SIGNAL CHANGES

[Fred W. Schneider III]

Beats me too Jim but I've seen the problem with spring tension.  When NOPSI 832 came
back from Barr Canon this summer, I ran it the first day.  It totally screwed up the
Nachods in one direction only ... the direction that used the improperly adjusted
pole.  Several trips ... every time we ran from a particular end.  As soon as Scott
Davis readjusted the spring tension on that pole, and reset the signals, the problem
never recurred.  He was the one who diagnosed the problem!

Funny thing about all this is that the most primitive of signals were sometimes the
most reliable ... I'm thinking of West Penn's hand operated strings of light bulbs.  I
frankly shudder to think of the FRA's reaction to them today, but they generally
didn't run cars together.

Now, lets twist the subject a little but stay somewhat on the same track.  I'll change
one word in the subject line.

Who out there knows why Conrail chose to replace the PRR color light signals with
their built in redundancy with the Reading Company color light version?  I really
can't believe the cost of changing three light bulbs instead of one would be
sufficient to justify such a monumental change in technology.

Jim Holland wrote:

> Greetings!
>
> Fred W. Schneider III wrote:
>
> > Pittsburgh Railways Co. didn't have the same problems with Natchod signals
> > actuated by trolley wire contactors, but our experience at PTM indicates a
> > totally different range of problems.  Natchods are most sensitive to trolley
> > pole spring tension, car speed, and the width of the wheel or shoe.  They don't
> > like weak poles.  They despise cars going faster than five miles an hour through
> > contactors.  Certain cars with shoes won't work consistently because our
> > contactor width is designed for wheels .
>
>         What kind of overhead contactors are used?  Is it the one that has a
> leaf paralleling the trolleywire for about 2-feet on either side of the
> trolley wire?  This is the type that PRCo commonly used for signals
> operated from the overhead; it was used on the 38A between Clearview and
> Castle Shannon.
>         If this is the type it befuddles me as to why spring tension would
> affect operation.  I can see speed possibly being a factor and
> definitely the size of the wheel or shoe, but I don't understand the
> spring tension being a problem.  Would be interesting to understand why.
>         Five-mph is almost a dead stop - I believe it was rather common for
> PRCo to be hitting these at 10-15-mph - but could see that going fast
> might be a potential problem.
>         The thing about the prototype is that it is in constant use and while
> this produces wear it does keep it functioning.  With a museum operation
> where there is sporadic operation the equipment can become sluggish,
> even electrical equipment!  There is a parallel to an auto sitting idle
> for many months - a parallel but a definite big difference in operating
> characteristics after sitting that long!!
>         I have seen that with some of the inductance turnouts used in the TC
> overhead here.  Some turnouts are rarely used - and trying to set the
> turnout for the first time in months usually does not produce results.
> It might work after several tries and then function normally after that!
>
>         There is a picture of one of the contactors I am describing on pg.19 of
> Harold A. Smith's book *Touring Pgh. by Trolley* - upper right - and I
> see at least 2-more in that photo!!  Also the picture on pg.22 we are
> looking up under one of those contactors; also pg.42 - pg.18; pg.71
> center photo 2-contactors; should be some on pg.43 but they are not
> discernible.
>         These signal operating contactors are distinctly different from the
> contactor used to throw a track switch as top photo pg.8 and the trolley
> pole of 1797 is ready to cross the contactor for the turnout; pg.12 top
> photo; pg.55 top left; pg.77 top photo; pg.79 the trolley pole has just
> crossed the turnout contactor.
>
>         From Volkmer's color book of the Pgh region, the signal operating
> contactors are on pg.72 top; pg.83 top; pg.105 bottom; pg.108 bottom;
> pg.113 top.
>
>         From Volkmer's color book of the Pgh region, the track switch
> contactors are on pg.96 bottom; pg.124 bottom; pg.49 JTC top right.
>
>         There was another style of contactor for signal operation that I saw
> only on the Drake to activate a safety stop near a school crossing south
> of Santa Barbara siding near Hultz (Bethel Village).  There were
> 2-contactors - one on either side of the grade crossing and these
> contactors were directional sensitive since this was a single overhead
> wire, not gauntlet as on Overbrook parallel to Saw Mill Run Blvd.
>         The contactor had a casing that was rounded on top and straight on the
> sides which paralleled the overhead on either side of it for about
> 2-feet.  Within this casing were two moving contactors placed at an
> angle to the trolley wire and on either side of the wire.  Approaching
> the contactor heading south, the contactor on the right side of the
> trolleywire was touching it and angled away from the wire.  The
> contactor on the left side was away from the wire but angled in to touch
> the wire on the south side.
>         As a trolley pole wheel entered the contactor southbound, it would
> actually ride on both the overhead and the right side contactor and
> would pull this right side contactor in against the wire as it
> proceeded.  It would just scrape against the contactor on the left side
> as it exited.  Pressing this right side contactor is like depressing a
> key on your keyboard to activate an electrical circuit and it is spring
> returned to its former position.
>         This then activated a way side signal (Nachod?) that was time delayed
> to force the interurban to make a safety stop.
>         Approaching the second contactor heading northbound and the left side
> contactor becomes the right side contactor - the two sides are mirror
> images of each other - and the time delayed safety stop signal was
> activated.  Going thru the second contactor on the far side of the of
> the grade crossing would not activate anything unless it was a recording
> device to record the time between activating the first and second
> contactor to make sure the safety stop was made!
>
>         Wouldn't it be fun to try to model something like that!  I have
> operated my turnouts using trolleywire contactors but it tisn't easy to
> do!
>
>         Interesting that Ohio Brass apparently did not make these items for
> trolleycars - nothing in their 1948 catalog.
>
> James B. Holland
>
>         Pittsburgh  Railways  Company  (PRCo),   1930  --  1950
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