Signal advice for this BLT

[AndyB]

I'm hoping that the ever helpful folk on this part of the forum might offer some advice regarding signalling for my BLT?

 

The track plan is not complex so in a nutshell I think my questions are as follows....

1. Ideally where would the signal box be placed? Intuition tells me it should be near the station's throat, but there's a level crossing at the other end straddling the headshunt.  Would this alter things? Should there be a line of sight to the level crossing? Or on a BLT would someone simply walk down to it and control it manually?

2. To add operational interest I'm considering adding a junction - perhaps leading to a military depot (hidden siding). Trains leaving the station would encounter this junction immediately after a tight curve. So where could/should the junction signal be placed? 

3. I'm thinking there should be a signal close to the platform end covering the bay and main platform departures.  Would/could/should this be combined with the junction signal at 2 above?

4. Ground signals covering shunting movements in the goods siding?

 

Context.

The layout is N gauge and 18 feet between fiddle yard and station throat. So whilst at scale it only covers the last few hundred yards of the line I've been able to give the impression of a much longer run. 

 

Era and region. 1950s/60s. WR but with passenger traffic from further afield.

 

Signals - hoping to be able to use the P&D Marsh range. How do people even paint neat chevrons onto those boards! 

 

Sight lines: I've introduced sinuous curves into the design, so there's no easy line of sight for the train crews. This may make placing signals a bit more interesting. There's also a view blocking castle at the station throat so if you're in the bay platform you may struggle to see too far! The link below will give you a better idea of the set up from a visual perspective.....

 

https://www.rmweb.co.uk/community/index.php?/topic/155376-a-return-to-nantford-spinney/

 

Lastly a scan of the track plan. 

 

As ever any suggestions or advice would be very welcome.

Thanks in advance. Andy

 

PS the layout name derives from the halt on the layout - and if you're wondering where all the trees are to allow this to make sense, the makings for the spinney element may hopefully be sitting under the Christmas tree soon!

[TheSignalEngineer]

Before considering signalling what is the traffic level? Will there be more than one loco on the branch and in the station/yard at the same time? This may determine whether signalling would actually be provided or whether there would just be a ground frame released by the Token.

The history of the branch may also play a part in this. Has it always been the terminus? Did it go or was it intended to go further but never happened?

Regarding the trackwork a trap point will be needed at the exit from the run round/goods. Another will be required in the bay if vehicles are left unattended there.

A trap could be omitted at the bottom end of the run round if passenger trains don't go beyond the end of the platform and nothing is stabled there.

Finding a level crossing in such a location would be extremely rare unless the line went beyond there for some reason e.g. a factory. If a level crossing were to be provided it may be traincrew operated.

Regarding the signal box or ground frame position I would put it at the top end of the station by the points.

How the MOD siding would be dealt with would depend on how far it was from the signal box and what amount of trafgic went in and out at what frequency.

 

[KingEdwardII]

I think the first question to ask is how the branch is intended to operate - in particular whether you're planning "single engine in steam" operation, or want a more complex operating pattern. The station is quite small and so single engine might be more common in practice. This might mean no more than some ground frames for controlling things.

 

If you're planning for multiple engines operating in the station, then the single line section is likely to be using staffs/tokens and this would typically imply a signal box somewhere near the bridge at the station throat.

 

Another question regarding the level crossing is whether it would be gated or not. Its position implies relatively low usage by trains and there are examples of ungated crossings where the road involved is also relatively minor. If the road is more substantial, then the crossing might be gated and operated from a nearby small hut and/or a ground frame - I have seen a couple of examples of this kind in the book on the East Somerset and Cheddar Valley Railways.

 

Mike

[AndyB]

Thanks for these additional questions.

 

As per the back story the line is going to see a fair bit of holiday traffic as well as local services. Also some local freight and traffic to the military depot. Sour definitely not "one locomotives in steam".

 

I'd imagined that this had always been a terminus with the head shunt on the quayside due to space restrictions. I'd assumed a level crossing as I think it adds visual interest. Accepting of course that often including items for visual interest may not be prototypical. I have a small hut that could be placed near it - in fact a tiny laser cut kit of the signal box at Wallingford. 

 

Catch points noted. Thanks. 

 

Military traffic would be occasional - maybe one train per day. Technically not that occasional!  But sufficient to add variety to the rolling stock and loads. 

 

Thanks again for taking time to read this thread. Andy

[Zomboid]

A cut down Swanage maybe? https://www.s-r-s.org.uk/html/srp/R274.htm

[AndyB]

So based on the thoughts above I've come up with this. I think it may be OK but others may be able to refine it? All contributions gratefully received.  Andy

 

[Chimer]

I didn't answer your first post as this is not my specialist subject , but that's about what I thought ..... I think the splitting signal might be a bit further round the bend and act as an advanced starter, which I think marks the limit of shunting when you're using the main line as the headshunt for the yard.  I also think the main post for this signal should be for the main with the bracket sticking out to the left for the MOD branch.  I assume the second signal on the main line post here is the distant for the next box down the line?

 

Then I think you need a splitting signal for an arriving train at the start of the throat, to indicate whether it's going into the bay or the main platform, bracket to the right, and the signal you've got an arriving train passing before the bend should be a fixed distant.

 

There may be other little details required to get it absolutely right (ground signals and so on) but these are entirely beyond my ken (and region-dependant I believe).

 

People who really know about these things will now rush to tell me where I'm wrong , which will hopefully indicate to you what's right .  If you don't get any joy, you could try asking the Mods to shift this thread to the "Permanent Way, Signalling & Infrastructure" sub-forum which is where they mostly live ....

 

All the best!

[DCB]

It looks very over signalled to me.   Its more a cut down Blagdon on the Wrington Vale light Railway than a cut down Swanage so a Ground Frame to operate the points at the Junction end of the station, FPLs etc, Home, Starter and fixed Distant signals, no crossing gates, bloke with red flag, hand points at country end of loop,  five trains a day, one running as a mixed train and closed to passengers in the mid 30s so one goods Mon Weds Fri and that's it. The standard 4 turnout late 19th Century branch station had one platform, a loop and two long goods sidings, it really needs a two platform Minehead/ Swanage/ Ilfracombe layout for your projected traffic  and then you can go wild with signals.

[Harlequin]

I'm no expert so I'm taking a risk here but, nothing ventured nothing gained, so here goes:

 

I think the catch points are not correctly positioned. The bay wouldn't need one because it's a passenger line. The goods catch point needs to be in the run round loop because it's not passenger rated.

 

So here's my stab at it:

 

• It is still "over-signalled" - it has to be if it's not one engine in steam. However, I replaced the bracket by separate starters for main and bay to lighten the feel a bit.
• Might be better if the loco release spur was just worked by a ground frame?
• Not sure of the relationship of the fixed distant to the military siding.
• Advanced starter in rear of the military siding just because of distance, not signalling that siding in any way.
• I haven't drawn all the elements of a true signalling diagram.

Experts, do your stuff.

Edited December 11, 2020 by Harlequin

[SZ]

3 hours ago, AndyB said:

So based on the thoughts above I've come up with this. I think it may be OK but others may be able to refine it? All contributions gratefully received.  Andy

 

 

Inward

 

First signal is fixed distant

 

Stop signal required just before the first facing point is reached - splitting if bay is passenger

 

Outward

 

Ground signal just before any trap point is reached

 

Trap point and starter signal for the bay are contradictory - no trap if it is passenger, no signal if it is non-passenger

 

Fancy signal top left not required - siding is entered using a token released ground frame, no signals required

Edited December 11, 2020 by SZ

[The Stationmaster]

46 minutes ago, Harlequin said:

I'm no expert so I'm taking a risk here but, nothing ventured nothing gained, so here goes:

 

I think the catch points are not correctly positioned. The bay wouldn't need one because it's a passenger line. The goods catch point needs to be in the run round loop because it's not passenger rated.

 

So here's my stab at it:

 

• It is still "over-signalled" - it has to be if it's not one engine in steam. However, I replaced the bracket by separate starters for main and bay to lighten the feel a bit.
• Might be better if the loco release spur was just worked by a ground frame?
• Not sure of the relationship of the fixed distant to the military siding.
• Advanced starter in rear of the military siding just because of distance, not signalling that siding in any way.
• I haven't drawn all the elements of a true signalling diagram.

Experts, do your stuff.

Basically quite ok although the Advanced Starter isn't essential (and the bracket has one arm drawn the wrong way round - but you knew that anyway.   I doubt the release crossover would be worked by a GF - far simpler in those days to work it from the 'box as it would then be 100% mechanical.    The trap points are niwe  worrect

 

The Distant Signal could actually be sited at something like a scale distance from the Home Signal on this layout - about 8ft 6" in rear of the Home would be pretty reasonable for a low speed dead end branch like this. (officially it should be at around the 17ft mark but many distants at branch termini were much closer to the Home than 880yds).

 

PS. I won't go into the question of providing or not providing trap points for passenger bay lines - it was complicated and this bay is probably ok without one,

Edited December 11, 2020 by The Stationmaster

[Harlequin]

56 minutes ago, The Stationmaster said:

Basically quite ok although the Advanced Starter isn't essential (and the bracket has one arm drawn the wrong way round - but you knew that anyway.   I doubt the release crossover would be worked by a GF - far simpler in those days to work it from the 'box as it would then be 100% mechanical.    The trap points are niwe  worrect

 

The Distant Signal could actually be sited at something like a scale distance from the Home Signal on this layout - about 8ft 6" in rear of the Home would be pretty reasonable for a low speed dead end branch like this. (officially it should be at around the 17ft mark but many distants at branch termini were much closer to the Home than 880yds).

 

PS. I won't go into the question of providing or not providing trap points for passenger bay lines - it was complicated and this bay is probably ok without one,

 

Great, thanks!

 

Adv starter: OK

Bracket: Oops - trying to get the drawing together too fast!

Loco release: OK

Trap/catch: I was using Andy's own terminology. OK "traps".

Distant: Great, OK.

Bay trap: Interesting, OK.

 

[Chimer]

I may be wrong , but I'm pretty sure the OP sees his "line to a military depot" as a fully-fledged branch (twig?) including passenger and freight traffic, not just a long siding (although he is going to use it as an extra hidden siding).  So I reckon the junction would be worked from the box and signalled as a branch - which now I think of it would also mean stop signals protecting the junction on both lines.  

 

He has also made clear he wants this to be a busy place, not "5 trains a day and that's it".  So the signalling is definitely needed.

[Izzy]

Could it just be confirmed please that all points on the main passenger line would feature FPL’s Including the locked ground frame worked ‘military siding’ and the loop one by the level crossing. Enjoy following threads like this and trying to see if anything I have learnt over recent times has actually sunk in.....!

 

Izzy

[KingEdwardII]

3 hours ago, Harlequin said:

...replaced the bracket by separate starters for main and bay...

 

Although there are some examples of a bracket being used for main & bay platforms, I suspect that the separate starters proposed by Phil are more usual. I have a photo of Carmarthen station which shows 2 separate signals at the Aberystwyth end of the station, one for the main, one for the bay.

 

Mike.

[The Stationmaster]

1 hour ago, Izzy said:

Could it just be confirmed please that all points on the main passenger line would feature FPL’s Including the locked ground frame worked ‘military siding’ and the loop one by the level crossing. Enjoy following threads like this and trying to see if anything I have learnt over recent times has actually sunk in.....!

 

Izzy

All points on the passenger line are legally required to have  FPLs and the ones worked by the signal box are are also required to have lock(ing bars.  As the connection to the 'MoD' (should surely be War Dept or whoever for the OP's dates?).  Because the branch./siding otr whatever connection is worked by a GF immediately next to it it would not be required to have a lock(ing) bar.

 

The engine release points are not in a passenger line and therefore it was normal GWR practice not to provide FPLs on such points although that changed when ground frames were used although they were almost invariably replacements for previously 'box worked connections.

 

2 hours ago, Chimer said:

I may be wrong , but I'm pretty sure the OP sees his "line to a military depot" as a fully-fledged branch (twig?) including passenger and freight traffic, not just a long siding (although he is going to use it as an extra hidden siding).  So I reckon the junction would be worked from the box and signalled as a branch - which now I think of it would also mean stop signals protecting the junction on both lines.  

 

Doesn't really make any difference if it is a siding 50 yards long or a connection into a network of lines, or a branch 5 miles long.   A ground frame with a shut-in facility is perfectly adequate.  If it was really busy - i.e. more than 4 - 6 movements per day  - then a small signal box might well have been provided (most likely during the war) but whether it would have survived long after the war is very debatable and it would by then only be opened when essential.  By the 1960s anything more than a ground frame would be highly unusual for something like this on the WR.

[Zomboid]

How would the lock-in facility work? Would there be a token machine at the ground frame so that the locked-in train could relinquish/ obtain the token?

 

Though in this instance given that it's so close to the signal box, presumably that would be within "station limits" so no token would be needed?

[Izzy]

1 hour ago, The Stationmaster said:

All points on the passenger line are legally required to have  FPLs and the ones worked by the signal box are are also required to have lock(ing bars.  As the connection to the 'MoD' (should surely be War Dept or whoever for the OP's dates?).  Because the branch./siding otr whatever connection is worked by a GF immediately next to it it would not be required to have a lock(ing) bar.

 

The engine release points are not in a passenger line and therefore it was normal GWR practice not to provide FPLs on such points although that changed when ground frames were used although they were almost invariably replacements for previously 'box worked connections.

Thanks Mike,

With respect to the loco release I was thinking it would also have a FPL because the line is ostensibly supposed to continue on through the level crossing as a passenger line - I think that is the premise anyway. I’m interested because I have a similar plan in mind, a convertible plank to be used with either one or two fiddle yards as a BLT or passing station.
 

Izzy

[DCB]

 

To give some context the OP has this pic on his other thread which shows the station. It looks like a quay beyond the station a la Mallaig, Fort William etc which is fair enough, but the text suggests the main platform holds 3 coaches.   If a busy location is required I would look for more run round, probably start it on the bridge (See Goathand)  maybe lose the bay for an additional goods siding, and give room for 5 coaches and a WC, Bob, T9 or N.   They would probably empty the goods yard on Friday and stable coaches there on Saturdays for/ from Summer Saturday Holiday trains,

[AndyB]

First of all may I say thank you to all who have contributed their thoughts, time and knowledge to helping me. 

I've now got a good idea how to move forward. Hopefully when signals appear on the layout I'll have interpreted things correctly.

 

A few thoughts and observations. 

Yep, Mike, you're quite right the MoD dates to the mid 60s whereas the layout is supposedly set a few years before then. I was rushing to get my sketch done before starting work the other morning!  Even though I'd looked it up beforehand. I suspect it may end up as a link to a RN facility.

 

To David's point about the length of train. There's actually quite a substantial gradient between the station and large bridge near the FY. This was unavoidable and part of it is on a curve. So 3 coaches is about the limit for reliable operation. I was also thinking about how trains such as the ACE would be split, so didn't feel a 3-coach train behind a tender loco wouldn't be too implausible. 

 

Yes, the amount of traffic is more than a true branch line. I wanted to include some justification for this so a seaside setting with a castle hopefully does that. 

 

Traps. I fell into this one by looking at the Peco website where they talk about CPs. Mea culpa.

 

Signals. Recognising my own clumsiness I'd hoped to use pre-made P&D Marsh signals but I suspect, based on your collective advice, I'll need to bite the bullet and use Ratio kits. 

[The Stationmaster]

17 hours ago, Izzy said:

Thanks Mike,

With respect to the loco release I was thinking it would also have a FPL because the line is ostensibly supposed to continue on through the level crossing as a passenger line - I think that is the premise anyway. I’m interested because I have a similar plan in mind, a convertible plank to be used with either one or two fiddle yards as a BLT or passing station.
 

Izzy

In his OP Andy describes it as a headshunt so I have regarded it as that.  if it is to be used for any other purpose - such as a siding in a simiiar manner to Looe then it would have to have a trap point (sensibly worked from the signal box which means a couple of ground discs as well.

 

18 hours ago, Zomboid said:

How would the lock-in facility work? Would there be a token machine at the ground frame so that the locked-in train could relinquish/ obtain the token?

 

Though in this instance given that it's so close to the signal box, presumably that would be within "station limits" so no token would be needed?

There would be an auxiliary token instrument in order for a train shutting in too place the token back into a machine.  UIT would then be possible for a token to be withdrawn at either end of the section for another train to pass through.  When the train/whatever wishes to leave the sidings the crew would obtain permission to draw the token from the auxiliary instrument and use it to unlock the ground frame.   The ground frame would be arranged in such a way that it had to be restored to normal (set for the running line) before the token could be removed from it it.

 

The ground frame isn't anywhere near Station Limits, it's in the single line section.   there are basically two ways of doing the job - a lock-n facility as I've described.   The alternative would be something akin to Thomas & Green's siding at Wooburn on the Wycombe branch.  in this case there was no shut-in facility so the siding  was either worked by passing trains or there was authority to proper all the way from BourneEend but a token had to be drawn for that movement (logically so for several reasons including the fact that the token unlocked the ground frame but also because it was much further than would be the case for simply shunting outside the Home Signalt).

[The Johnster]

If the military branch is to be accessed by ground frame, then an outer home to protect it will enable you to run trains on and off the military branch and have trains held at the outer home while this is going on.  If you are going to have an advanced starter as well, it needs to be on the 'outer' side of the military gf, otherwise your trains will be occupying the section in order to reach it.  But if you want to create the impression that the military gf is in the section, then you don't need the outer home or advanced starter.

 

For the incoming traffic, possible outer home 'country' side of ground frame, inner home to be either a 3-way splitter (left to right, goods loop, main platform (main aspect) and bay, or a single post with a calling on sub arm and a theatre indicator (Gds, Main, Bay), in which case all trains must be brought to a stand at this signal before it is cleared and the display shown.  The indicator can be used in conjuntion with the calling on arm. 

 

For outgoing traffic, any movement into the section (see advanced starter comment above, adv str is section signal if provided) needs a starter signal, so one for bay, one for main platform, and one for goods/runaround loop. 

 

A level crossing in this position is pretty unlikely unless this is not intended to represent the original terminus and the branch has been truncated (this is less likely, but not impossible at a coastal location).  In this case it would probably retain it's original 'full fat' gates but be operated by loco crew or shunter by hand when required.  The stub of track beyond it can finish in an abandoned overgrown look; perhaps it once led to a harbour.

[The Stationmaster]

18 hours ago, The Johnster said:

If the military branch is to be accessed by ground frame, then an outer home to protect it will enable you to run trains on and off the military branch and have trains held at the outer home while this is going on.  If you are going to have an advanced starter as well, it needs to be on the 'outer' side of the military gf, otherwise your trains will be occupying the section in order to reach it.  But if you want to create the impression that the military gf is in the section, then you don't need the outer home or advanced starter.

 

Not so easy as that.  You can't use a Clearing Point twice so the outermost Home Signal has to at least =440yds in rear of the connection to the siding and in reality it should be at least 440 yds further from the signal box than the Advanced Starting Signal.   The latter is the sort of arrangement some 'preserved' railways use because it allows them to handle a far more intensive train service and associated shunting movements than ever existed originally when their lines were part of the real railway,

 

But back in the day it was a rare arrangement and even where it did exist it was very unusual to find the outermost Home Signal 440yds beyond the most Advanced Starting Signal.

 

There is of course no problem at all about making a shunt into a single line section and most signal lines were far from sufficiently busy to prevent it happening.  And of course you could always make that shunt if a train was going away from your token station - no problem then with having two movements in a single line section (although it is around 45 years since i last did it, with two passenger trains on that occasion as it happens).

 

But we need to look logcally at what can and can't be done on the total track layout because with very limited accommodation at the terminus it's just as likely that a train for the sidings would arrive there without even going as far as the terminus as it would first go to the terminus to run round or whatever.

[AndyB]

On 25/12/2020 at 17:57, The Johnster said:

....

A level crossing in this position is pretty unlikely unless this is not intended to represent the original terminus and the branch has been truncated (this is less likely, but not impossible at a coastal location).  In this case it would probably retain it's original 'full fat' gates but be operated by loco crew or shunter by hand when required.  The stub of track beyond it can finish in an abandoned overgrown look; perhaps it once led to a harbour.

 

At the beginning of lockdown #1 I borrowed a library book which, among others, had the plan for Lymington and Lymington Pier. I was quite taken by this, although it wasn't quite suitable for the way we use our garage. That said, the basic idea that the line might have continued on further is not inconceivable. As it stands the basic use for that bit of track is as a head shunt. The reason for including the level crossing is more about aesthetic appeal rather than prototype practice. 

 

The idea I have for a military branch line is fundamentally to have greater and more varied freight traffic than a traditional BLT might have seen. I imagine freight trains would come down the line, reverse at the terminus and then head off to the military depot. 

 

Based on the advice above I've now got one signal built and another RTP which I believe will need one of the boards removed.

 

 

[The Stationmaster]

2 hours ago, AndyB said:

 

At the beginning of lockdown #1 I borrowed a library book which, among others, had the plan for Lymington and Lymington Pier. I was quite taken by this, although it wasn't quite suitable for the way we use our garage.

 

 

Does that mean that you couldn't justify filling part of your garage with water to accurately model a ferry terminal?

 

On a more practical note I reckon you could use that splitting bracket signal by cutting off the bracket and doll to the left of the main upright or simply remove the distant arm & associated lamp and use it as the Home Signal.