A great number of injuries when performing the work at height are recorded when falling from the stairs. Injuries due to falling from height including ladders are usually severe and even fatal. At the same time, about 70 % of injuries occur with portable ladders. Most often, the fall of a person is caused by the effect of sliding ladders and breaking the stability of its overall structure. One of the ways to increase the stability of the ladder is to use attachments on its upper part. Depending on the method of coupling with the support, the possibility of adjusting the coupling area, as well as the presence of built-in safety systems, different types of attachments are used.
The article considers the forces that cause the slip and fall of the ladder when using it in work. Engineering solutions aimed at preventing the upper part of the ladder from slipping while working on the support are presented. The systematization is carried out concerning the available attachments on ladder by the method of coupling with the support. The evaluation of these engineering solutions in various ways of their application is carried out. A mathematical model is proposed for risk assessment when performing work at height using ladders with attachments. The stability of the ladder with the attachment will be higher, the greater the coefficient of friction of the attachment and the less degrees of freedom of movement in the «attachment — support» bundle.
An empirical conclusion is made that the safest attachment at the top of the ladder will be the structure that is fixed on the support. The attachment with an anchor point ensures the safety of work at height, but it is not suitable in all cases. There is no universal effective engineering solution to ensure the safety of work at height from the ladder. Technical safety measures have great potential, since they allow eliminating the human factor in this process.
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