Junction Signalling

[pheaton]

Hi All,

 

One for the signalling experts out there....

 

Suppose the following layout

 

 

My question is....would there typically be GPLs for reversing moves, not signalled by the main aspects?

 

 

with GPLs at the following locations?

 

Thanks in advance

 

Simon

[ikcdab]

It's difficult as I don't think this is a prototypical layout.  Trains approaching from the right on the middle line are being signalled with a full running signal into wrong road running.  So from that point of view,  the signals you have indicated are not right.  If all these lines were bi-directional then it might be different. What are you trying to achieve?

[pheaton]

Hi ikcdab,

 

yes my layout used to be bi directional, but I have converted it to single direction running, so, that's my last of roger murray signals I need to sell :), but regarding the GPLs would they be as placed in the pictures if....the signals were correct?

[Grovenor]

GPLs are OK for position, IF there is any need for such shunt or reversing moves, there is nothing on the plan to suggest that they are required. Planning signalling needs the whole picture.

Rgds

Edited October 30, 2019 by Grovenor

[TheSignalEngineer]

Without knowing what is either end of the area to put the layout of the junction into context and what moves are required it's difficult to say about what GPL signals would be provided.

Separating the two L - R lines in that way doesn't look logical from an operation point of view unless there is a good reason for it off the bit shown.  As ikcdab says the provision of feathers shown is not correct in any instance.

[pheaton]

Hi,

 

the complete layout, the grey area is a station, im interested to see despite the unorthodox layout what the informed opinion is on the most prototypical operation possible with that layout, feel free to suggest line directions, the area immediately below the junction is a depot, the area in the bottom left hand corner is a stabling point

 

Edited October 31, 2019 by pheaton

[The Stationmaster]

I can't see how that track layout would work unless the innermost circuit is made bi-directional and signalled accordingly.  which means =

 

Signal on the outermost loop is ok,  the Position 4 JI (right hand 'feather') will read to the innermost loop

Signal on the middle loop also needs a Position 1 JI (i.e it reads to the left of the principal route) in order to signal trains to the innermost loop.

Signal on the innermost  loop is ok as it has a Position 1 JI to signal a train to the outermost loop.  

An additional signal is needed on the innermost loop approaching the junction from the opposite direction. (where you currently propose a GPL) with a Position 4 JI (right hand feather) to signal trains to the middle loop.

 

I can't really see any need at all for any GPLs as there's no operational needs for any trains to setback through any of the points at that junction - they simply cross to/from the innermost loop to access the innermost loop and bay platforms and sidings near the junction.

 

P.S.     JI = Junction Indcator

[DCB]

It doesn't really work as drawn as all the platforms are on the down line but change it so the middle road is a bi directional through line with up and down mains flanking it and suddenly its a good dad and lad layout, and very good visually with expresses overtaking slower trains.  A bit of a ladder each end to get up trains into the bay and down trains out and thats a fun layout to run for half an hour while the wife cooks dinner and another hour while it gets cold.

 I don't know of anything remotely like it on the full size railway but Rev Awdreys Thomas the Tank Engine books featured this configuration.    Your signal arrangement looks logical,    I don't believe you can  make it prototypical as prototypes don't exist, but it can still look good.