Incident Report

1994-09-07A diver entered a short sump with poor visibility wearing a drysuit. Available equipment used included one 6 litre cylinder two batteries and 12lb of lead on one belt secured with a roller buckle to form a stripped-down kit. This was not a known configuration of equipment to the diver but it was considered at the time that pressing circumstances permitted its used. During the dive the belt became undone resulting in the sudden freedom of this equipment. A careful exit was made.Investigation identified that a load gently pressing on the buckle rotates the buckle thus unlocking the belt. Discussions revealed that this failure mode was already known to some divers - but it was not generally known or made obvious at the time. (1) Do not use roller buckles for load-bearing applications under any circumstances. (2) Do not test or use a novel or unknown configuration of equipment in a committing environment. (3) Do not be afraid to speak out when a failure mode is identified; this diver would hate to have a fatality on his conscience as a result of putting ego before common sense. It is this incident that committed this diver to a policy of openness about failures. It is possible to increase the security of some roller buckles by threading the belt back on itself through the buckle or by securing the loose end in another way. Consider using two belts (to reduce the consequences of failure) or better using belts of a different design; purpose-made diving belts with a backing strip prevent equipment migration and hence this failure mode will not occur if such a belt type is used correctly.