Signalling on a single track branch

[Loxborough]

Guys,

 

I feel that this is a very noddy question but I have looked at the references that I have to hand and can't find the answer...

 

I am modelling a set of sidings off a single track branch (ex GER, date 1947), as shown below;

 

 

If the branch was run on a token system (single engine in steam) then we could presumably do away with signalling requirements. I would, however, like to posit stations (or oter doubled sections) on the branch which allow locos to pass. This would imply that I could have one loco shunting the sidings while another sails past (in either direction). Is this conceivable? If so there are three supplementary questions;

 

1. What would the signals look like on the running line (top of the trackplan)?

2. How (and from where) would the points (off the running line and the associated headshunt/trap) be worked?

3. Woud this justify/necessaiate a signal box to control the turnout (and/or a section break).

 

Told you it was a noddy question,

 

Would really appreciate any suggestions,

 

George

[The Stationmaster]

Most likely that the connection would be worked by a ground frame - only two levers, out in the open - with a small hut nearby to contain an intermediate token machine. That arrangement would easily allow a train to be 'shut-in' the sidings for other trains to pass.

 

The provision of fixed signals (i.e. what you would recognise as 'Home Signals' or stop signals) is quite unlikely. However you could probably justify a small 'break section' signalbox if it took your fanmcy although I don't know if ex GE single lines would have been into that sort of thing (possibly a wartime addition when the line got very busy serving airbases?).

[PaulRhB]

First it's a perfectly good question, Mikes answer is perfect for your idea just to add any other points within the sidings will be handpoints.

[Loxborough]

Frankly stunned at the near real time response, thanks guys.

 

Mike's answer is pretty much what I was hoping to hear; I am not a fan of cluttered models and I was thus hoping to avoid signals, a box etc.

 

Just one supplementary question; Mike talks about two levers; would the turnout on the running line not have had a facing point lock, and thus a third lever?

 

George

[beast66606]

Frankly stunned at the near real time response, thanks guys.

 

Mike's answer is pretty much what I was hoping to hear; I am not a fan of cluttered models and I was thus hoping to avoid signals, a box etc.

 

Just one supplementary question; Mike talks about two levers; would the turnout on the running line not have had a facing point lock, and thus a third lever?

 

George

 

No

 

Shut inside facilites weren't always provided so you could also dispense with the hut but remember, that if you do, any train which shunts the yard must continue on its way before any other movement (excepting emergency moves such as recovering a failed engine) can happen (if you want prototype fidelity)

 

Sorry - a bit slow in this response

[PaulRhB]

I would, however, like to posit stations (or oter doubled sections) on the branch which allow locos to pass. This would imply that I could have one loco shunting the sidings while another sails past (in either direction).

 

This part of the original post though means the token hut will be needed, which will help add more movement as the plan doesn't include the other stations.

[beast66606]

This part of the original post though means the token hut will be needed, which will help add more movement as the plan doesn't include the other stations.

 

I know - but its not very likely for a tiny yard to have shut inside facilities - but not my model.

[The Stationmaster]

Frankly stunned at the near real time response, thanks guys.

 

Mike's answer is pretty much what I was hoping to hear; I am not a fan of cluttered models and I was thus hoping to avoid signals, a box etc.

 

Just one supplementary question; Mike talks about two levers; would the turnout on the running line not have had a facing point lock, and thus a third lever?

 

George

 

Two levers George - one works the facing point lock and is painted blue or maybe blue above brown (depends on local painting convention, the addition of brown in this case signifies that it is also the release lever). The second lever, painted black, works the two point ends - i.e the one in the running line and the one which effectively makes the other end of what you can regard as a crossover although that end might only be a trap point).

[beast66606]

Two levers George - one works the facing point lock and is painted blue or maybe blue above brown (depends on local painting convention, the addition of brown in this case signifies that it is also the release lever). The second lever, painted black, works the two point ends - i.e the one in the running line and the one which effectively makes the other end of what you can regard as a crossover although that end might only be a trap point).

 

Doh - yes - sorry for confusion I was thinking of an electric release and not a key, been a bad day at work

[signalmaintainer]

This topic certainly has my attention. I've searched the Web several times, including the Home Signal site, trying to learn more about staff & token operation. Garnered some nuggets, but I'm still not conversant with the topic. And then I read above of intermediate token machines! So now I'm really perplexed.

 

I think I'd really like to model this type of operation on my layout. It is a light railway after all, and has two industrial spurs off the main track. S&T operation/one engine in steam seems more appropriate for the genre rather than a forest of home and distant signals. I could concetrate the block signals for entry into and egress from the BLT station.

 

Some questions:

 

Anyone know of any photos of intermediate token machines?

 

Would they be under the control of and in communcation with a signal box?

 

Would the trackside pole line supply power and communication functions to the intermediates?

 

Thanks for any insights you can offer.

[The Stationmaster]

This topic certainly has my attention. I've searched the Web several times, including the Home Signal site, trying to learn more about staff & token operation. Garnered some nuggets, but I'm still not conversant with the topic. And then I read above of intermediate token machines! So now I'm really perplexed.

 

I think I'd really like to model this type of operation on my layout. It is a light railway after all, and has two industrial spurs off the main track. S&T operation/one engine in steam seems more appropriate for the genre rather than a forest of home and distant signals. I could concetrate the block signals for entry into and egress from the BLT station.

 

Some questions:

 

Anyone know of any photos of intermediate token machines?

 

Would they be under the control of and in communcation with a signal box?

 

Would the trackside pole line supply power and communication functions to the intermediates?

 

Thanks for any insights you can offer.

 

Paul,

 

An intermediate token instrument can look exactly the same as any other token instrument - the term 'intermediate' basically explains its role rather than defining it as some sort of separate design (n.b. there are variations but there needn't be, particularly with 'modern' machines).

 

By the very nature of what they do intermediate machines are part of the circuit as placing a token into one of them, or withdrawing a token from one, must have exactly the same effect on the circuit as carrying out that action at one of the signalboxes (or whatever) at an end of the token section. Auxiliary token machines work in exactly the same way and all they serve to do is provide an additional machine for some reason at the end of a token section (see below).

 

Effectively intermediates are under the control of the signalboxes on the token circuit as a token can only be withdrawn when a release is given by a Signalman at one of those 'boxes.

 

The pole route (a rare thing in Britain now) is the comms link, power would come from either batteries or possibly - in more recent installations, local mains supply but from what I understand the power needs of an intermediate machine are very low. Also relatively uncommon in Britain for lineside pole routes to be used for power transmission although it sometimes happened over short distances - the normal method was battery supply at the point of power consumption. However running signalling power supplies through cabled routes is common.

 

Example of a modern arrangement - the token circuit is Evesham (signalbox) - Moreton-In-Marsh(signalbox) with an intermediate connection off the single line at Honeybourne. At Evesham the signalbox is situated well beyond the end of the single line section and station so auxiliary machines are provided on the station platforms to save time when trains pass there. An intermediate machine is provided at Honeybourne where there is a ground frame giving access to sidings and an occasionally used line to Long Marston (if it's still there) - That machine allows trains going off the main line to give up the token and this clear the main through route for another train.

 

Alas all my pics of token machines (which might include Honeybourne?) are b&w and at present I still haven't got a scanner working. But I hope the above helps.

Hope this helps

[Merfyn Jones]

Paul,

 

An intermediate token instrument can look exactly the same as any other token instrument - the term 'intermediate' basically explains its role rather than defining it as some sort of separate design (n.b. there are variations but there needn't be, particularly with 'modern' machines).

 

By the very nature of what they do intermediate machines are part of the circuit as placing a token into one of them, or withdrawing a token from one, must have exactly the same effect on the circuit as carrying out that action at one of the signalboxes (or whatever) at an end of the token section. Auxiliary token machines work in exactly the same way and all they serve to do is provide an additional machine for some reason at the end of a token section (see below).

 

Effectively intermediates are under the control of the signalboxes on the token circuit as a token can only be withdrawn when a release is given by a Signalman at one of those 'boxes.

 

The pole route (a rare thing in Britain now) is the comms link, power would come from either batteries or possibly - in more recent installations, local mains supply but from what I understand the power needs of an intermediate machine are very low. Also relatively uncommon in Britain for lineside pole routes to be used for power transmission although it sometimes happened over short distances - the normal method was battery supply at the point of power consumption. However running signalling power supplies through cabled routes is common.

 

Example of a modern arrangement - the token circuit is Evesham (signalbox) - Moreton-In-Marsh(signalbox) with an intermediate connection off the single line at Honeybourne. At Evesham the signalbox is situated well beyond the end of the single line section and station so auxiliary machines are provided on the station platforms to save time when trains pass there. An intermediate machine is provided at Honeybourne where there is a ground frame giving access to sidings and an occasionally used line to Long Marston (if it's still there) - That machine allows trains going off the main line to give up the token and this clear the main through route for another train.

 

Alas all my pics of token machines (which might include Honeybourne?) are b&w and at present I still haven't got a scanner working. But I hope the above helps.

Hope this helps

 

A picture may help of one of the simple arrangments as described above.

Blaenau Ffestiniog goods yard was originaly accessed from a signal box. When the box closed it was replaced by 3 ground frames, all unlocked by the token (only one at a time) The token machine was then in the station building. When the new station was built about a quarter mile away, the token section being extended, an intermediate token machine was provided at the No.1 ground frame.

The location left, contained the machine along with dry cell batteries. The release was given by the signalman at Llanrwst. The ground frame lever (1) has a lock in which the token is inserted enabling the FPL to be withdrawn followed by lever (2 - right) enabling the points and trap to be reversed to enter the goods yard. The token cannot be removed from the frame unless the points are returned to normal and the FPL inserted. This can be done with a train safely in the yard, enabling the token to be replaced in the machine and one issued to another train from Llanrwst.

Merfyn.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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[signalmaintainer]

Mike and Merfyn, thanks for your replies. Another layer of the onion peeled away as I learn more about British signaling practices!

[LNERGE]

The arrangement with a lock operated by the section key token and an intermediate instrument is fairly simple. This report is worth a read..

 

http://www.raib.gov.uk/cms_resources.cfm?file=/080611_R132008_Aylesbury.pdf

 

and it has some pictures too.

[signalmaintainer]

The arrangement with a lock operated by the section key token and an intermediate instrument is fairly simple. This report is worth a read..

 

http://www.raib.gov....8_Aylesbury.pdf

 

and it has some pictures too.

 

Superb source of information. Thank you!

[Loxborough]

So, maybe it wasn't such a noddy question after all...

 

Thanks very much all for the tremendous response; all I need to do now is to get on and build the hut (which I'm quite looking forward to) and source a groundframe.

 

Watch my challenge topic for results (though don't hold your breath!)

 

George