wrote:
Are the signals that are normally found on the upper left side of the
tunnel entrances at Victoria line stations actually starter signals
or are they platform repeaters? I notice that the stations do not
appear to have track-level starters, execpt for areas where there are
points, such as at Victoria.

I realise that the various equipments differ, but I it seems that
signal aspects on the Victoria line are the same as those on the
Central line. These include a danger aspect, an aspect allowing
trains on code to proceed and a clear aspect for all trains.

In any event, I notice that many drivers on the Central and Victoria
lines prefer to wait until they get a full clear before closing up
and proceeding, although some will depart when the signal indicated
clear for coded trains. Why is that?

The platform headwall corner signals are "true" starters. A Vic line train
running in usual ATO mode will not normally pass a red signal (white aspect
shown when an ATO train can pass, but train in manual cannot). The same
thing is true where signals are ptrovided away from stations (usually
confliction point protection or where there are more than one route from the
signal). Headway posts are not intended to be stopped at by non ATO trains.

The corner signals realy become significant in degraded mode where manual
driving is necessary or if non ATO equipped works trains are running on the
line outside a possession (not sure if that is still allowed).

The existing Vic line signalling (due for replacement in the near future)
uses coded track circuits with a very restricted number of codes (3 running
codes for 2 train running speeds and 1 "code" only identified as part of the
signalling system).

Being pedantic the Vic Line mixes ATO with ATP (automatic train
protection) - the latter is, in very broad terms, the auto equivalent of
the fail safe signalling system.

Peter
--
Peter & Elizabeth Corser
Leighton Buzzard, UK