Czech manufacturers make statestment

via ferrata accident criticism

via ferrata setDear valued users, customers and business partners, We, the Czech manufacturers of climbing equipment, feel it is important to issue the following joint statement after the tragic accident of August 5th, 2012,

when a fatality occurred while using a Via Ferrata set from a German manufacturer:

We criticize the lack of objective information about the tragic event, both from the German manufacturer and the certification bodies. The first official report about the accident was released at noon on August 30th, 2012 by the German mountaineering association DAV. Yet the report was incomplete and only identified products with the same construction and did not analyze the causes of the event. It was not until a month after the accident on September 6th, 2012 at a UIAA meeting in Bern, Switzerland, where we finally learned that the accident happened using a Via Ferrata set that was in a mountain chalet available as a free loan (and was placed there as an advertisement for a business in the valley). The instruction manual was missing, the user was not experienced, and the chalet was under construction (the Via Ferrata set came into contact with construction materials like cement and lime). No one can even estimate what condition the set was in, how many times it was rented, and how many falls the product had to absorb. An inexperienced, 94-kilogram hiker chose one of the most difficult Via Ferrata routes in the area (difficulty D/E), where there are no ladders or iron steps, and climbing is done only on the rock walls.

We consider inadequate and misleading the claim that the identified culprit was only the construction of and materials used in the damaged product. We maintain that, in addition to the possible effect of the construction and materials, this accident was mainly caused by ignoring the wear of the product, which was beyond the life of the product. We do not agree with the uncontrolled lending to “unknown people” with no instruction manual and no other instructions on how to properly use the product, and, especially that there was no record or evidence of who climbed using that Via Ferrata set, whether or not the set ever arrested a fall, and when the product was first put into operation. As we have verified in the Czech Republic, very few rental operations can submit evidence of rental frequencies, the identity of the client, let alone know the history of the product. On this point, we feel the lack of a guided methodology. Via Ferrata sets are missing required, periodic inspections and records of those inspections, especially regarding worn seams and straps. The problem applies not only to rental businesses, but also to the climbing clubs and other organizations, where such equipment is often available for lending. Renting Via Ferrata sets is a common practice; however, no one would rent a used rope for a week climbing in the Dolomites. And yet it is used in the same terrain with the same need for security.

Due to the relevance of the safety of Via Ferrata sets with elastic straps, we, as manufacturers, agreed to jointly review the effect of wear that could affect the safety of each company´s affected Via Ferrata sets. Our joint tests were performed by an authorized testing laboratory UIAA SZU Jablonec n/N according to the methodology TUV, and we have shared the results with each other for each company´s Via Ferrata products. The principle is that this is a simulation of the wear caused by cyclic stress (dynamic winding) on the elastic strap, which is subsequently subjected to a static test. The critical assessment boundary is 6kN, a limit below which the fall absorber should cushion the typical fall (1.2kN-6kN range is the working range of the absorbers according to EN 958).  Because we assumed that some wear would occur, we were interested in the attainment of the critical limit of 6kN and the measurements of strength in achieving it. In addition to the specific elastic straps used currently in our Via Ferrata set, we also tested an older, honey-combed strap (elastic core is strung through a hollow inelastic strap). Tests were made subjecting both straps to repetitive motions from 5,000 to 50,000 cycles. Here it should be noted that the actual cycle method used is a model, quickly prepared to verify the effects of wear. To date, this method lacks clear evidence that this leads to the deterioration of the material in practical use. Therefore, the results must be used only for orientation without specifying a confidence interval because, for satisfactory results, we would need to wait weeks (simulation with a rate of 2,000 cycles per hour).

tabulka
Static strength of elastic straps after cyclic loading.

From the initial results, it is evident that there is a difference in the course of wear between the newer elastic straps and the older elastic core/hollow straps. While the strength of the elastic core/hollow strap remained virtually unchanged after the cyclic testing, the elastic strap reached the critical limit of 6kN at an estimated 10,000 cycles. Starting at about 5,000 cycles, the strap shows visible wear and, at 50,000 cycles, the strap shows extreme wear.

via ferrata set 
Picture: A) a new strap 11. 5 kN, B) a strap produced and sold in 2010 and used since then as rental: 8.5 kN, C) strap after 50,000 cycles: 5kN (measured values are not average)

An expert is needed to describe what wear happened to the elastic material during the testing, and we will not attempt to do that. To understand the strength tests, however, we must assume that the fibers loosen due to friction. The fibers do not tear, but are pulled because during the tests as there are apparent jumps characteristic of inhomogeneous structures, which are gradually involved in groups (broken fibers do not transmit anything). The cyclic loads evidently shorten the strap, and the material apparently works under the influence of relaxation (different results after resting). Other factors come into play, such as strength, softness, and/or other modification of fibers after extrusion. It can be assumed that the elastic straps with rubber woven fibers will behave differently if they are made from a different material or with a different construction.

Identified wear of the material based on the simulation were compared with wear from other long-term used ferrata sets returned from a rental business. We wanted to compare whether or not the method corresponds to the actual practice of climbing on Via Ferrata routes. Strength in the returned rental sets, in which we knew the time and frequency of rentals, was always higher than the critical limit of 6kN. A critical limit of 10,000 cycles (6kN), according to our calculations, would roughly correspond to using a maximum of 150 uses (or 150 via ferrata routes).  This estimate is analogous to the relationship of normal wear and cyclic test. TÜV Munich created and developed a method of cyclic strain on the elastic strap, which is a similar analogy (the estimated number of cycles). In practice, however, the rate of the wear by the cyclic stress depends on many different circumstances, especially the experience of the climber and the length and difficulty of the Via Ferrata route.

Every manufacturer must acknowledge and deal with the above findings in determining the particular the life of a product, which is stated in the instruction manual. We recognize that the decline in strength of the elastic strap due to wear under the cyclic stress is higher than in other types of straps. The design of this elastic strap, in conjunction with a disregard for life of a product, can be dangerous. With this information, each manufacturer must decide how to inform and protect their users. Following this accident, there will certainly be increased pressure for stricter safety standards. We, as manufacturers, will insist not only on the introduction of a system of checks and reviews in any form of lending, but also for a higher degree of education for individual users. We contend that, with Via Ferrata sets, there is a need to know the history of previous use. In this area, we see a gross deficiency and an ongoing, potential risk because ignoring the history of use for any product threatens future users regardless of the material used and the brand name.
Our joint cooperation is leading toward setting just guidelines for commercial and non-commercial use.
On behalf of Rock Empire ®
Jiří Chaloupka, Ing.
Rock Empire s.r.o

On behalf of OCÚN ®
Vladimír Křapka, Ing.
RP Komponent s.r.o.


On behalf of Singing Rock ®
Jiří Hrdina, Ing.
LANEX a.s.

   [edit] 18:06 19.09.2012

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