Shenandoah Division Cab Signals -- Unresolved Questions

[NW Mailing List]

On 5/4/2023 5:34 PM, NW Mailing List wrote:
>
> Abe,
>     If I remember correctly the the first mandated application of ATC 
> on the Shenandoah Div. was later recinded on request from of the N&W 
> and replaced with only the "Cab Signal" version. This has been 
> documented in several puiblications. I am surprised that you haven't 
> seen it as yet. I have this somewhere deep in my library. There would 
> not be two different types of ATC on the Shen. Div. That just doesn't 
> make sense. I understand that there was a different type used on 
> engines assigned to operate between Petersburg and Richmond.
>     Later on the cab signals were removed from the Shenandoah Div. 
> north. One oddity about this was that somehow it still worked in 
> places unexpectedly. When Conrail units equipped with cab signals 
> started showing up on the head end of our trains there were quite a 
> few times where trains were put in a penalty brake application between 
> Randolph St. and Park St. I don't think anyone ever figured it out. 
> Penalty applications also happened out on the road from time to time. 
> The north end of Cloverdale was where I remember it happening to me 
> with a UP unit on the head end. IIRC, I was able to reset the alarm 
> with the lever on the annuciator box. Many were the times when trains 
> with NS units equipped with cab signals cut in (for use north of 
> Hagerstown) were put into penalty after passing the signal at North 
> Roanoke. The shop forces had to be called to come out and cut out the 
> cab signals before we could proceed.
>
> Jimmy Lisle
>
> *From:*NW-Mailing-List [mailto:nw-mailing-list-bounces at nwhs.org] *On 
> Behalf Of *NW Mailing List
> *Sent:* Tuesday, May 02, 2023 10:38 AM
> *To:* N&W Mailing List <nw-mailing-list at nwhs.org>
> *Subject:* Shenandoah Division Cab Signals -- Unresolved Questions
>
> We all kick ourselves for the questions we never asked while there was 
> still living memory to provide an answer.  And this one is no different.
>
> The N&W's Shenandoah Division was equipped with cab signaling, but the 
> north and south ends of the Division were equipped with different 
> types of equipment.
>
> The north end had the early Loop-and-Track technology, which depended 
> upon steady-energy AC currents being in-phase or out of phase.
>
> The south end of the Division used the much more modern Coded Track 
> principle of the 1930s, whereby an AC current was pulsed into the 
> rails at different pulse rates, and those pulses were picked up by the 
> engine's detector bar, amplified and decoded to give an in-the-cab 
> indication of the condition of the next signal block ahead.
>
> The use of different technologies (and thus different equipment) on 
> the north and south ends leads to some interesting QUESTIONS :
>
> 1. Were engines assigned to the Shenandoah Division equipped with BOTH 
> cab signal technologies, so they could be used on either district of 
> the Division ?
>
> 2. If so, did a passenger engine on a Hagerstown-Roanoke run have to 
> cut one one technology at Shenandoah, and cut in the other technology?
>
> 3. If so, where were the cut out controlls located, and was the 
> change-over performed by the Egineman or a round house electrician ?
>
> The attached photos show a Union Switch & Signal cab signal display 
> box of the same type used on the Shenandoah Division (top row, left 
> end.)  Lamps behind the roundels were probably 32 volt lamps, as that 
> was standard voltage on steam engines and early D-thingies as well.
>
> When I worked on the Shenandoah Division in the 1960s, I asked some of 
> the old Hog Heads for details about how the cab signals functioned, 
> and their answers were conflicting and obviously confused.  Several of 
> them could not even remember the colors of the glass roundels !  So 
> the matter of a good description of the equipment and its operation 
> still seems to be an open issue, at least for me. Obviously there were 
> written instructions covering all these matters.  Have they been found?
>
> -- abram burnett,
>
> Industrial Strength Liquid Turnips - 200 Proof
>
>
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