Jump to content
 

Singalling feedback for Bodmin


Recommended Posts

  • RMweb Gold

I've just finished my first draft of the signalling for my Bodmin Central layout, with the drawing attached below. the black circles are normal signals, black with a / is a signal with feather and the red dots are shunt signals. All of the signals are going to be scratch built following Tony Sissions' methodology.

Would appreciate any feedback on what can be improved, and on anything I've missed.

bodminsignalling.jpg

 

Operations wise, it is planned as a 2 track secondary line going into a terminus, and a bidirectional branch line

Link to post
Share on other sites

Hi Rich

A few comments/questions

First the station area

The signal for moves out towards the branch etc would not really have a feather since its the only route

possible, I guess a theatre indicator with B showing would be ok.

Secondly P2? again no feather since there is only one route possible IE the mainline.

Thirdly P3? Sound just have a standard Main aspect signal (think this is showing on the plan?) with a sub

for the neck/siding.

Not sure what the red dot is for in advance of this signal?

 

You need a sub signal to move out of the neck into P3?.

You also need a sub signal after the point work on the outbound line to allow a shunt move from

P2 to P3 or return...

 

Its a pity the branch line cannot join the mainline before the crossover as this would then allow

access to all three platform faces..

 

hope this helps a bit

 

cheers

 

Keith

Link to post
Share on other sites

  • RMweb Gold

 

Secondly P2? again no feather since there is only one route possible IE the mainline.

 

 

Its a pity the branch line cannot join the mainline before the crossover as this would then allow

access to all three platform faces..

 

 

cheers

 

Keith

 

 

The idea with the feather there was trying to work out a possible way to get out of P2 to get to the branch or change platforms. would this be done with a sub signal instead?

 

Unfortunately due to the prototype's civil Engineering it all rather limited on moving track about with the branch, as I have been trying to keep the plan similar enough to the real thing that it is recognisable as being Bodmin...

Link to post
Share on other sites

Hi Rich

I cannot see any way of a train departing P2 for the branch without some shunting via P1 first.

You could have a sub for shunts onto the mainline behind the main signal, don't forget the limit of shunt board

if space!

 

hope this helps

 

cheers

Keith

Link to post
Share on other sites

  • RMweb Gold

I'm happy to draw a signalling plan for you Rich, just say the word.

The prototype is single line, yours is double though ?

 

Miss P - I think one of your "applies to" arrows is pointing to the wrong road, the one to the right of the word "handlever" would apply to the nearer platform road I think.

Link to post
Share on other sites

Miss P - I think one of your "applies to" arrows is pointing to the wrong road, the one to the right of the word "handlever" would apply to the nearer platform road I think.

There was, and is, only one platform. The signal you refer to is the platform starter (number 1 in the frame, released by the shed crossover in normal and its FPL). It was sited on the other side of the loop, as were the junction starter (2 for the main, 5 for the branch) and the advanced starter on the main (3), for sighting reasons. Hence I drew those in the way I did. The loop and yard had only one starter, the ground disc 17.

Link to post
Share on other sites

  • RMweb Gold

There was, and is, only one platform. The signal you refer to is the platform starter (number 1 in the frame, released by the shed crossover in normal and its FPL). It was sited on the other side of the loop, as were the junction starter (2 for the main, 5 for the branch) and the advanced starter on the main (3), for sighting reasons. The loop and yard had only one starter, the ground disc 17.

 

Typical Western, adding extra signals to simplify the locking - was there a big distance (in the layout not the frame!) between #1 and #2/5 ?

 

PS - It's normal to show platforms on signalling plans

Link to post
Share on other sites

  • RMweb Gold

I'm happy to draw a signalling plan for you Rich, just say the word.

The prototype is single line, yours is double though ?

 

 

Thanks, that would be much appreciated.

 

With the line doubling, it started off as just a longer headshunt which passed beyond the bridge, but after looking at the plan again I couldnt help start thinking that given the assumptions I had based the changed to the prototype on, it would probably be better off with double tracks given the increased level of traffic. Of course if this completely messes up the realism of the rest of the track layout (butting points in the wrong place etc) I will have to rethink things...

Link to post
Share on other sites

Typical Western, adding extra signals to simplify the locking - was there a big distance (in the layout not the frame!) between #1 and #2/5 ?

LOL Dave! A fair point though, and Bodmin is a bit peculiar I suppose in that there wasn't that much distance between #1 and #2/5, but there was a reason, namely that a passenger train could be sitting at the platform, and protected by #1, and a short goods (a clay set) could be sitting in front of the passenger waiting for departure (#5) down the branch. Quite a common situation, hence the provision and distinction in the signals.

 

PS - It's normal to show platforms on signalling plans

Yes, my mistake, and I should also give all the numbers if I could remember them all! In the meantime:

 

bodminbox.gif

Link to post
Share on other sites

  • RMweb Gold

Typical Western, adding extra signals to simplify the locking - was there a big distance (in the layout not the frame!) between #1 and #2/5 ?

 

PS - It's normal to show platforms on signalling plans

 

The sketch is a bit misleading as signal No.1 was actually opposite the ground disc which reads to the loco shed and therefore on the station platform side of the signalbox as the point toe was immediately in front of the 'box. Quite why the signal was put on that side is difficult to explain but I surmise it would have had to be further from the points if it had been on the platform side due to the signalbox steps and that would have meant a locking bar that side of the points which would possibly cause difficulties for loco moves etc - so the signal went where it was easiest to put it without going to the expense of a bracket or adding to operating inconvenience. Track circuiting to lock facing points was a pretty rare commodity on the GWR in 1916 and very unlikely at a place such as Bodmin.

 

That also explains the position of the bracket signal 2/3 - clearly an early structure as it was a balanced bracket in its days with timber post and dolls. Again opposite the points to minimise a locking bar getting in the way of any moves made in rear of the signal prior to reversing or perhaps of a longer train arriving to reverse.

 

BTW to answer your question the distance between the two signals was about 3.5 coach lengths (of the 57ft variety) plus a 2-6-2 tank loco so typically GW of its time when track circuiting was none too widespread for point locking purposes and was in any case somewhat distrusted on the GWR.

 

The layout was latterly worked from a 3 bat VT frame installed in 1916 but judging by photos some of the signals (eg 2/3) predated that and I suspect that in some respects the signalling also reflected the constraints of stud locking.

Link to post
Share on other sites

  • RMweb Gold

Gissa break, guys - it was only a sketch. But you're right, Mike, so here's:

 

bodminbox.gif

 

No offence meant Miss P - but for peeps like me who know a bit (allegedly) about signalling it gets very confusing when I don't know the prototype and I'm trying to interpret diagrams :blink: :)

Link to post
Share on other sites

No offence meant Miss P - but for peeps like me who know a bit (allegedly) about signalling it gets very confusing when I don't know the prototype and I'm trying to interpret diagrams blink.gif smile.gif

No offence taken at all, and that's a fair point. Incidentally, concerning the placing of #1 and #2/5, the other reason for placing them on the 'other side' of the loop was because of the rodding run situated between the main and the loop.

 

Not quite sure how any of this relates to the OP though...

Link to post
Share on other sites

  • RMweb Gold

No offence taken at all, and that's a fair point. Incidentally, concerning the placing of #1 and #2/5, the primary reason for placing them on the 'other side' of the loop was because of the rodding run situated between the main and the loop.

 

The reason the semaphore signal wasn't placed there was because there was insufficient clearance for a full height signal structure even if it had a centre pivot arm. The rodding run was in any case clear (ie towards the overbridge)of the detector for the disc signal so wouldn't have been in the way of a signal post and in fact the drive to the detector for the running arm was straight as far as can be seen on photos (and also clear of the rodding run).

 

But - as you say - not quite relevant to the layout with c.l. signals of course :)

Link to post
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...