Clive D. W. Feather wrote:
In article . com,
TheOneKEA writes
In the case of Turnham Green, both lines do have home signals - the
EB line's homes are A631^A and A631^B, and the WB's are A630^A and
A630^B. Would the overlaps on these homes simply be longer than
usual, to allow a train to alternately stop or pass through at
linespeed?

Yes. Just as with a signal between stations. The overriding
principle is that a train stop hit at line speed should stop the
train before the point of danger.

Thanks, that was what I thought.

This doesn't make much sense. Are you saying that if a train passes
a red signal at linespeed or higher and gets tripped, the signal in
rear could change to green if the entire train manages to exit that
signal's overlap?

Yes. But, in that case, the situation will still be protected. Um,
let's see:

snip

Clear? Or have I answered the wrong question?

I understand now. But it doesn't seem sensible to place the signals
that close together, or only hold one signal in rear of the signal
protecting an obstruction at danger.