Railway safety lies in maintenance
Why is railway maintenance so important – and what could the consequences be if it isn’t carried out correctly?
“A railway system is a complex mode of transport with high demands on safety to eliminate the risk of accidents. If maintenance is not carried out properly it may result in delays or, in the worst case, accidents. To ensure a high level of reliability and availability, implementation of an effective maintenance programme is a must. Wear and rolling contact fatigue in rails and wheels are significant problems for the railway sector.”
What are some of the common causes of maintenance-related incidents?
“In general, maintenance-related incidents or accidents are the result of improper maintenance execution or poor maintenance strategy. Some of the research carried out at Luleå Railway Research Centre indicates that many accidents happen during execution of maintenance rather than as a consequence of lack of maintenance. However, lack of maintenance or poor maintenance has also been reported as a major cause of recent accidents.”
What sort of forces are rails, sleepers and their bolts exposed to?
“Temperature changes and fluctuations impose longitudinal stress on rails. These forces are then transferred to the sleepers and substructure via rail fastenings. When trains are operating, horizontal and vertical track forces, vibrations, and imposed forces from carriage steering ability, as well as poor subgrade/subsidence, are other types of interacting forces. Different vehicle types have different degradation processes: badly-maintained trains damage rails, sleepers and substructure and cause increased fatigue rates of materials. Poor maintenance of vehicles and wheel sets increases track forces and increases the degradation rate.”
What will the future of faster trains running with shorter interval mean for the forces that the rails and their bolts are exposed to?
“Nuts and bolts will have very high demands placed on them due to safety-related issues. The higher the speed, the greater the dynamic forces causing loosening of nuts and bolts. Since nuts and bolts will need more maintenance and service to ensure safe travel in a high-speed regime, any bolt-securing engineering solutions will definitely be useful investments for the railway sector. They would not only make the train journey safer but would also increase the capacity of the track and eliminate track maintenance-related accidents. I think any such bolt-securing solutions would be attractive to railway operators, especially those in the high-speed sector.”
FACTS: UDAY KUMAR
Position: Professor and Head of the Division of Operation and Maintenance Engineering, Luleå University of Technology, Luleå, Sweden.
Lives: Luleå, Sweden.
Career: Previously PhD student at Luleå and lecturer at University of Stavanger, Norway.