What does “sufficiently safe racking” mean?
A more accurate and commonly used definition is: “informed consent to the risk of an accident that is still acceptable.” “Informed consent” means that we are aware of the possibility of accidents occurring.
“Acceptable” means that we will risk accidents up to a level accepted by society. An important role here is played by the relationship between the risk of accidents included in the design process (number of accidents, their severity) and the cost-effectiveness of making racking resistant to them. It should be remembered that the range of collision risk acceptable to users changes over time, because our assessment of safety also changes. For example, the safety criteria that cars must meet today are much stricter than 25 years ago.
Between safe use and an accident.
In the case of load-bearing structures, and thus also pallet racking, “sufficiently safe” is defined as: “a sufficiently minimally guaranteed margin between the calculated stresses arising during the use of the racking and the stresses at which the structure fails.” (Fig. 27) The term “minimally guaranteed” means that data is taken into account during design that allows for the certainty of calculations to be established. To be able to rely on calculations, the following are taken into account, among others:
■ minimally guaranteed structural properties of the steel from which the racking elements are produced (certified steel);
■ standardized methods of performing tests needed to determine the structural properties of racking elements (see Fig. 3, 7 and 11);
■ appropriate interpretation of statistical test results, aimed at determining characteristic values in the design process;
■ the most unfavorable assembly errors of the structure that are still acceptable (this applies, for example, to the leveling of frames, shims, anchoring).
■ standardized methods of performing tests needed to determine the structural properties of racking elements (see Fig. 3, 7 and 11);
■ appropriate interpretation of statistical test results, aimed at determining characteristic values in the design process;
■ the most unfavorable assembly errors of the structure that are still acceptable (this applies, for example, to the leveling of frames, shims, anchoring).
The statement “calculated stresses” means the result obtained through calculation. It is impossible to approve racking for use only after it has been assembled and test-loaded.
The article comes from the magazine “Logistyka” 2001/4.