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Signalling assistance please


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Three years ago I set up my first layout for my son (honest it was for him, well maybe for us).

 

http://www.rmweb.co.uk/community/index.php?/topic/81269-how-to-signal-this-layout/

 

I mentioned one day to SWMBO that we could run a long shelf layout along the seven metre games room wall. The good lady suggested instead that if I cleared the computers from the computer room (ex large bedroom) and moved them to the games room, we could have the computer room all to ourselves.

 

I did not take long to think about it and the train room was immediately commissioned. There were some restrictions:

  • I was not to occlude the passage way running through the room along one wall.
  • I was to use and incorporate the existing boards set up as much as possible as it had had a considerable amount of landscaping added.
  • I had to work my way through a built in wardrobe.
  • The layout was to be an around the room layout with a 'hop under' entrance.
The layout was eventually built and converted into a dog-bone layout with under-board track loops. The layout is accessible form the inside, and along one outer side.

 

There are all sorts of compromises due to the use of existing parts, and the demands of the chief designer (harbour, continuous running, turntables etc)

 

A reasonable view of the layout can be seen below. The buildings and platforms can be taken with a pinch of salt as they are blocks to show rough sizes. The colours of the track have no relevance. Ignore the signals from SCARM.

 

post-21684-0-06883100-1488004127_thumb.jpg

 

The below board loops:

post-21684-0-82446900-1488003458_thumb.jpg

 

I will try and take some actual photos.

 

I intend, for each ground frame and signal box to use its own modratec locking lever frame, and have the points and signals driven electrically or by WIT.

 

My current issue is signalling Little Pigglington. Particularly the exit from the siding. Goods trains back in across the double slip from the up main, and head into the siding to run around and shunt. Those from the down main enter through the facing slip into the head shunt and back into the sidings. When locos go on shed they take the engine shed road.

 

My thoughts at this stage are that a single yellow disc or miniature arm would suffice. The normal movements out of the sidings are either up the main forward or backing into the down main. Other moves from the siding will be hand signalled. If two would be appropriate then let me know. A schematic is below: Point 4 is normally set for the sidings to protect the main line. There will be suitable interlocking.

 

post-21684-0-85505500-1488003411_thumb.jpg

 

I probably need a running shunt in rear of 7 (perhaps a GPL) so that when a train has backed out onto the down main, it knows when the points have been re-set so it can proceed to the starting signal.

 

Any other suggestions on the signalling are welcome.

 

The main layout is LNER, possible ex-GNR. The branch is GWR with LNER running powers (however unlikely!).

 

*edited for typos.

Edited by ColHut
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I'll stick my head above the parapet and make the following comments. Others who are more versed may well correct me in due course.

 

You will need a signal in the immediate rear of FPL 7 otherwise a "naughty" signalman may clear signal 13/14 to allow a train to pass and then restore the signal to danger after the loco has passed and change point 8 with the train between the signal and the FPL. Therefore I'd suggest that 13/14 needs to be at the other end of the platform and no further away from point 8 than the FPL's length.

 

Is there a reason why signal 12 is where it is rather than in the rear of the level crossing?

 

You'd almost certainly need a limit of shunt board or similar on the down line to indicate where any train reversing out of the yard must stop. Allowing this move will also impact on the acceptance of trains from the previous signal box as you are unlikely to be able to accept an approaching train whilst the shunt was taking place. I'd prefer to see the shunt via the Up line and conversion of the double slip to a single slip.

 

Lever numbers probably also need revising. For example 1 would probably the distant, with the home signal as 2 and the starter as 3 on the down line and the distant on the up line 16, home signal 15, starting signal 14 - the idea being that levers are arranged reasonably logically wherever possible.

 

I suspect I've only scratched the surface but have at least proved that one person has read your post!

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I'll stick my head above the parapet and make the following comments. Others who are more versed may well correct me in due course.

 

You will need a signal in the immediate rear of FPL 7 otherwise a "naughty" signalman may clear signal 13/14 to allow a train to pass and then restore the signal to danger after the loco has passed and change point 8 with the train between the signal and the FPL. Therefore I'd suggest that 13/14 needs to be at the other end of the platform and no further away from point 8 than the FPL's length.

 

Is there a reason why signal 12 is where it is rather than in the rear of the level crossing?

 

You'd almost certainly need a limit of shunt board or similar on the down line to indicate where any train reversing out of the yard must stop. Allowing this move will also impact on the acceptance of trains from the previous signal box as you are unlikely to be able to accept an approaching train whilst the shunt was taking place. I'd prefer to see the shunt via the Up line and conversion of the double slip to a single slip.

 

Lever numbers probably also need revising. For example 1 would probably the distant, with the home signal as 2 and the starter as 3 on the down line and the distant on the up line 16, home signal 15, starting signal 14 - the idea being that levers are arranged reasonably logically wherever possible.

 

I suspect I've only scratched the surface but have at least proved that one person has read your post!

Thanks for that. Appreciated!

 

Limit of shunt board noted, will add. Most likely all shunts will be within station limits. Either way as there will be no accepance under warning, The main lines will have to be clear to accept a train from either adjacent blocks.

 

I think a standard red disc at the toe of the point short of the locking bar wil suffice there with (in theory) track circuiting or mechanical depression bars back to 13/14 locking the points. I cannot move 13/14 up the line as passenger train engines or their carriages will often foul the slip during station duties, and I dont want the train straddling a home signal as well. I could be worrying too much.

 

The banner repeater (12) can certainly move to the other ide of the crossing. Again, regretabbly the level crossing will be obstructed by stopping passenger trains. An accident of this line's 1840s 'history'.

 

I am not sure I follow your comments about converting the double slip to a single. Perhaps you could say a little more?

 

The lever numbers were just added left to right for reference for the diagram, I should renumber them.

 

Thanks for your input.

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The use of a double slip in a running line to create a facing connection would be extremely unusual in the 1930s (and not much less so at any other time) - fair enough in a low speed situation such as teh approach to a terminus or major through station where speeds are low but not out on an open mainline situation - single slip, yes; double slip, no. 

 

The Up Home signal should be much nearer the platform end - it serves no purpose putting it that far back and it's there to protect the crossover in any  case.  Similarly No.12 needs to be at the platform end immediately in rear of, and protecting the level crossing which would then make it possible to bring a train into the station with the level crossing open to road plus, probably even more importantly, to allow shunts to/from the yard onto the Up Main with the crossing gates open to road - and there could be plenty of those in view of the access to yard and loco shed.

 

The Down home No.s 13/14 would in any case not be a splitting signal as it is much too far in rear of the points but as the facing part of the slip shouldn't be there anyway there's no need for it in any case - so 13 remains as a  straight post signal to form the Down Home Signal protecting the level crossing while you need a second stop signa at the platform end to immediately protect the trailing crossover/single slip.

 

You also need to change the numbering of the point ends - the point in the Up would work in conjunction with the slip in the Down to create a trailing crossover while the yard trap would work in conjunction with the slip road to create the connection to/from the yard.  All moves to/from the yard would be through wholly trailing (for running movements) connections and whichever direction they would be going to or from they would gain access via the Up Main and disc No.9.  There also needs to be a disc in the Down Main for moves in the opposite direction through the crossover.

 

No.3 could be a yellow arm ground signal (or yellow arm miniature semaphore by the 1930s.

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I would add, that given the distance from no 4 points to the main line it would be better to add a separate trap point close to the fouling point and move signal 3 adjacent to the new trap. It can then be a red disc as there will be no need for the shunting in the sidings to pass it.

Regards

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The use of a double slip in a running line to create a facing connection would be extremely unusual in the 1930s (and not much less so at any other time) - fair enough in a low speed situation such as teh approach to a terminus or major through station where speeds are low but not out on an open mainline situation - single slip, yes; double slip, no. 

 

...

 

You also need to change the numbering of the point ends - the point in the Up would work in conjunction with the slip in the Down to create a trailing crossover while the yard trap would work in conjunction with the slip road to create the connection to/from the yard.  All moves to/from the yard would be through wholly trailing (for running movements) connections and whichever direction they would be going to or from they would gain access via the Up Main and disc No.9.  There also needs to be a disc in the Down Main for moves in the opposite direction through the crossover.

 

A trailing connection from the yard headshunt to the Down line would allow simpler access for down trains in the absence of a facing slip. It would also allow running round using the Down main without needing a dedicated runround within the yard. This was a very common arrangement on the prototype.

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Thankyou all. In all fairness whilst not the ECML, it will not be a 25mph speed zone so I will try and put is a single slip in place of the double slip. The current double slip is rather dodgy so it is up for replacement anyway. Shunting can be on the up line.

 

I cannot put in a trailing crossover for the down main alas as the landscape is in place and there is no room for one. The slip exists only perhaps because of the shortage of room and perhaps justifiable in terms of its supposed early origins in the 1840s. If I were to start over....

 

I will renumber the points and add the extra ground signals.

 

I am undecided about a trap point as the trackwork is down, and it would also divert runaway stock towards the platform. Though it probably would not get vey far. I will ponder that. I will shortly upload a modified diagram.

 

The platforms are only 180-200 feet long so it seems inevitable given the length of even a short train that the level crossing will have to be fouled pretty much whenever a passenger train stops, so it seems pointless to move the up starter closer and in rear of the crossing. Where it is at least the engine is clear of the tunnel, if, having completed station duties, it is held up waiting for acceptance in the next block section up. That was my thinking, but feel free to suggest alternatives. The crossing only provides access into the yard.

 

Likewise I do not want to put a stop signal just in rear of the slip on the down as I will end up with stopping passenger trains straddling it if a full 3 coaches are to occupy the platform.

 

In this situation it seems best to accept that any shunting on the lines will prevent acceptance of other trains, and that a train could be held and halted at the down home, and then shunting could take place within station limits on occasion.

 

If you think this is way off let me know. :)

 

post-21684-0-93874300-1488090644_thumb.jpg

 

regards

 

thanks again.

Edited by ColHut
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The Limit of Shunt needs to go - think of it as a fixed red signal and you can then see it stops trains passing on the up main !

 

You're numbering is a little out, generally the main running signals are consecutive (not always but it's a good general rule to stick to), so on the up 1 distant, 2 home, 3 starter, on the down 13 starter, 14 home, 15 distant.

 

Making 3 red would depend on the space between points 8 and the running line,

 

I'd be tempted to provide a shunt signal for controlling the down main -> up main move (at the toe of 5) as you will likely be making the move a lot.

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The Limit of Shunt needs to go - think of it as a fixed red signal and you can then see it stops trains passing on the up main !

 

You're numbering is a little out, generally the main running signals are consecutive (not always but it's a good general rule to stick to), so on the up 1 distant, 2 home, 3 starter, on the down 13 starter, 14 home, 15 distant.

 

Making 3 red would depend on the space between points 8 and the running line,

 

I'd be tempted to provide a shunt signal for controlling the down main -> up main move (at the toe of 5) as you will likely be making the move a lot.

Limit of shunt, no go even for backing movements in the normal direction of travel? Okay. Silly me, a backing manouver from the down main onto the up main will be going in the normal direction and so will be limited by the up starter anyway.

 

Numbering is out but I seem to have run out of tipex. I will get to it.

 

On version 2, red disc 5 reads through the slip (7) to the up main. Disc 4 reads to the down main, and disc 9 to the siding.

 

thanks for your help.

Edited by ColHut
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Descriptoions of 7 and 8 look to be transposed. Top of a stack reads to the furthest left route.

 

Gate Stop and Gate Lock levers are usually at the end of the frame nearest the crossing rather than in the middle.

 

I'm not sure about the repeater for 3. I would tend to put a running signal there. That would mean that a loco off the shed or yard would not need the gates closed to come out into the platform

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Descriptoions of 7 and 8 look to be transposed. Top of a stack reads to the furthest left route.

 

Gate Stop and Gate Lock levers are usually at the end of the frame nearest the crossing rather than in the middle.

 

I'm not sure about the repeater for 3. I would tend to put a running signal there. That would mean that a loco off the shed or yard would not need the gates closed to come out into the platform

Thankyou. 7 and 8 are transposed. I will fix that and put the crossing levers at the end.

 

If I replace the repeater with a running signal this will allow light engines out on the up line from the yard without closing the gates, which will usually be closed over the road. My concern is that longer trains will need to run past that point, which will require the clearing of the signal, and will probably end up straddling the signal (and the crossing). Straddling the signal does not seem right, but if this was not uncommon then that would be good to know.

 

regards

Edited by ColHut
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Thankyou. 7 and 8 are transposed. I will fix that and put the crossing levers at the end.

 

If I replace the repeater with a running signal this will allow light engines out on the up line from the yard without closing the gates, which will usually be closed over the road. My concern is that longer trains will need to run past that point, which will require the clearing of the signal, and will probably end up straddling the signal (and the crossing). Straddling the signal does not seem right, but if this was not uncommon then that would be good to know.

 

regards

 

Nothing at all wrong with 'straddling' the signal - went on all over the place and isn't a problem with a semaphore signal as it remains off until the complete train has passed it in any event.

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Thankyou,

 

Assuming I put in a stop dignal as suggested where the banner repeater is, then the following sequence is possible.

 

With the crossing gates shut and no trains accepted, and after receiving an acknowledgemnt of blocking back inside the home signal from the box in rear on the up main, the signalmen can set the way from the siding to the up main. The signalmen then pulls off the yellow shunt disc (12), and the signal protecting the crossing, allowing a train to back out (but running in the normal direction) across the down main and up the up main. Here it may come to rest across the signal and crossing. After a toot on the whistle or whatever, the signalman can, having obtained the line lear clear for the next block section on the down main, set the way and pull off the shunting signal (8) and the starter (14). The train can then be on its way forwards now throgh the crossover formed and head on its way. The signalmen can now restore the stop signal in rear of the crossing on the up main, reset the rest of his points and signals to their default position, give the train entering section and send his obstruction removed.

 

With some allowance for brevity, does that sound right?

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That sounds good to me.

 

I worked for a while at Silvertown where the daily freight was accepted from Custom House and had to pass the (Silvertown) down starter before being set back across the up line and into the yard, The signalman then used a key to (I think) restore the down starter and, presumably then send shunt withdrawn to North Woolwich.

 

It was 53 years ago or thereabouts and I was only a very green booking clerk at the time but the train service was so infrequent and passenger traffic during the off-peak all but non-existent that I spent many an hour in the signalbox above the station building. The above movement detail may not be 100% accurate but I do remember the use of the key.

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Thankyou,

 

Assuming I put in a stop dignal as suggested where the banner repeater is, then the following sequence is possible.

 

With the crossing gates shut and no trains accepted, and after receiving an acknowledgemnt of blocking back inside the home signal from the box in rear on the up main, the signalmen can set the way from the siding to the up main. The signalmen then pulls off the yellow shunt disc (12), and the signal protecting the crossing, allowing a train to back out (but running in the normal direction) across the down main and up the up main. Here it may come to rest across the signal and crossing. After a toot on the whistle or whatever, the signalman can, having obtained the line lear clear for the next block section on the down main, set the way and pull off the shunting signal (8) and the starter (14). The train can then be on its way forwards now throgh the crossover formed and head on its way. The signalmen can now restore the stop signal in rear of the crossing on the up main, reset the rest of his points and signals to their default position, give the train entering section and send his obstruction removed.

 

With some allowance for brevity, does that sound right?

 

Basically yes but with one or two bits of finesse -

 

1. There is no need to close the crossing gates to road traffic if whatever is crossing onto the Up Main will stand in clear between the crossover and the platform starter, the crossing gates need only be closed to road (and the platform starter cleared) if extra length is required.  So a light engine or very short train can cross with the crossing gates still set across the railway.

 

2. Assuming the usual locking conventions apply the platform starter will have to be replaced to danger before the connection from the yard can be reset and will definitely have to be replaced to danger before the disc reading to the Down main can be cleared. 

 

3.  The Signalman only needs 'Line Clear' on the Down Main to clear the Section Signal (No.14) so he might well get on crossing the train or whatever it is over before asking Line Clear if the move is short enough to stand clear of the crossover at No.14 - that way he can clear back on the Up Main at the earliest opportunity - all depends on how busy, or not, the Main Lines are.

 

4.  In most cases I can think of the Signalman will send 'Train Entering Section' at the earliest opportunity - if No.14 is off he might well send it before the move has even reached that signal.  Technically on a strict interpretation of the Regulations he could send the 'Obstruction Removed' signal for the Up Main Line once the shunt is clear of that line but it is really good practice to put the crossover back normal first

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Presumably the end of the slip nearest No. 5 signal could be worked by No. 7 lever whilst No.6 & No.13 could also be a single lever, the normal lie for both being to the divergent (from the straight) route.

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Thanks Ray, your comment makes me realise I have missed off the other lever for the single slip!

 

regards

 

Edit:

 

Looking at the combinations though a single lever (6) will suffice for both as they will be both closed (Crossing) or both open (slip). The former being the normal position. Likwise (7) is normally closed for straight through traffic and (13) normally open (to divert traffic).

The operation of these three levers being independent to allow for the three main routes:

 

6N, 7N,13N yard isolated and main lines isolated

6N, 7R, 13R yard connected through crossing to up main point 7.

6R, 7R, 13N yard isolated and main lines connected through crossover formed by slip and point 7.

 

regards

Edited by ColHut
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The normal way to control such a slip connection is with two levers, each operating two ends as shown below, the levers would not be independent but locked as 6 released by 7.

post-3169-0-66610400-1488208067.png

 

This allows for the three main routes:

6N, 7N, yard isolated and main lines isolated
6R, 7R, yard connected through crossing to up main point 7B.
6N, 7R, yard isolated and main lines connected through crossover formed by slip 7A and point 7B.

Don't overcomplicate things with extra levers..

 

The shunt signal levers would usually be adjacent to the point levers, probably 4 on the down main, 5 from the yard and 8 and 9 from the up main.

Regards
 

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Thanks for that. I seem to have been confused about the need for both ends of the slip to be set in pairs. And always seem to get confused by the diagramatic representation of the slip.

This saves another point lever and simplifies things which is a good thing.

regards

 

Hopefully final version:

 

post-21684-0-52200300-1488382220_thumb.jpg

Edited by ColHut
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  • 2 weeks later...

Basically yes but with one or two bits of finesse -

 

1. There is no need to close the crossing gates to road traffic if whatever is crossing onto the Up Main will stand in clear between the crossover and the platform starter, the crossing gates need only be closed to road (and the platform starter cleared) if extra length is required. So a light engine or very short train can cross with the crossing gates still set across the railway.

 

2. Assuming the usual locking conventions apply the platform starter will have to be replaced to danger before the connection from the yard can be reset and will definitely have to be replaced to danger before the disc reading to the Down main can be cleared.

 

3. The Signalman only needs 'Line Clear' on the Down Main to clear the Section Signal (No.14) so he might well get on crossing the train or whatever it is over before asking Line Clear if the move is short enough to stand clear of the crossover at No.14 - that way he can clear back on the Up Main at the earliest opportunity - all depends on how busy, or not, the Main Lines are.

 

4. In most cases I can think of the Signalman will send 'Train Entering Section' at the earliest opportunity - if No.14 is off he might well send it before the move has even reached that signal. Technically on a strict interpretation of the Regulations he could send the 'Obstruction Removed' signal for the Up Main Line once the shunt is clear of that line but it is really good practice to put the crossover back normal first

Dear Stationmaster,

 

A variation on the above.

 

Should a train arrive on the down main, and passing the signal box all is complete, the signalman still cannot send the 'train out of section' (TOS) to the box in rear as the train has not passed the clearing point. (There is no outer home here, still less one a 1/4 mile in rear of the Home signal).

 

Before shunting the train across to the up main in preparation for a subsequent shunt into the yard, he does not have to 'block back' on the down main as he has not yet given the TOS. He must however 'block back' on the up main.

 

Were there to have been an outer home a 1/4 mile back on the down main, might a less zealous signalman not send the 'train out of section' to the signal box in rear on the down main until the shunt was complete and just 'block back' on the up main?

 

regards

 

Edited as I had forgotten about the clearing point requirements for giving the TOS.

Edited by ColHut
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Dear Stationmaster,

 

A variation on the above.

 

Should a train arrive on the down main, and passing the signal box all is complete, the signalman still cannot send the 'train out of section' (TOS) to the box in rear as the train has not passed the clearing point. (There is no outer home here, still less one a 1/4 mile in rear of the Home signal).

 

Before shunting the train across to the up main in preparation for a subsequent shunt into the yard, he does not have to 'block back' on the down main as he has not yet given the TOS. He must however 'block back' on the up main.

 

Were there to have been an outer home a 1/4 mile back on the down main, might a less zealous signalman not send the 'train out of section' to the signal box in rear on the down main until the shunt was complete and just 'block back' on the up main?

 

regards

 

Edited as I had forgotten about the clearing point requirements for giving the TOS.

 

Although on certain Railways they would have made pretty sure that Signal No.16 was at least 440 yards in rear of No.15  (assuming there was room to do so of course) but otherwise as you say (unless the Signalman was offered a train on the Down Main that he was authorised to accept under the Warning Arrangement).

 

Generally most Signalmen would probably hold the block (at ToL) until everything was done but if they had room they'd clear back and if there was a Clearing Point available they could legitimately accept another train on the Down Main.

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