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A Question For The Signal Experts Herein

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  • Member since
    January 2010
  • From: Omaha, Nebraska, USA
  • 31 posts
Posted by Jovet on Tuesday, January 10, 2023 7:11 AM

I am a bit late to the party here, but I do want to express regret that I don't have proper Canadian-railroad-in-the-US signaling guides on my website yet.  I don't live near those areas, and I'd first have to get my head around all the variations in order to know what to look for as far as rule books go.  And then find said rulebooks... 

I don't know everything, but I still consider myself a "signaling expert," having been studying it continoulsly since I was pretty small.  I'm at least somewhat familiar with signaling systems around the world, but US signaling and traffic control systems are the most familiar to me. 

It does look like blhanel got his question answered, as CN and CP have been adopting some of their "Canadian" speed signaling on the US lines they've bought. 

I'd like to point out the confusion around "distant signal."  It's a confusing term, because it essentially has two difference meanings in railroad signaling talk.  I break it down this way:

Distant signal: (capital D) A non-block signal that governs the approach to subsquent block signal(s). 

distant signal: (lowercase D) The block signal encountered one signal block from a track junction. 

The classic Distant signal is the yellow and black fishtail-ended semaphore arm.  It either indicates Caution, you're approaching one or more Danger signals, or Clear, proceed on your merry way.  It itself does not define a signal block, so it's not a block signal.  It also can't show any Danger aspect (e.g. red).  Distant signals are often used on unsignaled lines when approaching a rare signal, such as for a diamond crossing. The Distant signal may actually work, or it may be a fixed distant that always indidcates Caution and simply acts as a reminder.

The only thing special about a distant signal before a juncction is that signal usually has extra capabilities for aspects, depending on what the junction signal (home signal) might want to display.  As pointed out by someoene else, an absolute signal can be a distant signal, too, such as if there are two junctions in a row.

The best way to think about a Home signal these days is a signal that shows the status of the track immediately beyond it.  A home signal is not necessarily absolute.

"White" is not banned on signals.  At least, not in the United States.  As tree68 pointed out, color-position light signals use (CLEAR!) white on four of the marker lamps.  Note that these marker lamps are the bare incandescent color of the bulb, and are NOT lunar white.  The VirtualRailfan Deshler cam is a good place to get to see some CPLs still in use. 

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