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5 reasons why unique tree climbing PPE standards are needed

5 reasons why unique tree climbing PPE standards are needed

Richard Tregoweth - Wednesday, April 17, 2013

The UIAA have the right idea.

The UIAA Safety Commission works closely with mountaineering equipment manufacturers to develop standards with an aim to minimize gear failure accidents.

The UIAA also act as technical advisers to the CEN (European Committee of Standardization) who, in turn, issue the EN Standards.

Tree climbing should be going down the same path!

Here's five reasons why the tree climbing community should develop their own PPE standards to harmonize with European Norm and ANSI:

1) EN Standards are not always applicable to tree climbing

The recent discussion surrounding applicable standards for the Rock Exotica Unicender and the Petzl ZigZag are a case in point - what standards should be applied to these devices?

Both fall outside the European norm. Are they Ascender? Descender? Friction device?

The Uni and the ZigZag both 'slip' when loaded which, in theory, makes them difficult to break under current static and dynamic testing regimes.

Configured knot-based systems like CE Climb, also slip when loaded, yet manage to conform to multiple criteria based on appropriate EN standards; static strength (23kN for 3-minutes), dynamic strength, grab function at speed as well as stationery and overall residual strength (following the previous series of tests).

CE Climb EN Standards include EN1891A, EN795-B, EN566, EN 12278, EN 12275, EN 362 and, to a degree, EN12841.

Bar a derivative of the descender standard EN 12841 none of the other standards can be applied to mechanical devices like the Unicender and the ZigZag and yet they should conform to the same CE Climb criteria.

2) EN Standards can the 'flexed' to meet appropriate safety criteria

As stated in No:1, the current EN standards are not always applicable.

When a suitable standard cannot be found (in the current EN portfolio) it appears manufacturers follow the 'philosophy of parts'.

That is, they find the most appropriate standard and test to the criteria applicable.

This, more-or-less, happened with the CE certification for the ZigZag.

The device was tested to parts of the descender standard EN 12841. That's why the ZigZag does not bear the full standard in its' documentation since only 'parts' of the standard were attained.

This scenario is not Petzl's fault, the company was doing the best they could with the current situation.

3) Some EN testing does not meet the rigors of tree climbing

Treetools works with aerial arborists everyday. We see the demands placed on gear and we witness plenty of broken equipment.

In most instances, the breaks are due to freak situations. In others, it's climber incompetence.

The CE Climb-style certification is built on multiple 'rated' components configured into a system. When you strip away the components and have one device comprising all components the testing variables increase exponentially.

Tree branches are round and hard. Tree climbers ascend, descend and work three dimensionally through the tree.

The current EN standards where based on the original UIAA mountaineering standards and further developed to accommodate the height safety and rope access markets.

These disciplines are two dimensional; you ascend, descend and go sideways - never through.

Testing criteria for two dimensions do not always apply to three dimensional activity and navigation.

4) Most manufacturers do not understand tree climbing

Further to No: 3 not all manufacturers understand what is actually involved in tree climbing.

Tree climbing and the structure of a tree is not pure engineering in action; anchors are unpredictable, slack is introduced, climbers ascend, descend and move laterally… and at speed.

Dynamic forces are applied, sudden stops happen and the loads and angles on the climbing line are constantly changing.

Epicormic and branches do interfere with mechanics and carabiners do get cross-loaded (albeit inadvertently).

Not ideal, but that's the reality.

Consequently, gear must be designed, tested and manufactured with these variables in mind.

Unfortunately engineers cannot always achieve these testing scenarios with the current EN Standards.

5) Acceleration of tree climbing gear development

The last few years has seen a proliferation of new gear becoming commercially available. Most of this new tree climbing equipment has tested the relevance of the current EN Standards to the max.

The Lockjack, Spiderjack, Rope Wrench, Unicender and ZigZag are fast on the way to becoming 'mainstream' products in tree climbing.

And yet, none of these products are 'fully certified' to the letter of the (EN) law.

The new developments in Single Line Work Positioning will only serve to further exacerbate this issue.

So… let's follow the UIAA model and develop our own set of standards, and not rely solely on European Norm or ANSI, to ensure the future health and safety of everyone in the tree climbing community!

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