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Proper Placement of Signals, AWS Ramps and Junction Boxes?


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I'm after some advice on the above subject, I have no idea how to prototypically place the items mentioned - obviously the signal posts will be at the ends of the platforms, and if I remember correctly AWS ramps are positioned on the approach to further signal posts(?)

I've attached a picture of my layout, a plan view would probably have been better...

It's a terminus, with four platforms and five lines (one is a holding area) and there are four sidings opposite the station.

  I'm confused about the signal posts positioning above all, any help would be gratefully received!IMG_20210130_185458886.jpg.c08ecbf2a68f6878803df8fac600b06b.jpg

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6 minutes ago, Grovenor said:

Can you provide a track diagram that signals could be added to, and specify the period you are interested in?

Thank you - I'll try and do a diagram in a bit, it's late seventies / early eighties suburban Southern Region.  Hope that's ok for now.

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Quite a remarkable track layout! However one simple thing that you have wrong is the platform numbering. The Southern had a standard practice for numbering platformat terminal stations and that was that, looking from the concourse (or buffer stops if you like), platform 1 was always at the extreme left hand, the other platform numbers following in sequence. The principle was even followed at stations like London Bridge and Portsmouth & Southsea which had a mix of terminal and through platforms, and the Southern Railway renumbered the platforms at stations which hadn't previously conformed to the principle in the pre-grouping era.

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Hi,

 

Could I recommend a good book as a first port of call (sorry, thought I'd get a quick plug in) ;);)

 

https://www.crowood.com/details.asp?isbn=9781785006258

 

I can do a proper sketch tomorrow if you want, but there are a few key points:

 

  • The Platforms would have 2 or 3 aspect (depending on the required headway on the prototype, but could be either on the model, it doesn't make a difference really) signals at the end of the platform. There is no need for an route indications.
  • The Platform 3 (assuming platform 3 is at the 'top' of the sketch) would also have a position light for moves into the Scrap Yard sidings.
  • The Holding Siding would probably have an independent position light (aka shunt signals) controlling exit from them. They could also have the same set up as Platform 3, but that's an operations decision.
  •  The scrap yard sidings would have independent position lights controlling exit from them (they don't need route indications) positioned to the left of the entry / exit points). The top two scrap yard sidings could have a single signal to the right of the points between them.
  • The single lines would have each have a red / yellow 2-aspect signal with a standard route indicator for moves into the platforms. The one for the bottom single line would also have a position light for moves into the holding sidings.
  • AWS magnets (NOT ramps, sorry it's a bugbear of mine! :)) are only required for the platform approach signals on the single lines, these are in theory a scale 180m on approach to the signals. AWS Magnets are not provided for signals on terminal lines or for shunt signals.

 

Simon

Edited by St. Simon
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1 hour ago, woodyfox said:

AWS ramp 200m in advance of the signal. Relay boxes near the signal in the cess. Usually where most convenient. 

Cheers

 

Hi,

 

AWS Magnets started off at 200 yards on approach to a signal, which was then reduced to 183m and now the standard is 180m.

 

The position and number of Location Case (NOT relay boxes, again one of my bugbears!) is based on a having a suitable location to site them and how much equipment they house / interface with (which is not just relays, but power supplies, fuses, disconnection links, TFM modules, telephone equipment etc etc.).unted in the 10 foot or on the platforms, with the orientation such that the doors open parallel to the track (i.e., a technician looking into case would be facing along the track).

 

There's no real rules I can give on the design of Location Cases, every installation is unique.

 

Simon

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24 minutes ago, St. Simon said:

Hi,

 

Could I recommend a good book as a first port of call (sorry, thought I'd get a quick plug in) ;);)

 

https://www.crowood.com/details.asp?isbn=9781785006258

 

I can do a proper sketch tomorrow if you want, but there are a few key points:

 

  • The Platforms would have 2 or 3 aspect (depending on the required headway on the prototype, but could be either on the model, it doesn't make a difference really) signals at the end of the platform. There is no need for an route indications.
  • The Platform 3 (assuming platform 3 is at the 'top' of the sketch) would also have a position light for moves into the Scrap Yard sidings.
  • The Holding Siding would probably have an independent position light (aka shunt signals) controlling exit from them. They could also have the same set up as Platform 3, but that's an operations decision.
  •  The scrap yard sidings would have independent position lights controlling exit from them (they don't need route indications) positioned to the left of the entry / exit points). The top two scrap yard sidings could have a single signal to the right of the points between them.
  • The single lines would have each have a red / yellow 2-aspect signal with a standard route indicator for moves into the platforms. The one for the bottom single line would also have a position light for moves into the holding sidings.
  • AWS magnets (NOT ramps, sorry it's a bug bear of mine! :)) are only required for the platform approach signals on the single lines, these are in theory a scale 180m on approach to the signals. AWS Magnets are not provided for signals on terminal lines or for shunt signals.

 

Simon

Thanks very much, that's really informative!  A sketch would go a long way to help me, if you are sure you don't mind? 

In my box of scraps I have four double aspect signal posts, looks like I won't need the AWS magnets (they're only left over from another build.) 

Cheers.

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40 minutes ago, iands said:

Not sure you've got room for any AWS magnets. Is the station intended to be served by what appear to be two single lines? 

Yes, that's the plan with the available space I have.  I'm still undecided as to whether the lines merge "out of sight" or are a convergence from different places...

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14 hours ago, Ray Von said:

Yes, that's the plan with the available space I have.  I'm still undecided as to whether the lines merge "out of sight" or are a convergence from different places...

Depending on where it was on the Southern in the 1970s/80s there might not be any AWS magnets.  Don't forget that colour light signalling installations could have a comparatively long life so the signalling at a place in the 1980s might well have been installed in the 1950s to the standards of the time when they were installed - I was talking photos of SR colour light signal details in the early 1990s of signal installed 30 years earlier.  

 

Therefore the part of the Region on which the layout is situated and when it was resignalled make a considerable difference to what signalling there would be as SR colour light signalling practice detail changed during the 1960s.  What I would suggest is looking here for your area of the SR and at notices from the late 1950s/early '60s onwards right up to the 1980s.  Non members can't download all of them but you will find some that you can download to give you some ideas.  

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16 hours ago, woodyfox said:

AWS ramp 200m in advance of the signal. Relay boxes near the signal in the cess. Usually where most convenient. 

Cheers

No, AWS ramps should be in rear of the signal to which they apply - not much use if you get to the signal before the ramp ! :-)

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20 minutes ago, RailWest said:

No, AWS ramps should be in rear of the signal to which they apply - not much use if you get to the signal before the ramp ! :-)

'In advance of' means before or prior to in time or space..... Or in this case the applicable signal. 

 

 

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1 hour ago, The Stationmaster said:

Depending on where it was on the Southern in the 1970s/80s there might not be any AWS magnets.  Don't forget that colour light signalling installations could have a comparatively long life so the signalling at a place in the 1980s might well have been installed in the 1950s to the standards of the time when they were installed - I was talking photos of SR colour light signal details in the early 1990s of signal installed 30 years earlier.  

 

Once the Southern Region was eventually persuaded to introduce AWS (it dragged its heels because of the considerable extent of double-yellow running on the Region), the magnets spread like wildfire. I can't actually remember now whether the 1930s Brighton line c/l signals got them or whether it was decided to defer until the ~1984 resignalling (I suspect not), but otherwise, by the late 1970s, if a line had c/l signals it had magnets. Furthermore, few Southern suburban termini received c/l signals before the mid-1970s, Bromley North in late 1961 may well have been the first (and an interesting semi-automatic installation at that) but after that little happened before the "big box" schemes and they had magnets from the start.

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2 hours ago, woodyfox said:

'In advance of' means before or prior to in time or space..... Or in this case the applicable signal. 

 

Hi,

 

In signalling terms, 'in advance' is beyond the signal, not on approach:

 

433061133_AdvanceRear.JPG.5b4b34c078b2192f5d17a9b167eb16bb.JPG

 

Simon

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I'm sure Simon will give the 'official' response when he next sees this but in the interim (and from a Track engineer so some of the terminology might not be 100%)

 

Red Circles - AWS magnets. The letter P means (I think) they are suppresed so the extra long variety

Blue circles - standard 2 aspect (Red/Green) colour light signal

Green circles - ground shunt signal

Yellow circle - 2 aspect (Red/Yellow) signal with route indicator box

Orange circle - 2 aspect (red/yellow) signal with route indicator box and call on aspect

Purple circle - 2 aspect (red/green) with call on aspect.

 

Cheers

Jeff.

 

Screenshot 2021-02-01 153144.png

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3 hours ago, woodyfox said:

'In advance of' means before or prior to in time or space..... Or in this case the applicable signal. 

 

 

Afraid RailWest is correct (and subsequently St. Simon). I've always understood this way for my 46 year railway career. However, it was noticed by Railtrack (of all people) that not everyone could grasp this concept, so they produced a diagram in the WON to explain to all.

In Rear of or In Advance of_original.pdf

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1 hour ago, jeff mcghie said:

Red Circles - AWS magnets. The letter P means (I think) they are suppresed so the extra long variety

P means Permanent Magnet Only. The arrow on a bi-directional line denotes that it has a suppressed Permanent Magnet,  the direction in which the magnet acts on the receiver is denoted by the direction of the arrow.

It is worth remembering that if the magnet is 200 yards from the signal that is almost 8 feet at 4mm scale.

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6 minutes ago, TheSignalEngineer said:

Regarding the track layout I notice that you haven't got trap points in any of the sidings to protect passenger trains in and out of platform 3. These are a requirement for sidings connected to passenger lines.


You could argue that the double slip (with suitable restoration controls) can act as the trap point.


Simon

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1 hour ago, jeff mcghie said:

I'm sure Simon will give the 'official' response when he next sees this but in the interim (and from a Track engineer so some of the terminology might not be 100%)

 

Red Circles - AWS magnets. The letter P means (I think) they are suppresed so the extra long variety

Blue circles - standard 2 aspect (Red/Green) colour light signal

Green circles - ground shunt signal

Yellow circle - 2 aspect (Red/Yellow) signal with route indicator box

Orange circle - 2 aspect (red/yellow) signal with route indicator box and call on aspect

Purple circle - 2 aspect (red/green) with call on aspect.

 

Cheers

Jeff.

 

Screenshot 2021-02-01 153144.png

Thank you, that's very useful - I'm learning a lot.  Are the signal posts (with indicator boxes) readily available in N gauge, or is it a case of altering existing examples? 

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