Some European countries use what are called a signal
emulators/repeaters where there is a limited sight
distance to the home signal. The emulator, which looks
quite different from the standard signals, simply
shows the indication of the next signal. It
conveys no authority by itself.

In other words, an emulator showing stop can be
passed by the train -- but it makes the engineer
aware and/or reminds him that the next signal is
stop.

I wonder if such an emulator would be useful at
stations where the train is in the middle of a block
and there is no clear sight line to the next signal.


In Austria, the country with which I am most familiar,
the emulator is in the form of a position indicator,
consisting of a series of iluminated dots that look
somewhat like a semaphore. If the emulator displays
this:

o o o o o o
o
o
o
o

Then the next signal is displaying stop.


If the emulator shows the line pointing up
at 45 degrees, the next signal is clear:

. . . . o
. . . o
. . o
. o
o
o
o
o
o

(Please excuse the somewhat imperfect text
graphics. I've had to insert some periods
because HTML does not permit multiple blank
spaces in succesion. Ignore those periods.)

If the emulator points down 45 degrees, then
the next signal displays a restricting indication,
but can be passed.

o o
o . . o
o . . . o
o . . . . o
o

I'll try to find a photo showing one of these
emulators.

Installing these emulators would be a relatively
inexpensive and quick solution for station stops
located within a block.

Of course, a better solution is to space the signal
in such a way that the engineer sees a block
signal on departing a station. But, that's easier
and cheaper to do if you are doing a new signal
installation.

-- Ernest