A simple signalling question.

[dclift]

Some time ago Mark Davey very kindly provided me with a signalling diagram for Chipping Sodbury on the GWR and on which I am (very) loosely basing my layout, though building and wiring the slip ladder is proving to be an ‘interesting’ exercise. I have a query regarding disc 34 as shown on the diagram. Am I correct in assuming that this disc would have been interlocked with crossover 35 and when off would permit a locomotive to exit the dock and enter the crossover, but, when on, a locomotive would still be permitted to proceed onto the No 1 up siding? This seems to me to be a little odd because if the crossover is reversed (and signal 6 thus locked on) there is nothing to prevent the locomotive being driven over it onto the up platform road irrespective of the setting of the disc. Or, would disc 34 have been mechanically connected to the turnout tie bar simply to provide an indication of the setting of the crossover?

If this is the case, presumably something similar would apply to disc 33 and turnout 32, though the interlocking would have been more complicated because of the slip ladder. Likewise, could I assume that all of the other discs shown here might be similarly connected mechanically to the corresponding turnout tie bars?

Disc 34.JPG

I hope that I have made myself clear.

As an afterthought, I should say that I have so far built all of the track shown here and wiring is in progress, but the thought of building all of the signals is very daunting.

Edited to correct the number of the disc adjacent to turnout 32 and two spelling mistakes..

[Hardwicke]

I can see a disc 33 next to point 32 but 37 seems to be a MFB (Mechanical Fouling Bar) on the Down Main.

[dclift]

Sorry, that should have been disc 33 and turnout 32. I tried to edit the post as soon as I had sent it but failed! I also tried to move it to a more appropriate place in the forum but failed on that as well. I am sure that one of the moderators will be able to help.

Original post now corrected.

[Alastairr]

Hi David,

The Signalling Record Society archives can help with these sorts of queries. See: https://www.s-r-s.org.uk/html/gwb/S601.htm

A combination of the lever leads, locking table and signal box diagram should be able to answer all your questions.

The locking table there shows that disc 34 is released by 35 and 40. So I would say it requires 35 points reverse and 40 fpl reversed, so reads through the crossover to the up platform line. It could have been a yellow disc so read straight onto the siding when in the on position. Similarly Disc 33 reads across the ladder to the down lines and as it locks 26 both ways it would read either to the down main or down platform. It could also have been a yellow disc to read into the dock when on. A colour copy of the signal box diagram would confirm the colour of the discs for sure.

Hope that helps.

Thanks,
Alastair

[dclift]

Thank you Alastair. That all makes sense to me. I shall contact the SRS archives tomorrow; it is nearly 11 p.m. here.

Cheers,

David.

[Tim V]

Hi David,

The locking table there shows that disc 34 is released by 35 and 40. So I would say it requires 35 points reverse and 40 fpl reversed, so reads through the crossover to the up platform line. It could have been a yellow disc so read straight onto the siding when in the on position. Similarly Disc 33 reads across the ladder to the down lines and as it locks 26 both ways it would read either to the down main or down platform. It could also have been a yellow disc to read into the dock when on. A colour copy of the signal box diagram would confirm the colour of the discs for sure.

Hope that helps.

Thanks,
Alastair

Yellow disc is not GW practice (some other funny railway). It would have had a white light in the on position, so could be passed along the siding. Do you have access to a copy of the 1936 General Appendix?

[dclift]

Thanks Tim. Alas, I don't have, or have access to the General Appendix.

[Noel]

Or, would disc 34 have been mechanically connected to the turnout tie bar simply to provide an indication of the setting of the crossover?
If this is the case, presumably something similar would apply to disc 33 and turnout 32, though the interlocking would have been more complicated because of the slip ladder. Likewise, could I assume that all of the other discs shown here might be similarly connected mechanically to the corresponding turnout tie bars?

The station was built in 1903, so the answer is 'no' in all cases. Point indicators were not normal practice by then; independent discs were used [and expected by the BoT Inspectors], so point detection but no direct link.

[Tim V]

This from the 1960 Regional Appendix, the 1936 appendix was the same , my copy not in colour!

img 4597.jpg

[dclift]

Thank you Tim, that is very helpful.

Thanks also to everyone else who provided helpful advice both here and privately. I am gradually absorbing it. Now I need to get on with finishing track and wiring and then producing the necessary signals, of which there are a great number. I will also need some motive power. So much to do, so little time.

[stephenfreeman]

Knowing which signal and positioning it correctly is one thing actually building it is another aspect altogether. For prototype matters GWR I have always found Mike Romans very helpful, you can find him on RMWeb where is known as "The Stationmaster".

Building GWR ground signals has a few traps especially if you want them illuminated as the commercial castings don't have the location of the bearing hole in quite the right place. They have it central whereas it should be off centre, if you don't adjust it, the aspects will not line up with the lamp correctly. Modelu make some very nice lamps by the way.

[dclift]

Knowing which signal and positioning it correctly is one thing actually building it is another aspect altogether. For prototype matters GWR I have always found Mike Romans very helpful, you can find him on RMWeb where is known as "The Stationmaster".

Thanks Stephen. I searched for “The Stationmaster” on RMWeb but was somewhat daunted by the 1059 pages that the search returned. I shall search further when I have more time.

Building GWR ground signals has a few traps especially if you want them illuminated as the commercial castings don't have the location of the bearing hole in quite the right place. They have it central whereas it should be off centre, if you don't adjust it, the aspects will not line up with the lamp correctly. Modelu make some very nice lamps by the way.

I see that Wizard Models offer GWR 1890 ground signals but for which there is not, as yet a picture on their website. Although it is a very long way away from here, both in time and distance, I plan to be at Scaleforum next year where I hope to have a look at them and make some purchases, though I know that Andrew Hartshorne no longer attends exhibitions, so, hopefully, someone else will have them on display. Thanks also for the tip on Modelu lamps which I expect that I shall actually be able to see at Scaleforum.

I am currently contemplating the range of Dapol signals which, by all accounts are excellent, but I have a slight problem with them. This is that the few semaphore signals that I already have, mostly made from MSE components, are operated by solenoids and I have already installed the wiring to do this for the entire station area of my layout (which is still under construction). The Dapol signals have electronics that require an instantaneous pulse from a pushbutton which is incompatible with the on-off ex-GPO switches that I have already installed and wired to interlock the signals with their relevant turnouts and track feeds. So far I haven't come up with a solution, but it will be quite some time before I am up to the point of installing signals. I am sure that there must be an electronic work around, but I don't know of one. Maybe I should consult MERG of which I am also a member, but I find most of what comes from that source to be pretty incomprehensible.

[stephenfreeman]

I know the type but not seen the Wizard ones, as far as I understood he only did the two circular ones, the 1890 one must be new to wizard possibly ex D&S.

To be honest I'd stick with the MSE ones, upgraded as you see fit. I don't think you would otherwise be satisfied.

[martin goodall]

Just to clarify on the question of GWR ground signals, I photographed and measured a preserved example of the (c.1890) semi-circular faced type at Williton, and my drawing was published in MRJ No.12, and also in Pannier No.11 (the journal of the GWSG). This drawing was later reproduced in GWR Branch Line Modelling Part 2 (WSP), and in GWR Signalling Practice (GWSG).

I sent a copy of my drawing to Dan Pinnock, and (at my suggestion) he used it to make the master for his D&S kit of this type of ground signal. The masters for that kit later passed to MSE/Wizard, although I am not sure whether they have it in current production.

[dclift]

Thank you Stephen and Martin. I have dug out MRJ 12 and read the article. I will make a copy and file it with the signal parts that I have already accumulated. I see that the Wizard Models website shows “GS006/2: GWR 1890 arm or disc ground signals”, though no photograph as yet, but it will be a while before I need them. Purchasing Dapol signals seems like the easiest way for the others that I will need, and yesterday, while retrieving more ex-GPO switches from a telephone switchboard that I acquired several decades ago, I had a brainwave, or more accurately a neurone ripple, as to how I can modify them by making a simple connection between two of their twenty four terminals to make those I need operate as passing contact switches while still preserving the terminals needed for interlocking and track feeds. Two minutes with the soldering iron proved that it actually works. The switches in question are toggle switches but have a central position as well as on and off positions.

Happy New Year to all on the Forum and thanks for many hours of interesting reading.

[Hardwicke]

Thank you Stephen and Martin. I have dug out MRJ 12 and read the article. I will make a copy and file it with the signal parts that I have already accumulated. I see that the Wizard Models website shows “GS006/2: GWR 1890 arm or disc ground signals”, though no photograph as yet,

Happy New Year to all on the Forum and thanks for many hours of interesting reading.

If you have an old MSE booklet I think there's a drawing in there.

[Hardwicke]

The book I've got only show GS0006 not GS0006/2

IMG20240102231100.jpg

IMG20240102231109.jpg

[Hardwicke]

http://www.gwr.org.uk/no-groundsigs.html
Photos on here and a mention of MRJ 12

[Tim V]

http://www.gwr.org.uk/no-groundsigs.html
Photos on here and a mention of MRJ 12

I'd forgotten that - mostly my pictures!

As for the MSE kit, as far as I remember (it's been years since I bought one), the casting was for the tall signal, but the disc was only 12". I had to make my own disc by punching out for some shim.

I think Dart castings used to make the short signal.

[stephenfreeman]

GS006/2 will be the ex D&S one. There is also a photo of a prototype signal in Adrian Vaughans book. Originally probably used as a points indicator, that practice was subsequently frowned upon of course.

[Ian@Exton]

Yes, Wizard/ MSE do market a kit for the 1890 GWR ground signal.

However, having built both, I can advise that the kit is not the same as the old D&S kit. The current Wizard offering is a simplified kit of the prototype drawn by Martin Goodall.

Ian

[dclift]

Thanks again everyone. This topic seems to have expanded well beyond my original request and provided much more information than I expected, all of which will be very useful when I eventually get to the point of installing signals. At the current rate of progress, and taking into account travel plans for this year, that could be well into 2025.

[stephenfreeman]

Yes, Wizard/ MSE do market a kit for the 1890 GWR ground signal.

However, having built both, I can advise that the kit is not the same as the old D&S kit. The current Wizard offering is a simplified kit of the prototype drawn by Martin Goodall.

Ian

Useful to know. Andrew re-issued a lot of the D&S stuff, so perhaps he thought it better for whatever reason to do a simplified version. For the standard GWR arms the Wizard individual etches are the best. The ex D&S etches for the GNR are better imho than those previously available for instance, so best to pick and choose which you prefer.