Why a diesel failed to stop at Beddgelert
THREE recommendations have been made by the Rail Accident Investigation Branch (RAIB) following an incident in which a diesel was unable to stop as it approached Beddgelert station on the Welsh Highland Railway.
After passing through the station at about 10mph around 9.17am on April 16 last year, Funkey Bo-bo Vale of Ffestiniog passed a signal at danger and then entered a single line section without authority, said an RAIB report. The driver tried various ways of applying more braking effort but was unable to slow the locomotive down.
After travelling for just over a mile, the locomotive came to a halt when the gradient levelled out. The driver was uninjured, and no other train was on the line at the time.
The incident occurred because the locomotive’s brakes had been modified in a way that limited the movement of the brake blocks, said the report. This, the state of the adjustment of the brakes and the wet conditions on the day prevented the brakes applying the necessary brake force to slow the locomotive down.
The issue with the brake system modification had remained undetected during the 18 years since the modification was made. The RAIB investigation found that the change to the locomotive’s brakes had not been adequately documented or controlled.
Recommendations
The RAIB found the locomotive did not have a documented brake inspection procedure, and the‘deadman’safety system was not enabled on the locomotive when the runaway occurred. RAIB also observed that the railway’s investigations of its incidents could be improved to better understand underlying systemic issues.
As a result of its investigation,
RAIB made three recommendations to the Festiniog Railway Company regarding the improvement of its management of engineering change, ensuring its maintenance processes are documented and controlled and the use of the ‘deadman’ safety system. It was further recommended that the Heritage Railway Association distributes the report to other heritage lines.
The RAIB has also reminded heritage railways of the importance of carefully assessing, checking and documenting safety critical modifications, understanding the risks associated with all safety critical systems and assessing existing control measures and dependence on human performance and carrying out a thorough investigation of safety incidents, which can help to ensure that risk mitigation measures are appropriate and proportionate.