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Post by xtmw on Apr 19, 2022 13:49:07 GMT
What's the closure for this weekend?
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Post by PiccNT on Apr 19, 2022 13:55:48 GMT
I believe it's for rail grinding work between Epping and Woodford.
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Post by xtmw on Apr 19, 2022 14:53:49 GMT
I believe it's for rail grinding work between Epping and Woodford. There's also a closure which is only going on for an hour. Leytonstone - Loughton. What's going on here then? |
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Post by Dstock7080 on Apr 19, 2022 15:50:54 GMT
I believe it's for rail grinding work between Epping and Woodford. There's also a closure which is only going on for an hour. Leytonstone - Loughton. What's going on here then? To allow the engineering trains from Hainault depot access to the closure between Woodford and Epping. |
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Post by PiccNT on Apr 19, 2022 15:53:29 GMT
In connection with rail grinding work between Epping and Woodford, the Central Line train service will be suspended as follows:-
Friday, 22nd April: from approximately 01.30 until 02.30 between Leytonstone and Epping/Hainault (via Roding Valley).
Friday to Sunday, 22nd to 24th April: from approximately 02.30 between Woodford and Epping. (Services via Roding Valley
will operate in both directions during normal traffic hours).
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Post by xtmw on Apr 19, 2022 16:42:28 GMT
Shouldn't they be focusing on grinding in the tunnelled section as that is the most loud?
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Post by MoreToJack on Apr 19, 2022 17:26:31 GMT
I think we can trust the highly qualified and experienced engineers to know which bits of line need grinding for safety and which need grinding for comfort.
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Post by xtmw on Apr 19, 2022 19:20:38 GMT
I think we can trust the highly qualified and experienced engineers to know which bits of line need grinding for safety and which need grinding for comfort. Ahhh ok. How often should rails be grinded/replaced? |
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class411
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Post by class411 on Apr 19, 2022 22:08:53 GMT
I think we can trust the highly qualified and experienced engineers to know which bits of line need grinding for safety and which need grinding for comfort. Ahhh ok. How often should rails be grinded/replaced? When a rails need to be ground is probably very much dependent on location. |
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rincew1nd
Administrator
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Post by rincew1nd on Apr 19, 2022 22:17:10 GMT
I think we can trust the highly qualified and experienced engineers to know which bits of line need grinding for safety and which need grinding for comfort. Ahhh ok. How often should rails be grinded/replaced? It will depend on the wear. Curves will need grinding back to the correct profile far more frequently than straights. |
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Post by jimbo on Apr 20, 2022 4:21:20 GMT
Is rail grinding a modern occupation? I can't recall such trains back in my day, some 40 years back. What happened back then?
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class411
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Post by class411 on Apr 20, 2022 8:01:46 GMT
There seems to be an implication, here, that rail grinding reduces noise.
And yet I'm sure I've seen it suggested that noisy sections have been caused by rail grinding.
Is it a bit hit and miss on the noise front?
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Post by t697 on Apr 20, 2022 11:24:01 GMT
Rail grinding is often done to restore rail surface that had become corrugated and causing the horrible roaring rails noise. Straight after grinding there is usually a different and quieter higher pitch sound due to the relatively fine grinding marks. That normally reduces after a period of weeks. If things have gone well, the rail corrugation stays away but often it returns later if track stiffness and other parameters haven't really changed much.
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Post by quex on Apr 20, 2022 11:53:43 GMT
Is rail grinding a modern occupation? I can't recall such trains back in my day, some 40 years back. What happened back then? It certainly dates back some time although not sure of exact dates; LU used to have a rail grinding car in the Engineering fleet that was an old Standard Stock trailer. That was 1970s, 80s, maybe? I wouldn't swear to it but I vaguely recall one of the C&SLR cars was converted, way back in the day. |
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Post by t697 on Apr 20, 2022 12:02:20 GMT
The old rail grinding car converted from Standard Stock was a rather crude scheme compared to modern rail grinders. It just had grinding blocks pressed down on to the rails so the amount removed was probably minimal and wouldn't restore profile and level very well. Modern machines use proper rotating grinders with much better control of the amount removed and profile produced.
There is evidence that current 'modern' Tube rolling stock propulsion equipments influence rail corrugation adversely. This and other threads have also discussed the effects of different track forms and resilient baseplates etc.
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Post by d7666 on Apr 20, 2022 15:56:19 GMT
There seems to be an implication, here, that rail grinding reduces noise. And yet I'm sure I've seen it suggested that noisy sections have been caused by rail grinding. Is it a bit hit and miss on the noise front? Rail grinding introduces it's own, different, noises*** that diminish within a few days; at least on main lines it tends to be similar to a whirring sound. Rail grinding may reduce existing rail noise conditions in certain circumstances, but, if so, that noise is a symptom of a rail problem being addressed, not the problem itself. Yes grinding may eliminate what was a noisy section, and the result is tangible to travellers, but what it has really done is rectify whatever the underlying fault was causing noise to appear as a symptom. *** on main line again; my residence is close-ish, but not adjacent, too the main lines through Luton; can always tell these days when the rails are fresh ground as today's 700s wheel-rail noise is near identical to yesterday's loud 319s noisy traction motor \ pinion noise; in the transition period from 319s to 700s I could not tell the difference between the two. After a week or two the newly introduced rail noise diminishes. |
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Post by d7666 on Apr 20, 2022 21:05:19 GMT
RCF
Rolling Contact Fatigue
One of the main reasons - if not the principal reason - for grinding and one not mentioned so far is reduction in RCF; at least on the main lines this one is possibly the biggest driver behind all these grinding machines now operated by contractors for NR. It was RCF that caused the 2000 Hatfield accident.
I don't know how much of an issue RCF is with LU, but rails are rails, wheels are wheels, and the principles of steel wheel on steel rail applies to LU same as anywhere else.
It is a technical subject, and apart from me not understanding a good deal of it myself, TBH I can't really post much more.
One thing though is that them across the pond seemed to have cracked (pun intended) the issue ahead of the rest; UK main line I think had one not-that-large train-machine (the Speno) - until Hatfield - after which they proliferated here. One of the US suppliers is Loram, and, ok, accepting this is from a concern that wishes to sell you something, it is quite a good explanation of modern grinding:
EDIT site is defying me posting URL maybe it don't like some of the ascii; going to find another way to link to it
not sure if that URL will survive; if it don't then suggest paste it into google as a search item and it'll probably find the right one.
One fact too is that fatigue of any sort is proportional to load cycles, and LU (pre covid) is ever more busier, more trains, longer trains, longer heavy loads peaks, in turn then fatigue load cycles go up that induces rail issues in shorter durations. Even trains braking - and LU brake rates are quite high - impose stress loads on rails - while your braking mechanism may be friction on the wheel or pad or electric on the motor axle, that braking effort is still transmitted from wheel to rail (it don't work otherwise!). It all adds up.
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Post by xtmw on Apr 23, 2022 8:00:38 GMT
How are trains reversing this weekend from Woodford? I went onto the live departures and I saw a few trains going to South Woodford, Hainault via Woodford and the odd few just going to Woodford.
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Post by Dstock7080 on Apr 23, 2022 8:48:45 GMT
How are trains reversing this weekend from Woodford? I went onto the live departures and I saw a few trains going to South Woodford, Hainault via Woodford and the odd few just going to Woodford. Trains aren’t terminating at Woodford but operating around the loop in each direction. Trains from platform 2 to Ealing Broadway Trains from platform 3 to West Ruislip |
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Post by aslefshrugged on Apr 23, 2022 16:26:54 GMT
How are trains reversing this weekend from Woodford? I went onto the live departures and I saw a few trains going to South Woodford, Hainault via Woodford and the odd few just going to Woodford. Trains aren’t terminating at Woodford but operating around the loop in each direction. Trains from platform 2 to Ealing Broadway Trains from platform 3 to West Ruislip Not quite At Hainault Trains from Woodford arrive Platform 1 then via Newbury Park WB Trains from Newbury Park arrive Platform 2 then via Woodford WB |
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Post by scheduler on Apr 24, 2022 22:09:19 GMT
Most trains round through Roding Valley in quite some time.
Basically there is no Eastern end terminating, they just carry on round the loop and head back west.
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