More on signal "roolz"

NW Mailing List nw-mailing-list at
Fri Aug 16 21:44:38 EDT 2013

I think that says a lot on various circumstances.
Railroad had to designate a direction superior such as the westbound
freight vs the eastbound,
to avoid engineers getting into fights who takes the siding....

I tend to think the N&W had a predominate coal traffic move westbound so
its obvious to me to make westbound trains the superior direction.
After acquiring the VGN they could study traffic moves and adjust track,
signals to their liking design, removing the double track is to single
with sidings one example.
Technically the siding may be only one signal block long so you would
not display a R/G going into the siding. Exiting you could get the R/G.
Even if the block ahead the siding was clear you probably would not get
the R/G entering it, mainly because that track ends and passes back into
the main.

I have a yard throat with working target signals and it gets interesting
deciding how the signal aspects should be.


On 8/16/2013 11:34 AM, nw-mailing-list-request at wrote:

> Subject:

> More on signal "roolz"

> From:

> NW Mailing List <nw-mailing-list at>

> Date:

> 8/16/2013 10:22 AM


> To:

> NW Mailing List <nw-mailing-list at>



> Okay,

> the other day the subject came up about why do some signals give a

> Diverging Clear, while others will only display a Diverging Approach.


> This gets LONG and complicated and is hard to explain. If you get

> confused, ask before you throw tomatoes at me, because I may not word

> it the best way. I'm a signalman, not a book writer! And, I'm lousy

> and proofreading my own stuff, so...


> This is more or less how it's been explained to me by the signalmen

> who trained me through the years.


> It depends on how the track is designated in the operating rules. If

> a track is designated as a Double Track situation, with Main One, and

> Main Two, (or in the old rules as Eastbound, Westbound, Northbound,

> Southbound), the signals will be able to give a Diverging Clear coming

> out of a siding, but will not be able to give a Clear coming out of

> the siding. Why? Because the siding is the inferior route. Yes,

> there were and are exceptions to this, but for the most part, that's

> how the N&W's doubletrack was everywhere I've been.


> A good example of this is the Christiansburg District. It used to be

> double tracked as we all know, and now is designated as a Double Track

> to Single Track situation because some of the double track was removed

> after the Virginian merger. For the mostpart, the westbound track was

> left intact, and the eastbound track that remained became the sidings

> and also became the inferior route (because you'd be traveling

> westward on what was the eastbound track). Confused yet? It gets

> worse.


> A single track with sidings had no directional designation, so there

> was no inferior and superior route. (Or well, actually there was, but

> because the track itself was bi-directional, the inferior route

> received a shorter signal mast to designate it as the inferior route).

> Still not confused? I'll keep trying!!


> Here's a good example of confusion: At the new Ashby and Marsh Run

> double track north of Front Royal, those signals were set up for

> Diverging Clear out of the siding as a double track would be. That

> was because they originally were setting it up as a Main One/Main Two

> operation. Then, they changed their mind at the last minute and

> designated it as a Main One/Siding setup. We left the signals as they

> had been designed when we put all that in service. The new siding

> extensions between Berryville and Audley can give clear out of the

> siding, and this only adds to the confusion!


> Here's another exception: Before the pole line elimination/signal

> changeover on the Bristol Line, the east end of Abingdon and the east

> end of Glade Spring could only give Diverging Clear coming out of

> their sidings, but they were not in double track territory. So, why

> were they set up this way? They were in Yard Limits when they were

> originally installed, and I assume that was why, but I'm not certain.

> Now, they give Clear coming out of the sidings because they are

> designated as Main One track and Siding and the yard limits are long

> gone.


> If I've got anything wrong, maybe Mr. H.W. Bundy can straighten me

> out. But, learning how signal systems work takes years of dealing

> with them. When I hired, I was told it would take me ten years to get

> a good grasp on them, but they told me I had that in five years.


> With signals, there are situations and rules and so many other factors

> to consider, that each situation requires its own specific

> engineering. That is why they are so hard to understand. Every

> location is a little different, and specific to what is around it.

> Switches nearby, crossings, slide fences, foreign railroads, etc.all

> factor in to the design and engineering. It is not an exact science.

> They design it for what they need at the time.


> So, for the modeler, if you had a signal that seemed to be "out of

> place", you can explain it with your specific rules. If I had all

> position lights on my layout except for one searchlight signal, I

> would justify it by saying its "bulletined in the special

> instructions"!


> That's enough rambling for now.


> Ben


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