[PRCo] Re: WP signals

[Phillip Clark Campbell]

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.'