PCC Speed

[Jim Holland]

Greetings!

Vigrass, Bill wrote:
> 
> . . . But to save flashovers, SHRT introduced
> an Agastate delay relay somewhere in the controls -- I dunno where,just
> heard it from non-technical motormen -- that, I believe, delayed the input
> of dynamic braking while coasting.

	Yes - rode Shaker in the late 60s early 70s and I noticed that they
coasted much more freely than any other PCC I had ridden.  Part of the
*railfan lore* (aka, railfan propaganda - aka railfan lies) concerning
PRCos PCC interurbans (which I heard in the 50s) is that they were
specially geared without the dynamic governor when the power pedal was
released.  But that was not true; the dynamic governor was there, but it
did not seem quite as strong as in other PCC cars, and most definitely
not as strong as some of the GE cars from the North Side.  And the
gearing on all PCC cars was the same!

> Most, perhaps all, PCC's didn't really
> coast, as the circuit was set up for braking as soon as power was removed,
> so I was told.

	Don't know if it was designed as such, but the dynamic retardation when
the power is released is a good safety feature to *help* prevent
runaways.  Of course, this can not take the place of standard braking
downhill, but the fact that the GE cars of the Northside were set up
with strong dynamic governors (so strong that interurban motormen
*strongly* disliked them when they were brought to the South Hills)
indicates that this automatic dynamic retardation was used as such!

James B. Holland
------- -- ---------
        Pittsburgh Railways Company (PRCo), June of 1949 -- June of 1953
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