wrote in message
oups.com...
Was at London Bridge the other day platform 6 waiting for a Bedford
train watching trains pass through the platform and noticed that
signal L100 which appears as a 2 aspect but actually capable of
showing double yellow had a indicator box at side which was showing CD
this then changed to RA the signal was showing the same aspects during
the time the sign changed. anyone explain what this was etc.

Most of ther trains which use this platform are Driver Only Operated, so
platform staff have to assist in dispatching trains (see other thread). When
station work is complete, the dispatcher turns a switch which turns the 'CD'
display on, telling the driver to 'Close Doors'. When the doors are closed
and the orange indicator lights on the train have akll gone out, the
dispatcher will turn the switch, to extinguish the 'CD' display and
illuminate the 'RA', telling the driver 'Right Away'.

Is the 'RA' indicator interlocked with the signal, so that it cannot be
displayed if the signal is at red?

Presumably the signal itself uses an LED display, so that the upper head can
display green or yellow, and the lower head yellow or red, and the signal as
a whole can display all four aspects R, Y, YY, and G.

Peter

On 31 Mar, 16:46, "Peter Masson" wrote:
wrote in message

oups.com... Was at London Bridge the other day platform 6 waiting for a Bedford
train watching trains pass through the platform and noticed that
signal L100 which appears as a 2 aspect but actually capable of
showing double yellow had a indicator box at side which was showing CD
this then changed to RA the signal was showing the same aspects during
the time the sign changed. anyone explain what this was etc.

Most of ther trains which use this platform are Driver Only Operated, so
platform staff have to assist in dispatching trains (see other thread). When
station work is complete, the dispatcher turns a switch which turns the 'CD'
display on, telling the driver to 'Close Doors'. When the doors are closed
and the orange indicator lights on the train have akll gone out, the
dispatcher will turn the switch, to extinguish the 'CD' display and
illuminate the 'RA', telling the driver 'Right Away'.

Is the 'RA' indicator interlocked with the signal, so that it cannot be
displayed if the signal is at red?

Presumably the signal itself uses an LED display, so that the upper head can
display green or yellow, and the lower head yellow or red, and the signal as
a whole can display all four aspects R, Y, YY, and G.

Peter

Thanks must go to the back of the class should have worked it out.

"Peter Masson" wrote in message
...

Presumably the signal itself uses an LED display, so that the upper head
can
display green or yellow, and the lower head yellow or red, and the signal
as
a whole can display all four aspects R, Y, YY, and G.

I think I read somewhere that both heads can display red, but that normally
the lower one is used for red. The upper head can be used in emergency to
display red if the lower one has failed for any reason. BICBW.

Regards

Jonathan

On Mar 31, 5:59 pm, "Jonathan Morton"
wrote:

"Peter Masson" wrote in message

Presumably the signal itself uses an LED display, so that
the upper head can display green or yellow, and the lower
head yellow or red, and the signal as a whole can display
all four aspects R, Y, YY, and G.

I think I read somewhere that both heads can display red,
but that normally the lower one is used for red. The upper
head can be used in emergency to display red if the lower
one has failed for any reason. BICBW.

That is wrong. The signals used on the Manchester South scheme can do
that, but they aren't LED type.

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