After much research, a bit of electronics and a lot of help from David Crow, I have succeeded in building a theatre indicator and associated 4 aspect CLS and sub with a repeater on the reverse.
The signal has been built into a model of Dicky Bridge at York, which is in accordance with the prototype. In 1951 the re-signalling of York Station was completed and this 1877 bridge was used as a signal gantry.
In accordance with the prototype, the indication is yellow to the front and white to the rear.
Colombo
Last edited by Colombo on Mon Sep 23, 2013 12:17 pm, edited 2 times in total.
Reason:Photos too large
Spent many happy hours train spotting on that bridge.
My drawing of the resignaling dated 10-11-50 shows the signals on the bridge, with their repeaters on the other side of the bridge, but one signal set is a bit indistinct - it shows a route indicator with repeater between signals 34 down Doncaster main and 35 up Leeds, do you know which it applied to, I think it would be to 34.
The repeaters were on the down side of the footbridge for the three down lines. The up signals had no repeaters as far as I can tell. So referring to my signalling diagram, the repeater should have been for signal 34 Doncaster Down Main.
I visited the Search engine at the NRM had access to the booklet on the York New Signalling by A P Hunter Divisional
Operating Superintendent dated 1951. It details the meaning of every indication of the 248 signals in the scheme.
The wiring is very complex. There are ten for each display, 5 for the CLS and two for the sub. In addition there is another four aspect CLS for the up main.
Besides the microprocessor provided by David Crow to drive the display, I had to build a diode matrix to select the indication, which for my version of "York" have to be one of 1, 2, 3, 8, 9, 11, M, G and X.
That is a very impressive set up.
The drawing I have of the re signalling is BR - NER YORK SIGNALLING ARRANGEMENTS Drwg 50 YS 633 and covers the area from south of Copmanthorpe/Naburn bridge to the Harrogate junction on the ECML and the Hull junction on the Scarborough line.
PM me if you would like a copy and I will email it.
I must give full credit to David Crow who has been working on this system for some years. He has learned how to program the microprocessor which drives the 5 x 5 display and also how to assemble the 25 surface mounted LEDs on the printed circuit board which constitutes the 8mm square display.
Thats a great bit of work! I remember this bridge because some nutters used to actually walk along the top of the girders and I think some got down onto the signal stages to get a better view.
I am afraid that my working theatre indicator has been working no more for a while now. Some of the pixels are far too bright and we have put this down to the control board with the Picaxe chip. My so has said he can replace it with a Raspberry Pi and I am looking forward to seeing it. I have set my mind on the objective of adding to my signals and these will include the theatre indicators.
However, as of yet, I have so far failed to produce a 5x5 dot matrix display 8mm square.
