Braking induced impact for train to train rescue

ABSTRACT

Train to train rescue means that a disabled train without power supply is rescued by another train. However, the in-train stability problem caused by braking has significant effect on the longitudinal train dynamics. In this paper, the field test for a set of coupled assisting and disabled trains is firstly presented. It is indicated the instability in train or coupler jackknifing phenomenon only occurs under compressed in-train forces. The dynamic models of the rescue train as well as the coupler and draft gear system are then established. The calculated in-train forces and draft gear deflection are compared with that from measured results. The occurring mechanism and subsequent effect of the coupler pitch motion of train to train rescue on tangent tracks are discussed. The coupler yaw motion of the coupled train on curved tracks is also discussed. The braking induced coupler forces if combined with rotational motions can adversely affect the train dynamic performance. An efficient manner to deal with issue is to decrease the braking induced in-train forces by proper train configurations or braking levels. Another approach is to limit the carbody and coupler rotational angles by decreasing secondary clearance of the air spring.

KEYWORDS:

• Train to train rescue
• coupler and draft gear
• field test
• braking
• train dynamic model
• tangent track
• curved track

Acknowledgements

Acknowledgements are also made to Mr Kai Chen in Sifang Rolling Stock Research Institute for providing precious suggestions to this research.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [Grant U1334206] and the Ministry of Railways project [Grant 2014J004-A].