3.5.4 Load Chain Collecting Box
Where a hoist is to be fitted with a load chain collecting box the following points should be borne in mind:
Chain is a load in itself and the uncontrolled fall of a length of chain could inflict serious injury upon any personnel in its path, as well as subjecting the hoist to a high shock load. Where such a risk is identified it should be eliminated through use of a load chain collecting box that is properly designed for the job.
It should be of adequate capacity for all the load chain when the bottom hook is in the highest possible position, i.e. when the hoist is fully drawn up. If the box is of inadequate capacity, the chain will spill over the edge and, rather like a siphon, once this occurs ALL the chain in the box will be pulled out at an accelerating rate.
Where moisture or condensation is likely the box should be provided with a suitable drainage hole to prevent a build-up of water.