Layout design case study

[Mikkel]

Hi Colin, somehow I had missed all your fantastic shots from the line - that is quite a collection, perhaps even unique for showing so many of the structures together after closure. Thanks very much for sharing them here! 

 

I like the trackplan and wiring diagram. Quite a project this! You might be excused for not doing the chairs, although they do add something extra of course.

[Zero Gravitas]

Hi Colin,

 

Thank you for the update - it's coming along!

 

And do the chairs. If you don't, then every time you look at the finished layout, you'll see that they are not there, and you won't see everything that is.

 

Best Regards,

 

ZG.

[colin penfold]

OK, with some trepidation as there are far more knowledgeable folk than I on signalling matters. I have been giving thought to the signalling diagram for Southampton - as with the wiring, Iain recommends thinking this bit through before tracklaying so that provision can be made for fitting posts and operating mechanisms (in my case, cord system based on fishing line and counterweights/springs)

 

I aim to use GWR practice but there might be a couple of SR signals dotted about reflecting the fact that the GWR would have installed the signals but the line transferred to SR control in 1953.

 

I have tried to use photos of Southampton Terminus for inspiration too, as the track  layout is based on it

 

So here we go, hat in ring, await incoming.......

 

The location of signals is as follows

 

 

The key to this is as follows (with one or two queries highlighted)

 

1. Soton advanced starter / distant for docks box  road A
2. Gantry with advanced starters for roads  B,C,D
3. Starter from goods yard
4. Ground signal from GY
5. Gantry with inner homes for roads A,B,C. Each road has Home, Calling On arm and route indicator
6. Starter for Plat 1
7. Starter for Plat 2
8. Starter for Plat 3
9. Starter for Plat 4
10. QUERY starter from sidings, is this needed or could 9 be used?
11. Ground signal from sidings
12. Exit from docks QUERY ground signal or full post?
13. QUERY Is a Ground Signal needed for loco release?
14. QUERY Is a Ground Signal needed for loco release?
15. QUERY Is a Ground Signal needed for loco release?
16. QUERY What would be here for a line entering the public highway? Sign, Signal, Gate?
17. Inner Home for Road D – Home, Calling on and route indicator

Lastly, a visual representation of the more complex signals

 

 

Question over the correct style of calling on arm. There seem to be baby arms with C O on them, and larger arms with a big C stuck on. Which would be more likely?

[The Stationmaster]

Colin,

 

Can you first please refresh me on the purpose of each of the lines A, B, C, and D?

 

Is the line to the docks a passenger line or a goods line?

 

I'm also slightly confused about some signals in relation to the track layout - as far as I can see the Inner Home on Line C can only read to one place (apart from the fact that it should be in rear of the diamond crossing it is protecting  - instead of in the middle of it it).

 

Depending on how you intend to work things disc 13 should be at the toe of the points and not teh other way round (and there should be a signal at the point toe in any event - sensibly the crossover should be turned round if it is only meant for engine release).

 

I'm totally confused by 14 & 15 - are there release crossovers there?  (in any case I would think ground frame operation more likely for the release crossovers so no fixed signals at all)

 

Technically there should be a gate at 16 but I'm fairly sure that was not the case on certain lines in Southampton - anyone know better?

 

Various trap points are missing but the need for them will be decided by the answers to other questions above.

[colin penfold]

Thanks Mike, I'm so pleased you turned up for this one !

 

Colin,

 

Can you first please refresh me on the purpose of each of the lines A, B, C, and D?

 

They are designed to look like Bi Directional lines although A is to the docks and B,C,D are to Soton Central and the DNS. D would also have an entry to the local shed very close, hence the junction signal on that post on the gantry (2). In reality A and B go to the spiral and onto the FY, C goes to a small FY which will be an automated shuttle in and out of P1. D will be a Loco holding area.

 

Is the line to the docks a passenger line or a goods line?

 

Passenger and goods trains will both be handled. Stuff will also stand on line A between the two viaducts whilst changing locos from arriving loco to pilot.

 

I'm also slightly confused about some signals in relation to the track layout - as far as I can see the Inner Home on Line C can only read to one place (apart from the fact that it should be in rear of the diamond crossing it is protecting  - instead of in the middle of it it).

 

I think I got the actual location of the gantry slightly wrong on the drawing as I was thinking more of the overbridge that will be above that diamond. I will make sure it does protect the diamond. The diamond is actually impersonating a slip (hence trying to disguise it with an overbridge.) I am representing a slip with a diamond because I am automating line C, so I want it to appear like a complex layout but in fact the only movements will straight across the diamond, the slip functions are not needed on the model.

 

Depending on how you intend to work things disc 13 should be at the toe of the points and not teh other way round (and there should be a signal at the point toe in any event - sensibly the crossover should be turned round if it is only meant for engine release).

 

I will turn the crossover round as you describe

 

I'm totally confused by 14 & 15 - are there release crossovers there?  (in any case I would think ground frame operation more likely for the release crossovers so no fixed signals at all)

 

There is no crossover at 14/15 - My question is given that I will be using pilot working, how is the released loco going to be allowed to exit the platform after the stock it has brought in is removed? Would it simply run up to the relevant starting signal after the stock has gone, or does it need a controlling ground signal to allow that move?

 

Technically there should be a gate at 16 but I'm fairly sure that was not the case on certain lines in Southampton - anyone know better?

 

Thanks,  I will look at photos also

 

Various trap points are missing but the need for them will be decided by the answers to other questions above.

 

Oh Oh, that's why we love you (in a very respectful and totally appropriate way, that is)

[The Stationmaster]

Colin I think you need to carefully reconsider the amount of bi-directional working as it strikes me as excessive for the era you are portraying I don't think anything on the GWR, including Paddington (!!) was quite that complex in terms of having so much bi-di working.  Hence I think a bit of rationalisation of it would be a good start.

 

I'm off to cogitate while watching that scheming Boelyn woman heading for her come-uppance!

[colin penfold]

Would it be a better premise if I say the lines a-d are docks, down and up main, and loco? I then would not model the advanced starters and assume that the final crossovers to route trains from the various platforms and sidings are "off stage" Would it not then be reasonable that trains would be running in both directions on all roads? For example a service leaving P4 would still be on the "down" on my 4 track stretch, because the crossover to reach the "up" and its associated signaling is beyound the next bridge?

[The Stationmaster]

Colin delving back through the thread and looking at what happens on the other side of the wall as you previously intended to do it the way I'm beginning to see it is thus (Down being towards your terminus/docks entrance)

 

1. I am assuming that your original idea of lines A, B, & D coming together 'beyond the tunnel' with C having its own fiddle yard will still be the situation

2.I am going to assume for a moment that D is still meeting the original idea of an engine shed line, and that

3. Line C will be served by a shuttle service of trains which do not need to run round.

 

So I would reclassify the lines as follows -

 

Option 1.

Line A becomes the Down Main, Line B becomes the Up Main, Line C is the basically separate branch to/from Central, and Line D serves the engine shed.  Operationally that means that DN&S type passenger trains can only arrive at Platform 4 and effectively Platforms 2 & 3 would become departure platforms.   Line C would be served by a shuttle service and the imaginary slip connection would cease to be imagined (odd but probably explainable.  Although if you want to carry on with the imaginary slip so be it - but the signalling will get rather forest like at the platform ends as what goes in also has to have a  signalled route out).

 

Option 2.

 

I think this might appeal a bit more as it removes certain constraints in Option 1.

Line A becomes the Docks Arrival Line

Line B becomes the Down Main - and can reach 3 platforms for arrivals (and the Docks line)

Line C remains as the shuttle line

Line D becomes the Up Main - and can be reached from 3 platforms plus the Docks Line

 

That results in the same situation of only one bi-directional line as Option A.

 

Now this becomes a lot better to work in many respects - some of which are shared by Option 1.  The main need for a docks line is to hold and possibly break up arriving trains, out bound trains would come out of the docks fully formed (and some would go in like that although they might first change engines).  Departing trains would simply cross to the Up Main.  

 

The Down & Up Mains are entirely self explanatory (I hope) and you could still assume a connection to the engine shed off the Up Main although as there is a tunnel involved I would think bi-directional working over Line D would be fairly unlikely.

 

The shuttle line would be worked as such (which of course is all you can do with it anyway) and would have slightly simpler signalling as a result.

 

Right now have a think through that lot and we'll see where we go next

[KeithHC]

Hello Colin, I have just come across this thread and spent an enjoyable couple of hours looking through it. A couple of points of interest have you looked at the National Library of Scotland maps collection (site appears to be down at the moment). Also Rail Map online http://www.railmaponline.com/UKIEMap.php?lat=53.53306&lng=-2.38792. One other interesting article that I found as well gives some more info on the route through Southampton http://www.fosjp.org.uk/hist_railway.html. I have also toyed with the idea of a GWR terminus at Southampton using the DN&SR as the basis. My imagined route was from Shawford junction becoming an overbridge an routing through Chandlers Ford crossing the Romsey/Eastleigh railway complete with a junction from the west. The line would then go through Chilworth and Shirley and cross the LSWR close to central station and terminate the other side of the town wall from your proposed location. Connecting with the Romsey line would potentionally allow M&SWJR line trains to terminate there as well. So now you could also add Midland region services maybe a mini pines express.

 

Keith, Dursley 

[colin penfold]

Colin delving back through the thread and looking at what happens on the other side of the wall as you previously intended to do it the way I'm beginning to see it is thus (Down being towards your terminus/docks entrance)

 

1. I am assuming that your original idea of lines A, B, & D coming together 'beyond the tunnel' with C having its own fiddle yard will still be the situation

2.I am going to assume for a moment that D is still meeting the original idea of an engine shed line, and that

3. Line C will be served by a shuttle service of trains which do not need to run round.

 

 

Right now have a think through that lot and we'll see where we go next

 

Hi Mike,

 

As usual I am really grateful for the time you take to help with this sort of stuff.

 

I Will fully digest your comments in due course but just to confirm your assumptions above are still correct with the exception that line D will not join with A and B . Option 2 would not work in model world because as you say line D is the loco handling area, and will not connect with lines A and B due to insufficient space to curve round.

 

I should clarify, I think, that there are two docks areas in my head - one exit stage left on line A, the other beyond the bottom right hand corner of the layout. Bargate is placed centrally to the main docks areas so logically could have serviced more than one dock.

 

I have done  a quick sketch of the thought I had in post 184

 

 

In the sketch, line x - x is the tunnel through the wall as well as the cut in the diagram. My premise is that the throat continues off-stage as shown. Incoming trains for platform 1 use the off-scene crossover to arrive in platform 1 via line C.  Departures from all platforms can access the main (given that the eye accepts my cheat of hiding that the second slip is in fact only a diamond)

 

This I hope provides a rationale why trains would travel in both directions on line C ( rather than the earlier bi-directional overload!)

 

Removal of the gantry to "off-stage" prevents the signalling from giving away the illusion. The advanced starters would be beyond the additional track, and I won't try to show them on the plan as they will not be modelled. 

 

I hope you might think this would work. I did look in my GWR OPC books and found plenty of layouts with up and down main flanked by single line branches and goods loops or sidings so I'm hoping this is plausible

Edited February 19, 2015 by colin penfold

[colin penfold]

Hello Colin, I have just come across this thread and spent an enjoyable couple of hours looking through it. A couple of points of interest have you looked at the National Library of Scotland maps collection (site appears to be down at the moment). Also Rail Map online http://www.railmaponline.com/UKIEMap.php?lat=53.53306&lng=-2.38792. One other interesting article that I found as well gives some more info on the route through Southampton http://www.fosjp.org.uk/hist_railway.html. I have also toyed with the idea of a GWR terminus at Southampton using the DN&SR as the basis. My imagined route was from Shawford junction becoming an overbridge an routing through Chandlers Ford crossing the Romsey/Eastleigh railway complete with a junction from the west. The line would then go through Chilworth and Shirley and cross the LSWR close to central station and terminate the other side of the town wall from your proposed location. Connecting with the Romsey line would potentionally allow M&SWJR line trains to terminate there as well. So now you could also add Midland region services maybe a mini pines express.

 

Keith, Dursley 

 

Thanks Keith, I am intrigued by the reference in the FOSJP article to a book by a Bob Culley - I have not got that one nor can I find in on Google. Is it a local history publication perhaps?

[petethemole]

I knew Bob Culley. He was an amateur archaeologist and local historian. I very much doubt if his text on the DNSR was published as such. It was probably a privately circulated duplicated typescript, possibly produced under the auspices of one of the local historical societies. The very comprehensive Local Studies section at the Central Library doesn't have a copy; I just searched their on-line catalogue. I've never seen a copy.

 

There was another, earlier, railway proposal in the same part of Town. The Manchester & Southampton Railway, proposed in 1846, was planned to run down the Test shore and round the south of the Town to the Docks: http://www.railwaymapsanddocuments.com/page-36.htm

 

Pete

[The Stationmaster]

Colin,

 

I think you are hitting on answer although one or two aspects worry me a little - read on.

 

Firstly - yes - shove the docks -docks line out on its own and that makes a lot of sense (some trap points now required but that's a straightforward thing and just a matter of popping them in the right place).  

 

Equally the loco siding works well with no problems but the Up & Down Mains pose one or two headaches vbeacuse of the tunnel.  Logically and for technical reasons the two ends of the tunnel would be under the control of two different signalboxes - thus any bi-directional working would, fairly unusually, be between the two signalboxes.  Now the GWR happily did this for shunting movements but I'm trying hard to think of a situation where they did it for train movements on a  more than occasional basis (it was done between Paddington and Subway Junction over one line but only under some fairly special Instructions and not as a  regular traffic feature although the arrangement was supposedly tested by one ECS train a week, on a Sunday).

 

So effectively at the tunnel mouth both the Down and Up Lines would be unidirectional.

The simple answer would be to make the diamond crossing under the bridge a single slip, or better still a double slip and also to alter the connection between Line D and Line B to a trailing connection between Line D and Line C - a facing connection being very unusual in such a situation and not really of much use as far as I can see  (because nothing can run head on into those short sidings as the engine would be trapped).

 

With these changes you can freely work the place as a terminus, some trains will have to arrive and be shunted by a pilot if they have parcels vans to go to the short sidings (if it's still meant for parcels, could equally be perishable/fish etc of course) and you would have full flexibility to make shunts via Line D - as it most likely would have to be in real life although Line C would probably be the real life favourite.

 

So how are we doing now?

[colin penfold]

I think I can solve a couple of the problems you raised Mike.

 

Firstly the diamond under the bridge is pretending to be a slip! I dont want to actually install a slip because I wont be making any of the "slip" movements (plus the cost!) I am banking on the fact that it wont be noticeable as it will be under a bridge.

 

Secondly the tunnel is not a model of a tunnel. I refer to it a a tunnel because I REALLY tunnelled through the wall! The scenic break will be an overbridge, not a tunnel.

 

The crossover from the small goods yard at the front is to allow freights to depart from that yard. Of course, it should exit onto line C. The best rationale I can give is that if anyine queries the movement I will say the train in question is accessing the dock branch via the off-scene crossover.

 

In answer to your questuon, it feels like we are geting there, if there is a liveable compromise between prototypical acceptability, play value, and real life practicalities of space and geometry.

 

Thank you yet again!

[colin penfold]

Have some pics in my collection of gantries to base mine on. Also an image of the Route indicators. MSE sell these although it looks like they are only part of a larger etch so I reckon I will be putting up a want ad in due course!

 

Newton Abbot. I quite like the idea of cantilevering off a bridge.

 

 

 

 

 

Westbury

 

 

 

Aller Jct

 

 

[colin penfold]

Question over the correct style of calling on arm. There seem to be baby arms with C O on them, and larger arms with a big C stuck on. Which would be more likely?

 

 

 

Various trap points are missing but the need for them will be decided by the answers to other questions above.

 

I have spent some time this afternoon with "Great Western Signalling" by A. Vaughan (OPC)

 

I believe the answer to the calling on arm question is, for my period, a 3' arm with red edges and a white central horizontal stripe (as on the photos at Newton Abbot, above)

 

I think, although part of me expects to be corrected, that I need two catch points - adjacent to signals 8 and 3 protecting the exit from the upper and lower yards respectively

[The Stationmaster]

I have spent some time this afternoon with "Great Western Signalling" by A. Vaughan (OPC)

 

I believe the answer to the calling on arm question is, for my period, a 3' arm with red edges and a white central horizontal stripe (as on the photos at Newton Abbot, above)

 

I think, although part of me expects to be corrected, that I need two catch points - adjacent to signals 8 and 3 protecting the exit from the upper and lower yards respectively

Nice set of pics - I have little need to be reminded of the one at Westbury having once spent a goodly part of Boxing Night on it, in pouring rain, replacing lamps which had gone out (the Lampman did not get my sympathy vote - we sacked him the next day!

 

Use the modern pattern of Calling On arm Colin as you said - there were very occasional examples of the GW pattern around int the 1950s but i seriously doubt if any made it into the last part of that decade (now awaiting informative photo with interest).

 

You need one trap in advance of signal 5 position on the dock line coming in from the left, one again on the dock line coming in from the right roughly where you have number 8 on your plan.  You don't need one by 3 assuming taht Line D remains a loco only line. 

[Joseph_Pestell]

I think I can solve a couple of the problems you raised Mike.

 

Firstly the diamond under the bridge is pretending to be a slip! I dont want to actually install a slip because I wont be making any of the "slip" movements (plus the cost!) I am banking on the fact that it wont be noticeable as it will be under a bridge.

 

Secondly the tunnel is not a model of a tunnel. I refer to it a a tunnel because I REALLY tunnelled through the wall! The scenic break will be an overbridge, not a tunnel.

 

The crossover from the small goods yard at the front is to allow freights to depart from that yard. Of course, it should exit onto line C. The best rationale I can give is that if anyine queries the movement I will say the train in question is accessing the dock branch via the off-scene crossover.

 

In answer to your questuon, it feels like we are geting there, if there is a liveable compromise between prototypical acceptability, play value, and real life practicalities of space and geometry.

 

Thank you yet again!

 

In the overall scheme of things (total cost of a layout) replacing a diamond with a slip is not a major expense. It would add a lot to the layout.

[colin penfold]

It's not just the cost of a the slip, its the switches and two point motors. Having said that, the main reason is that line C is designed to be a self contained automated shuttle line between platform 1 and an off scene fiddle yard, which will showcase some railcars and push pull services. I don't want to switch trains onto that route from other lines, nor do I want to switch trains off from it. I do acknowledge that in the prototype it would be a slip, hence I shall disguise it under a bridge

[colin penfold]

Nice set of pics - I have little need to be reminded of the one at Westbury having once spent a goodly part of Boxing Night on it, in pouring rain, replacing lamps which had gone out (the Lampman did not get my sympathy vote - we sacked him the next day!

 

Use the modern pattern of Calling On arm Colin as you said - there were very occasional examples of the GW pattern around int the 1950s but i seriously doubt if any made it into the last part of that decade (now awaiting informative photo with interest).

 

You need one trap in advance of signal 5 position on the dock line coming in from the left, one again on the dock line coming in from the right roughly where you have number 8 on your plan.  You don't need one by 3 assuming taht Line D remains a loco only line. 

 

 

Thanks Mike, just for clarification, if I am treating line A as a single track docks branch which will have boat trains running on it, would I still need the trap at location 5?

[The Stationmaster]

Thanks Mike, just for clarification, if I am treating line A as a single track docks branch which will have boat trains running on it, would I still need the trap at location 5?

Technically 'yes', practically - inevitably

[colin penfold]

any views from the house as to the suitability and look of the PECO catch points as against me knocking something up? Obviously we are basing our comparison on the fact that the rest of the track is code 100, not hand built P4 sorcery.

[The Stationmaster]

any views from the house as to the suitability and look of the PECO catch points as against me knocking something up? Obviously we are basing our comparison on the fact that the rest of the track is code 100, not hand built P4 sorcery.

Being ex GW the traps would very likely be single rail if in bullhead, probably both rails if the other lot had relaid them in flatbottom.

[colin penfold]

Two catch points duly "constructed" in readiness for tracklaying at Southampton

 

http://www.rmweb.co.uk/community/index.php?/topic/96496-scrap-points-to-catch-points/&do=findComment&comment=1797497

[colin penfold]

So I have received a major purchase from Marcway in Sheffield this week, and got some time this morning to have a close look, particularly with a view to finalising the baseboard joint positions for the Burghclere boards. (edit to say the brief, and track diagram for this is work in post 177 above)

 

These photos are laid out on the Southampton boards which are the same size but on the lower level.

 

General views:

 

 

 

 

 

Some close up detail of the pointwork

 

 

 

This shows how C&L flexi track works with Marcway

 

 

 

Planning for platform length

 

 

One slight disappointment with Marcway. They made this as bespoke work in three sections, and the three sections do not match up and will need jiffling to join

 

 

Edited March 8, 2015 by colin penfold