Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jan 11, 2022 15:52:24 GMT
Apparently rail grinding is supposed to give off a high pitched sound. What is the point of it? Does it combat noise?
I've linked 2 videos below to confirm the noise I'm hearing is rail grinding.
[ Bethnal Green - Mile End ]
[ Tottenham Court Road - Holborn ]
One thing I've noticed is that the speed limit at the British Museum sidings is still there? From what I know the siding was decommissioned, so there is there no point of a speed limit anymore? Can this be changed from the control room?
Thank you!
|
|
|
|
Post by Dstock7080 on Jan 11, 2022 16:00:08 GMT
Apparently rail grinding is supposed to give off a high pitched sound. What is the point of it? Does it combat noise? 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. |
|
|
|
Post by zbang on Jan 11, 2022 17:54:49 GMT
There's "rail grinding" as Dstock7080 describes, which is standard railway maintenance. There's also what some people (erroneously, IMHO) call "rail grinding" which is the the noise created as steel wheels scrape over the railhead, most people I know just call it squealing or screeching. This usually happens in curves so tight that one wheel on the axle can't move fast enough and slides instead. (See en.wikipedia.org/wiki/Rail_squeal for a nice short description, better than I can write at the moment.) |
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jan 11, 2022 18:44:35 GMT
Thanks for that - does anyone know why the British Museum limit is still there? I thought the sidings were decommissioned?
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Jan 11, 2022 19:51:36 GMT
The siding (singular) at British Museum was decommissioned a few years back. Whether any or some of the track in the actual siding remains, I don't know.
|
|
|
|
Post by d7666 on Jan 11, 2022 21:32:15 GMT
The siding (singular) at British Museum was decommissioned a few years back. Whether any or some of the track in the actual siding remains, I don't know. Indeed decommissioned years back this was one of the last jobs I was involved with before I moved away from the Central Line. |
|
hobbayne
RIP John Lennon and George Harrison
Posts: 516
|
Post by hobbayne on Jan 11, 2022 21:47:15 GMT
Thanks for that - does anyone know why the British Museum limit is still there? I thought the sidings were decommissioned? Increasing the speed restriction would affect the timetable. The current timetable TT 70 still uses the timings that were prevalent before the removal of the points. I suppose they are happy with the timings through the area at present. |
|
|
|
Post by d7666 on Jan 11, 2022 22:05:41 GMT
Thanks for that - does anyone know why the British Museum limit is still there? I thought the sidings were decommissioned? Increasing the speed restriction would affect the timetable. The current timetable TT 70 still uses the timings that were prevalent before the removal of the points. I suppose they are happy with the timings through the area at present. 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. |
|
|
|
Post by d7666 on Jan 11, 2022 22:21:31 GMT
Thanks for that - does anyone know why the British Museum limit is still there? I thought the sidings were decommissioned? Increasing the speed restriction would affect the timetable. The current timetable TT 70 still uses the timings that were prevalent before the removal of the points. I suppose they are happy with the timings through the area at present. On the bit about existing timings, where there is a speed restriction adjacent to a station, raising that speed limit per se may only result in gaining a very small number of seconds. Due to ever continuing increasing passenger loadings (pre covid that is) station dwell times ever creep upwards. That increased dwell time adsorbs up any other saving. You only need average 1 sec dwell time increase at each station through the West end and City core, and even a big 10-15 sec gain made elsewhere by infrastructure change is completely adsorbed. |
|
|
|
Post by d7666 on Jan 11, 2022 22:39:27 GMT
Apparently rail grinding is supposed to give off a high pitched sound. What is the point of it? Does it combat noise? I've linked 2 videos below to confirm the noise I'm hearing is rail grinding. [ Bethnal Green - Mile End ] [ Tottenham Court Road - Holborn ] One thing I've noticed is that the speed limit at the British Museum sidings is still there? From what I know the siding was decommissioned, so there is there no point of a speed limit anymore? Can this be changed from the control room? Thank you! 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. |
|
Tom
Administrator
Signalfel?
Posts: 4,196 
|
Post by Tom on Jan 11, 2022 23:04:29 GMT
I'm going to go partially off-topic as this is British Museum related: 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. Indeed they were in 'as built' condition, some of the rail chairs were dated 1897 (or 98/99, I can't remember now), others were of LER vintage stamped 1922. The tie plate on one point end still featured riveted (not welded) stops! However, the bit about impracticality simply isn't true or we wouldn't have surveyed it to scope a renewal at least twice. The reasons it was removed (which were more politcal than engineering based) are here - a renewal was feasible but costly and a now-departed senior manager didn't believe the cost of renewing it was worth doing, before managing to con vince the operators into agreeing to remove it. It remained in situ as the signals remained controlled - because as hinted in my linked post, nobody looked beyond the cost of not doing the track renewal, rather than taking into account the full costs of the required signalling alterations to abolish the crossover. It remains a perennial pain in the backside that I have to deal with (and the work still isn't complete). The line speed was never increased - whilst it should have been theoretically possible from a track perspective nobody wanted to pay for the associated signalling costs, which is little surprise (q.v. above). The removal of 2105/06 points at Ealing Broadway was done to make provision for a speed increase which was similarly never realised. The siding (singular) at British Museum was decommissioned a few years back. Whether any or some of the track in the actual siding remains, I don't know. I believe some was retained in the siding for the storage of Permanent Way Trolleys and the like. |
|
Tom
Administrator
Signalfel?
Posts: 4,196
|
Post by Tom on Jan 11, 2022 23:19:31 GMT
Apparently rail grinding is supposed to give off a high pitched sound. What is the point of it? Does it combat noise? I've linked 2 videos below to confirm the noise I'm hearing is rail grinding.
Yes, that noise is typical of what is heard when passing over recently ground rails. The reprofiling of rails through grinding does help contribute to reduce noise and vibration issues, but it is not the only solution and is only ever a short term one.
You have previously asked the question about the sounds in this thread though I note you weren't given a conclusive answer there.
Was it really necessary to start a new thread to ask the same question again? |
|
|
|
Post by d7666 on Jan 11, 2022 23:57:19 GMT
I'm going to go partially off-topic as this is British Museum related: 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. Indeed they were in 'as built' condition, some of the rail chairs were dated 1897 (or 98/99, I can't remember now), others were of LER vintage stamped 1922. The tie plate on one point end still featured riveted (not welded) stops! However, the bit about impracticality simply isn't true or we wouldn't have surveyed it to scope a renewal at least twice. The reasons it was removed (which were more politcal than engineering based) are here - a renewal was feasible but costly and a now-departed senior manager didn't believe the cost of renewing it was worth doing, before managing to con vince the operators into agreeing to remove it. It remained in situ as the signals remained controlled - because as hinted in my linked post, nobody looked beyond the cost of not doing the track renewal, rather than taking into account the full costs of the required signalling alterations to abolish the crossover. It remains a perennial pain in the backside that I have to deal with (and the work still isn't complete). OK thanks, I didn't look up any previous thread in here I was going on memory. It is entirely possible the presentation I was given, when first got involved, was part of that con vincing ..... as something I did following it was generate usage statistics compared with Marble Arch and Liverpool Street based on Wood Lane archived logs (that go right back to start of ATO) as that they had it the siding was used "once a year". However "once a year" was actually the answer to timetabled reversing trains there by engineering works meaning "one weekend per year". It failed to account for hundreds and hundreds of times Service Control used it to actually run the service and or dump a 92TS casualty there out the way. It was true HOL was the least used of the three, the usage ratio was something like 1:2:4 HOL:MAA:LST, but HOL still ran in 100's per year, even after discounting the Sundays rusty rail moves from the arithmetic. That rusty rail move then was something like westbound in service to MAA, go out of service, rev at MAA, rev one of the two LST sdgs, rev at HOL, rev at the other LST sdg, then back in service (TBH I forget the exact sequence). I did suggest prior to closure of HOL siding could we run that in crank service one day for the "must do every last inch of track" bashers, but, while this did grab the attention of one Central Line senior manager who thought it feasible, nothing further happened. |
|
|
|
Post by brigham on Jan 12, 2022 8:40:06 GMT
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
|
|
|
|
Post by Chris L on Jan 12, 2022 9:49:31 GMT
A few years ago I was working nights at Maryland.
One night the Network Rail Measurement Train ran through the platform where we were working.
The next night a new German built rail grinding train ran very slowly through the platform. The noise was very loud but the smell was awful.
|
|
), the noise you hear there is not rail grinding - but freshly ground rails.
