PCC Controllers

[Jim Holland]

Greetings!

	This question is mainly intended for Dr. Fred Schneider, III!

	My understanding of a description of the controller for the PCC cars is
that the motorman is just choosing acceleration rate when he depresses
the power pedal, not speed.  At any depression of the power pedal the
car would theoretically get to full speed if left in that position long
enough.

	Yet in actual practice, it seems that only the all-electric PCCs
operated this way, but not  a-l-l  all-electrics (the St. Louis cars
come to mind and the ex-St. Louis cars used in SF as well as the SF
double ended torpedoes, 1006-1015.)

	I remember riding PRCo PCC 100 (M11) as a stow-away on a PERC or PRMA
charter back in the 50s.  If the motorman had the pedal to the floor and
then backed off to half-way depressed, the car would slow down.  But if
the same was done on a 17, the car would not slow down but would
continue accelerating but only at a slower rate of acceleration.

	I noticed that the 10s, 11s, 12s, 14s, and 15s also acted like 100 -
the cars would slow down as the power pedal was released.

	The 16s seemed to be in a class by themselves - they were a blend of
air- and all-electric car features with extended range dynamics and a
different controller package.  If the power had been floored and the car
had accelerated to about 25 mph and then the power pedal was backed off
half way, I *think* the car maintained speed and might have continued
accelerating.  But if the power pedal was only halfway depressed after a
full stop, the car would not accelerate to full speed.

	I remember riding a 16 home from town.  As we entered the tunnel, the
motorman depressed the power about 1/2 to 2/3 and the car was gently
clicking off the rail joints.  About a quarter of the way up through the
tunnel, the motorman put it to the floor and that 16 took off like a pig
stuck with a hot poker and it sounded like the speed doubled as the car
really clicked off the rail joints!  The 16 city cars seemed much more
powerful and swift than the other cars, even the 17s.

	Also, on the 16s, if the pedal was kept to the floor, the power would
cut at full speed.  The motorman would have to release the power, allow
the car to slow, and then reapply.

	On the 17s, the motorman could keep the pedal to the floor and when the
car slowed sufficiently (to about 38-39 mph) the power would cut back
in.

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