Help Appreciated - Colour Light Signalling - Am I On The Right Lines?

[scottystitch]

Hi all,

 

I'm wondering if some of you would be able to take a look at the attached AnyRail illustrations and tell me if my proposed signalling thoughts are on the right lines?

 

 

The Layout is based in Glasgow and consists of a terminus station with a twin track mainline descending as through lines to the North of the platforms. The main line looping across the top of the plan is restricted to 40 mph running in both directions. The station approach and the through line will be restricted to 30 mph in both directions.

The platform section should be obvious. To the left in lilac is a carriage shed, in red a DMU fuelling point and in purple further left, in the corner is a diesel fuelling and light-servicing point.

I am suggesting that all semaphores have been ripped out and replaced by coloured light signals, controlled from a power box. Perth had this kind of treatment in the early 60s, so I think that's plausible.

 

 

I have given each platform a starter signal. Should these be three or two aspect? The two lines into and out of the station are not bi-directional. Should the starters have some kind of route indicator on them? I'm guessing not.

At the bottom of the descent into the subterranean tunnel of the through line I have placed a signal. About a quarter mile after entry into the subsurface, there is a junction. Should this signal be two or three aspect?

 

 

I have placed a signal just before the scissors crossing on the arrival line, I am proposing a theatre style route indicator on top. Again what aspect should the signal be. I am assuming two.

I have placed a similar signal on the loop from the carriage/diesel fuelling areas. Should this just be a ground signal?

 

 

On the departure line I have placed a signal to protect the junction and a similar one on the carriage/diesel fueling areas. You'll have guessed by now I don't know how many aspects to use.

I have also placed one on the corresponding through line.

There is another signal on the arrival line, again protecting the junction. This one would need some form of route Identification. What would be more likely, A theatre box or a feather? I'm think theatre box to prepare the driver for the arrival platform as well as indicate the branch for the through line.

 

 

Finally there is departure signal just before the obligatory/cliche'd tunnel. Would that be right or is it too close to the last signal, further back at the junction?

 

 

I am assuming all other turnouts would be protected by ground signals. Would the carriage/fueling areas be power operated points/ground signals or would they use a ground frame?

 

All help and advice would be gratefully received in this regard. It doesn't have to be 100% accurate, but I'd like it to be plausible at least.

 

I hope I have explained things well enough.....

 

Best

Scott

Edited April 19, 2018 by scottystitch

[LNERGE]

Nice looking layout. I'd make all the platform starters three aspect but there will be complications there if you make them read to multiple routes. If they only clear up to the next signal on the main it's simples. Have subs for all other routes etc. It'll be a lot of wiring but worth it..

 

https://www.flickr.com/photos/32297024@N08/39360269832/

[scottystitch]

Nice looking layout. I'd make all the platform starters three aspect but there will be complications there if you make them read to multiple routes. If they only clear up to the next signal on the main it's simples. Have subs for all other routes etc. It'll be a lot of wiring but worth it..

 

https://www.flickr.com/photos/32297024@N08/39360269832/

Thank you very much for the reply. There is only one route out of the stationThree aspect starters it is. They will clear only to the junction signal on the departure line. 

 

What is "subs" please?

[E3109]

A subsidiary signal, basically gives authority to proceed past a red main aspect but at caution as the section may be occupied.

Imagine there is a unit occupying the block section, and you are the driver of another unit that needs to enter the section in order to couple to it.

If there were no sub, then the signalman would have to give the driver verbal authority to pass the danger aspect.

In layman's terms, a GPL mounted on the signal post and associated with that signal.

 

Incidentally there is currently a right kick off at Bristol TM, as apparently the new signalling system does not have subs but instead NR are proposing that trains can enter the section on one yellow even it is occupied.

Aslef have kicked off about this, and rightly so. It's a blatant contravention of Network Rail's own rule book and is asking for trouble.

[scottystitch]

Thanks for that, most informative. Is that like a "calling-on" arm in semaphore.

 

I'm assuming this is one here, below the main signal, at Perth.

 

R0038 66429 DRS Intermodal Perth Station DSC_5721 by ScottyStitch, on Flickr

 

Would these then be used to send a DMU, for instance, from a platform towards the carriage shed loop?

 

EDIT: The layout is N gauge so I am not sure if i am able to get working subsidiary signals/ground signals, but maybe non-working will suffice.

Edited April 21, 2018 by scottystitch

[E3109]

Hiya bud.

I almost included the phrase 'calling on' but I assume the signalling grades may point out a potential inaccuracy.

But in a nutshell yeah, serves the same function.

[scottystitch]

Another one just discernible in this shot. I will need to see whats available in N.

 

Perth, August 1965. by Mike Mather, on Flickr

 

Thanks for the help.

Edited April 21, 2018 by scottystitch

[St. Simon]

Incidentally there is currently a right kick off at Bristol TM, as apparently the new signalling system does not have subs but instead NR are proposing that trains can enter the section on one yellow even it is occupied.

Aslef have kicked off about this, and rightly so. It's a blatant contravention of Network Rail's own rule book and is asking for trouble.

Hi,

 

Sorry, but that’s incorrect, at BTM if a train is sat in the platform between the protecting signal and the mid platform signal, then a position light is displayed. If a train is beyond the mid platform signal, then a single yellow is displayed as the train is not in the route. Which is in accordance with signaling principles.

 

The difference is that there is a very small (or 0m, I’m not entirely sure) Overlap, and there is the potential for a train with a long nose to overhang the joint, that’s what there has been fuss about, but it has been mitigated against.

 

The signalling at Bristol Temple Meads has been through several assessments to ensure that it is safe, which it is.

 

Simon

[St. Simon]

Hiya bud.

I almost included the phrase 'calling on' but I assume the signalling grades may point out a potential inaccuracy.

But in a nutshell yeah, serves the same function.

A ‘Call-On’ route is used to mean a permissive version of a main route, basically.

 

Simon

[E3109]

Hi,

Sorry, but that’s incorrect, at BTM if a train is sat in the platform between the protecting signal and the mid platform signal, then a position light is displayed. If a train is beyond the mid platform signal, then a single yellow is displayed as the train is not in the route. Which is in accordance with signaling principles.

The difference is that there is a very small (or 0m, I’m not entirely sure) Overlap, and there is the potential for a train with a long nose to overhang the joint, that’s what there has been fuss about, but it has been mitigated against.

The signalling at Bristol Temple Meads has been through several assessments to ensure that it is safe, which it is.

Simon

Cheers for that Simon. Just something I was reading in the union notice case the other day, it may be something to do with a proposed resignalling, rather than the current one?

Not been to BTM for years, so I can't really add anything, thanks again.

[St. Simon]

Cheers for that Simon. Just something I was reading in the union notice case the other day, it may be something to do with a proposed resignalling, rather than the current one?

Not been to BTM for years, so I can't really add anything, thanks again.

The whole station has just been resignalled and re-controlled to TVSC (commissioned on Easter Weekend), so I presume that’s what they refered to.

 

Simon

[luckymucklebackit]

That type of calling on signal was used extensively in Scotland for new MAS schemes around 1960, the Glasgow North Electrification scheme in particular, there was one which controlled the approach to the bay platform at Airdrie Station, so it could be used to control passenger workings, go to this link https://www.s-r-s.org.uk/ArchiveSignals/brscot.php and select the date next to Airdrie for the plan

The Signal AD41 is described as follows

 

Main Signal (no indication)-to Signal AD.42.

Main or calling-on Signal with route indication B-to Bay platform. (Main if bay is unoccupied, call on if a unit is already there)

Subsidiary Signal (with no distinguishing letter)-Shunt along

Up line. .

Right-hand miniature yellow-to Carriage sidings.

 

Jim

[The Johnster]

I may be a bit out of my depth here as no doubt things have changed since the 70s when I last worked on the railway, but a single yellow aspect indicates (or indicated) that the section was clear as far as the next stop signal, which is taken to be at red.  It is completely wrong to enable a train's driver to pass a yellow aspect into a section that is occupied; he must first come to a stand at a red aspect and be called on by a subsidiary signal of some sort.  In this way he knows that the section is occupied and proceeds with appropriate caution; IIRC the wording we used was 'at a speed consistent with his being able to stop the train safely in the distance that he could visually verify that the line ahead was clear', or something of the sort.

 

If you think about it in this way, the purpose of railway signalling is to enable a driver to confidently proceed at line or train speed even though he cannot see that line is clear ahead in a distance he cans stop within.  This requires complete confidence in the signalling system and those operating it, and, since the introduction of GWR ATS and the BR AWS system, drivers are able to run at speed with confidence even in thick fog when they cannot actually see the signals (or any obstacle) from any appreciable distance at all.

 

I had a similar dispute with the powers that be when the Swansea MAS scheme was brought into use; the last signal on the down main approaching Swansea High Street was a 2 aspect which could show red or green.  It seemed very wrong to me that a driver should be allowed to approach a red signal, which is what the red light on the stop blocks effectively is, directly after a green aspect and with no yellow.  I was told that traincrew route knowledge made such a precaution un-necessary, and that no driver was likely to mistake this particular location, which is correct and there has never to my knowledge been an issue with this signal, but I still maintain that it is in principle unrailwaylike and contravenes general principles whose value has been proven over a very long time.

[Grovenor]

I had a similar dispute with the powers that be when the Swansea MAS scheme was brought into use;

What date was this?

In the 60s, following on from semaphore practice it was usual to ignore terminus buffers in the aspect sequence and provide for run in on green signals throughout.

Later the rule was changed so that a standard aspect sequence was enforced treating the buffer stop lamp as a RED.

AFAIK it was mandatory to change all the existing installations to the new standard, usually involved changing the colour of the lenses and rewiring the controls.

Example of the early standard here http://www.norgrove.me.uk/signalling/plans/Euston-a.gif

Regards

Edited May 20, 2018 by Grovenor

[E3109]

IIRC, the last main aspect signals in the tunnels approaching Lime St would appear to have been fitted with green aspects at one time, I'm pretty certain they were 3 aspect, which is daft when the next 'signal' (apart from GPLs) is the stop block.

 

Never saw a green displayed there thankfully, but it seems it was permitted at some point in time.

This would fit in with The Johnster and Grovenor's comments.

[beast66606]

IIRC, the last main aspect signals in the tunnels approaching Lime St would appear to have been fitted with green aspects at one time, I'm pretty certain they were 3 aspect, which is daft when the next 'signal' (apart from GPLs) is the stop block.

 

Never saw a green displayed there thankfully, but it seems it was permitted at some point in time.

This would fit in with The Johnster and Grovenor's comments.

 

I often rode the greens to the buffer stops at Lime street, back in my 1970s RailRover days we often used to finish the day via Liverpool LS, a line of greens down the cutting was a welcome sight as the mad dash for Mersey service meant you would actually make the train rather than miss it and have a half hour wait. The signals at Lime Street were changed ca 1977, I think they also removed the home 3 signals at the same time and moved the platform routing back to the home 2s.

 

The green to the buffers was changed to a mandatory yellow after Moorgate and the buffer stop became effectively a fixed red.

[The Johnster]

Swansea area MAS was commissioned 1972 or 3 IIRC, with later stages to include Llanelli and beyond following.  The boundary with the original Port Talbot scheme was Neath, then you were on the semaphores, with the same happening at Dynefor Jc on the District line.

 

I am happy to be corrected by anyone who knows the right date!

[The Stationmaster]

Swansea area MAS was commissioned 1972 or 3 IIRC, with later stages to include Llanelli and beyond following.  The boundary with the original Port Talbot scheme was Neath, then you were on the semaphores, with the same happening at Dynefor Jc on the District line.

 

I am happy to be corrected by anyone who knows the right date!

 

Landore - Swansea High St commissioned October 1973. (and still causing the Shunters some grief when I was i/c there in December that year!).  The fringe 'box for the original Port talbot scheme was Skewen East but that came after a somewhat delayed original boundary at Neath East.