I have been working on this whole plan for over 18 months so far, but I have begun to notice that this particular "railway that could have been" has started to become quite popular of late - see, for example, the latest RM. Where my ideas differ is perhaps that I have taken things further and imagined PD as a terminus junction between the GWR/LNER and LMS - all drawn by the lure of a second route to Dublin. This leads to a boundary terminus ala Bath Green Park but MR/ER/GWR in the period modelled - circa 1960. The imaginary "faction" shenanigans to get that to happen are set forth in this document which also contains ideas about typical train movements at PD.
The track diagram - as far as I have got - is here. I took a late vintage Holyhead, foreshortened it, welded on a soupçon of Bath Green Park, completely altered the MPD and the local goods yard which is more Buckingham GCR... My abject apologies for the myriad mistakes of omission and commission I have made - all of which will certainly revolt you.
- I'm having trouble with call-on signals - which will be needed for the station pilot to grab carriages from Pl1 and move them to Pl2 or Pl3 and for new locos to back down onto trains that are in Pl4. It seems likely that I will want to be able to call those engines out of MPD Out and hold them before they enter the Platforms - so that implies calling on over the Up and Down - which I suppose means a "normal" signal as well above each? In my current plan I have used a ground signal and a ground calling on subsidiary. But I have never seen one of the latter - although I have seen a picture of a ground distant. Do they always need to be post-mounted miniatures instead?
- The detailed trackplan of Holyhead I have is of a late vintage - since it was re-modelled in between about 1970 and 1980. There are a reasonable number of theater/indicators in that plan - but I don't know what is typical for a 1960 period, and when to use a set of miniature arms and when a stack of ground signals instead.
- The necessary compression to get the station into 15' length including a rapidly diverging "branch" has pushed the throat together quite a bit and led to several slips (although nothing as dense as Newcastle!) - but it also means that most signalling will have to be at the edge of the throat, I think. I do hanker after a gantry as marked - but it would mean that for some routes the signal would be over the center of the points or slip it controls - is that ever OK - or would you have to move it either further out (left) or further in (right) or have two gantries (or none)?
- Gantry sighting - the current gantry is maybe 140 scale feet from each of two road bridges. What would the plan be there - co-acting under-slung repeaters, perhaps? What is the standard on when they are required?
- When you have a boundary station - does the signalling type change abruptly as control of the metals changes over? I envisage that at one time there were two signalboxes, one of which controlled the GWR branch (still could be modelled as there, in fact). But even suppose they were rationalized into one - would we see LQ arms on the ex Cambria/GWR as whereas the rest is UQ with perhaps as an odd survivor or two of LQ MR days - like the famous advanced starter for Pl2 at Holyhead ?
Anyway, thanks so much for looking and I welcome any pointers you can give - however radical. The entire folder of stuff including the above am working on is here.
PS You are all welcome to reuse any of the signal parts I have in the Illustrator file inside that folder. If there's interest I can put them into a separate template file.