Running safety analysis of a freight train passing through a single crossover during braking

Abstract

In addition to the discontinuity of the rail profile of a normal turnout, the unique S-shaped curve of a crossover significantly affects the negotiation performance of a train. For heavy-haul freight trains, the in-train forces generated during the braking process may further deteriorate the running safety. Investigating the dynamic behaviour of the train passing through the crossover under braking forces, therefore, can provide a reasonable basis for ensuring train safety. This paper analyses the dynamic response and wheel wear of a three-vehicle train negotiating a single crossover under variable conditions, including variable braking forces, wheel-rail friction coefficient, and crossover layout forms. The results show that the three factors have considerable influences on train safety. If one of the three factors keeps an ideal level, the safe probability of empty wagons can be significantly improved. Considering that there are still some crossovers with tight curves in the existing railway system, avoiding large braking or lubricating the wheel flange in the crossover is still an effective solution to improve the vehicle's performance. In addition, for a new single crossover, a 600-m-radius curve is a good option for balancing permissible train speeds and construction costs of the crossover.

KEYWORDS:

• Crossover
• freight train
• braking force
• wheel-rail coefficient
• track layout
• wheel wear

Acknowledgement

The rail profile data was obtained from the “Switches & Crossings Benchmark” activity led by Dr Yann Bezin and Dr Björn Pålsson. The authors would like to acknowledge them. For detailed information concerning the rail profile data, see Ref. [1]. In addition, the authors would like to thank their colleagues Mr Jonas Vuitton and Mr Max Schischkoff for their help in modelling the turnout and wagon, respectively.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The first and second authors are supported by China Scholarship Council (grant number 201907000128 and 201707000113). The support is gratefully acknowledged.