parallels to situations an arborist might find him or herself in their daily work. At one point he even discusses (mis)configuration issues! Yayyy, way to go, Atul! That’s our hobby horse!

OK, so this is not really a review, and I am clearly not doing this book justice in any shape or form… what I am essentially trying to say is that I definitively took a number of points with me after having read the Checklist Manifesto that I found myself applying to my everyday work. Gawande’s level-headed and clear approach to these topics really drives the key points home, even apparently obvious insights, such as that well-conceived structure need not necessarily be restricting, but rather can ensure a higher degree of safety and performance by decluttering your perception, certain issues will automatically be flagged so long as you methodically apply your checklists, this in turn leaves you more space to focus on other matters around you and respond to unforeseen incidents.

Worth reading.

Customising PPE

After yet another Facebook post about a bridge failure with non-approved cordage (8mm Beeline) and people saying that the importance of using only the approved rope bridge is not common knowledge, I thought I’d re-post this blog entry from August 2014 (!).

Yes, a competent climber is able to make his or her own choices given proper guidance by the manufacturers. In this instance, the harness manufacturer offers very clear, concise guidance, which is: use the specified rope bridge only – and that statement right there strikes me as being about as unambiguous as it gets.

Use. The. Approved. Bridge. ONLY.

Part of the certification process of Personal Protective Equipment (PPE) is that the manufacturer is making a statement about the performance of a configured assembly or system, for example in regards to dynamic or static breaking strain, maximum load, correct use etc.

This obviously also is true of elements of an assembly, such as the rope bridge on a harness. People often ask, whether it is ok to replace the specified Globe rope bridge on the treeMOTION with a different rope – and the answer is always the same: If you do so, the statement the manufacturer makes in regards to the certification of the harness is no longer valid.

The FB post shows the risks involved, especially – but not only – when using high-modulus fibres. These are extraordinary at some things but perform poorly at others, so for instance, a fibre may be highly tolerant of heat, but very brittle and performing poorly at handling repeated bending. So this needs to be taken into careful consideration when assembling systems.

My recommendation for certified assemblies and systems is to simply go with what the manufacturer specifies, in the case of harness rope bridges, I do not really see what you gain in regards to function by switching to a different line. The line is cheaper, because you had it kicking around the workshop? Not a very strong argument when your life is on the line…

To quote Clifford W. Ashely’s The Ashley Book of Knots: 

A knot is never “nearly right”; it is either exactly right or it is hopelessly wrong, one or the other; there is nothing in between. This is not the impossibly high standard of the idealist, it is a mere fact for the realist to face.

When working at height, get it right – and do not cut corners!

Footlock is for chumps


I read this statement on one of the arb forums recently and it made me feel a bit dispirited.

Many of the views expressed in these forums have become increasingly parochial, to the point that I sometimes wonder how positive a contribution they are actually making. Views seem to have become so entrenched, rather than using these new(ish) channels of communication to debate issues in a balanced, informed and fair manner, the opposite seems to be happening. You are either for or against something, there is not ground in-between the two positions.

Well, that is simply not the way I roll, sorry.

I am not prepared to turn climbing techniques into a quasi-religious matter, to the go on a crusade to convince others of their merit. Seriously?! Most of this is quite simply down to personal preference – and personal preference depends upon any number of things, such as your physique, the environment you work in, the trees you climb, your level of competence, your preconditioning, to name but a few.

I enjoy footlocking (😂 autocorrect turns footlocking into bootlicking, go figure).

I enjoy the simplicity of it, the flowing motion and the ease of installation and transition to my climbing system. Also, footlocking is part of our heritage, it is a traditional technique, but more than that, it teaches a trainee arborist about analyzing a sequence of movements, assessing your centre of gravity in relation to your body and builds confidence in being able to hold your own weight.

But I also enjoy using mechanical ascent systems to access the canopy, especially on long ascents, on ascents up against the tree trunk or on a work site that demands many ascents during a day. Yes, this technique is efficient and less tiring.

Every time I switch between the two it is as though I were discovering anew the advantages of the technique I am using, the switching allows me to contrast and compare.

It is interesting watching trainee arborists using mechanical systems for the first time: you get them all set up, and you can see the expectation in their eyes, they have seen the apparent ease with which people walk up a line – all the more so the disappointment is visible when they come down after their first ascent, realizing that it is not quite as easy as all that.

Of course, both routes – mechanical ascent or footlocking – demand practice, but that is what it takes to get proficient at something. Both can be done well or badly. Footlocking killed your knees, you say? To this I would respond that maybe you did not understand and apply the movement correctly (or it was not suited to your body or it uncovered pre-damage from past activities): any sequence of movements can hurt you if the force is applied at the wrong moment.

Take rowing for example: a sequence of movements that uses all major muscle groups in the body and is low-impact. It is, however, important on the backstroke to wait until your legs are fully extended before you start the pull backwards with your upper body. If these movements are not well synchronized, you put a lot of strain on your lower back. Does this make rowing bad for your lower back? No, all it means is that your are applying force at the wrong moment and that the motion is therefore desynchronized.

The same thought is applicable to footlock: If you apply the full strength of the upward push from your thighs when your knees are fully extended outwards, yes indeed, you are going to apply pressure sideways across the knee. BUT, if you start the movement gently when your knees are in the extreme, outward position, letting the upper body and arms take care of the first part of the motion and only apply maximum force from your thighs when the legs are in a more upright position… voilà, no cross-load being applied to the knees.

Apart from this, what I am trying to say is why don’t we stop getting tripped up over the choice of different techniques, which are personal preference, and rather use that time and energy to discuss bigger issues we have to deal with, such as high incident/ accident rates, health and safety organizations demanding (for instance) permanent back ups, anchor point failures or struck-bys.

Now this would seem to me to be time and energy more wisely spent.

Fruity puzzle resolved

Before you think I have morphed into a total numpty and to put Thomas’ mind at rest, who kindly mailed me regarding this matter: The orange that Petzl refers to has nothing to do with fruit (or beg) but rather refers to the colour orange in Henry Margusity‘s thunderstorm classification system, which defines a scale consisting of five categories: TS1, TS2, TS3, TS4 and TS5, with TS5 being the most severe in terms of damage and impact.

I still think the idea of climbing in fruit is funny.

But hey, you know what they say: truth is stranger than fiction.


Fruity puzzle

I read with interest Petzl’s article on how to fell a tree which was recently uploaded to the tree care section of the Petzl Professional website. The article touches upon a number of relevant points, such as the decision process to select the right method to dismantle the tree, the risk assessment process, safety considerations, choice of tools etc.

Petzl illustrates all this with images from a job site where Laurent Pierron removed a tree for the city of Valence in the south of France. Laurent is a really nice chap, very competent and a central figure in the French arborist community. He is certainly well placed to offer advice in such matters.

Having said all this, I do however have one remaining niggling question…

Dear Petzl, why does French legislation explicitly forbid climbing in oranges? How about kiwis then, or bananas or grapes? Would passion fruit be ok to climb in? Or pears? Apples? Strawberries, maybe? The article states that current legislation forbids this – so maybe former legislation forbade a larger range of fruit (and maybe veg, too), but oranges turned out to be especially dangerous? All of that vitamin C, I suppose.

I am confused.

Load-sensing Impact Blocks

Normally I would not use this blog to promote a product, but in this case I will make an exception – and that for good reasons.

I firmly believe that it is essential that we gain a better understanding of the forces we generate in climbing and especially in rigging. This is true of training as well as in everyday work situations and is one of the reasons I am so excited about load sensing devices becoming more affordable and readily available for our line of work. I am convinced that in a couple of year it will be a standard operating procedure to log the forces encountered during a day on a laptop or other mobile device and to include the data thus accumulated in the debrief.

The big plus of course, apart from immediate safety aspects, is that we stand to gain a more thorough understanding of the peak forces we generate, and consequently of course can define safety factors that are based on fact, rather than mere speculation. These tools will allow us to work in a more precise and accurate fashion.

The first of  a couple of projects we have been working on in conjunction with Straightpoint and DMM, the load-sensing Impact Blocks, are now available to purchase.

These units boast all the beefiness of a normal large Impact Block, such as a MBS of 300kN, a WLL of 60kN or the hollow spindle. The bodies are CNC’d from a solid block, sharing all the rope-friendly characteristics with the rest of the hot-forged Impact Block family. The upper sheave opens via a threaded locking axle for added security, the block attaches directly into textile rigging slings, removing the need for any connectors.

Added into this package are wireless dynamic load monitoring electronics and strain gauge technology, offering a highly durable and robust means to measure loads right where they are occurring – at the anchor point. The sampling rate can be set up to 200Hz, i.e. 200 measurements per second, this data can then be transmitted wirelessly via a radio link either to a handheld readout which allows you to keep track of peak forces, or to a USB dongle on a laptop which will allow you to plot out graphs of the forces being generated.

For further spec and for price quotes, get in touch directly with Straightpoint, read more about their rationale regarding this product here. Obvious takers for this device in my opinion might be training organizations, large companies – or arborists who are simply interested in quantifying forces to see how accurate their guesstimates have been during all those years.

All very well and good, you say, but how tough can electronics really be?

Fair point, we were also interested to find out, so we took a couple of the blocks up into the highlands a few years back and gave them a thorough pounding, leaving nary a trace! The blocks featured in the video below are still in service today.


I missed celebrating blog post 400! So I have ended up having to auto-highfive myself for post 402. Oh well, worse things happen at sea, without a shadow of doubt.

Thank you all of you who have been bearing with me for this time – even during my less lucid moments. Plenty more where all of this outpouring came from, I keep on jotting topics down I would like to write about… the question of when I get round to it is more often than not it a time issue rather than a lack of things to chat about.

Consider yourselves warned, stay tuned.

Aerial Rescue scenario @ ETCC 2016

When arborists meet other professionals who work at height, discussions regarding anchor points will often ensue.

On the one side are professionals who are obliged to work off work positioning systems with a permanent back-up. Also, their anchor points are rated and certified – or at least go through a thorough, formalized process before they are cleared for use.

On the other side are arborists, who, for very valid reasons, do not use a permanently backed-up work positioning system. Also, they get to chose their own anchor points.

Says the arborist: But we are cool, we rely on our training, experience and competence to assess our anchor points and can therefore rest assured that all is well.

I have to disagree with this assessment.

Anchor point incidents, failures and near-failures are too ubiquitous in our industry for this to be true. In my opinion this is a classic example of risky shift, a phenomenon which describes how operators, who left to their own devices would make sound decisions, in a group can have the opposite effect on each other: I see you are using a very low diameter anchor point, therefore it is also ok for me to to do likewise. And vice versa… ach, don’t get me going on anchor points, this could go on for hours otherwise.

I was going to talk about the AR scenario at ETCC this year, so let’s carry on there…

For the reasons outlined above I believe it is a good idea to focus on the topic of anchor point selection and failure whenever the possibility arises at industry events. For instance when considering Aerial Rescue scenarios for tree climbing competitions. Phil Kelly came up with an interesting one for ITCC in San Antonio in March, which involved a secondary anchor point failure during work on a stationary line. For ETCC we chose a primary anchor point failure – or delamination, to more specific.

We installed the event in a double stem Maple into which we added a delaminated Larch limb (see above). This was bent by almost 90° and was leaning against the other stem, with the dummy anchored to it. The scenario described a situation in which the climber had overlooked damage at the base of the stem he anchored to, this resulted in the failure of the limb and a pendular swing. He took a blow to the head against the other stem, managed to install his lanyard and is now suspended, semi-coherent. The access was installed round the back of the tree and was not affected by any of this.

Gabriel Dovier was head judge for this event and the discussion with him and his team during set up was highly interesting. The delaminated limb was sizable and weighed a good 100kg (we did a very thorough job of securing it with multiple back ups). What would the correct way to proceed be in such a case? The climber was not unconscious, so it is not a crash rescue. Further, the first priority of rescue protocols is to avoid injury to the rescuer, so in this instance, an unsecured mass suspended aloft above the casualty, the first step has to be to secure the limb.

Having said that, during the de-brief session with the climbers after the event, a very valid point was raised which was the risk that moving across to secure the other side of the limb might potentially dislodge the delaminated part and that it might therefore be preferable to proceed straight to the casualty.

Food for thought indeed. I am clear in my mind that, based on the considerations above, first and foremost I would want to ensure my and the casualty’s safety and would therefore secure the limb.

Either way, such scenarios achieve exactly what we are aiming for with such events, which is to foster critical and wide-ranging discussion around these topics. The solutions put forth may well just be a snapshot of that point in time and can evolve in years to come – but the key point is that we build awareness and start talking.

ETCC 2016 review

Right, after the treemagineers’ blog having taken a break, I felt it is now time for a bit of a look back at ETCC in Prague.

ETCC is one of those events in the year that is so intense that it takes me a while to sort through the myriad impressions I leave it with. So many aspects… some irritating, some annoying or tedious, but mainly moments that are extremely funny, motivating, inspiring and moving. Being part of the ETCC  Operations Committee is all of the above – and more.

Prague Expo building next to the park
Prague Expo building next to the park

I love doing stuff in the Czech Republic.

People there seem to me to be switched on and problem solvers (although I am not very keen on this kind of stereotyping, this is something I can’t help but comment on). The whole site set up in Stromovka Park was spot on: camping, indoor space for gear check, receptions and party as well as the comp and trade show site were all within five minutes walking distance. This was a major plus for the whole event, as it brought together the various aspects of the comp, making it feel more compact and coherent.

IMG_6684 (1)

What was weird this year was we were really struggling with volunteers. There were simply too few.

This fact makes set-up feel very wobbly and less than pleasant as you are constantly having to juggle the names you have (and that are on site), rather than being able to allocate volunteers to tasks and getting stuck in. Still, it came together in the end, but this is the sort of stress one could do without. Of course, some jobs may seem more glamorous that others, but if no one were to run a stop watch, there would not be much of a competition. Me? I do not really care what I do, put me on a menial job, these need to get done as well (I was going to write, task me with emptying the Port-a-Loos, but decided not to as I have a serious aversion to these, especially when they have been standing around in the sun for a couple of days and are ripe for harvest *gag* This is the kind of job I feel happy to leave to the pros).

Set-up lunch break
Set-up lunch break

One of my highlights this year was having former competitors, such as Anja Erni or Laurent Pierron who were competing last year return as volunteers. Likewise former volunteers, such as Jan Hoorne taking part as competitors. This kind of permeability is exactly what I envisage for ETCC, there is no them and us, but rather it is a true together, a shared event that belongs in equal parts to all that turn up and contribute something.

Set-up resulted in an interesting set-up for the comp, I was especially pleased with Aerial Rescue, which I will describe in a separate blog post. Speedclimb and Work Climb were also interesting: The trees were not huge, but the teams on the events made the most of them, creating challenging climbs, worthy of this level of competition.

Work Climb
Work Climb

The set-up days are my favorite days of such an event, working with the volunteers, making sure everybody feels welcome, appreciated and are functioning well in their team. We finished off Thursday evening with a session for the gear inspection techs, that Puk and I ran together. This is an item on the agenda we have been holding as a public session for the past few years, the idea being to explain to the persons present the thought process behind decisions relating to allowing equipment, which items we allow and where we draw a line, in the hope that this will contribute to a better understanding at chapter level, but also for the individual climber, judge or tech. What was fun in Prague was that, unlike other times when this was an indoor session based around a on-screen presentation, we did this one outdoors in a hand-on fashion, which seemed to work well. The evening ended with an opening reception sponsored for DMM for all involved in set-up which was a nice note to end the day on.

Friday was uneventful: set-up was finalized, walk through with competitors and gear inspection (a long one this time, lots of gear! And an overflowing quarantine Bag o’ Doom) went smoothly. In the evening Teufelberger sponsored a nibbles and drinks reception which had to battle it out with the Belgium vs. Wales football game that was on at the same time… put it this way, the Belgian and Welsh attendance of the reception was low.

Aerial Rescue
Aerial Rescue

The prelims on Saturday day started smoothly, with a field made up of lots of strong climbers, amongst which I was very happy to see many female competitors. As is often the case during the preliminary events, you never really know how the individual climbers are doing, until all scores come together, however I spent quite a bit of time watching Aerial Rescue and saw a number of very strong climbs there. It transpired that the Throwline tree was a throwline guzzling fiend, which slowed things down considerably. Also around lunch time we had some very heavy wind gusts come through with heavy rain and lighting, which led to us having to clear the site, however we were able to continue after an interruption of about one hour. In the afternoon a climber snapped a rib during his work climb, after which he continued and finished the climb – but was very poorly once he was on the ground. Consequently he was taken off to hospital for a check up (to return later and finish off his comp 😳 When we discussed this later his comment was, But I didn’t do the footlock, he said. No shit?! I replied).

To continue the theme of snapping things, shortly thereafter the limb walk got snapped out. Aaaaargh!  Our Arb CIS concluded that this was  probably due to the last climber having installed his lanyard far out and exerting a lot of upward pressure. As you can imagine, this presented a bit of a conundrum: half the field had gone through work climb on this limb, so now what? We ended up rigging the limb back onto the tree with lots of ratchet straps and Duck tape, it ended up looking a bit zombie-like, like something out of Shaun of the Dead – well may you laugh, but it did the trick.

For preliminary results check out the ETCC web page.

Sunday’s Masters’ Challenge went smoothly, I was sorry to miss the first couple of climbs as I was busy doing gear check for the other Masters’ competitors, what I saw was very impressive and of high quality. Again, for results, see above.

After tidying up the site and a short de-brief we hit the road direction of home. I left exhausted, but also exhilarated and enriched, with feeling of having contributed something meaningful towards the climbers’ community, and also having made new friends and had a good laugh or two!