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08/09/2018 11:30:00

how to handle track circuit failures?

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how to handle track circuit failures? 18/02/2018 at 19:08 #105987
kalleffm
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Hello.
I am a signaler from germany and have found this beautiful simulation about UK signalboxes.
At work i know how to handle everything in my signalbox but some things with the UK signalbox is not clear by now.
I used a signalbox when i got a message 'track circuit failure switch xy' so the switch was red/occupied. In germany i would call the train driver to examine the route/switch - and would get a message from him 'nothing found/i left the section with all vehicles'. At this point i could press some button to throw the 'occupied/red' switch.
I was looking for something like that inside the sim but did not found anything.
So my question is: how do signalers in the UK handle such a situation?
Is there any homepage to learn more about rules of signaling in the UK?

Thanks :-)

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how to handle track circuit failures? 18/02/2018 at 20:04 #105989
Steamer
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There's a lot of information on the Wiki, including this page which details the correct way to handle a Track Circuit Failure.

In the UK, signallers cannot force a track circuit that's occupied to show clear. In some cases, it may be possible for a technician to briefly force it into the 'unoccupied' to release a route, but only briefly- it would then remain at 'occupied' until the failure was fixed. This can't be done from the panel.

Where axle counters are in use, the situation is different, but I'm not sure what the procedure is for resetting them, however axle counter resets aren't simulated in SimSig.

Let the challenge... Begin!
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how to handle track circuit failures? 18/02/2018 at 22:21 #105990
kalleffm
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and what about the thing with the 'occupied' switch when there is a track circuit failure, is there no possibility to turn this switch ?
I did something different when this happened: i diverted a train towards another station and let it reverse so it could continue on its old route (one timetablestop needed to be skiped)
it was standing in front of a red signal - behind the signal there was the occupied switch which was in the wrong position so no route possible.

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how to handle track circuit failures? 18/02/2018 at 22:25 #105992
Steamer
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I'm not sure what you mean by occupied switch- could you describe it, or tell me which simulation you're playing and which signal it's near?

Whatever the switch you're describing is, it doesn't do what you think it does.

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Last edited: 18/02/2018 at 22:25 by Steamer
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how to handle track circuit failures? 18/02/2018 at 22:31 #105994
postal
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Steamer in post 105989 said:
Where axle counters are in use, the situation is different, but I'm not sure what the procedure is for resetting them, however axle counter resets aren't simulated in SimSig.
Rule book Module TS11 (on line here) but it's not very helpful.

Section 21 reads:

Resetting and restoring axle counters

You must be sure that the affected section of line is clear and the protecting signal is placed to and kept at danger, or the route closed before starting the resetting and restoration procedure as shown in the Signal Box Special Instructions
.
You must arrange to examine the affected section of line before the resetting and restoration procedure is completed. If the equipment requires a train to pass through the affected section as part of the resetting process, the train being used to examine the line can do this.

"It is a most mortifying reflection for a man to consider what he has done, compared to what he might have done." - Samuel Johnson, English author, 18/09/1709 - 13/12/1784
Last edited: 18/02/2018 at 22:33 by postal
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how to handle track circuit failures? 18/02/2018 at 22:44 #105996
kalleffm
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a track circuit is on a track or a switch so:
when a switch is red (which means occupied) after a train passed or a TCF happened it can not be turned from left to right or way round.
So if the switch is in wrong direction you cant drive over it.

Simulation is Victoria Central, will look it up tomorrow and will post a photo of the situation.

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how to handle track circuit failures? 18/02/2018 at 22:53 #105997
Steamer
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Sorry- when you said 'switch' I thought you meant a control, not the type of track. In the UK, they're usually known as 'Points'. 'Switch' is generally used in America.

If a track circuit failure has locked a set of points in one direction, you can open the incident control panel (F11), go to the 'Points' tab, click the little mouse icon at the top of the list, and click the point you want to move on the screen. It will be highlighted on the list for you. Then, in the box at the right marked 'Hand Crank', click either the 'Normal' or 'Reverse' button (depending which way you want them) to move the points- this simulates a person on the ground moving the points manually. Don't forget to put them back into 'Auto' mode when the TCF is fixed.

Note that in real life, it would take a significant amount of time before someone arrived at the location to move points manually.

Let the challenge... Begin!
Last edited: 18/02/2018 at 23:00 by Steamer
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how to handle track circuit failures? 18/02/2018 at 23:00 #105999
kalleffm
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ah... points... my fault :-)
so there is no chance for the signaler to set the occupied point to another direction from his signalbox?
I hope the guys have more technicians than we have... here you can wait for an hour or two to get a technician when a point is not working any more, or a signal is defect, etc.

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how to handle track circuit failures? 18/02/2018 at 23:13 #106000
Steamer
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kalleffm in post 105999 said:
ah... points... my fault :-)
so there is no chance for the signaler to set the occupied point to another direction from his signalbox?
No. It would need a technician to physically move the points using a hand crank, or to alter the track circuit wiring briefly so that the track circuit appeared unoccupied to the interlocking, so that the point could be moved. Obviously, there are strict rules about how and when those actions can be done, because they bypass the safety provided by the interlocking.

(If you haven't seen the word before, 'Interlocking' in the UK is the safety-critical part of the signalling system, which prevents a signaller setting conflicting routes, among other things. It can be mechanical, electrical or electronic. Again, the UK definition of 'Interlocking' is different to the American definition)

Quote:
I hope the guys have more technicians than we have... here you can wait for an hour or two to get a technician when a point is not working any more, or a signal is defect, etc.
That's typical of the UK too

Let the challenge... Begin!
Last edited: 18/02/2018 at 23:14 by Steamer
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how to handle track circuit failures? 18/02/2018 at 23:42 #106001
9pN1SEAp
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Would it ever be possible for signallers in junction boxes (e.g. Paignton) to hand-crank points under protection?
Jamie S (JAMS)
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how to handle track circuit failures? 19/02/2018 at 00:20 #106002
Jan
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To give a little more context to those questions, German relay interlockings (and their electronic successors) traditionally give the signaller a greater degree of override control than what is commonly provided in the UK. This includes the ability to move points that are showing occupied.

On the other hand we don't have swingable overlaps, which I've come to appreciate as quite a nice feature through Simsig.

Two million people attempt to use Birmingham's magnificent rail network every year, with just over a million of them managing to get further than Smethwick.
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how to handle track circuit failures? 19/02/2018 at 09:19 #106006
Giantray
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At Three Bridge ROC, signallers have the facilities, under strict instructions, to release track circuits and points. Called TREL and PREL.

We also have POSA Signals (Proceed On Site Authority) which enables us to signal trains with interlocking through track failures. We only have to talk to the train driver to examine the line in the first instance signalling it with the POSA and then signalling subsequent trains with the POSA signals. Cuts out the use of route cards ( normally required to manually set a route before getting a train to pass a signal at Danger), but does not negate the fact we have to watch each train go through the section and clear the section ahead before POSAring a following train.

Most overlaps are swingable except when the train arrives at the Signal, the points in the overlap are locked for a predetermined amount of time until they are again free to move.

In the UK, the switch is the movable part of Points. Permanant Way Engineering Staff normally call pointwork S&C (Switch and Crossings). A lot of older staff used points and crossings (P&C).

Last edited: 19/02/2018 at 09:20 by Giantray
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how to handle track circuit failures? 19/02/2018 at 10:14 #106011
kbarber
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Steamer in post 106000 said:
kalleffm in post 105999 said:
ah... points... my fault :-)
so there is no chance for the signaler to set the occupied point to another direction from his signalbox?
No. It would need a technician to physically move the points using a hand crank, or to alter the track circuit wiring briefly so that the track circuit appeared unoccupied to the interlocking, so that the point could be moved. Obviously, there are strict rules about how and when those actions can be done, because they bypass the safety provided by the interlocking.

(If you haven't seen the word before, 'Interlocking' in the UK is the safety-critical part of the signalling system, which prevents a signaller setting conflicting routes, among other things. It can be mechanical, electrical or electronic. Again, the UK definition of 'Interlocking' is different to the American definition)

Quote:
I hope the guys have more technicians than we have... here you can wait for an hour or two to get a technician when a point is not working any more, or a signal is defect, etc.
That's typical of the UK too :)

In the old days (pre-1994), there would usually be a member of staff at the nearest station who would be qualified to work points by hand crank. That would usually mean failed points (including points locked by a failed track circuit) could be attended in not much more than 20 minutes, even if they were fairly remote from the station. (And of course staff would be expected to check the points on arrival; if it were just a piece of ballast preventing points from closing, they would be able to restore normal operation immediately.)

After the railways were restructured for privatisation, station staff were regarded as not being railway operators and were no longer permitted to attend such failures.

I was under the impression that Mobile Operations Managers were also qualified to crank points, not only technicians. or has that changed? Mind you, the MOM would often be at the wrong end of the patch and might well arrive after the technicians had restored normal working in any case. But it's privately run so it must be better...

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how to handle track circuit failures? 19/02/2018 at 21:31 #106025
kalleffm
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Learning new things every day.
So if there is a TCF the signaler has to write something to the train driver that he is allowed to pass the signal at danger and examine the route, right?
The mentioned POSA signal is a separate signal which tells the driver to pass the signal at danger, also right?
In germany we have such a signal on a lot of signals so we dont need to write something to the driver to pass the signal at danger and examine the route - nice feature but...

... compared between UK and germany the UK signalboxes look more safe. Here we could bypass nearly everything in the signalbox (turn points while they are occupied, release looked points while a train is driving on it and things like that) which caused some small and/or heavy accidents...


Question: if there is no POSA signal installed (which seems to be rare) the signaler always needs to talk to the driver and write him a permission to pass a signal at danger and things like that.

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how to handle track circuit failures? 19/02/2018 at 21:46 #106026
GW43125
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kalleffm in post 106025 said:


Question: if there is no POSA signal installed (which seems to be rare) the signaler always needs to talk to the driver and write him a permission to pass a signal at danger and things like that.
Signallers don't have to write anything to tell a driver to pass a signal at danger; it's just done verbally, the driver and signaller come to a clear understanding.

A conversation would be something like this:
Drv: "Hello Everglades, this is the driver of 2L01 standing at signal ES28; over"
Sig: "Hello driver of 2L01 standing at ES28, there is a track circuit failure in advance of the signal; I am authorising you to pass signal ES28 at danger, proceed at caution and obey all other signals; over"
Drv: "You are authorising me to pass signal ES28 at danger, proceed at caution and obey all other signals, over"
Sig: "That is correct, driver. Everglades out"

No paperwork, just a clear verbal understanding.

PoSAs are still relatively rare I believe, I think they're only on the East London Line and the Thameslink Core for now.

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how to handle track circuit failures? 19/02/2018 at 21:55 #106027
Steamer
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kalleffm in post 106025 said:
So if there is a TCF the signaller has to write something to the train driver that he is allowed to pass the signal at danger and examine the route, right?
Permission is given verbally over phone or radio- it isn't written. Until recently, the call was via telephones installed at signals, nowadays calls are made via secure GSM-R radio.

Quote:
The mentioned POSA signal is a separate signal which tells the driver to pass the signal at danger, also right?
POSA signals are mounted just underneath normal signals, and consist of two white lights at 45 degrees. The lights are normally extinguished; when the signals are activated, they flash white. They look the same as normal calling-on signals (used to allow a train into an occupied section), the difference being that those signals show steady white.

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how to handle track circuit failures? 22/02/2018 at 10:13 #106068
Chromatix
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Quote:
PoSAs are still relatively rare I believe, I think they're only on the East London Line and the Thameslink Core for now.

...and High Speed 1. But that's part of the French TGV-style signalling; if there's a failure of the cab signal system, some of the block markers can be passed at caution in any case, the others have a ground signal for emergency use.

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how to handle track circuit failures? 22/02/2018 at 10:49 #106069
9pN1SEAp
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Do PoSA signals de-energise the TSS grids? I presume not and TSO is still required.
Jamie S (JAMS)
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how to handle track circuit failures? 22/02/2018 at 20:23 #106085
GW43125
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Chromatix in post 106068 said:
Quote:
PoSAs are still relatively rare I believe, I think they're only on the East London Line and the Thameslink Core for now.

...and High Speed 1. But that's part of the French TGV-style signalling; if there's a failure of the cab signal system, some of the block markers can be passed at caution in any case, the others have a ground signal for emergency use.
Apologies, forgot about that one! :doh

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how to handle track circuit failures? 23/02/2018 at 06:43 #106089
Giantray
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Chromatix in post 106068 said:
Quote:
PoSAs are still relatively rare I believe, I think they're only on the East London Line and the Thameslink Core for now.

...and High Speed 1. But that's part of the French TGV-style signalling; if there's a failure of the cab signal system, some of the block markers can be passed at caution in any case, the others have a ground signal for emergency use.
All of the resignalled lines in the London Bridge Area have POSA Signals

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how to handle track circuit failures? 23/02/2018 at 06:47 #106090
Giantray
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9pN1SEAp in post 106069 said:
Do PoSA signals de-energise the TSS grids? I presume not and TSO is still required.
By TSS grids, do you mean the TPWS Loops? If so, yes the TSS grids (TPWS Loops) are de-energised. Reason being is that the Signaller has given the Train Driver a Proceed Signal, albeit a POSA signal, it still gives the Driver authority to go past the signal concerned so TPWS is not required to be armed.

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how to handle track circuit failures? 25/02/2018 at 17:07 #106160
kalleffm
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interesting things i am learning here, thank you guys
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