The ATSB's report into the Epping rail accident reinforces the limitations of reliance on automatic train stops and 'deadman's handle' devices in the event of driver incapacitation and highlights the importance of improving these defences as well as medical standards and processes for train crew.
The sole purpose of ATSB investigations is to improve future safety and the Bureau acknowledges the safety actions taken through the Victorian Department of Infrastructure as a result of ATSB's investigation such as reviewing signalling systems and defences, developing new medical standards and setting up an inquiry into pilot valves such as the 'deadman's handle'.
At 0914 on 18 June 2002, a suburban electric train with passengers collided with a suburban electric train without fare-paying passengers at Epping. Both the trains and the rail infrastructure sustained damage as a result of the collision. There were no major injuries to either passengers or crew. The Victorian Government asked the Australian Transport Safety Bureau to conduct an independent investigation of the collision. The team of ATSB investigators were supplemented by consultants engaged to provide technical expertise on specific aspects of brake systems and transport medicine.
The ATSB established that train maintenance was not a factor in the accident. While the signalling system, which incorporates automatic train stops, operated within its design criteria, it could not maintain a minimum safety margin between trains to prevent the collision at the speed involved.
Trains are fitted with pilot valve devices (including the 'deadman's handle') so that in the event of driver incapacitation an additional defence operates so that the train should brake and be brought to a halt. On this occasion the driver of train 1648 had become incapacitated but the pilot valve did not activate to apply the train's emergency brakes. Because train 1648 was travelling at about double the posted speed of 40 km/h, the subsequent application of automatic braking after passing a red stop signal could not stop the train in time before it reached the collision point.
The report also addresses factors that contributed to the driver working when unwell and recommends improved medical standards and procedures in addition to other recommendations.
The Investigation Team reviewed the factors surrounding the Footscray collision on 5 June 2001 (available on the ATSB Web Site) which involved some similar safety issues including with respect to driver incapacitation and pilot valves such as the deadmans handle.
The issue of drivers becoming incapacitated whilst driving a train, and the train pilot valves not activating, are also factors currently being considered in the Special Commission of Inquiry into the Waterfall Rail Accident (New South Wales). In February, the ATSB briefed officers of the Commission on the possible significance of the Footscray and Epping accidents, including the limitations of pilot valves.