Safety cages efficiency during ascent and descent on vertical ladders

Abstract

Issues of ensuring the safety of working on height do not lose their relevance. Civil engineering is in the first place of the amount of injuries and deaths. It accounts for 17% of the structure of the main types of economy activity. The main reason of injuries is the fall from a height (30.5% of all injuries) More than 40% of accidents are lethal or cause partly or complete inability to work. The paper considers safety during ascent and descent on caged ladders, representing a way of collective protection. The construction of vertical ladders, arc cages and the mechanic of worker ascent are considered. Preliminary kinematic model of human fall has been considered during tests, using falling mannequin on caged ladders, with additional safety systems and without them. The analysis show, that caged ladders cannot provide enough protection and create an imaginary protection threat especially when the construction has three vertical bars, which has been set and tested. There is a high probability of falling on the ground or another platform. The paper shows, that cages are not as safe as personal protection equipment, installed on ladders. Some normative documents about vertical ladders allow falling from height less than 10m, which raises many questions about the safety of using that standards.