Bad vibrations

Readers letters

Article regarding the Javelin train - PE 22 September

I think the article in PE (22 September) “Bad vibration for Javelin passengers” cannot go unchallenged.

Apart from the obvious error in that these trains do not go to London’s Kings Cross, (they run into St Pancras International), the description of the yaw damper is completely incorrect and I am surprised that for a professional publication, such as PE, such an inaccuracy can appear.

Contrary to the description in the article that appeared to state that the yaw damper “which sits on the bogie, are transversely mounted… and prevent railcars swaying excessively from side to side “ this device is not mounted transversely at all, but longitudinally, between the bogie frame and the vehicle body. Its function has nothing to do with side to side body movement (that is controlled by the side control mechanism within the bogie traction centre) and sway is controlled by the anti-roll bars. Its function is to control bogie oscillations about its pivot centre (more commonly known as bogie hunting) generally at high speed, the cause of the vibrations I suspect from my experience as a regular Javelin passenger.