N&W signal route diagrams

[NW Mailing List]

This is where the question of the ages comes up.

A horizontal indication on the top head with nothing on the bottom head is an absolute stop.  It doesn't become a stop and proceed.  Why?  Like your mama used to say "because I said so".  It's called out in the rule book as "an improperly displayed signal will assume its most restrictive aspect".

The question of the ages? Why?  This is the difference between N&W and Pennsy signals.

On the Pennsy each block signal had a lower marked lamp.  That makes it more a permissive signal, stop & proceed.  If the lower marker is out it looks like the absolute signal on the PRR stop & stay.  It looks like a safer way to handle things to me but it uses up a lot more light bulbs to put those markers on every intermediate signal.

So if you go out and buy a lot of Pennsy signals you have to take all of those lower markers off.

Stoney

Rick Stone
NWHS Mem #1

I was asking my self the question about the dark bottom on the signal 
with the red. 

It would be a stop indication no matter what, since we are at an 
interlocking (passing siding) 
I was interpreting how the green and reds are working. 

For an all clear the green only was lit on top, for a stop if the 
turnout was not thrown theoretically you could have Red/dark. But since 
you may want to indicate you have a turnout present, that may be the 
purpose of the signal, so you need red/red. 
For the circumstance a train in the main track of the siding, turnout 
not thrown, train behind gets the red/red. Lets say the train ahead is 
not moving, the 2nd train stops, the dispatcher throws the turnout and 
lets the 2nd train pass, it gets the red/yellow. 

-Lynn-