Safety net ageing: level of confidence in the degradation evaluation

Abstract

Safety net performance, only evaluated at the design stage, must last throughout the net’s life: the net should effectively retain a person if he accidentally falls. Standard No. NF EN 1263-1:2015, which defines the safety requirements applicable to such nets, proposes calculating a coefficient to take into account the ageing deterioration and make it possible to determine the breaking energy for a new net, established from a natural or artificial ageing test. This study presents a comparative analysis between coefficients obtained for three types of nets aged naturally and those from samples of the same nets subjected to two cycles of artificial ageing. Standard No. NF EN ISO 4892-2:2013 therefore appears to be an interesting alternative to the currently proposed cycle. Otherwise, this study shows, for the same conditions of natural ageing, an underestimation of the effect of ageing when calculated from samples as opposed to from a whole net.

Keywords:

• safety net
• fall from height
• artificial ageing
• natural ageing
• mechanical test
• deterioration coefficient
• breaking energy

Acknowledgements

The author would like to thank P. Bertrand, D. Bruant, S. Mansuy and P. Marchal for their contribution during the realization of the mechanical and ageing tests.

Disclosure statement

No potential conflict of interest was reported by the author.

Notes

1 Located in Vandœuvre-lès-Nancy, France.