2016 THOMAS HAWKSLEY GOLD MEDAL 

For their paper: ‘Theoretical and experimental analyses on stabilization of hunting motion by utilizing the traction motor as a passive gyroscopic damper’, published in the Proceedings Part F: Journal of Rail and Rapid Transit 2015 Vol 229(4), 395-401.

The maximum speed of railway vehicles is limited by the phenomena called ‘hunting’ which is an un-damped oscillation of the vehicle caused by the complexity of wheel/rail contact. This paper describes a novel method for increasing this speed. Using the gyroscopic effects of traction motors and a new ball gear drive mechanism, the relative angle between the motor and a wheelset can be used to stabilise the system, and the maximum vehicle speed can be increased.

Hiroshi Yabuno is the corresponding author and explains what winning this medal means to the authors: “We are extremely honoured to be awarded the Thomas Hawksley Gold Medal and are grateful to the Institution of Mechanical Engineers for recognising our work. We are also very delighted to receive this highly prestigious medal for the study of railway vehicles in the United Kingdom - the birthplace of the railway. I also wish to thank all of the previous and current colleagues in my laboratory for their dedicated and tireless efforts.”

This work is impressive, not only in its academic depth but also due to the experimental rigour with which the novel ideas are tested and the benefits evaluated. Yabuno explains: “The wheel of a railway vehicle is different from the tyre of a car; the tread of a railway wheel has a conicity and the tighter the curve on which the vehicle must run the higher the required conicity.  Unfortunately, high conicity results in a lower maximum running speed on straight track due to the occurrence of hunting.  

Hence, the increase in running speed on a curved track and the increase of running speed on a straight track are in conflict. This unavoidable trade-off in railway vehicles has been known since their invention.  We believe that the utilisation of gyroscopic damper is an innovative method to overcome this trade-off.  We hope that the international recognition from winning this award, will mean that the proposed stabilisation of hunting using gyroscopic dampers becomes well-known in the rail industry, and is implemented as widely as possible.”

Find out more about the Thomas Hawksley Gold Medal Award.