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MaxB wrote:
Why does the signal at the country end of the down Central Line at
Stratford
have Red, WHITE and Green aspects? It wasn't just a faded yellow!

It's part of the Automatic Train Protection/Control system. There
isn't a signal at the entrance to every block, trains being controlled
by codes transmitted in the blocks. Where signals are retained, a
green aspect indicated that all blocks up to the next signal are
transmitting a proceed code. A white light indicates that a proceed
code is being transmitted, but not by all blocks to the next signal.
Red means stop (proceed code not being transmitted).

It wasn't appropriate to use yellow, as on traditional signalling
systems that would indicate to the driver that he was clear to the next
signal.


Definitely the running signals, so I am sure this is the correct
explanation. Thanks.

MaxB