SIGNALLING ADVICE / CRITIQUE PLEASE

[Badger boy]

During the lockdown I built a typical BLT set in the early 1950's. I am going to make a few changes and would appreciate any constructive criticism / advice on my intened signalling for it please. It is not set in any particular region ( a bit "rule 1") but I favour upper quadrant signals purely by personal preference. The intened changes have been influenced by Bodmin General in that the scenario is the branch has been linked from a nearby junction thus forming a 'through terminus' and increased train traffic required a second passenger platform so the cattle dock has been moved from opposite platform one to the goods yard and a second platform built in its place. This is a short platform (locally known as the bay) able to take a loco and autocoach / single carriage without fouling the crossover. Trains in platform one need to be set back for the loco to run around and shunting needs to take place over the minor road level crossing. Ground signal numbers 7 & 12 will be yellow and I am yet to decide if ground signals 13,14 & 15 are to be stacked or a single disc with a 'theatre' over it showing Y-M-L (yard - main - loop). The drawing is schematic, condensed and not to scale. Many thanks in advance.

 

SIGANLLING DIAGRAM.pdf

[RailWest]

A few random observations:-

 

1. You really do need to decide the Region or original railway company, as that will guide your choice on such matters as whether to have yellow disc or not, whether to have stacked disc or not.

 

2. Disc 2 and 3 should be on the Main and Bay lines respectively, at the toes of point 3 1, not part the way across the crossover as drawn.

 

3. If the Bay Road is going to be used for passenger traffic then there must be a trap point at the exit from the turntable road. Likewise you might also need one at the exit from the spur road to the left of crossover 10, depending on the purpose of that spur.

 

4. You need FPLs on both ends of 10, the Main end of 11, the Loop end of 1 and also the point leading into the turntable road, which doesn't seem to be worked by anything?

 

5. What controls a move from the Main over 1 and into the turntable road?

 

6. Are 4 and 5 meant to be in rear of 1? 

[Badger boy]

Hi Chris - thanks for your helpful input.

 

1. Re which Region - probably more Southern than anything else although Western (ex GWR) would get a look in (sort of a reverse Bodmin General)

 

2. Re discs 2 & 3 discs should be at the toes - senior moment on that one !

 

3. Yes agreed I should have a trap point on the exit from the turn table road. The spur from the left of crossover 11 used to lead to an engine shed but it I found it kept blocking my eye line so a Luftwaffe bomb hit it in WW2 !  Rubble cleared away and now just used for the odd wagon or brake van. Would the spur negate the need for a trap point ?

 

4. Point taken about FPLs. And yet another senior moment - totally missed the need for lever (and FPL) for the  point for entry into turntable road !

 

5. Missed that also - assume I would need a ground signal at toe of point into turntable road to control entry to it ?

 

6. Yes 4 & 5 are in the rear of 1. 

 

Steve

[5BarVT]

Being a Western man, I didn’t like your 13, 14, 15 discs with main signals reading over them.  However, looking at various Southern drawings I see that a facing disc signal in such situations is not unusual (Tunbridge Wells West and Salisbury East both have).  I think possible that it would only be a single disc without route indicator - shunter/driver would have asked for the move and disc off is just showing that the signalman has done it,

Paul.

[The Stationmaster]

3 minutes ago, 5BarVT said:

Being a Western man, I didn’t like your 13, 14, 15 discs with main signals reading over them.  However, looking at various Southern drawings I see that a facing disc signal in such situations is not unusual (Tunbridge Wells West and Salisbury East both have).  I think possible that it would only be a single disc without route indicator - shunter/driver would have asked for the move and disc off is just showing that the signalman has done it,

Paul.

Should definitely be a single disc, with no route indication, for SR practice - and it should lead the running signals.

 

BTW 17 should be a Shunt Ahead arm, not a disc

[Badger boy]

Hi Paul and Mike - many thanks for the input.

 

1. Discs 13.14 & 15 being just a single disc makes a lot of sense particulary as when shunting the loco always pulls back to the signal box or over the crossing so comms between the driver / shunter could easily take place. I will have to resist the urge to invoke rule 1 just because I think 3 stacked dics would look good !  Not sure Mike what is meant by it "should lead the running signals" ?

 

2. I like the idea of 17 being a shunt ahead signal particulary if I can make it a working one. Should it be a shunt ahead signal just because of shunting movement over a level crossing or for some other reason ?  Out of interest would it also be the case if the crossing was railway priority with road traffic requesting opening ?

 

3. Re shunting arms - if I can make working ones I fancy making 5 & 9 shunting arms also - would this be correct practice ?

 

Thanks for the advice

 

Steve

[5BarVT]

“Lead the running signals” means you have to clear the shunt signal before the running signal is allowed to clear.  Somewhere on the lever would be a list of numbers - all levers which had to be pulled first.  On GWR they were on a white plate on the front of the lever (know as a lever lead). LMS did the same and called them Pull Plates, I have also seen them painted down the side of the lever.

Just to shunt out over the level crossing you only need the normal signal to get out there.  On a single line, that would require release by the token etc, so you could only shunt when nothing was using the line (in either direction).  A shunt ahead could be used to shunt out behind a train still in section but going away.

 

Paul.

[Badger boy]

Thanks Paul that all makes perfect sense.

Steve

[RailWest]

By coincidence, I looked at the matter of Shunt Ahead arms at Southern BLTs some while ago and came to the conclusion that, in contrast with the GWR), they were a pretty rare thing, at least on the L&SWR.

 

If you are going to have a level-crossing then you need at least one lever for the Gate Bolt, if not also one for the Gate Stops and perhaps even the wickets (if there are any). But do you want/need a LC really? - you could simplify things quite a bit if it was omitted (eg there would be no need for 9).

[Nick C]

I'd say that signal 9 isn't needed - I can't see you're ever going to have a movement out of the platform without it being clear to 16. As others have said 13/14/15 would be a single disc in SR practice. 

 

The two discs for the loco release crossover should be at the toe of the points, you've shown them partway along the crossover? Depending on the distance between the turntable access points and crossover 10, they might both be protected by the same shunt signal rather than having multiple.

[RailWest]

47 minutes ago, Nick C said:

I'd say that signal 9 isn't needed - I can't see you're ever going to have a movement out of the platform without it being clear to 16. .....

But - even if the line is clear to 16, under the normal interlocking convention of 'lock two back' you would not be able to clear either 8 or 4 without first having locked the gates across the road even if 16 is kept 'on' and there is no intention for the movement to cross the road. It may well be the case that the same constraint would apply to 7 and 12 also (as well as 9).

[Nick C]

3 minutes ago, RailWest said:

But - even if the line is clear to 16, under the normal interlocking convention of 'lock two back' you would not be able to clear either 8 or 4 without first having locked the gates across the road even if 16 is kept 'on' and there is no intention for the movement to cross the road. It may well be the case that the same constraint would apply to 7 and 12 also (as well as 9).

ah, good point!

[The Stationmaster]

20 hours ago, 5BarVT said:

 

Just to shunt out over the level crossing you only need the normal signal to get out there.  On a single line, that would require release by the token etc, so you could only shunt when nothing was using the line (in either direction).  A shunt ahead could be used to shunt out behind a train still in section but going away.

 

Paul.

Er No.  You did not require release by a token to shunt outside the Home Signal on a single line (worked by instrument such as token etc as it was covered bya particularRegulation.  and as the Regulation permitted shunts outside the Home Signal to be made at both ends of the section at the same time it would be impossible in any case to use a token etc (unless special shunting tokens were in use.

 

As the running signal can't be cleared there are two alternatives, viz_

1.  the Signalman instructs te Driver to pass the running signal at danger for the purpose of makinga shunting mpvement, or

2. A Shunt Ahead subsidiary arm is provideds - especially where such shunts were common.

 

A particular problem here is the need to make a shunt across the level crossing so signal protection, interlocked with the level crossing, should be needed.

[Badger boy]

Thanks everyone for the feedback on this - it is very informative and educational. Re discs 2 & 3 - although I knew where they should be postioned I drew them very badly. Also as there is a reasonable distance between the turntable point and crossover 10 I think there would need to be another disc for it. I now realise the level crossing complicates things but it will have to stay as removing it and making good all the stuff around it would be a fairly big job. I think I'm up to about 25 levers on the diagram now including FPL's and gate locks - seems a lot but I like a lot of signals !

As an aside my interest in signalling was stirred by a signal box experience day at Holt signal box on the North Norfolk Railway - so much so that I've volunteered to train as a signalman on the NNR and am waiting to start training soon. I realise there is an awful lot to learn and hope my brain has not gone too rusty to learn new stuff !

[Nick C]

1 hour ago, Badger boy said:

As an aside my interest in signalling was stirred by a signal box experience day at Holt signal box on the North Norfolk Railway - so much so that I've volunteered to train as a signalman on the NNR and am waiting to start training soon. I realise there is an awful lot to learn and hope my brain has not gone too rusty to learn new stuff !

Congratulations, you won't regret it!

 

I've been a volunteer signalman on the Mid-Hants for a few years now, and very much enjoy it - if you've any questions feel free to PM me, though I'm sure there are plenty of helpful people at the NNR who will guide you through it!

[5BarVT]

7 hours ago, The Stationmaster said:

Er No.  You did not require release by a token to shunt outside the Home Signal on a single line (worked by instrument such as token etc as it was covered bya particularRegulation.  and as the Regulation permitted shunts outside the Home Signal to be made at both ends of the section at the same time it would be impossible in any case to use a token etc (unless special shunting tokens were in use.

As usual (!) I was thinking of the engineering and Mike is adding the impact of regulations to give a fuller and better picture.

Paul.

[The Stationmaster]

16 hours ago, 5BarVT said:

As usual (!) I was thinking of the engineering and Mike is adding the impact of regulations to give a fuller and better picture.

Paul.

Far better to think that way than a certain (now retired I believe) signal engineer of my acquaintance who also considered himsef t be an expert on operational matters.  Having both known him in BR days and having come across various of his efforts, including a scheme he designed for a particular power station, I have long believed that he should stick to signal engineering and ask real operators if he wanted to know about operating.

 

Signed BASE - 'Bl**dy Amateur Signal Engineer' using a term a certain Scheme Development Engineer at Reading used to use - in a friendly manner in my case as we worked together on various schemes and design jobs over the years.