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The 7 deadly sins of SRT Ascent

Richard Tregoweth - Thursday, January 17, 2013

The TCIA have given us the definitive 'Best Practice Guideline' for SRT and they should be applauded for this excellent publication.

But, unfortunately, not everyone reads the TCIA BPG for SRT or receives the correct training in SRT before they decide to get into single line ascent. This results in common mistakes being made.

Below is a list of 7 potentially deadly SRT Ascent sins (in no particular order) witnessed by Treetools on a daily basis - the list is by no means the be-all and end-all of SRT issues - it's more a matter of food for thought. Please think about these 7 Deadly Sins before you invest in SRT Ascent equipment.

1) Mis-configured 'frog-style' set-ups

Thanks to YouTube 'training' all a tree climber needs to do is purchase a hand ascender, Petzl Croll, Petzl Pantin, foot loop and chin-strap bungee and they have a 'frog-style' ascent system - at least, that's what they think they have.

Almost all new climbers to SRT miss the vital 500mm life-line connection between the hand ascender and the Petzl Croll.

When this omission is pointed out, quite a lengthy debate ensues centered around the need for two points of attachment when using toothed cammed ascenders.

Some SRT newbies are receptive to the idea while others see the connection as a sales pitch from Treetools to sell more gear!

2) Incorrect ascent line: in both construction and diameter

Kernmantle ascent lines were not common in tree work.

Until the large scale adoption of SRT Ascent most climbers used 12-strand, 16-strand or 24-strand climbing lines - none of which are designed for the toothed cammed ascenders used in SRT Ascent systems. The sheath dependent 12 and 16-strand ropes are a positive no-no and 24-strands are not much fun either.

Kernmantle ropes have a braided outer sheath which protects the load bearing (65-70% of load) inner core from the aggressive toothed cams.

Ascent lines are generally low in elongation so climbers readily adapt once they have the opportunity to climb on such a line.

But a new ascent line with a diameter matched to their hardware is an expense too far for most tree climbers when putting together their SRT Ascent system.

The cost is exacerbated by the length of line required - typically 3-times the height you intend to climb - and… most SRT proponents are looking at BIG trees.

3) Force at crotch; double loaded when using a basal anchor

Here's another concept which produces a blank, faraway stare when first introduced: the force at the crotch is twice the force on the rope when base anchored.

Doh! Please explain again. You are putting twice the load on the top anchor point when you throw the line over the branch and tie it off at the base of the tree!

Thankfully Treetools can easily demonstrate the physics, and potential dangers, involved with a basal anchor system by setting a line up on our demonstration tree, but I would not like to count the number of times I have had to repeat this information.

The basal anchor also introduces a degree of complexity with all the different options available - fertile ground for tree climbing myths and legends where additional problems can easily be introduced (this Deadly Sin will require a separate blog post).

Use of a basal anchor is not a Deadly Sin in itself; its the lack of understanding regarding the forces generated in the tree that presents the problem.

And for God's sake, when using the basal anchor, do not roll over or step up onto the branch when you get to the top; odds are 50:50 for taking a tumble.

4) Work positioning during ascent

If the climber manages to configure his frog-style system correctly, with an appropriate ascent line, anchored accordingly; the next big mistake is to 'work' on the way up.

SRT Ascent systems are designed to accommodate the movement of a passive load (you the climber) ascending perpendicular up the line. No amount of slack - eg stepping up onto branches - should ever be introduced to the system even when using kernmantle ropes. No sideways movement should be made.

Unfortunately the temptation for many SRT climbers to complete a little bit of the job on the way up is just too hard to ignore - regardless of the risks involved.

5) Transitioning to another system at the top

Every transition aloft increases the margin for error.

There was a YouTube clip doing the rounds late last year where the climber ascended into the tree on a single line and proceeded to transition to his DbRT system, securing himself with his lanyard first.

So far so good.

Once he set the canopy anchor and moved off the single line he somehow managed to 'forget' to re-attach himself to his DbRT system.

When he released his lanyard he fell to the ground - with disastrous and painful results.

Tree climbers need to be well versed in the art of transitioning before they decide to get into SRT Ascent.

6) Self rescue ignorance

The excitement of seeing Drew Bristow (in video above) run up a single line is too overwhelming for some.

A decision to descend part way up the line (for whatever reason) can present a real dilemma.

Toothed cam ascenders are designed to go one way only. Using these devices makes it impossible to descend with any speed or decorum.

The question 'how will you get yourself down in case of emergency?' receives the same blank stare as in Deadly Sin No:3

7) Crew ignorance

So you turn up to work with your fancy new SRT Ascent gear, set a canopy anchor with your super-low-elongation kernmantle line and ascend like a pro.

But, during this very stylish ascent, something manages to go wrong and you end up suspended in your system, unconscious.

The canopy anchor means you cannot be lowered from the ground so another climber must get into the tree to rescue you.

Ask yourself. Has the rescuing climber got any idea on how your SRT system works? Have they even seen a system like that before?

Tree climbers depend on the competence of their ground crew and if these guys are not trained in SRT Ascent and rescue you have a potential problem on your hands.

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