Andrew Waugh wrote:A lot of work!
Do you know the history of the drawing registration scheme?
I am afraid that the registers do not give any clue as to the dates they run from.
The early numbers do not have papersizes ascribed to them. Paper sizes being only routinely recorded in the register from the 1950s when a lot of redrawing was undertaken. Prior to that, the register only lists a plain number as entered. From my own drawing holding, early drawings often did only have just the plain number with and without the 'M'. On up issue they often acquired a paper size letter, and some early drawings have a paper size without being an up issue, and some have just had it added. Dates are only recorded routinely in the register from 1938.
When they acquired a paper size letter, it was often 'E' or 'D' as drawings usually had all the components on the one page rather than spreading it across several drawings. The 1950s exercise of redrawing many drawings split parts either onto seperate drawing numbers, or on to /nn sub pages.
The early register is all very nicely written in copper plate, much by the same hand so presumably the drawing office had a clerk who kept the records. In order to facilitate locating drawings, they would appear to have been stored in 'packets' . For example Packet 4, drawings 9, 10 & 11 were all nuts and bolts; Packet 14 was Cranes; Packet 6 Facing Point Locks. Packet 25, Level Crossings some 106 drawings have in most cases had the the paper sizes added in at a later date, as has packet 26 for Signal Boxes. Either squeezed in as a pencil or ink addition to the entry along with other comments. Coloured pencil was also used occasionally.
The numbering allocates blocks of numbers by discipline. This all seems very uniform up to about packet 65, from then on drawings are allocated to packets already issued and others to new packets. This may suggest that previous to this point, drawings were either not numbered, and were now numbered, or they were renumbered into a uniform series. This later idea would seem to be supported by the dates on the drawings. 223 Horrabridge Crossing 1911; 263 Bovey Crossing 1918, but 270 Bridport East Street Crossing 1914 and 286 Bradpole Level Crossing 1911.
The last drawing to be allocated a packet was no. 1990 - F.P.L. Chair 01 Section to packet 11. Packet 11 was all rail chairs. You will be surprised what was a Reading Signal works product, but you will have to wait for the rest of the early numbers to be added.
For the record Swindon Works just used a plain serial number system until it adopted the BR numbering for standard wagons, coaches and locomotives. The serial system continuing for non standard items until the metric paper numbering system came in, with I suppose BREL.
Reading works did not as far as I can see adopt the BRS/SM numbering system for its drawings, and from such BR/SM items as were used by the western region as far as I have ascertained were redrawn as Reading drawings with a cross reference. MAS etc still continued the same drawing formats even though size A had become A4 and B A3 etc at some point in the process.
Where a level crossing had gates replaced by barriers, it was just an up issue of the earlier drawing, with the gates removed and barriers substituted.