Signals and Traffic Control

[NW Modeling List]

This is a larger question than you imagine right now.   Railroad signals are
nothing like traffic signals with the 'stop, go and caution/about to
change' information displayed.  The railroad signals on a district are set
up to guarantee safe train spacing and safe stopping distances for the
trains to be run on a certain district.  They then display the diverging or
'straight' information necessary to safely control the train speed to
achieve safe stopping.  They are not strictly 'generic' , but are designed
to fit the operations on the district itself.   While each district uses a
range of basic aspects to control trains, each district is different and the
aspects are unique to the district's characteristics and movements.  

 

While you can consider that you could use the signals as specified off of
the track diagram for the district modeled, you really should learn what you
need about signals and then design your signals accordingly.  This will
allow you to design your signals for aspects that you can use to control
your model layout either as you build it or for a project in the future.

 

Also, we have a booklet available through the commissary that is the signal
standards such as poles/masts, relay bases and signal heads.  In addition
you should obtain the signal aspects diagrams and/or an operating rule book
which has those aspects and describes out how they work.  In proceeding to
an operating layout with operating signals, you should consider how the
layout will run or function within the model layout itself.

 

As an example of the differences one might encounter, on the Cincinnati
District, proceeding eastbound out of Clare Yard, a train would see a
'distant' signal approaching ANCOR siding and then a 'holdout' with a stop
and stay configuration.  Coming westbound and approaching ANCOR siding, a
train would see the standard approach signal and then the two heads of the
mainline and siding signals.  This configuration was used because an
industry was in the middle of the ANCOR siding (Baldwin Piano or later
Heekin Can) and switching moves to run around their cars had to come out of
Ancor Siding at its west end to get on to the mainline to go around the cars
sitting on the siding.  So a short block was necessary at the west end that
was not required at the east end.  Otherwise the siding was a standard
passing siding.  

 

Ted Benson did a book on signals and signaling which is quite useful.  Also,
seek out a book on the rights of trains or a NERAC rule book.  This will
explain what first, second and third class trains have as rights as well as
the 'second' sections or extra trains rights.  These are assigned with
respect to the Districts Employee timetable.  In the days of dispatching by
telegraph and telephone with operators in towers and stations, the rules,
timetables and a full understanding of the rights of trains was of deadly
seriousness.  Today, dispatching by radio has simplified the process
significantly, but the deadly seriousness has not diminished. 

 

In addition, a district is roughly 100 miles long on a railroad.  In HO this
scales to about 15,000 real feet.   You will need to design with extreme
compression of the actual railroad to fit this in the space available for
either and HO or N scale layout in a normal home or out building.

 

Gary Rolih at INFO @N&WHS  

 

From: nw-modeling-list-bounces at nwhs.org
[mailto:nw-modeling-list-bounces at nwhs.org] On Behalf Of NW Modeling List
Sent: Tuesday, February 07, 2012 8:34 AM
To: NW-Modeling-List at nwhs.org
Subject: Signals and Traffic Control

 

Good Morning,

 

I am working a 1950 n&w layout that will either be on the Shenandoah
Division or the Christiansburg District. I have come to the point of
planning my signals and i am finding it hard to find data on what signal
systems were installed where.

 

So here is the question: On the Shenandoah Division, what type of control
over trains was used in 1950? ABP, ABS, CTC? How would the N&W signal a
mainline with a passing siding? I have seen many photos, but cannot find
them from the 1950's to figure out what types they would use (Signal
bridges....bracketed towers). Same question for the Christiansburg District.


 

Any resources that the group could point me to would be awesome also!

 

Thanks

 

David

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