THE TECHNICAL GENESIS OF MACHINE FAILURES LEADING TO OCCUPATIONAL ACCIDENTS

This paper is concerned with machine failures that occur in automated installations that lead to occupational accidents. It is based on inve stigations of 76 cases of automation accidents. A conceptual apparatus has been developed which has the aim of describing the technical gene sis of machine failures. Its external validity has been confirmed in l arge parts through its correspondence with concepts developed by other researchers. The apparatus has been applied to the automation acciden ts investigated. The factors, 'manifestation of fault', 'machine failu re' and 'human intervention' have been utilized to describe 64 automat ion accidents involving machine failures. In nearly a third of the cas es, the courses of events resulting in injury were similar: a work pie ce became stuck, or crookedly or incorrectly positioned; this led the machine to stop; the injury occurred while a person attempted to corre ct the position of the work piece. Four factors, 'origin of technical fault', 'history of fault', 'type of fault' and 'location of fault', h ave been employed in the investigation of 28 accidents. A majority of the technical faults were known to persons at the work site before the accident occurred, which suggests that opportunities are available fo r improving the handling of machine failures.