Rail grinding? + British Museum sidings

Rail grinding re-profiles the top of the rail and removes corrugation which is a source of noise.
The high pitched whistle reduces over time.

Thanks for that - does anyone know why the British Museum limit is still there? I thought the sidings were decommissioned?

Indeed decommissioned years back this was one of the last jobs I was involved with before I moved away from the Central Line.

I'm not sure the speed limit on the running line was related to the points.

Part of the reason the siding was removed was that the points had remained in more or less the as built condition retaining geometry way out of alignment with current requirements. This concerned movements to and from the siding, not the running line.

When those points came up for renewal, it was impractical to put in new points corresponding to even the most restrictive geometry without some significant - and above all exceedingly costly - civil engineering work to running tunnels (the greater radius curves involved meant lengthening the aperture in the tunnel wall); or something like that; it was well over 10 years ago received the presentation on it, and moved on a lot since then so can't remember the full details of the track and civils part.

For the signals control system at Wood Lane, apart from modifying the overview diagrams, the biggest element was that Holborn local site computer (one of the 16 line LSC) became an LSC without any divergences or convergences; hitherto all LSC were located at or nearby junctions and or reversing locations etc. ((To be clear, that does not mean every location on the railway that had route controlled signalling with points had an LSC, each LSC served several adjacent locations.)) In effect, HOL LSC became completely "auto through working" or whatever the correct term is. Not sure what happened with the emergency local control panel, there was some suggestion about removing it, but I never saw any more happen with this. I am sure someone else here will know!

OK, thats a digression from rail grinding.

On a pedantic point (what ? who me ? ), the noise you hear there is not rail grinding - but freshly ground rails.

Rail grinding is the act of a big yellow machine (or other means) actually doing the grinding as it passes over those rails, and I can assure is a somewhat more spectacular audible and visual experience than 92TS running over the result.

Here is one of the GB main line Loram units at work at night at Didcot :


THAT is rail grinding !

I take an interest in these Loram thingies as in the past I got involved with their onboard equipment control systems (and, putting on my anorak, have been on all three of the orginal GB ones in motion, so in the Book Of Numbers they get red underlines for haulage).

One interesting point living here in Luton not that far from the main line is that a Thameslink 700 unit running over freshly ground rails sounds exactly like a 317 or 319 with noisy traction motor commutators. When we were in mixed 319s and 700s running, the two sounds were indistinguishable.

The real aim of rail grinding is not to reduce noise nor is the result to make a different noise. The real aim is removal of surface fatigue cracks that would in time result in rail breaks if left unattended. Reducing rail noise is a side effect - a useful one at that - and, while yes it is true some grinding operations are carried out at some sites to reduce rail noise, those locations that do suffer from high rail noise tend to be high stress locations i.e. curves hence need more crack relief attention.

The sound from the running rails is swamped by the ghastly sound of the 'artificial AC' generator, a loathsome parody of the iconic straight-cut gear sound of electric traction.

Other unwarranted and irrelevant parts of post removed - Tom