Let’s hear it for Cd!

OK, so I admit it: I am not a big fan of basic training courses in January. Cold, dark and often damp, by far from my fave combination. Just had a day hanging around in the snow… brrrr. Looking forwards to getting back to work. Oh, have I mentioned that I reckon snow is grossly overrated? Well, it is.

Sometimes you come across misnomers during courses like this which are really quite humorous albeit in an unintended fashion. Do not get me wrong, I am not poking fun here, I have been know to do just the same in areas I am unfamiliar with and in such instances am also able to laugh at myself.

One time we had one guy who insisted upon referring to his false crotch, aka cambium saver, as a cadmium saver.

Fair enough, everybody is alway down on poor old cadmium. Bad cadmium this, bad cadmium that, of course cadmium has issues… but does no one ever consider Cd’s feelings? Maybe cadmium just wants to be loved? Needs to be saved?

I have since caught myself referring to a ring saver as a cadmium saver, just because I like the idea of someone standing up for poor old element 48.


Time flies

Tomorrow it is ten years to the day since Steve Jobs first announced Apple’s plan to launch the iPhone. The first video on YouTube, Me at the Zoo, dates back to 23 April 2005. What a difference a scant ten years can make! Today for many of us, it is a given to be in constant interaction with a range of devices and platforms, be it for social reasons, to organise aspects of our lives, to keep track of appointments, to monitor our health, to take a selfie etc.

Yet… at the same time, storing memories in bits and bytes is so ephemeral, if you flick back through the diary on your phone, you will find it going blank at some point. Unlike hard copy diaries, this information, which essentially documents a period of your life, is lost for good. Or if you forget to back up your data and your phone were to fall in the sea, that data will in all likelihood be lost to you. Or if your laptop fell into a bottomless abyss filled with boiling lava and orcs, or your iPad were swallowed by a rabid polar bear… well, you get the idea. It’d be bad news if you hadn’t backed up your content – it would be gone, kaputt.

Imagine if, in a steam-punk alternative reality, all those Victorian explorers had been keeping notes on 19th century iPads, rather than field books, what would we be left with today? Probably not much, a stack of dead electronic devices. Archiving data has become a major issue, with many switched on people racking their brains about how and what we are going to leave as a legacy to future generations from this information age. Just think floppy discs, you can hardly stick them in your DVD drive!

There is something very pleasing about hard copy, actually making notes on paper with a pen or pencil –it has a permanence and real quality to it. For that reason I always carry a notebook around with me to keep track of… stuff: to make a note of an thought or quote, to stick an interesting newspaper cutting into, to sketch something and so on. My orange book is finally full, time to retire it, fare ye well, orange book… and roll on, weird berry-coloured notebook. I find it fascinating being able to look back through the book to events from the past one and a half years, things I found to be of interest – a bit like peering through a window into that period of my life.

Hairy business


While you were sleeping last night, a horde of eight-legged creatures were celebrating an orgy in your eyebrows!

True story.

Demodex folliculorum, face mites, are one of many denizens inhabiting the menagerie which is our body. This critter, which is a close relative of ticks and spiders, grows up to a length of 0.4 millimetres, inhabiting human hair follicles, normally found in greater numbers around the cheeks, nose, eyebrows, eyelashes, and forehead.

They spend their days buried head-down in the follicles, to crawl out under cover of darkness to feed and copulate. Did I mention that they have no anus? Yep, so on death, they discharge a lifetime of faeces into you pores like a miniature poo grenade going off.

Right, this is it! Mark has finally snapped, you are thinking to yourself, what on earth does this have to do with anything arb or tree-related?

The answer is nothing at all. The truth is, I simply love the idea of all these tree guy rushing out after having read this blog post to get hold of wax strips to do a Brazilian waxing number on their eyebrows…

P.S. If you do not have any wax strips to hand, simply use Duck Tape! Should work a charm. Thank me later…

Climbers’ Forum 2017

It is that time of year again… finishing this year’s program for Climbers’ Forum in Augsburg was a bit breathless, but I am glad to say that finished it is – and published on-line. Same as the past couple of years, the whole event will be simultaneously translated between English, French and German.

This year we have subdivided the three days, 25 to 27 April, into half day topics: Tuesday will be a joint opening with the academic conference by Francis Hallé, whose very moving film, Once Upon a Forest, you may have seen a couple of years ago. Then the rest of Tuesday morning will be dedicated to the topic of PPE and equipment, with Taylor Hamel offering short input sessions on a range of topics, The Fairy Tale of Hairline Fracture in Karabiners,
Maintenance of Karabiner Gates
, Karabiner Shapes and Examples of Applications, followed by Knut Fischer from GRUBE, asking why vendors sell low-quality equipment, merely because there is a demand for it.

Tuesday afternoon the topic will be rigging. Again, starting off with an input session with Andreas Detter, How Can You Estimate the Load Capacity of Green Branches When Using Them as Anchor Points?; 
What Forces are to be Expected When Climbing and Rigging?
; What Are the Consequences of Having Friction at the Anchor Point When Rigging?, followed by Phil Kelly expanding upon the theme of friction at the anchor point of rigging systems, I will doing something on moving loads from A to B, building on last year’s balancer theme, Hannes Seibert and Knut Foppe will round off the day with a presentation on vector forces acting on rigging anchor points.

Wednesday morning will be spent discussing health and safety, as well as ergonomic issues.

Carsten Beinhoff from the German health and safety will kick this session of with a review of last year’s accident statistics, followed by Nina Landwehr who will demonstrate practical means to stay healthy in tree care. Roland Schindler will finish off the morning with his topic, Twenty felling seasons to go – thoughts on coping with the inevitable as an ageing arborist.

The next theme bloc will be climbing techniques.

Richard Allmond will start this one off with an input session, Can This Component, Assembly or System be Put Into Service as Category 3 PPE?; Am I a Suitable Person to Carry Out an Inspection On This Equipment?
; Go configure! – What criteria Do You Apply When Assembling Your Own Lanyard?, followed by Peter Vergote and Jo van Bouwel examining where there is overlap between competition and everyday work practices and techniques. Next up are Max Broeckmann and Thoren Benk who have given some thought to the matter of rescue techniques which can be employed in a stationary line situation.

Andreas Detter will present practical tests looking at the load tolerance of branches when used as anchor points, and the day will close with a joint presentation by Kay Busemann and Carsten Beinhoff on the use of cranes during tree removals and the analysis of an accident, the aim of this session it to develop means to recognise limits and to put strategies in place to ensure safe use.

Wednesday evening the traditional Climbers’ Forum party will take place, the venue is yet to be announced. In the past this has been a memorable event, to put it mildly…

Thursday morning will be started off by a review of the developments of the past sixteen years from the point of view of a rep of a rope manufacturer by Wolfgang Scholz, followed by Peter Vergote who will doing a talk called Passion before Fashion. The rest of the day will be spent examining certification issues, with an input session regarding various aspects of certification, including the legal view of the German authorities on non-certified PPE. Wolfgang Schäper will do a talk discussing the the legal situation when introducing non-certified PPE to the market, and Puk and Bernhard Schütte will finish the whole thing off explaining how they handle non-certified PPE in competition or training situations.

The final presentation is again a joint one with the academic conference by Neville Faye on a lifespan approach to tree care.

All of the above will be a mix of indoor presentations and demos outdoors on the treemagineers drop tower. Add into the mix one of Europes largest dedicated trade shows which many manufacturers time their releases to and you end up with a fairly comprehensive package. Not to mention an unique opportunity to meet and interact with fellow arborists from all over the world.

Put it this way, if you are planning to travel to Europe this year, why not plan it to coincide with this event?

What goes around

When I first got involved in treework in the early nineties, a rigging operation involved a large diameter polypropylene, single braid rigging line – a horrible, spiky, fuzzy and stiff monster of a line – and a topping strop (see pic below). This strop was again made of polypropylene, with a thimble in the eye.

That’s it.

No pulley, no lowering device… zilch.

The topping strop was installed at the anchor point with a Timber Hitch, the line passed through the thimble, then you took wraps on the stem – effective for generating friction, I will grant you that, but not so great for dynamic lowering, on a large stem it was nigh on impossible to avoid shock loading the rigging anchor point. I have vivid, strictly non-fond memories of walking the line round the base of a large beech tree, which also happened to have a climbing rose growing up it.

Grrrrr! Rigging lines, climbing roses and a grumpy trainee arborist? Not a good combination.

Returning to theme of the Dodo post from the other day, the use of these strops at the anchor point demonstrates how the evolution of rigging and climbing equipment is exactly that: an evolutionary process. As such, concepts are used, evolved, discarded – and re-discovered again, or developed upon.

The rigging rings used in certain rigging applications today are such an evolution of the humble topping strop.

This iteration of the topping strop is  proving to be popular: it is robust, easy to install, no moving parts which could fail or gum up, they can be configured into a tool you can deinstall from the ground… yet I have to admit that personally (and this is purely personal preference) I do not use them, as I like to be able to install the rigging line into the pulley mid-line, i.e. not have to thread it through the ring and I like also the fact that when rigging in a friction-optimised fashion with pulleys at the anchor point, the lion-share of friction is isolated on the lowering device, allowing for very precise lowering and winching.

On an objective note, I would comment upon the fact that where a pulley is in constant motion, therefore the friction is not acting on the same point all the time – however, when using rings this may the case: it is possible for the line to wear a grove into the ring, and once that has happened, it will tend to locate itself in that grove. This can be managed, but is certainly something one needs to keep an eye open for.

Finally, I mentioned that back in the day we were running single braid lines through the topping strops.

Double braid lines, essentially a line in a line, are designed to be used in a friction optimised environment, for instance over pulleys. When this is not the case, e.g. in a natural crotch rigging scenario, imbalances may be induced between the inner and the outer line due to greater friction acting on the outside part of the line, this can lead to damage, as the load is no longer being shared equally between the two parts of the line. Hollow or single braid lines are better suited to this kind of rigging.

Do not get me wrong, I am not knocking this use of rings, as I have often stated in the past, I love rings in the right place, but am merely pointing out that whilst changes may superficially seem small, such as switching from a pulley to natural crotch rigging or rigging rings, they may mean that you need to go through the process anew of assessing compatibility between neighbouring components in your system.

All of the above reminded me of a drawing I did for Friedrich Drayer’s catalogue back in 2003… dry-land waterskiing, I reckon we’ve probably all been there. Call the boss, it is time for a lowering device!

Non-linear processes

I recently started reading The Song of the Dodo, Island Biogeography in an Age of Extinctions by David Quammen, because… well, I rather like Dodos. One of the points Quammen discusses in the book is how evolutionary processes are messy, hard to predict and non-linear.

This, paired with a rummaging/ clearing session in the cellar, got me thinking about the evolution of equipment, which shares a couple of parallels with the Song of the Dodo.

As an example, take the Hitch Climber story:

Initially, this started as a discussion regarding wide loading of karabiners, configuration of equipment and general compatibility of components. There came a point when we started wondering whether the truth of the matter was that we were lacking a tool to tick all the boxes we were identifying. Sooooo, we got talking to manufacturers… we started off with a very ambitious design that was aiming to be all singing, all dancing, doing all sorts of stuff – to realise that whilst that is all well and good, the design spec would make the device prohibitively expensive and very hard to manufacture. So we started working backwards – process such as this are one of those typical kill your heroes instances, where you need to let go of your most cherished precepts in order to see other ways to achieve a goal.

This was definitely the case with the Hitch Climber pulley.

I remember that when Chris first ran the idea of a three hole pulley past me, I was less than convinced, after all this was a very different line of thought than the original direction we had been thinking in. Once we started discussing the merits of this idea, though, after some thought I understood the rationale and the potential of this approach. In hindsight, we would seem not to be the only people to see a degree of merit which the features of this set-up offer: The Hitch Climber pulley and the HC hitch configuration, I think it is not exaggeration to say, have since become fairly ubiquitous in tree care.

The point I am trying to make though, is that the route of getting there, similar to an evolutionary process, was one of trial and error, of trying out different configurations and concepts, of putting prototypes through their paces in the field – and keeping an open mind to the possibility that there might be another, unanticipated alternative just waiting to be discovered.

Also, like the Dodo, at a given point in time pieces of equipment may become obsolete, superseded by an evolution or development, pushing the earlier version towards extinction.

Well, in actual truth of course, the poor old Dodo was relentlessly hunted by sailors stopping off on Mauritius, its lack of fear of humans becoming its demise – humans really are pretty rubbish, methinks.

Poor old Dodo.

Spinning in a particle accelerator

I was reading an interesting interview the other day in the Tagesanzeiger with psychologist Sarah Diefenbach on the addictive potential of social media.

In the article she discusses how nowadays it seems that simply experiencing the moment is no longer sufficient, what is relevant is the response of others to it. Parallel to the experience we will frequently already be considering how to upload this content to social media, how to present the experience and what sort of photo will generate the most links.

Especially in a professional context, I find this an worrying development, as the mass of video footage and photos force people to generate increasingly extreme material in order to get noticed. It is no longer simply a matter of portraying a job well done, it needs to be crass in order to harvest those Likes! This in turn raises the question how such material portrays our profession and also what kind of message it sends to youngsters new the industry. Is there a risk that due to this trend, crass becomes the new normal?

Seeking confirmation from the people around us is not per se something new, it is something we are all eager for.

Yet with these virtual platforms the degree of support in the form of Likes which you can gain has become so much higher – this in turn can create stress, the pursuit of recognition in form of Likes. Yet at the same time the Likes devalue recognition, as the degree of commitment needed to like a post is very low – as easy a clicking a button. This is something which Evgeny Morozov discusses in great depth in his book The Net Dillusion, where he demonstrates how social media does not create freedom, on the contrary, it lowers peoples willingness to commit deeply to a cause, to take to the streets, to organise themselves with friends, to become part of a movement – all that becomes obsolete once you can subscribe to any number of political or social causes… without leaving the comfort of your sofa and with zero risk involved!

Another phenomenon which Diefenbach mentions is how behavioural patterns translate from social media into real-world contexts, it is after all not surprising that there should be such a transfer, given how much time people spend on these platforms. Examples herefore are giving opinions on everything – whether it is appropriate or not – , due to being in comment-mode all the time, rating people or behaving in a provocative fashion, i.e. troll-mode.

Reasonable people usually do not feel compelled to force their opinion upon others, reasonable people apply a filter when considering whether something has to be said, or can be left unsaid, waiting to see how the situation pans out, reasonable people do not go around shouting at the top of their voices. Unreasonable people are a less restrained in these matters, they will let you have it full bore without a moment’s hesitation! This in turn creates echo chambers, making the unreasonable opinion seem like a mainstream one.

In many ways it feels like sitting in a particle accelerator, turning ever faster, making our life increasingly stressful and breathless. In a professional context, issues are discussed at a level, in a tone and in a fashion which would have been unthinkable up until a few years ago.

Do not get me wrong: I am not advocating turning the clock back, I also use these platforms and tools to a degree. But as I have said before a number of times, I believe we need to be selective and wise in how we do so, aiming for high-quality upload and moderate download – and not forgetting to differentiate between the virtual and the real world.

Tom Gauld, an illustrator whose scientist geek humour I appreciate a lot, sums it up rather nicely in the cartoon below…

Managing slack

I was thinking of this post yesterday, one of my favorites from back in November 2014, so I decided to repost it, seems a bit of a pity for these things to get buried in the damp, dusty depths of the blog archives – it is the story of how different professions manage slack, and the story goes like this…

Managing slack is a reoccurring theme when discussing work positioning in trees.

We use semi-static lines with low elongation, work positioning and sit harnesses unsuitable to arrest a fall and use ventral attachment points that in case of a fall could cause substantial, whiplash-type damage.

But despair ye not, for help is at hand in form of industry best practice guidelines. A key element in all BPGs is the concept of keeping slack to a minimum. Yet still, despite all this, people struggle with this, from a conceptual and from a technical point of view.

But believe me, other industries also need to manage their slack.

Consider laying underwater cables, such as the one allowing maybe allowing you to read this, which might be an intercontinental fibre optic cable, such as Hibernia Atlantic, Hawaiki Cable, Apollo or one of the myriad of other submarine cables spanning the oceans. In his fascinating essay, Mother Earth Mother Board, published in Wired a couple of years ago, Neil Stephenson really submerges himself in the topic of how, physically, data gets piped around the world – it is well worth the read.

The part that I found fascinating was about how, when cables are being laid on the sea bed, slack is managed. The challenge being that if you lay it too tight, it will end up suspended and be prone to snapping or damage. If you lay down too much slack it ends up in a snarl on the seabed which subsequently can get snagged by trawlers – and then there is also the question of expense: the FLAG (Fibre-Optic Link Around the Globe) cable, for example, costs between $16,000 to $28,000 per kilometer, depending on the amount of armoring.

The amount of slack depends on the topography of the seabed.

The average amount of slack aimed for is about 1%. So based on that, the 2500-kilometer route between Songkhla in southern Thailand and Tong Fuk Beach on Lan Tao Island would require 25km of slack. But the big question is where to put it.  If the seabed is dead flat, minimal slack may be required. On the other hand, if it is rugged terrain the cable is being laid over, up to 5% slack may be necessary. For this reason the boats laying down the cables are constantly making highly accurate maps of the seabed with the aid of sidescan sonar and satellite geo-positioning data as they are laying down the cable and are constantly juggling the boat’s speed, position and the tension on the line, whilst at the same time modeling the drift that underwater currents may be causing in order for the cable to touch down on the seabed with the exactly the correct amount of tension for the terrain – and in the right place to boot.

Depending on the depth of the ocean, touchdown may occur several kilometers behind the boat. Phew!

Slack management during cable laying operations at sea

Slack management during cable laying operations at sea

Admittedly, specialized software is used to assist in these operations, but still, I found the number of factors involved and the level of complexity quite mind-blowing.

So, getting back on topic… managing slack whilst work positioning in trees is hard?

Really? You reckon?

Compared to some of the formidable challenges the folk laying cables across the oceans face, our difficulties pale somewhat. I believe that we have all it takes: we have the understanding of what the issues are – and also the tools and techniques to mitigate the risks that climbing with too much slack brings with it.

Finally, it is up to the individual to be diligent and to consistently apply best practice at all times when it comes to managing and preventing slack. This is not rocket science and I am confident that it is something we can manage.