(24b) On the Use of Consequence Models for Accident Investigations

Accident investigations are performed to understand the cause of an accident and to help avoid such an event from happening again. Consequence models can contribute to understanding the chain of events that led to the accident such as identifying the source of leak of flammable material released, how much fuel was involved in the accident, where the ignition occurred (including indicating what the ignition source was), explaining the damage that was seen, and helping the estimation of the potential consequences of an event. The models can also be used to identify and design protection measures after an accident.

The use of a consequence model in an accident investigation typically involves the development and implementation of new sub-models to be able to verify observations made and to identify possible related causes of the accident, necessary validation of these sub-models, and ?accurate? representation of geometrical details including failing structural components. Laboratory experiments and scale-model tests are also often used and the consequence model is validated against them to verify that it can be used.

In the present paper several examples of use of a well-validated consequence model (FLACS) for accident investigations performed are given. The accidents that were considered include among others an aeroplane crash (TWA 800), a tank explosion (Sløvåg), a coal mine explosion (Sago) and a chlorine release (Festus). A brief description of each accident is given. The paper focuses on the developments, geometrical representation, and validation carried out in these accidents and describes how the FLACS model has evolved as a result of each accident investigation.