What causes racking to collapse?
There are a number of different factors that could result in a racking collapse. The cause might not be a single factor, but can be a number of combined factors which ultimately weaken the structure to a point where it collapses.
The most widely used racking type is adjustable pallet racks (APRs). The main components of this racking system are the racking frame, which usually consist of two uprights and diagonal supports, and the pallet beams, which are supported by the frames. Image below .
The design of the uprights is such that they are slender members, making them very strong in compression but susceptible to buckling. This type of racking transfers the loads on the pallet beams, caused by the weight of the goods stored on the racking, through the uprights to the floor. If an upright is damaged, installed incorrectly, or moves in such a way that the downwards forces act eccentrically relative to the upright, then it is prone to failure due to buckling.
The main causes of racking collapses are;
- Inadequate design;
- Incorrect installation;
- Overloading at pallet locations;
- Mechanical handling equipment (MHE) impacts;
- Supporting floor failure;
- Environmental or chemical deterioration;
- Change of configuration away from that for which the racking was designed;
- Poor weight distribution on pallets, or pallet failure.