The Great Bear Posted July 21, 2013 Share Posted July 21, 2013 On a signal diagram for an ex GWR station I have seen the label DA. I think this means a Draw Ahead signal, but I am unclear what this means, what it looks like and in the context of the track layout what move is it for. Photos from behind in books show a tiny arm. Is it like a "calling on arm"? Extract from drawn copy of diagram below. The original SRS diagram in thumbnail is here: http://www.s-r-s.org.uk/html/gwa/S232.htm Any help, as always, much appreciated. Many thanks Jon Link to post Share on other sites More sharing options...
The Great Bear Posted July 21, 2013 Author Share Posted July 21, 2013 Yeah, I know. Mike has helped me an awful lot already - but it would be a bit presumptuous to title the thread FAO The Stationmaster! Link to post Share on other sites More sharing options...
RailWest Posted July 21, 2013 Share Posted July 21, 2013 >>>I think its for leaving the branch into the bay area rather than the Up Main...." But in that case surely it would be on the RH doll? Link to post Share on other sites More sharing options...
rovex Posted July 21, 2013 Share Posted July 21, 2013 With no expertise in this area at all, I wonder if its to allow a shunting movement onto the Up main. Assuming I read the signals correctly (big assumption) a train approaching the bracket signal from the branch, will be signalled into the bay (bracketed arm) or onto the main (main arm). But if it is only collecting coaches that are stood in the up main platform road (perhaps detached from another train) would the "draw ahead" be used for that and then once coupled up it presumably pulls them back onto the branch line and into the bay or off down the branch? just a thought, but SM is really your man for this. Dean Link to post Share on other sites More sharing options...
The Great Bear Posted July 21, 2013 Author Share Posted July 21, 2013 Thanks for suggestions so far. The right bracket I think is for the bay, the main arm to the up mainline. As there's a double slip I am wondering if the DA arm is for shunting move onto the Down mainline? Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted July 21, 2013 RMweb Gold Share Posted July 21, 2013 Drat and whatever but my SRS disc doesn't include Kidlington! Anyway I think it could be one of two things - firstly a Calling On arm logical in some respects but not a common feature in such situations on the GWR although there were a few about. Secondly it might be short (3ft) arm to read to the Down Main Line but the form would be unusual for that and it has nothing to read towards.. So I did a bit of delving on the 'net and found a none too good photo of the back of the signal at the bottom of this page - http://www.railuk.info/gallery/images_search.php If this does not link you to the correct page type Kidlington in the search box at top left and carry on from there Which I think answers the question - the back of it looks very much like a standard GWR subsidiary arm/lamp, the higher elevation doll on which it is mounted reads to the Up Main Line while the other reads to the bay. As a Calling On arm it would allow shunts to be made onto teh back of trains standing on the Up Main or even the branch train to run to the Up Main platform to connect with a train already standing there. Now why is it called a DA on the drawing? - I haven't got a clue as it was not a term readily used on the Western until the colour light era As far as I'm aware and I've only come across it in talking to signal engineering folk in contexts which post dated the closure of the Woodstock branch. In teh meanwhile I'll search my library to see if I have anything on Kidlington or better views of the signal' Link to post Share on other sites More sharing options...
The Great Bear Posted July 21, 2013 Author Share Posted July 21, 2013 Drat and whatever but my SRS disc doesn't include Kidlington! Anyway I think it could be one of two things - firstly a Calling On arm logical in some respects but not a common feature in such situations on the GWR although there were a few about. Secondly it might be short (3ft) arm to read to the Down Main Line but the form would be unusual for that and it has nothing to read towards.. So I did a bit of delving on the 'net and found a none too good photo of the back of the signal at the bottom of this page - http://www.railuk.info/gallery/images_search.php If this does not link you to the correct page type Kidlington in the search box at top left and carry on from there Which I think answers the question - the back of it looks very much like a standard GWR subsidiary arm/lamp, the higher elevation doll on which it is mounted reads to the Up Main Line while the other reads to the bay. As a Calling On arm it would allow shunts to be made onto teh back of trains standing on the Up Main or even the branch train to run to the Up Main platform to connect with a train already standing there. Now why is it called a DA on the drawing? - I haven't got a clue as it was not a term readily used on the Western until the colour light era As far as I'm aware and I've only come across it in talking to signal engineering folk in contexts which post dated the closure of the Woodstock branch. The box diagram has been drawn by the SRS so maybe that's the reason for the nomenclature. I have other pictures in a couple of books showing same signal but still only from the back. With what I've read about workings of the Woodstock branch and Kidlington I'm struggling to see that it would be much used, if at all. So it could be an optional extra. However in context of my layout, with a creamery on my fictional version of the branch, maybe it woudl serve a purpose in allowing the branch loco to attach a milk tank to a train standing at the platform? Once again, thanks for your help. Jon Link to post Share on other sites More sharing options...
RailWest Posted July 22, 2013 Share Posted July 22, 2013 You might want to read the thread at http://www.signalbox.org/forum/viewtopic.php?f=2&t=3225&p=38476&hilit=draw+ahead+signal#p38476 where there is a reference to a Draw-Ahead signal at Dunstall Park. Note in particular the comment:- "The GWR rule book describes four types of subsidiary : Call-on, Warning, Shunt-ahead, and Draw Ahead under rules 44-47 respectively. Shunting signals are also lumped in with the last of these. The first three may display the initial letter, presumably because it was felt that crews should be able to distinguish them, but there was no D for Draw-ahead." A DA arm seems to have been so rare on the GWR that one wonders why they needed such a thing at all. Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted July 22, 2013 RMweb Gold Share Posted July 22, 2013 You might want to read the thread at http://www.signalbox.org/forum/viewtopic.php?f=2&t=3225&p=38476&hilit=draw+ahead+signal#p38476 where there is a reference to a Draw-Ahead signal at Dunstall Park. Note in particular the comment:- "The GWR rule book describes four types of subsidiary : Call-on, Warning, Shunt-ahead, and Draw Ahead under rules 44-47 respectively. Shunting signals are also lumped in with the last of these. The first three may display the initial letter, presumably because it was felt that crews should be able to distinguish them, but there was no D for Draw-ahead." A DA arm seems to have been so rare on the GWR that one wonders why they needed such a thing at all. The reference to a Draw Ahead signal in the GWR Rule Book first appeared in an amendment dated 1 January 1937 and was almost certainly an alteration to bring the 1933 GWR Rule Book into line with changes to the 'standard' RCH Rule wording in Rule 47 etc. There is of course no reference in the 1936 GWR General Appendix - either as published or as amended - to 'Draw Ahead' signals and in fact the GWR had earlier banned the use of Calling On signals for other than their intended purpose and not - according to the Minute Books - provided any sort of fixed signal alternative. The Dunstall Park reference is - I note undated - and of course Draw Ahead signals did appear on the WR (without the G) for a relatively short period, the first reference I know of them is in 1960 but they might well have appeared in a Sectional Appendix prior to then. The history of the use, and meaning, of Draw Ahead signals is quite complex and I recall going through some of it, dated wherever I could, on The Signalbox site a number of years ago, might even still be there as JH runs a good ship for older stuff. There are incidentally a number of misleading/inaccurate statements in that thread as the Rule Book amendment dates have clearly not been correctly researched by those quoting them - the correct GWR Rule Book date is given above. Getting back to Kidlington I've delved out nothing more so far but teh signal could be used, quite accurately, for making attachment etc moves to trains standing on the Up Main. Link to post Share on other sites More sharing options...
The Great Bear Posted October 23, 2014 Author Share Posted October 23, 2014 Can I just check the colour of the calling on arm, please? Almost all photos I've seen (eg Vaughan Great Western Signalling) show a white arm with red edges but date from 1960s or so. I believe the earlier design was red arm with CO letters on it, indeed one photo in Vaughan shows that. When was the change made? The signal as discussed above was a 1940s wartime addition. Thanks Jon Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted October 23, 2014 RMweb Gold Share Posted October 23, 2014 Can I just check the colour of the calling on arm, please? Almost all photos I've seen (eg Vaughan Great Western Signalling) show a white arm with red edges but date from 1960s or so. I believe the earlier design was red arm with CO letters on it, indeed one photo in Vaughan shows that. When was the change made? The signal as discussed above was a 1940s wartime addition. Thanks Jon The red-white-red horizontal striped version is shown in the 1936 General Appendix as 'New Pattern' while the Red with letters 'CO' on it is shown as 'Old Pattern' which suggests that they were about, or about to be about, by late 1935 when the content of the 1936 GA was signed-off. Link to post Share on other sites More sharing options...
The Great Bear Posted October 26, 2014 Author Share Posted October 26, 2014 The red-white-red horizontal striped version is shown in the 1936 General Appendix as 'New Pattern' while the Red with letters 'CO' on it is shown as 'Old Pattern' which suggests that they were about, or about to be about, by late 1935 when the content of the 1936 GA was signed-off. Thanks, Mike. Would I be right in thinking the back of the arm is plain black, looks that way in photos I have seen? Link to post Share on other sites More sharing options...
The Great Bear Posted October 27, 2014 Author Share Posted October 27, 2014 The back of the calling on arm looks plain black to me in this photo (but it is a long way away), is that correct, chaps? Thanks Jon Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted October 27, 2014 RMweb Gold Share Posted October 27, 2014 The back of the calling on arm looks plain black to me in this photo (but it is a long way away), is that correct, chaps? Thanks Jon Most of what you can see is the back of the lampcase Jon. Look at my pics in Post No.343 in this thread - http://www.rmweb.co.uk/community/index.php?/topic/80426-cwm-bach-a-south-wales-branch-line/page-14 And it appears that my earlier reply didn't (appear) - the back of the arm is white with a black vertical stripe Link to post Share on other sites More sharing options...
RailWest Posted October 27, 2014 Share Posted October 27, 2014 So did the GWR not ever change to white with horizontal black stripe then? Link to post Share on other sites More sharing options...
The Great Bear Posted October 27, 2014 Author Share Posted October 27, 2014 Should have thumbed further through Vaughan's Pictorial Record of Great Western Signalling before asking! Plate 44 and 45 show front and rear of complex bracket signal at Carmarthenough, 1959, shows rear of calling on arm white with thin black vertical line. Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted October 28, 2014 RMweb Gold Share Posted October 28, 2014 So did the GWR not ever change to white with horizontal black stripe then? Not that I have ever come across or seen a picture of Chris. Link to post Share on other sites More sharing options...
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