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| Releasing a locked route 17/07/2012 at 18:25 #34110 | |
John
884 posts |
Does anybody here have any knowledge and/or experience of the procedure when the S&T are asked to release a locked route following a track circuit failure? I'm guessing it's a fairly rare occurrence, as I've never known it to be mentioned in any of the control logs that I have read.
Last edited: 17/07/2012 at 18:25 by John Log in to reply |
| Releasing a locked route 18/07/2012 at 03:04 #34132 | |
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Woodhead Signalman
64 posts |
In all the 'modern' OCS or NX panels in the boxes I have worked at and/or visited, if a track circuit over a point/s fails and so locks said point/s, upon being fixed by the S&T the track circuit (TC) and any associated route setting, 'drops out' and the points are free to move again as per normal. As far as 'procedure' goes for calling the S&T in my day we just rang them on the phone and then waited for them to arrive, which could be anything from minutes to hours depending on how far away the local team was at the time of the callout. And of course record the problem and visitation in the TR book. At certain manual lever frame boxes of my acquaintance, there has sometimes been a button inside a sturdy box, protected by a 'break in emergency' label and pane of glass relating to a specific point, in order that it might be released to be moved by the lever frame when locked under extremely unusual circumstances. I cannot now remember but such a breaking of glass may well have had to be specially authorised by local or regional management. And of course if one has had recourse to break the glass, then you had to call the S&T out to replace the glass.  I remember having to do that at one box I worked at, but I cannot now remember which box it was, as it was such a very long time ago.
Last edited: 18/07/2012 at 03:13 by Woodhead Signalman Log in to reply |
| Releasing a locked route 18/07/2012 at 05:33 #34133 | |
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pilotman
189 posts |
The release button protected by a glass cover is used with manually operated points. There aren't many of these now on NR, but we have a few on the Bluebell Railway. Before using the button you must check carefully the reason for the TC "failure" (e.g. is there a train sitting on it?), then make a note of the occurrence in the relevant book and call S&T, who should replace the glass promptly once the fault is cleared. Motored points are not so equipped, so you/someone authorised needs to get in the "6 foot" with a winding handle. If you get detection after winding you will also get the relevant signals, otherwise the points need to be "clipped and scotched" and the train handsignalled. Most of the latter is impractical on NR where the points might be 10's of kilometres from the panel or signalling centre. Ray Last edited: 18/07/2012 at 08:48 by pilotman Log in to reply |
| Releasing a locked route 18/07/2012 at 06:29 #34134 | |
GeoffM
6376 posts |
Releasing a route can only be done when the relevant TCs are clear. IIRC forcing a TC to show clear when failed (or even occupied) requires all trains within the interlocking stopped. S&T can then false feed the TC by whatever means necessary, but having all trains stopped within indistinct interlocking boundaries (in relay areas; not so much computerised interlockings) means the situation would have to be pretty dire to request this done. The opposite can also occur: falsely occupying a track to get an overlap to drop, allowing traffic through the former overlap's track and pointwork. I don't know the rules behind this but do know track circuit operating clips have been used to good effect in the not so distant past. SimSig Boss Log in to reply |
| Releasing a locked route 18/07/2012 at 07:14 #34135 | |
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Firefly
521 posts |
I cannot speak from a signallers point of view, however I would be certain that it's a decision that would be taken by control and not at a local level. I would further assume it requires a Local Manager to authorise the request. From the S & T's point of view once again I would expect an on call supervisor to authorise the release of controls. The request having come in form RT3186 would need to be completed by both the S & T and the signaller. Form 3186 Rule Book Module T1A Section 5 gives details of the procedure to be followed here As Geoff says all trains within the interlocking area must be at a stand (This includes SSI). FF Log in to reply |
| Releasing a locked route 18/07/2012 at 08:16 #34136 | |
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Danny252
1461 posts |
At least in Western Region practise, those glass covered release buttons come with a small form to fill in detailing who/when/why the release was used.
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| Releasing a locked route 18/07/2012 at 08:44 #34137 | |
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pilotman
189 posts |
Of course the "glass fronted box" release applies to an era before route locking and only applies to one set of points locked by one TC. It therefore only releases 1 backlock. Our Regulation 39 states: Sealed releases. These are provided for use when a lever working points or facing point lock is locked either in the normal or reverse position by failure of a track circuit. Before using a sealed release the Signalman must satisfy himself on each occasion[u][i][/u][/i] that it is safe to do so, that the position of the line affected is clear and that no movement is about to be made over that portion of line. Sealed releases must be used only in the case of failures and not for traffic purposes. (Note that the Signalman is not required to seek approval from higher authority.) When a sealed realease has been used in consequence of a failure of a track circuit, treadle or other apparatus, the Signalman must report the fact to the Lineman and make an entry in the Occurrence Book. In the case of sealed releases the glass or paper front must be renewed immediately normal working is renewed. Log in to reply The following user said thank you: Woodhead Signalman |
| Releasing a locked route 18/07/2012 at 09:37 #34138 | |
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indian_railways_fan
72 posts |
" said:Does anybody here have any knowledge and/or experience of the procedure when the S&T are asked to release a locked route following a track circuit failure? I'm guessing it's a fairly rare occurrence, as I've never known it to be mentioned in any of the control logs that I have read.Let me describe a few facilities provided on relay interlocking panels on the Indian Railways.Four buttons are provided for emergency operations: ERRB:Emergency Route Releasing Button: This button is used to release the full route from the entrance to the exit signal including the overlap portion.This button needs to be used when a signal has been restored to red after setting route.On most signals,approach locking of 2 minutes is provided.After the timeout,the route will not release by itself but will remain "held" till an appropriate sequence of buttons-including ERRB has been operated.It should be noted that the operation of this button will not bypass any of the interlocking requirements.For example,if the train passes the signal during the approach locking period,then back-locking on the route will become effective.In such a situation,the ERRB cannot be used to release the route. RRBU:Individual sub-route releasing button This button is used to release any individual subroute(a subroute will encompass at least one point zone but may have more depending on the design and layout). This button needs to be used carefully as it can be used to release any sub-route-effectively bypassing the interlocking system.Once released,it is also possible to move the points over the that sub-route.Due to this reason,dual control is maintained over this button by the S&T staff and the panel operator.A button is placed inside the sealed panel and a key lock is provided on the panel.Both must be operated simultaneously to pick-up the concerned relays to effect the required operations. EBPU-Emergency point operation under track relay down condition: I think this button is most relevant to our discussion here.This button can be used to move the points,even if the track relay is dropped.To prevent careless operation,it is protected by a sealed disc which remains under the button.The wire seal applied to the disc must be broken first and then the disc is rotated out and then the button can be pressed.Needless to say that the station master/panel operator must verify first that the point track is not occupied and no traffic is headed towards it. EGBS:Emergency button to throw a signal to red.It must be pressed with the relevant signal button simultaneously to throw the signal to red in an emergency or due to exigencies of traffic. In Indian Railways practice,it is necessary to press at least two buttons simultaneously to effect any operation like route setting,point operation,route releasing,etc.Also,all the operations I have detailed above have an individual counter on the panel and any such operation must be recorded in the relevant register with the reasons.Such operations would also need to be recorded in the Charge Book and the Train Signal Register. Detailed guidelines and instructions on panel operation are available in the following link: http://indianrailways.gov.in/railwayboard/uploads/codesmanual/operating%20manual-traffic.pdf Khalid. Log in to reply |
| Releasing a locked route 18/07/2012 at 10:40 #34140 | |
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John
884 posts |
Thanks all for the replies.
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| Releasing a locked route 18/07/2012 at 10:45 #34141 | |
jc92
3687 posts |
" said:The release button protected by a glass cover is used with manually operated points. There aren't many of these now on NR, but we have a few on the Bluebell Railway. Before using the button you must check carefully the reason for the TC "failure" (e.g. is there a train sitting on it?), then make a note of the occurrence in the relevant book and call S&T, who should replace the glass promptly once the fault is cleared. Motored points are not so equipped, so you/someone authorised needs to get in the "6 foot" with a winding handle. If you get detection after winding you will also get the relevant signals, otherwise the points need to be "clipped and scotched" and the train handsignalled. Most of the latter is impractical on NR where the points might be 10's of kilometres from the panel or signalling centre.at peak rail we also have sealed releases for pointwork, but they do also apply for motor points, the only time we would wind a motor point is if it was failing to detect. procedure is the same, check it is safe to do so, break glass, plunge button and throw points across "We don't stop camborne wednesdays" Log in to reply |
| Releasing a locked route 18/07/2012 at 14:19 #34145 | |
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Woodhead Signalman
64 posts |
Thanks Pilotman for your reply concerning Rule 39. Having mainly only worked on manual frame boxes in the late 70's/early 80's, the conditions for use of the emergency point/point lock buttons was precisely as you state it in your post. Thank you very much for reminding me. I was trained at one point on how to manually pump over clamp locks on a point controlled from Guide Bridge signal box (formerly Ashton Jcn box) after it had been converted to an NX panel as a "just in case I need to" sort of thing. The point in question was the one leading into DCE sidings/'mobile quarry' adjacent to signal 979 on sheet #1 of this diagram. http://www.s-r-s.org.uk/archivesignals/brmr/1984-225e.pdf Happy days! :cheer: Last edited: 18/07/2012 at 14:22 by Woodhead Signalman Log in to reply |
| Releasing a locked route 19/07/2012 at 05:40 #34158 | |
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pilotman
189 posts |
You are welcome Woodhead. My experience really only dates from 1994, although I was working boxes on the GN mainline out of KX "unofficially" in 1957. We have some experienced platform staff trained to hand work points in the case of failure under the intructions of the Signalman. Long gone are the days when platform staff on the "big railway" were authorised to do such things (Elf and Safety), which is why working round failures now takes so long.
Last edited: 19/07/2012 at 05:40 by pilotman Log in to reply |
| Releasing a locked route 19/07/2012 at 06:29 #34159 | |
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Noisynoel
989 posts |
John, You should have read Monday's log as we got a route release at Loughborough. Just to clarify for some, if a track circuit fails over a set of points that are say 'reverse' thus locking them in that position with a route set in from the protecting signal, but in orde rto keep things moving you may need those points normalised, then the S&T can, as Geoff says, false clear the track circuit to get the route to drop, this then allows the points to be wound to the required position, the false clear is then removed (It is a failure after all). The request for this to be done will normally come from Control, however, in boxes with an SSM, they can request it. The S&T will normally get the OK from the local section manager for this to be done. Noisynoel Log in to reply |
| Releasing a locked route 19/07/2012 at 09:19 #34164 | |
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John
884 posts |
Thanks Noel. I've been off since Sunday, so I'll have a look at that log item when I get in this afternoon.
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| Releasing a locked route 04/08/2012 at 15:41 #34625 | |
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button_pusher
56 posts |
Its a last resort item. I carried out one a few weeks ago, it was the first time i've done one/seen one done in my time on the railway. The signaller has to ask the S&T techician to carry out the release, the S&T technician can't offer. It can only be done once for that failure. You are basically bypassing any safety afforded by the interlocking. Log in to reply |
| Releasing a locked route 04/08/2012 at 15:45 #34627 | |
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Stephen Fulcher
2080 posts |
The S&T cannot officially offer, but it has been known, and to be honest as long as the procedure for actually carrying out the release is followed to the letter, it should not really matter who says "shall we release controls?" Rules are silly at times. Log in to reply |
| Releasing a locked route 04/08/2012 at 15:52 #34629 | |
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button_pusher
56 posts |
There is that but if it all goes Pete Tong and the voice logs are pulled then it's my neck on the block and I'm quite fond of my neck...
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| Releasing a locked route 04/08/2012 at 15:55 #34630 | |
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Stephen Fulcher
2080 posts |
I am not suggesting it should not be done the way the rules say, just that it has been done and there is not really any sensible reason it should not be allowed.
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| Releasing a locked route 04/08/2012 at 16:20 #34631 | |
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ralphjwchadkirk
275 posts |
As long as the RT3186 is filled in properly...
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| Releasing a locked route 04/08/2012 at 16:31 #34632 | |
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Stephen Fulcher
2080 posts |
My point entirely.
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