ABSTRACT
Some of these mechanisms will be recognised from the earlier model of operator error. Most are, however, quite specific. They occur repeatedly in accident reports.
When something out of the ordinary occurs, there is often a perceived need to adapt equipment to meet the need. An example is the case of acid leaking from a road tanker. This was pumped over to an available tanker, to stop the leak, but as a result, the tanker contained contaminated acid. Subsequent purification attempts led to an explosion, because the extent of the contamination was unknown.
