Small Diorama - track and signalling queries

[Orinoco]

I quite fancy building a small 2mm scale diorama. Looking through various ideas I found a very early plan for Deptford, a small through station with an adjacent loco shed. With a few minor changes, it might be ideal. My version would be based in Scotland, in BR days, just to be awkward!

 

 

To make the diorama more attractive, I would make the land rise steeply to the right, with the railway disappearing into a tunnel.  I hope to make this single track, if possible, to add to the operational interest. In real life, the whole complex was changed out of all recognition. My version would assume that it stayed more or less the same into BR days.

 

The site is very tight and was designed when locos were very small. Modifying it for larger locomotives would be quite a headache. I would also need to take into account the introduction of railway regulations. By stretching the site very slightly, I came up with the following track plan

 

 

My initial problems are as follows:

 

1. There might ideally be a single slip at A, (to enable a loco to reverse off the upper line onto the lower line prior to reversing again into the loco shed), but the site forces a 1:5 or just maybe a 1:6 angle - a bit steep for a normal slip. An outside slip would not be practical either, due to the adjacent running line. Instead, I have added a crossover at B, which I hope would be a reasonable solution on the prototype.

 

2. At C the line converges into single track before diving into a tunnel. I thought a sand drag would be good, as it would enable locos to be signalled beyond A towards C awaiting a path onto the opposite line prior to entering the loco shed. Someone told me you would not have a sand drag like that on a passenger line, so I am not sure if that would be OK.

 

Any comments would be greatly appreciated.

 

Once the track plan is sorted, I will no doubt have some signalling questions too.

[Grovenor]

The headshunt at C would not be a headshunt as there is no shunting to do there, it would be a sand drag to safely stop any train that overan the signal.

Keith

[Orinoco]

The headshunt at C would not be a headshunt as there is no shunting to do there, it would be a sand drag to safely stop any train that overan the signal.

Keith

 

Many thanks for that correction Keith - that is the kind of expert help I really appreciate. Original post now amended!

 

I should also have mentioned in my original entry that the diamond at A has to be curved - even more reason not to model a single slip!

[Madcaravanner]

For Sand drags there was a prototype one on a passenger line for Ravenstor branch a mineral only branch which joined the main line at Wirksworth in Derbyshire on the Ecclestone Valley Railway

 

The sand drag has been removed a long time ago when the track was realigned to the platform and a small head shunt left in its place when preservation commenced

[Grovenor]

Sand drags were required on a passenger line in this sort of situation, (ie if not enough space for an overlap distance between signal and convergence) although more common  where a slow line ended and rejoined the fast line. For a goods line a sand drag was not required, just a trap point, but the railway company might still provide a sand drag if they thought it would help.

Keith

[Orinoco]

Many thanks for the replies. A sand drag there will be!

 

No other comments have been made, so I assume what I have proposed is more or less believable. On that basis I will make a start on a signalling diagram. I will be adding catch points and facing point locks too.

 

The main puzzle I have straight away is how many signals would be required on the up line, heading towards the tunnel, and where they should be placed. I presume there needs to be one at D, but the end of the platform is right next to the diamond leading to the loco shed. Also, the distance between D and E is only about 120 yards, so would an advanced starter be required at E?

 

 

The location is Scottish, a joint line,- and if it makes any great difference, I might as well make it ex-North British/LNER signal equipment.

[The Stationmaster]

That signalling would be quite ok for that situation.  There might also be one to protect the trailing crossover in the opposite direction with the signal in rear of it back just inside the tunnel.

[Madcaravanner]

Signalling can be a pain but this place may be the start for research on which to use and how many there are a lot of sites you could use

 

http://myweb.tiscali.co.uk/gansg/3-sigs/003-index.htm

[beast66606]

Signalling can be a pain but this place may be the start for research on which to use and how many there are a lot of sites you could use

 

http://myweb.tiscali.co.uk/gansg/3-sigs/003-index.htm

 

RMWeb is also a good one, there's a few of us on here who know a thing or two ...

 

 

I had a glance at the site and whilst looking like a good start there were several mistakes in the couple of pages I glanced at - so tread carefully.

[Orinoco]

That signalling would be quite ok for that situation.  There might also be one to protect the trailing crossover in the opposite direction with the signal in rear of it back just inside the tunnel.

 

Many thanks for your comments - and those of the two successive posts too. My diagram was just a tentative start, as I was very nervous about the up line in particular.

 

I have looked at several sites for advice, including The Signal Box, but they tend to cover "typical" installations, rather than a real oddball one like mine. I would ideally have chosen a real location, but I could not find anything half as interesting to operate, in such a small space.

 

I hope to draw a full diagram this evening or tomorrow for comments and suggestions, so please watch this space!

[The Stationmaster]

RMWeb is also a good one, there's a few of us on here who know a thing or two ...

 

 

I had a glance at the site and whilst looking like a good start there were several mistakes in the couple of pages I glanced at - so tread carefully.

I found enough mistakes on one page of it!!! (that site - not RMweb of course ).

[beast66606]

I found enough mistakes on one page of it!!! (that site - not RMweb of course ).

 

I was going to mention the back to front signals on the diagrams, but then a good mate of mine used to draw them like that - and he's now a signalling engineer for NR !

[Madcaravanner]

RMWeb is also a good one, there's a few of us on here who know a thing or two ...

 

 

I had a glance at the site and whilst looking like a good start there were several mistakes in the couple of pages I glanced at - so tread carefully.

 

I am not an expert when it comes to signalling and railway operation so I wouldn't know of any mistakes  can you help em out for my reference by messaging me with some so I not to make those mistakes 

 

Many thanks in anticipation

[The Stationmaster]

I am not an expert when it comes to signalling and railway operation so I wouldn't know of any mistakes  can you help em out for my reference by messaging me with some so I not to make those mistakes 

 

Many thanks in anticipation

Best thing to do is ask on here - if you can give a track layout, the Company/Region, and the era we can usually help from there as between us we've a reasonable spread of knowledge of the practice of different companies and the BR Regions.

 

Regrettably if somebody wishes to create a website on a specialised subject without getting their own research ducks in a line and providing correct or peer checked information I'm blowed if I'm going to do it for them - unless they happen to somehow 'reward' me for my efforts.  That might sound unhelpful but there's more than enough plagiarism and poorly researched stuff on the 'net without the need for me or others to do their job for them by sorting out their errors and correcting them - it could become a full time job  .  That might not sound very helpful but you will get help here by the simple expedient of asking and we do our best to try to get things as accurate as we can or note where there are gaps in our knowledge.

[Orinoco]

I now have a full set of signals on the diagram - more rather than less, but hopefully not overcooked. Having lots of signals to operate will make the diorama more interesting - though not if I get lots of unfavourable comments and criticisms from signalling experts at exhibitions, once the diorama is finished

 

I put a shunt ahead signal on the up line for locos to draw forward from the station before setting back over the crossover. I am not sure if this is necessary here, but have noticed them in some photos and signal diagrams.

 

I also drew the far right-hand signal on a gantry at the tunnel mouth, so that spectators can see it, rather than inside the tunnel as The Stationmaster suggested.

 

There is a locking bar at the facing point on the up line before the tunnel. I am guessing that this might have been replaced by a track circuit by c1960?

 

I wish to represent a very busy location, despite the single line tunnel. I envisage the signalman having a real battle trying to fit all the light engine movements in between the frequent trains. Just to explain all the light engines, I will pretend that there is a terminus or junction station a mile or so beyond my diorama, in the down direction.

 

Once again, advice is more than welcome!

[Orinoco]

Best thing to do is ask on here - if you can give a track layout, the Company/Region, and the era we can usually help from there as between us we've a reasonable spread of knowledge of the practice of different companies and the BR Regions.

 

Regrettably if somebody wishes to create a website on a specialised subject without getting their own research ducks in a line and providing correct or peer checked information I'm blowed if I'm going to do it for them - unless they happen to somehow 'reward' me for my efforts.  That might sound unhelpful but there's more than enough plagiarism and poorly researched stuff on the 'net without the need for me or others to do their job for them by sorting out their errors and correcting them - it could become a full time job  .  That might not sound very helpful but you will get help here by the simple expedient of asking and we do our best to try to get things as accurate as we can or note where there are gaps in our knowledge.

 

Hopefully, the advice being given here is ample proof that RmWeb works!

[Madcaravanner]

If you don't ask...........................

 

I am asking question but at present all I have is the Region track plan is liable to change so I was looking for a little enlightenment  no probs 

When I am far enough on to say that this is definitive I will draw a diagram 

 

No worries 

No Stress 

LOL

No work either the Doc won't let me

[The Stationmaster]

I now have a full set of signals on the diagram - more rather than less, but hopefully not overcooked. Having lots of signals to operate will make the diorama more interesting - though not if I get lots of unfavourable comments and criticisms from signalling experts at exhibitions, once the diorama is finished

 

canna0002b.jpg

 

I put a shunt ahead signal on the up line for locos to draw forward from the station before setting back over the crossover. I am not sure if this is necessary here, but have noticed them in some photos and signal diagrams.

 

I also drew the far right-hand signal on a gantry at the tunnel mouth, so that spectators can see it, rather than inside the tunnel as The Stationmaster suggested.

 

There is a locking bar at the facing point on the up line before the tunnel. I am guessing that this might have been replaced by a track circuit by c1960?

 

I wish to represent a very busy location, despite the single line tunnel. I envisage the signalman having a real battle trying to fit all the light engine movements in between the frequent trains. Just to explain all the light engines, I will pretend that there is a terminus or junction station a mile or so beyond my diorama, in the down direction.

 

Once again, advice is more than welcome!

There is no need for a subsidiary arm beneath the signal at the end of the platform - just bring a loco more or less to a stand at it then clear it to allow the loco to slowly draw forward (Shunt Ahead arms are found only below the signal controlling entrance to a block section - that's the one on the approach to the tunnel, and it doesn't need a subsidiary arm).

 

The locking bar might well have been replaced by a track circuit by 1960 although there were still an awful lot of them about the even on main line routes.

 

Otherwise all ok in my view.

[Orinoco]

Thanks very much for the additional information. That wasn't too painful for me - much easier than I expected! Here is the final version.

 

 

I guess the next step is to design the 3D version......

[dave55uk]

Assuming we are travelling in a down direction, coming from the tunnel, wouldn't a locking bar be required on the first point?

[beast66606]

As Dave mentions there's an FPL missing off the points to the right.

 

On some companies the disc in the platform reading back along the down line would be a double one, one for the yard and one to continue to the next disc protecting the crossover.

[dave55uk]

Referring to the disc that Beast mentions, I think it would/should be much nearer the toe of the point, and not out beyond the down starting signal.

[Orinoco]

Thank you for the extra comments!

 

I did query (see above) if there might be track circuits rather than FPLs by 1960. I forgot to add one or the other at the tunnel mouth when I received an answer. I do wonder if a track circuit would be a better idea for a single line tunnel (as long as it's reasonably watertight), but am not an expert, so can't be sure.

 

Dave55UK - the platform is unimaginably short. See the plan of what this is based on in my first post. The toe of the point is more or less where the disc is. Apologies if I drew the signals out of sequence. My drawing was more to establish what was required, rather than exactly where they should go. I was going to query the exact siting and detailed design of the main signals when I had part-built the model, as clearances and sighting might be an issue. My gut feeling is that the starting signal would be some way beyond the end of the platform in reality.

 

Beast - light locos would generally come from and go off to the left of the diagram. A move out of the loco shed onto the down line and then back over the crossover to the up line would be rare, if it happened at all. That thought makes me wonder if I really need a disk on the down line, at the crossover.

[The Stationmaster]

Thank you for the extra comments!

 

I did query (see above) if there might be track circuits rather than FPLs by 1960. I forgot to add one or the other at the tunnel mouth when I received an answer. I do wonder if a track circuit would be a better idea for a single line tunnel (as long as it's reasonably watertight), but am not an expert, so can't be sure.

 

Dave55UK - the platform is unimaginably short. See the plan of what this is based on in my first post. The toe of the point is more or less where the disc is. Apologies if I drew the signals out of sequence. My drawing was more to establish what was required, rather than exactly where they should go. I was going to query the exact siting and detailed design of the main signals when I had part-built the model, as clearances and sighting might be an issue. My gut feeling is that the starting signal would be some way beyond the end of the platform in reality.

 

Beast - light locos would generally come from and go off to the left of the diagram. A move out of the loco shed onto the down line and then back over the crossover to the up line would be rare, if it happened at all. That thought makes me wonder if I really need a disk on the down line, at the crossover.

I think a disc would invariably be provided 'just in case' (and in any event would be useful to prove the point in 'unusual' working situations.

 

And yes - as discussed previously - a track circuit is quite possible by 1960 although there were still plenty of locking bars about then.

[phil-b259]

Thank you for the extra comments!

 

I did query (see above) if there might be track circuits rather than FPLs by 1960. I forgot to add one or the other at the tunnel mouth when I received an answer. I do wonder if a track circuit would be a better idea for a single line tunnel (as long as it's reasonably watertight), but am not an expert, so can't be sure.

 

You have confused an FPL with a point locking bar.

 

Facing point locks are still mandatory for facing passenger moves, even today, its just that with point machines (and by that I include hydraulicly as well as motor worked setups) the FPL is included within the machine setup so a separate control (i.e. lever / switch) is not required.

 

What track circuits started replacing was the 'fouling bar' which stopped the points from being moved if a train was traversing them (the wheel flanges prevented the bar from rising and releasing the points to be moved). With the introduction of track circuits this mechanical device could be replaced with an electric lock fitted to the lever in the signal box.