Jim Summers wrote:
Many thanks for clarifying the "Green Book" situation for 1960 Jim. It is a bit of an irony that we all castigate the WR for marching out of step, yet in truth it was the Southern that was most different in signalling matters - mainy because they were a very different railway and although they were "brought into line" with the 1960 Green Book, their Is Line Clear codes were a foreign language - a parcels was still a 4-2-2 in 1972 and a 4 was still Branch Entering section!
The point you make is valid and really illustrates that a procedure which works in a quiet backwater with four trains an hour is hopeless in a box with four parallel routes and a train every four minutes on each of them. That said, I doubt Management would have been prepared to sanction what actually went on in the Southern Boxes in London - after all this particular form of slack working had already (indirectly) cost lives at Battersea Park and South Croydon because it depended on the interlocking between the instruments and train treadles / track circuits - fine till someone used a release key when the system was trying to prevent a mistake.
I agree about the Stockport CD - great stuff and for anyone interested in in a big busy box, the workings at Exter West in 1960 can be seen here.
Unfortunately, my simulation is not able to re-create a "King" thundering past at 55 with 14 on! And its imitation of the bankers "crow" whistle is a bit poor! To bring things slightly back on topic, (ha!) this video is a good illustration of why putting the running signals at the outer ends of the frame is a bad idea - you need two signalmen just to pass trains and on two or three occasions the lad has to help out on the bells...! In a Southern box of this size "reapeater" bell pungers or tappers were always provided to save the walking about.
Also worth a look is this one(and its partners) showing the workings around Manchester in the nineties - the GW method for OOS is alive and well, amongst other shortcuts!
Before anyone says that things were getting slack towards the end of these boxes, I knew this area 20 years earlier and the only difference was that there were a lot fewer spare levers! This video is a good illustration of the main problem with BR "Lego" block instruments - 6 bells in this box and they all sound much the same!
Hope they are of interest for anyone who has not seen them.