[PRCo] Re: WP signals

[Dwight Long]

Phil

I did not realize you were old enough to have ridden the Charleroi line!

Of course its USS signal system, which used not only color light signals (outside of cities, where Nachods were used) but also head block indicators or "come-ons" was far more sophisticated than West Penn's.

If you might have a copy of the original PERC West Penn booklet from 1952, there is a diagram drawn by the late Bob Brown which shows how the signals worked. This was probably carried forward into the reissue put out by PRMA later, but I would have to check to be sure.  At any rate, Brownie's diagram and text pretty well explain the whole thing.  BTW, WP Coke Region nominal voltage was 700--PRC's 600.

Dwight
  ----- Original Message ----- 
  From: Phillip Clark Campbell 
  To: pittsburgh-railways at dementia.org 
  Sent: Tuesday, 23 November, 2010 20:58
  Subject: [PRCo] Re: WP signals


  Mr.Long,
  Thank you for your efforts.  I was re-reading the WP books;
  the signal system always interested me.  I am basically
  familiar with how it worked;  just had a couple questions for
  clarification.

  Thank you for mentioning the lights were in series;  I didn't
  ask this figuring the Rwy wouldn't run this risk of failure
  while the block was occupied.  The thought did cross my mind,
  however, because I believe it was mentioned that lights used
  in / on the equipment were used for the signals.  These are
  often strung in series to operate off the 600 aren't they.  Headlights
  are an obvious exception.

  I observed the same on Prc;  operators were very professional.
  Exceptions exist of course so the word 'accident' may be employed.
  Operators into Charleroi were more like family to many of us who
  rode regularly;  locals often brought them food and treats for their
  long journeys.


   Phil
  Without  a   'coast'   but  not  a   'cause.'





  ________________________________
  From: Dwight Long <dwightlong at verizon.net>
  To: pittsburgh-railways at dementia.org
  Sent: Tue, November 23, 2010 8:37:39 PM
  Subject: [PRCo] Re: WP signals

  Phil

  I don't know what the frame of reference was for this post, but I can add this:

  Yes, there were two "paddle" switches in the West Penn system--one turned off 
  the lights in the section just vacated and the other turned them on in the 
  section ahead. West Penn often operated their spring switch-equipped crossing 
  sidings left-handed so that the motormen could lean out the door and throw these 
  switches when located in the space  between the tracks.  This, however, was not 
  universally true.

  The system over the years presented very few problems from "signal failure."  
  But it was not a fail safe system.  Such a system would have had the lights on 
  constantly except when the block was occupied.  In that manner, signal lights 
  out would have meant that a car could not enter the block.

  The biggest problem was that the lights were connected in series, just like old 
  fashioned Christmas tree lamps, and if one went out, all did.  However, the most 
  likely time for one to fail was when first switched on from cold, and motormen 
  were not permitted to pass into a non-lit section without dispatcher authority. 
  The problem was mitigated somewhat by running the voltage at less than for what 
  the lamps were rated.

  Second sections were rare on WP, but one could follow into the block on its 
  leader, maintaining visual contact but with sufficient distance to stop if the 
  leader did.  The alternative, for a not-too-close following section, or an 
  excursion car, was to wait for the leader to vacate the block ahead (lights 
  out!) and then proceed as normal, lighting up the block before entry.

  There were intermediate lights at places such as curves with limited visibility, 
  etc, but this of course did not help the spacing problem with following moves, 
  just alerted the motorman if an opposing car had ignored the crossing point and 
  entered the block.

  Human error as well as electrical error was always a potential in a system as 
  primitive as this.  However, on the up side, WP motormen were very professional, 
  conscientious, and alert to their surroundings, the schedules and normal 
  crossing points, and the like.  Such a system would probably be asking for a 
  collision with today's far less well trained and disciplined work force.

  What prompted this enquiry?

  Dwight
    ----- Original Message ----- 
    From: Phillip Clark Campbell 
    To: pittsburgh-railways at dementia.org 
    Sent: Tuesday, 23 November, 2010 19:59
    Subject: [PRCo] WP signals


    I assume that releasing the signals behind at a siding and
    activating the signals ahead were separate functions.  The
    drawing suggests they 'may' work simultaneously.  This is
    in regards to the manual signals.
    With 30-60 min headways there isn't much problem with
    following cars, just opposing.  Did this system of signals
    present many problems?  Did WP have cornfield meets
    from signal failure?

    How were signals handled when a second section was added
    to a schedule?  Did both cars occupy the single track at the
    same time?  Spacing could be a problem with all the curves.
    I could see the first car forgetting about the second section
    then shutting down the signals at the next siding.  This could
    allow an opposing car to meet the second section on single
    track.


     Phil
    Without  a   'coast'   but  not  a   'cause.'