The inquiry into a collision involving two freight trains in New South Wales, Australia in 1997 identified driver inattentiveness as the cause of the crash. Signals were passed at danger but the crew still acknowledged the vigilance control system up to a point where a collision was inevitable. This paper presents the results of a case study which reviewed the effectiveness of the driver vigilance control system used on similar locomotives and recommended improvements to the effectiveness of the system in ensuring attentiveness in critical situations. The vigilance control system used on these locomotives requires that a member of the crew acknowledge the system by pressing a button at least once every 60 seconds. If this is not done, a light will flash followed by a bell. If no acknowledgement is received during this period, the brakes on the train are automatically applied. The analysis of the current situation concluded that the vigilance control system can be operated in a largely automatic manner and does not require conscious attention or vigilance to respond to the system. A number of ergonomic issues related to the location, colour and mode of use of the lights and auditory signals were also noted. Technological systems to prevent collisions or derailments were not considered feasible across the network in New South Wales. Given this constraint, recommendations were developed to improve the performance of the vigilance control system. These improvements will reduce but not eliminate the possibility of a similar incident occurring in the future. (A)
Abstract