Treetools Blog RSS

Continuous update of new tree climbing products, equipment and tools

Petzl respond to latest ZigZag failure

Friday, January 23, 2015

Petzl engineers have undertaken additional testing overnight to try and replicate the deformation visible in the photographs Treetools published Wednesday on FaceBook and again in the Treetools Blog yesterday - here are the results of those tests (ad verbatim) - make of it what you will:

"Based on our understanding of the causes of the crack, and the analysis of each returned ZIGZAG, we know that cracks on the bottom link (worst case scenario) may appear only on one side of the chain.

In fact, due to the assembling process, the the bottom link on the side of the body with the Petzl marking can not have a crack (there is no riveting process on this side of the bottom link).

In order to get value on the resistance in such a case, we have pushed further our tests on a broken bottom link up to a complete breakage of the chain, and we have obtained the following results:

As visible on Treetools website, a ZIGZAG with a completely broken bottom link on one side and on the other side a bottom link free of crack, can support a load greater than 15KN.

At forces around 17KN, we observe a complete separation of the chain from the body."

For the very latest ZigZag update from Petzl follow this link. Please keep a close eye on your ZigZag if you are climbing on one.

Posted by Richard Tregoweth Google+

In some cases cognitive connection defies logic

Thursday, January 22, 2015

Marketers know all about 'cognitive connection' and 'emotional empathy' towards products - achieving this state is the holy grail for many brand owners.

Anecdotally, most of us can identify with this phenomenon - simply put, we fall in love with the gear we buy, especially if it works well and is produced by a reputable manufacturer.

But… as in other forms of 'love', when the emotional connection is in full bloom, logic often goes out the window.

Puppy love, even in trees

A living example of 'product love' is the Petzl ZigZag.

No matter how many times ZigZag lovers see pictures of defective ZigZags they discount the images as fake, having no back-story, it's the same picture regurgitated, only in New Zealand etc, etc.

"Sure the Petzl ZigZag has cracks and broken links… but what's your problem man!"

This attitude seems quite strange when life and limb are at risk. And yet this is a reality today.

Same hairline crack, supposedly remedied

Up until recently all of the defective Petzl ZigZags presented to Treetools had a hairline crack on the top left hand link, extending from the spring hole to the outer edge. (This problem is supposedly remedied in later versions of the Petzl ZigZag).

Then, a few weeks back, we saw an example where the bottom link had collapsed around the rivet (along with four other cracked links on the same device).

Incredibly, the owner of the said ZigZag did not see these cracks or busted link as a major problem (ZigZag love-sickness in action).

In his mind the ZigZag had not 'failed' and he was happy to continue climbing on it.

To make matters worse he did not purchase the device from Treetools, so he felt it unfair for Treetools to make the exchange.

Only after insistence did he take the replacement ZigZag.

The second Petzl ZigZag (where the link has detached from the rivet) failed during descent. According to the owner of the device the climber was about 1m off the ground, moving around a thin diameter stem.

The ZigZag links were fully deployed when he made the jump to the ground which resulted in the device smacking up against, and around, the stem.

The climber was not injured and the climbing line did not detach from the device.

According to the ZigZag owner, there was no apparent defect at the start of the climb (this company owns two other Petzl Zigzag so they are familiar with the gear check procedure).

Are these breaks for real?

Treetools cannot be sure exactly what happens in the field with these devices - we rely solely on the credibility of the user when they present at the shop with a defective unit.

Did these guys pull the ZigZag apart with a winch? Mis-configure it? Or deliberately sabotage the device in some other way?

Treetools cannot say with absolute certainty but one thing is for sure - there are problems with the Petzl ZigZag.

Posted by Richard Tregoweth Google+

A good tradesman does not blame his tools

Friday, January 16, 2015

The New Zealand silly season got underway with two major tree-climbing incidents just before Christmas. The New Year rang in two more, equally serious.

Two of the four accidents involved seasoned practitioners and the other two were inexperienced tree climbers… to the point where they should not have been aloft alone in a tree.

Problem caused by a loose nut

Over the holiday break an old farming mate of mine offered this pearl of wisdom regarding the proliferation of quad bike accidents in New Zealand: the most common reason for (quad bike) accidents is not the quad bike itself.

According to my friend, the problem is almost always caused by the loose nut connecting the seat to the handlebars.

That got me thinking about tree climbing.

From experience, it’s almost always the ‘loose nut' connecting the harness to the climbing system who causes the accidents.

The interesting thing about the four silly season accidents is the attribution of blame.

The two seasoned climbers recognized they were the ‘loose nut’ in the equation.

Both accepted the blame, accepting the fact they momentarily took their eye off the ball, with broken limbs as payment for their lack of attention to detail.

In contrast, the two inexperienced climbers blamed 'gear failure' for their misfortune (independently).

Catastrophic gear failure? Yeah right.

As you can imagine PPE gear failure is a significant event – it’s a rare day indeed when hardware and/or climbing lines catastrophically fail without some form of prior warning (the very reason for daily gear checks).

That’s not say gear cannot fail - or wear out (the pile of redundant equipment on Treetools front counter is testament to the fact that indeed it does).

But, as suggested in the quad bike anecdote, the most common cause of accident is the ‘loose nut’ connected to the harness… not the gear itself.

Worn and busted tree climbing equipment is a permanent fixture on Treetools front counter… much to the fascination of visitors, particularly those not directly involved in the industry.

Posted by Richard Tregoweth Google+

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