More on dampers

EMT-liveried power car at King’s Cross: No 43047 (left), on hire to LNER, departs with a service to York as No 43290 MTU Fascination of Power emerges from Gasworks Tunnel with the 05.26 from Stirling on 10 July 2018.
Graham Nuttall

Analysis of Mk 3 coach ride in last month’s column had the e-mails lowing in from informed sources. An important piece of the jigsaw puzzle was a report of early trials with the New Measurement Train at the Old Dalby test track.

A set of brand-new Pegasus dampers was itted and the vehicle instrumented. According to my informed source, test running showed that the Pegasus dampers matched the obsolete Woodhead damper performance up to 75mph. Above that speed ride quality tailed of markedly.

Of course, one of the problems with the latest trials described last month was that readings were taken from only two vehicles, when ideally you should have three instrumented and measure the central vehicle because the adjacent coaches can afect ride. This was not possible because the train was full.

Another engineering chum with a calibrated Mk 1 human posterior ride meter carried out a back-to-back (bum-to-bum surely? – Ed) comparison in an IC125 set itted with both Pegasus and the alternative SV dampers.

He reports that the SV units gave ‘a signiicant improvement’. However, ride comfort is subjective.

Readers who might like to apply their own subjectivity to the issue should note that the LNER set with the EMT power cars is itted with SV dampers. As are around 75% of the EMT leet.

Finally, a retired civil engineer wonders whether a slackening of the track quality index (standard deviation) before maintenance interventions are ordered might be relected in the ride.