Derailment coefficient?

[bcp]

Can someone tell more about it?

Thanks,

Bruce




From:
http://news.xinhuanet.com/english2010/china/2011-05/30/c_13900990.htm

CRH380A series trains to be used on the Beijing-Shanghai high-speed rail are under 0.13 derailment coefficient, far lower than the international standard of 0.8, the Chinese-language daily cited Liang Jianying, a designer for the trains, as saying.

The lower the derailment coefficient figure, the less chance the train has of derailment.

 

[shay2305]

It appears to me that from the context that derailment coefficient is an expression of the probablility the train will derail. The lower the number the less likely the train will derail.

I can't say that I've ever heard the term used before.

 

[DrewSD]

This is the best I could find, if you can understand some of the jargon you get an idea.

A new criterion for prediction of train derailment is presented in this article. A three-degrees-of-freedom (3 DOF) wheelset model is used to identify the main dynamic parameters that affect wheelset derailment. Using these parameters and conventional definition of derailment coefficient, a new criterion for prediction of wheelset derailment is introduced. The proposed criterion, in addition to providing the required precision in prediction of wheel set derailment, requires measurements that are easy to perform. To evaluate the capability of the new criterion in prediction of derailment, a full wagon model with 48 DOF moving on a track with different random irregularities was used. The track is assumed to be mounted on a viscoelastic foundation. The wagon model is a three-dimensional, non-linear model of a train passenger car. The model includes non-linear elements for primary and secondary suspension systems. Friction and slack between elements, the centre pivot with kinematics constraints, forces between pads, and bolster are also included in this model.

The motion of the wagon on tangent and curved tracks is simulated for different travel speeds. Derailment coefficient and a new derailment criterion are used to investigate the possibility of wheelset derailment in each case. The study shows that the new criterion can very well predict wheelset derailment and can duplicate the predictions by conventional derailment coefficient

http://journals.pepublishing.com/content/n5mv708071835330/