To repeat or not

I my time we were told that repeaters were only provided where the siting (sighting) of the signal was such that it could not be seen within a normal braking distance in rear of it. I.E. The approach to it was straight for a distance of 400 yards or more before it was seen by drivers. It would however be provided with a fog repeater

Yes Russ if you cannot see the signal after the junction 400 yards or more prior to it then the first would have a repeater beneath it. If you were approaching the second signal around a left hand bend for instance then there would quite possibly be more than one repeater for it. It would depend on the radius of the approaching curve.

If you can get a cab ride video of the District or Hammersmith & City Lines ((video125 I think) you'll see the principle at Praed Street and Minories junctions

Thanks Q8. The signal in question is not visible for a reasonable braking distance. So presumably you would have expected to see:



(I have added a little bit of modelling context, which incidentally will be District circa 1960s.)

Russ
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I just noticed this Russ. The notice you attach reagrding sighting would not be posted at the first signal but the second one.

Yes you are making sense Russ. However I will make some remarks.
Signals A56, A57 would not in fact be auto's but A58 could be. A56/57 would in fact be semi's something like DL10 & DL 11 (Cabin letters & lever number) The repeater's below DL10/11 would be numbered R58 on BOTH branches (No "A" on repeater plates) Sequential repeaters would be "R58 (1)" "R58 (2) and so forth. In semi automatic areas the letters "a" "r" "i" "o" "s" "x" are NOT used (yes I know there are places where they ARE used) this is to avoid possible confusion with automatic signal numbers/letters.

Incidentally when the underground SSL lines were first electrified there was a minor kerfuffle between the Metropolitan and the Distrct (so what else is new?) The argument was over numbering the new electric signals wether semaphore or colour light. The District wanted (and adopted) code letters for semi-automatic signals dependent on geographic location. This meant WEST of Earls Court (WB, WC,WD and so on) and EAST of Earls Court (ED, EE, EF etc). for automatic signals they favoured "S" for SIGNAL later changed to "A" for AUTOMATIC.

The Met as was their practice went their own way and lettered semi auto signal plates with a code system as follows, Signal cabins on the circle line were prefixed with an "O" (denoting "circle") and an individual cabin letter. So you got "OB", "OC" "OD" and so forth. On the extension signal cabin letters were prefixed with an "M" for "Main" followed by the cabin code. "MB" MC" "MD" etc. Met automatic signals just had a sequential number dependent on the direction of running. E.G. "101" "103" "105" for one direction and even numbers for the other. The system eventually adopted was a compromise between the two and survives to this day.

This was all told to me by a very senior old driver on the DR who started on the job in 1899! He told me this in the sixties and after he was retired and in his 90's. He lived just down the road from our house.

I get the impression that the numbering of autos along a particular line direction, although usually in a sensible sequence, does not need to correspond with the non-auto numbering. >>>>

In General correspondence is not needed.

This would seem to be the case for repeaters approaching converging junctions (as above, and which is the context here) but would not seem to be the general case, e.g. from Harsig's: >>>>>

You know in all me years on the underground I never noticed that. I assumed that repeaters were numbered (1) (2) etc was to eliminate any confusion with actual track circuit numbers.

Again to (mis)quote another member "you learn sumfink every day"

I'm sure there are exceptions here, but does any convention apply to this, e.g. even numbers for westbound and odd numbers for eastbound?

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Well on the District AFICR the numbers were even eastbound and odd westbound. Any present District driver will correct me toot sweet if I am wrong.

WK 1 and WK11 are multi home signals so the a and b etc are used to differentiate the different signals in the same section. The repeater for WK1a would be RWK1a.

If a repeater is repeating 2 stop signals in a multi home area for example A123a and A123b, then the repeater will be labelled R123ab. This just tells us that the repeater, tells us the aspect of the next 2 signals.

Q8 - you are quite correct, we still use the system of (1) and (2) if there is more than 1 repeater for a stop signal. The best one we currently have is approaching Hammersmith Eastbound. The stop signal is RWDX589a There are 3 repeaters for it, labelled RWDX589a (1), RWDX589a(2) and RWDX589a(3)
Alternatively we use another system where the bracket is replaced with a / . So the plate would read something like R123/1, R123/2 etc.

Finally approaching PG from Fulham, there are 2 repeaters for WF3, one attached to the starter and the other by 28rd. Both repeaters just simply say RWF3. There's still lots of consistency on the big green rly! ;D

So it all depends how many repeaters for a stop signal or vice versa as to which suffix is used.

Hope this helps

Keeps you in busieness and checkcerts though, eh Pat? ;D

I'm personally not in favour of the numbering scheme using slashes, eg RPK1/2. In this case (and this is a real example) drivers were confusing the slash to mean the stick repeated both PK1 and PK2, and came along only to clobber PK2. (If it does repeat two controlled signals it would read RPK1.2 or RPK¹₂ (with the 1 annd 2 above each other).

Dunno why they dont adopt a simple system where the signal numbers it is repeating are separated by a "plus" sign

E.G. RPK 1 + 2 or whatever

Gets a bit confusing though where you have home signal all numbered the same with a letter suffix.

E.G A828a 828b and so on. Then the repeater should just have the plus sign like so R828+