Returning to the approach side of a signal

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Returning to the approach side of a signal 07/09/2019 at 21:18 #120324
TUT
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Looking at rule book module S7 Observing and obeying signalling indications Train warning systems Reporting signalling failures and irregularities, I have to say I'm having a little bit of trouble following regulation 3.3 Returning to the approach side of a signal:

Quote:
If you have made a shunting movement on the authority of a position-light signal, a shunt-ahead signal or a semaphore shunting signal, you must not proceed on your journey until:

- the movement has returned to the approach side of a signal
- the signal displays the appropriate proceed aspect or indication for the movement.

If the shunting movement cannot return to the approach side of the signal, you must carry out the instructions shown in section 4.2.
I'm having a little bit of trouble picturing the scenario in my head.

"You must not proceed on your journey until the movement has returned to the approach side of a signal" - so is that any signal? What sort of scenarios does that cover? Proceeding to a limit of shunt and swapping ends so that you're now behind a signal? Continuing on until you come to another shunt signal or a main aspect?

In what scenarios, then, would it not be possible to return to the approach side of the signal?

I notice this time it does not say a signal. It says the signal. Why would you shunt past one signal and then go back behind it? And on what authority would you make the movement back behind the signal on whose authority you have just proceeded?

Is anyone able to translate this regulation, perhaps with a nice example or two?

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Returning to the approach side of a signal 07/09/2019 at 23:00 #120329
jrr
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Had an example on the heritage railway I signalled for a while. There was an engineer's siding operated manually and normally left clamped and padlocked. When shunting was being done the loco involved had permission to go to and fro locally to that siding, but to return through the station to the yard had to end up on the main line back behind the inner home, not least because it controlled movements across a level crossing into the station but also which track the loco would come forward on.
Last edited: 07/09/2019 at 23:02 by jrr
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Returning to the approach side of a signal 08/09/2019 at 03:01 #120331
Hap
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TUT in post 120324 said:
Looking at rule book module S7 Observing and obeying signalling indications Train warning systems Reporting signalling failures and irregularities, I have to say I'm having a little bit of trouble following regulation 3.3 Returning to the approach side of a signal:

[quote]If you have made a shunting movement on the authority of a position-light signal, a shunt-ahead signal or a semaphore shunting signal, you must not proceed on your journey until:

- the movement has returned to the approach side of a signal
- the signal displays the appropriate proceed aspect or indication for the movement.

If the shunting movement cannot return to the approach side of the signal, you must carry out the instructions shown in section 4.2.
I'm having a little bit of trouble picturing the scenario in my head.

"You must not proceed on your journey until the movement has returned to the approach side of a signal" - so is that any signal? What sort of scenarios does that cover? Proceeding to a limit of shunt and swapping ends so that you're now behind a signal? Continuing on until you come to another shunt signal or a main aspect?

In what scenarios, then, would it not be possible to return to the approach side of the signal?

I notice this time it does not say a signal. It says the signal. Why would you shunt past one signal and then go back behind it? And on what authority would you make the movement back behind the signal on whose authority you have just proceeded?

Is anyone able to translate this regulation, perhaps with a nice example or two?[/quote

The important part that has been missed is the rule of 4.2 a & b. A train can stand beyond a signal and before he can move, he will need to seek authority move.

In general a train can make shunting movements with two GPS signals (one in each direction) off. until the movement is needed to go onto the mainline, he can continue as much as he wants. When/if shunting movements require a continuous mainline movement and the train in question is beyond the shunt signal, the the driver would need authority from the signaller to proceed . (only for a full mainline movement onwards past the next block signal).





4.2 Train standing beyond a signal
a) When the signal can be cleared for the reverse
movement
If any part of your train is standing beyond the signal controlling
the movement, you must not start the movement until the signal is
cleared.
If you cannot see the signal, you must ask the guard, shunter or
driver at the other end of the movement to tell you when the signal
is cleared.
If any part of your train is standing beyond the signal controlling
the movement, you must not give the signal to the driver to start
the movement until the signal is cleared.
If you cannot see the signal, you must check the signal yourself or
ask the driver to tell you when the signal is cleared.

b) When the signal cannot be cleared for the reverse
movement
If the signal cannot be cleared, you must:
• find out whether a movement can be made which will allow the
whole train to be positioned on the approach side of the signal
• if necessary ask the signaller for permission to do this.
If it is not possible for the train to return to the approach side
of the signal, you must ask the signaller for permission to proceed
beyond the signal in the direction to which it applies.

HAP
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Returning to the approach side of a signal 08/09/2019 at 03:25 #120332
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Thank you for your help hap!

Yeah I tried reading section 4 and it got even more convoluted and less concrete and clear in my mind.

I think I understand section 4 fairly well in isolation, it's just this 3.3

I suppose I read it and I wonder would operational scenario would involve drawing a train forward on the authority of a position-light, subsidiary or shunting signal and then drawing back behind it again? What scenarios is this regulation intended to cover?

I appreciate that opposing locking may be omitted between GPSs, but isn't that usually for the benefit of run rounds inside yards, marshalling, forming trains or to move within sidings? What's the scenario where you proceed past a GPS that's off and then draw back behind it to head onto the mainline?

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Returning to the approach side of a signal 09/09/2019 at 06:08 #120333
Late Turn
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I wonder if this is one that’s been moved into a different module and thus lost some of its context. My understanding is that this relates to situations where the movement was initially authorised to proceed only as far as required to clear connections in rear, e.g. a trailing connection into a siding. A relative rarity now, but it’s orobably most critical on an absolute block line, where the ‘shunting into forward section’ bell signal might’ve been sent/acknowledged to allow a train to pass the section signal sufficiently for the rear to get clear, but it needs to be brought back inside the section signal, shunt withdrawn and the train offered/accepted under reg 4 before it can continue through the section.
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Returning to the approach side of a signal 09/09/2019 at 06:40 #120334
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Late Turn in post 120333 said:
I wonder if this is one that’s been moved into a different module and thus lost some of its context. My understanding is that this relates to situations where the movement was initially authorised to proceed only as far as required to clear connections in rear, e.g. a trailing connection into a siding. A relative rarity now, but it’s orobably most critical on an absolute block line, where the ‘shunting into forward section’ bell signal might’ve been sent/acknowledged to allow a train to pass the section signal sufficiently for the rear to get clear, but it needs to be brought back inside the section signal, shunt withdrawn and the train offered/accepted under reg 4 before it can continue through the section.
Do you know what? I think you're exactly right.

What's causing me the grief though is picturing how exactly this comes up.

You authorise a train to proceed only far enough to clear the points with shunting into forward section - I can totally picture that scenario.

What then happens to make you go right, now let's bring it back behind the same signal I shunted past just now (obviously nothing can overtake or have overtaken the shunting train since it's occupying the forward section), and have another go?

If you intended it to proceed through the section, why not offer it under reg 4 in the first place? And if you didn't, what is the real world scenario that necessitates this rule?

Sorry if I come across in the wrong way, I'm just genuinely not sure I've been able to explain the source of my confusion and I don't wanna waste anybody's time, I just can't see the application?

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Returning to the approach side of a signal 09/09/2019 at 08:59 #120335
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TUT in post 120334 said:

What then happens to make you go right, now let's bring it back behind the same signal I shunted past just now (obviously nothing can overtake or have overtaken the shunting train since it's occupying the forward section), and have another go?

If you intended it to proceed through the section, why not offer it under reg 4 in the first place? And if you didn't, what is the real world scenario that necessitates this rule?
One obvious (to me) case is where you don't want to block the overlap at the box in advance because the clearing point is beyond a trailing junction or contains yard access points in it. In other words, you want to be able to shunt in advance at your box *and* shunt in rear at the next box at the same time.

Another possibility, though I don't know if it's valid: could you have fast and slow section signals next to each other, then a turnout into the yard on the slow, then the fast and slow converge. You want to allow fast trains to be signalled past while you shunt off the slow. I agree that in this case there ought to be an advanced starter beyond the convergence, but was that always actually done?

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Returning to the approach side of a signal 09/09/2019 at 10:12 #120336
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clive in post 120335 said:
TUT in post 120334 said:

What then happens to make you go right, now let's bring it back behind the same signal I shunted past just now (obviously nothing can overtake or have overtaken the shunting train since it's occupying the forward section), and have another go?

If you intended it to proceed through the section, why not offer it under reg 4 in the first place? And if you didn't, what is the real world scenario that necessitates this rule?
One obvious (to me) case is where you don't want to block the overlap at the box in advance because the clearing point is beyond a trailing junction or contains yard access points in it. In other words, you want to be able to shunt in advance at your box *and* shunt in rear at the next box at the same time.

Another possibility, though I don't know if it's valid: could you have fast and slow section signals next to each other, then a turnout into the yard on the slow, then the fast and slow converge. You want to allow fast trains to be signalled past while you shunt off the slow. I agree that in this case there ought to be an advanced starter beyond the convergence, but was that always actually done?
The old AB Reg 31 (Shunt into Forward Section) permitted the advance box to accept a shunt (bell signal 3-3-2) with his clearing point occupied. By analogy, I would expect a shunt ahead in TCB areas to be signalled by a subsidiary, which would be able to clear with the overlap occupied.

In general, a move signalled in with a 3-3-2 would proceed only as far as necessary for shunting purposes, and would be required to return inside the section signal when shunting was complete before proceeding on its way. That is a good reason for not letting a shunt simply proceed when ready - no clearing point/overlap at the box/signal ahead. Offering it as a train, of course, ties up the overlap/clearing point ahead; not what you want if there's a lot of shunting to do. AB, of course, used to have Reg 8 (Train requiring to stop in section); the train was signalled with the code 2-2-3, the advance box was required to accept it under Reg 5 (warning arrangement) and the clearing point was left free. But that would normally be for a train servicing a mid-section siding rather than one immediately beyond the section signal. Nowadays, I would expect the signalling to provide for that in some way and it would be most unlikely that a train servicing such a siding would need to return behind the signal in rear.

(There are/were, of course, exceptions to everything; I understand that, at Newton Abbot, it was permissible for shunt to proceed through the section between East and West boxes (effectively within the station) and in these circumstances the SBSIs permitted it to be cleared by the advance box giving 2-1 (whereas, if it returned inside the rear box section signal, it would be cleared in the usual way with 8 bells). Whether any analogous provision exists in TCB areas I really don't know.)

Of course, if there were a yard connection (not just a siding) beyond the section signal, the shunt could set back inside and be shut in, to work for as long as it liked. In that case it would of course be cleared with 8. Cricklewood had just such a setup, with Reg 31 authorised on the up goods to Watling Street (later West Hampstead, then Finchley Road, as boxes were abolished) to get freights off the Dudding Hill/Acton Wells branch into the yard. I would normally expect that the outlet would have a section signal in that case, so there would be no need to come back inside the 'main line' section signal. But where there was just a siding, it might be necessary for a shunt to cut off a brake van or rear portion in rear of the section signal, put some vehicles into the siding, then return for the portion left on the main line before proceeding on its way. In that case you would definitely need to cancel off the 3-3-2 before offering the train forward.

Clive's scenario of sections signals protecting both a convergence and the siding connection seems unlikely (unless I've misunderstood your description, Clive). The convergence itself would need signal protection, otherwise you have the possibility of pulling off on the fast while the shunt on the slow is ahead of the section signal and the junction points are effectively unprotected. (If the yard connection were a facer, there would be no need for any shunt ahead provision, as a train going into the yard would not be considered to be entering the section.)

All good stuff, particularly under AB before the 'simplifications' of the 1990s and afterwards.

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Returning to the approach side of a signal 09/09/2019 at 15:58 #120337
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Interesting stuff, thanks everyone.

I was thinking about the Swindon A & B IECC sim. In the default Swindon Summer 2005 timetable, we bring 6B36 out of Didcot TC onto the Up Relief line at Didcot East Junction.

One can set the route from SB920 signal to the white exit arrow.

Pilot engine 0T02 then divides off the front of 6B36 and the rest of 6B36 then reverses via SB6405 and heads off through platform 4 at Didcot Parkway and on to Ashcurch MOD.

0T02 then calls up for permission to draw up to SB6407 GPL and then heads into Didcot TC.

Just wondering, is this rule applicable here?

0T02 calling up for permission to draw up to SB6407 GPL would seem to be an application of rule 4.1 a)

Quote:
When a train or shunting movement is required to reverse, you must only allow the movement to take place when one of the following applies.

[...]
- The signaller gives you permission to move towards a signal which will control the further movement of the train.
[...]
But I was thinking, if either 6B36 or 0T02 is for some reason required to divert and run on to Reading is this rule then applicable? Do we then have to go back behind SB920/918/916? Is that what the rule's saying?

Or, thinking about Didcot a little more, say we have an exceptionally long train. We bring it into, say, platform 5, but it's too long, so we set the route to the white exit arrow so that the rear of the train is behind SB925. Let's say something divides off the rear of our long train and heads to the fuel point or something, for the sake of the example. And now, the rest of our train. Does this rule now apply? We bring the train back behind SB918 or else apply rule 4.2?

Is that what this rule is saying? Cause I can see that you know. The only problem is, it makes me wonder what the perceived benefit of the white exit arrow is at Didcot. I mean the overlap of SB906 signal doesn't even extend over Moreton Cutting Junction...

Last edited: 09/09/2019 at 15:59 by TUT
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Returning to the approach side of a signal 10/09/2019 at 02:51 #120342
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Does the rule apply when, as part of a run round, a light loco needs to shunt into forward section then reverse to join the train, and it must not interpret the shunt into forward section as permission for the joined train to proceed (instead it must back up clear of the signal and obtain a new authority)?
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Returning to the approach side of a signal 10/09/2019 at 09:52 #120344
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TUT in post 120337 said:
Interesting stuff, thanks everyone.

I was thinking about the Swindon A & B IECC sim. In the default Swindon Summer 2005 timetable, we bring 6B36 out of Didcot TC onto the Up Relief line at Didcot East Junction.

One can set the route from SB920 signal to the white exit arrow.

Pilot engine 0T02 then divides off the front of 6B36 and the rest of 6B36 then reverses via SB6405 and heads off through platform 4 at Didcot Parkway and on to Ashcurch MOD.
I'm not familiar with this move. Do I take it the shunt comes to a stand with the London end between 6405 and 6407 signals?

TUT in post 120337 said:
0T02 then calls up for permission to draw up to SB6407 GPL and then heads into Didcot TC.

Just wondering, is this rule applicable here?

0T02 calling up for permission to draw up to SB6407 GPL would seem to be an application of rule 4.1 a)

Quote:
When a train or shunting movement is required to reverse, you must only allow the movement to take place when one of the following applies.

[...]
- The signaller gives you permission to move towards a signal which will control the further movement of the train.
[...]

That sounds exactly right, if it's as I asked above.

TUT in post 120337 said:
But I was thinking, if either 6B36 or 0T02 is for some reason required to divert and run on to Reading is this rule then applicable? Do we then have to go back behind SB920/918/916? Is that what the rule's saying?

If 6B36 is required to run to Reading, the route will be set from 920 to 906, without using the shunt route exit, and it will proceed on its way like any other train. In those circumstances, of course, the shunt engine will not be detached in any case - the train will have the loco at the London end on departure.

I can't imagine any signalman who values his job letting a shunt engine out for Reading (15mph all the way... oh joy, oh rapture!!!) anywhere near 07:00. But if you were making that sort of move, I imagine you'd set a main route from 920 to 906, with the train stopping anywhere once the country end was clear of 6407. Once the pilot has hooked off, both can then proceed on their way.

What is crucial about this is that all concerned must have come to a clear understanding about the moves to be made before anything is signalled anywhere, and as all concerned should know the rules it will all just happen, including the necessary phone calls, without further ado.


TUT in post 120337 said:
Or, thinking about Didcot a little more, say we have an exceptionally long train. We bring it into, say, platform 5, but it's too long, so we set the route to the white exit arrow so that the rear of the train is behind SB925. Let's say something divides off the rear of our long train and heads to the fuel point or something, for the sake of the example. And now, the rest of our train. Does this rule now apply? We bring the train back behind SB918 or else apply rule 4.2?

I think that might well be, although I would say it's entirely theoretical in this case. You will block East Junction whether you use the shunt route or the main route, so you might as well set the main route so the forward train can get going as soon as the rear portion has been hooked off. If the train is proceeding forward as soon as the detachment is finished, you don't really want it sitting over the junction while the detached portion clears itself at the rear, then setting back (with the junction still blocked until it's in clear), before you can get anything on or off the Avoider.

TUT in post 120337 said:
Is that what this rule is saying? Cause I can see that you know. The only problem is, it makes me wonder what the perceived benefit of the white exit arrow is at Didcot. I mean the overlap of SB906 signal doesn't even extend over Moreton Cutting Junction...

Actually, I think I may have just worked out why there's a shunt exit at 906. If I'm right, you would use that to get the train out of the yard.

Normally, opposing signals are interlocked so you can't set a route (say) up road from 906 and down road from 6407 at the same time. It may be that setting the main route to 906 activates that locking, so if you've used a main route from 920, approach locking will hold the opposing locking up until it has been used in its entirety - that is, until the pilot has passed 906 and gone on its way. Just what you want for a quick move... not. It may be that if you use the shunt exit, that opposing locking is not included in the route and the train that's been dragged out can proceed on its way before the pilot has even reached 906. The control tables ought to tell all... this is yours, isn't it Peter? Can you enlighten us?

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Returning to the approach side of a signal 10/09/2019 at 09:54 #120345
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Hawk777 in post 120342 said:
Does the rule apply when, as part of a run round, a light loco needs to shunt into forward section then reverse to join the train, and it must not interpret the shunt into forward section as permission for the joined train to proceed (instead it must back up clear of the signal and obtain a new authority)?
I think that's exactly right. Likewise for an engine change.

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Returning to the approach side of a signal 10/09/2019 at 14:46 #120346
TUT
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kbarber in post 120344 said:
TUT in post 120337 said:
Interesting stuff, thanks everyone.

I was thinking about the Swindon A & B IECC sim. In the default Swindon Summer 2005 timetable, we bring 6B36 out of Didcot TC onto the Up Relief line at Didcot East Junction.

One can set the route from SB920 signal to the white exit arrow.

Pilot engine 0T02 then divides off the front of 6B36 and the rest of 6B36 then reverses via SB6405 and heads off through platform 4 at Didcot Parkway and on to Ashcurch MOD.
I'm not familiar with this move. Do I take it the shunt comes to a stand with the London end between 6405 and 6407 signals?
Yes exactly

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Returning to the approach side of a signal 11/09/2019 at 10:50 #120351
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I think it refers to several scenarios. Another case of trying to get one Rule to fit all. One scenario, often a train has to shunt into a forward section to clear pointwork in the rear to then shunt back into a siding. The signaller will give a Shunt Ahead Signal in the form of a Shunt Ahead Semaphore Arm/Disc or a Position light signal. It is only authority for train to pull ahead of the signal to clear the point work of a siding entrance. It is not authority to carry on to the next signal. If once clear the points cannot be reserved to gain entry to the sidings, the train will need to carry on forward. Now the Signaller can either get the train to set back behind the original signal, or under 4.2. permit the train to start ahead of the signal.
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Returning to the approach side of a signal 11/09/2019 at 16:23 #120353
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Thanks Giantray that really helps.

So, if I've got this all straight in my head, it should look something like this?

Suppose we have a long train destined for the sidings. It is too long to fit between the section signal (27) and the disc giving access to the sidings (7). So we send shunting into forward section (3-3-2) to the box in advance and, when it's acknowledged and we have come to our 'clear understanding' with the driver, we can pull off the shunt ahead signal (26) and send train entering section.



The train "[makes] a shunting movement on the authority of a position-light signal, a shunt-ahead signal or a semaphore shunting signal" and we end up in this situation:



But then, perhaps 9 points fail, we can't get them reverse and now we're in a situation where the front of the train is standing beyond the section signal, having made a shunting movement on the authority of a shunt-ahead signal and we want it to continue its journey through the section to the next signal box.

Is this the scenario rule 3.3 of S7 was written for? Have I got it straight in my head? We now have to bring the train back behind 27 signal or else see rule 4.2 (Train standing beyond a signal)?

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Returning to the approach side of a signal 12/09/2019 at 09:41 #120361
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TUT in post 120353 said:
Thanks Giantray that really helps.

So, if I've got this all straight in my head, it should look something like this?

Suppose we have a long train destined for the sidings. It is too long to fit between the section signal (27) and the disc giving access to the sidings (7). So we send shunting into forward section (3-3-2) to the box in advance and, when it's acknowledged and we have come to our 'clear understanding' with the driver, we can pull off the shunt ahead signal (26) and send train entering section.



The train "[makes] a shunting movement on the authority of a position-light signal, a shunt-ahead signal or a semaphore shunting signal" and we end up in this situation:



But then, perhaps 9 points fail, we can't get them reverse and now we're in a situation where the front of the train is standing beyond the section signal, having made a shunting movement on the authority of a shunt-ahead signal and we want it to continue its journey through the section to the next signal box.

Is this the scenario rule 3.3 of S7 was written for? Have I got it straight in my head? We now have to bring the train back behind 27 signal or else see rule 4.2 (Train standing beyond a signal)?
I think I would see it a bit differently. I suspect this rule is a bit of a hangover from t'owd days, back when I were a lad. But the scenario may well be valid for non-revenue traffic; I suspect engineers' trains often come marshalled unhelpfully.

Imagine the vehicles you need to put into the siding are at the head of the train. In that case, you'd hook off the rear vehicles and leave them stood between 9 and 18 while you shunt ahead (as shown) and into the yard. The loco then draws out on to the main line. Two possible scenarios at this point, but little to tell between them.
(a) 8 bells is not sent forward, 26 is left pulled off, the loco draws forward under the same authority he originally had for getting in to the sidings, then sets back without further ado. At this point 26 is put back, 8 bells is sent and the train is offered normally.
(b) As soon as the set back move into the sidings is behind 26, it is returned to danger and 8 bells is sent forward. When the loco is ready to draw out, 3-3-2 is sent forward again and 26 duly cleared for the loco to draw out and set back on to its train, then as for scenario (a).

Scenario (b) might be wanted if there were a train waiting to come out of the sidings that could get out and through the section while the shunt is still inside, otherwise there is no point whatsoever - once you've had 3-3-2 acknowledged, you can shunt (but only far enough to clear the points) to your heart's content, as the section has never (in block working terms) been cleared.

Rule 4.2, of course, may well cover an awful lot of situations other than shunting ahead. The reference in 3.3 is just to ensure there's not too many loopholes, I would think.

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Returning to the approach side of a signal 13/09/2019 at 07:49 #120374
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Yes that is one scenario Tut and the most common use of the Rule. As i said there are several possible scenarios, but the one I mentioned is a throwback from Absolute Block Days when to gain access to a siding, the train needed to shunt ahead of the AB Section signal by means of a Shunt Ahead Signal. The exact bell coding given to the box in advance I have long forgotten because under Track Circuit Block this scenario (probably?) would never happen and I haven't worked AB for over 28 years.
P.S. Nice diagrams Tut explains the Rule exactly.

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Returning to the approach side of a signal 13/09/2019 at 09:41 #120378
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Giantray in post 120374 said:
Yes that is one scenario Tut and the most common use of the Rule. As i said there are several possible scenarios, but the one I mentioned is a throwback from Absolute Block Days when to gain access to a siding, the train needed to shunt ahead of the AB Section signal by means of a Shunt Ahead Signal. The exact bell coding given to the box in advance I have long forgotten because under Track Circuit Block this scenario (probably?) would never happen and I haven't worked AB for over 28 years.
P.S. Nice diagrams Tut explains the Rule exactly.
Regulation 31.
Shunt into forward section: 3-3-2
Shunt withdrawn: 8

On an AB line, Train Entering Section would be sent once the section signal/shunt ahead signal had been cleared. Where Permissive Block was in use, TES was not required whether or not the shunt was offered into an occupied section. (That's certainly how Cricklewood worked it to Finchley Road between the abolition of West Hampstead in April 1978 and abolition in 1981.)

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Returning to the approach side of a signal 13/09/2019 at 10:10 #120379
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Also used by Rotherwood box to Woodhouse Jc when 76s were shunting from the up to down side
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Returning to the approach side of a signal 13/09/2019 at 17:48 #120385
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kbarber in post 120378 said:
[quote=Giantray;post=120374]Yes that is one scenario Tut and the most common use of the Rule. As i said there On an AB line, Train Entering Section would be sent once the section signal/shunt ahead signal had been cleared.

Was this a late 1970s/1980s change? The 1972 book only requires TES if no shunt-ahead signal is provided (and the section signal is locked by the block). In other circumstances it says that the block should immediately be placed to TOL when 3-3-2 is received (providing the line is clear to the outermost home signal).

Last edited: 13/09/2019 at 17:50 by Zoe
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Returning to the approach side of a signal 13/09/2019 at 23:53 #120402
Late Turn
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TUT in post 120353 said:
Thanks Giantray that really helps.

So, if I've got this all straight in my head, it should look something like this?

Suppose we have a long train destined for the sidings. It is too long to fit between the section signal (27) and the disc giving access to the sidings (7). So we send shunting into forward section (3-3-2) to the box in advance and, when it's acknowledged and we have come to our 'clear understanding' with the driver, we can pull off the shunt ahead signal (26) and send train entering section.



The train "[makes] a shunting movement on the authority of a position-light signal, a shunt-ahead signal or a semaphore shunting signal" and we end up in this situation:



But then, perhaps 9 points fail, we can't get them reverse and now we're in a situation where the front of the train is standing beyond the section signal, having made a shunting movement on the authority of a shunt-ahead signal and we want it to continue its journey through the section to the next signal box.

Is this the scenario rule 3.3 of S7 was written for? Have I got it straight in my head? We now have to bring the train back behind 27 signal or else see rule 4.2 (Train standing beyond a signal)?

Excellent diagrams!

I'd suggest that the rule in question is intended primarily to cover scenarios such as a long train shunting as you describe but with the loco still in advance of the section signal once it's fully set back into the sidings, perhaps a long train detaching vehicles from the rear. At some locations, the section signal isn't very far at all beyond a trailing connection, so it's not inconceivable. A variation on that might be where 26/27 don't exist at all and the section signal is in rear of the siding connection, the outlet signal also acting as the section signal in that case, if the train doesn't fit fully in the sidings. It'd work just as well in the situation that you describe with the failed points though!

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Returning to the approach side of a signal 13/09/2019 at 23:55 #120403
TUT
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Thank you
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Returning to the approach side of a signal Today at 10:34 #120437
kbarber
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Zoe in post 120385 said:
kbarber in post 120378 said:
[quote=Giantray;post=120374]Yes that is one scenario Tut and the most common use of the Rule. As i said there On an AB line, Train Entering Section would be sent once the section signal/shunt ahead signal had been cleared.

Was this a late 1970s/1980s change? The 1972 book only requires TES if no shunt-ahead signal is provided (and the section signal is locked by the block). In other circumstances it says that the block should immediately be placed to TOL when 3-3-2 is received (providing the line is clear to the outermost home signal).
That really hasa got me scratching my head! Long long time since George Morgan taught me this at Carlow Street! But I think I recall him saying you sent TES unless you were working PB, with no qualification.

The only places I had owt to do with Reg 31 were Finchley Raod, where it was authorised on the up goods from Cricklewood, and Kensington (where we used it to run round the 'Kenny Belle' from Clapham a couple of times each peak). In both cases, the lines concerned were PB and calling on signals were provided, so TES was never used in any case. We used to have Reg 31 at Bewdley South; I don't recall using it (a surprise, I would usually try to use every regulation available when I had the chance) but the section signal there was locked by block so TES would have been compulsory. By the time I was in the box there were few locations left with free starters (I wasn't aware of any at all) where Reg 31 was authorised. Maybe that's why George taught sending TES on AB lines regardless of other provision.

Mind you, George had a reputation for being particularly careful and steady. No wonder, perhaps, having been the signalman involved in the Penmaenmawr collision http://www.railwaysarchive.co.uk/documents/MoT_Penmaenmawr1950.pdf

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