The Critical Of Ignorance: (Re) Writing Expertise Reports On The Brétigny Derailment (France)

This paper tackles mechanisms of knowledge production after accidents comparing four expert reports on the last major derailment in France (at Brétigny in 2013, causing seven deaths). The purpose is not to provide a socio-technical explanation of the accident. It is to highlight how mechanisms of knowledge and ignorance production strongly depend on experts' "social position." More precisely, it shows that the extent to which certain groups of experts consider the knowledge of other groups of experts depends on their institutional and administrative base. Four types of report are examined chronologically. They differ in their framing of expertise work. Whereas the railway company experts try to impose a purely technical definition of the accident, other experts (working for the employees, the Transport Department, and the examining magistrate) highlight the conditions of maintenance work and the dilapidation of the railway network. The paper analyzes the explanatory processes at work in the reports, focusing on how some causal elements evolve, become more complex, or disappear. Depending on the data used, the definition of the accident and of the responsibilities change. Building upon works on the production of ignorance, the paper identifies two mechanisms of ignorance production: ignorance by omission and ignorance by submersion. The comparison of the four types of reports shows that what is silenced by one group of experts becomes a resource for another to criticize and contest previous analyses of the accident.