N&W intermediate signals

NW Mailing List nw-mailing-list at nwhs.org
Thu Nov 17 08:42:42 EST 2016

On 11/17/2016 6:17 AM, NW Mailing List wrote:

> Jimmy,
> Thanks for your note.  So if you were Northbound from control point A 
> to control point B.  The dispatcher would "clear" a Southbound route 
> from B to A and the facing intermediates would "tumble down" against 
> you?  I suppose that the Southbound intermediates would show clear 
> except for the ones guarding the block you were in and the  one in 
> advance (showing stop and proceed, and approach respectively)?  So as 
> your caboose left a block, I am assuming that the signal would change 
> to approach and then to clear when you left the next block, is that right?
> Thanks again for the help,
> Jim Cochran
     As the cab passed the signal at control point A, it would still be 
Stop because we had occupied the block that signal protected. As we pass 
the first intermediate, it would change to Approach. Then the next 
intermediate turned to Clear, or the most favorable signal that it could 
display, meaning that it could be an Advance Approach if that was the 
way the signal system was set up. And, any other intermediates passed 
would turn to Clear.
     Just to confuse things, remember that the intermediate signals were 
not always side by side, as in Northbound & Southbound. They many times 
were staggered, NB here and a little farther up the road would be the SB 
signal or vice versa. So depending on how the signal circuits were 
wired. The opposing signal that you just passed might not change right 
away, just when you clear the circuit.
     I don't understand all there is to know about signal circuitry. It 
is a bit of an art form. And, I heard before I left the scene that one 
of the reasons for the track and signal changes through downtown Roanoke 
was because there was only one signal maintainer left that knew the 
system forward and backward and he was close to retirement!

Jimmy Lisle

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