Control terminology

[Fred W. Schneider III]

Jim Holland wrote:
> 
> Greetings!
> 
> > . . . Charleroi and Tylerdale
> > barns generally had cars with Westinghouse HL control, really a knockoff
> > of General Electric type M form K in that the PRC cars used solenoid
> > switches instead of pneumatics.
> 
>         What are the advantages and disadvantages of each system - solenoid and
> pneumatic?

They both work.  Both had acceptable reliability.  There are no chances
of solenoid switches freezing up.  Its curious that, in the Type M /
Unit Switch control era, Westinghouse used pneumatics and GE didn't. 
When we got to PC/PCM/PCC control, GE moved to pneumatics, and
Westinghouse went to electric pilot motors.  
> 
>         Looking at this super detailed roster that lists each car number and
> dates separately, I will completely quote  *Group--23*  and then
> interpret it afterwards:::::::
> 
> 
> 
> -->>-->>        What does 3-sp. stand for with the Jones control?
>                         And I am not asking Ken because I
>                         know the answer from him already!!

Unfortunately, when the PERC or PRMA management had the chance to get
all of the individual car record cards from Pittsburgh Railways, only
selected cards were obtained and the rest were destroyed.  This, of
course, makes it impossible to answer a lot of questions about which
cars had different forms of Jones control and which were rebuilt, and
how were they rebuilt.

There were several different control schematics for Jones control, in
particular a Westinghouse scheme and a General Electric scheme.  The
common threads are that all schemes used resistance only on point 1 and
changed motor connections on the remaining points.  But not every scheme
connected the motors the same way on the same points starting with
perhaps point 3 or higher.  I think point two was always all four motors
in series.  The highest point was all four motors in parallel. In
between their were things like one motor dead, two in series, one in
parallel.  All sorts of wierd combinations that would lead to a slippery
car.  If someone wants the schematics, I can mail them.

I cannot give an explanation but I can give you a SWAG (Scientific Wild
Assed Guess). It may have stood for three running points in which all
motors are powered, i.e.
     1.  All motors in series  (motor voltage 137)
     2.  Two series pairs of motors wired in parallel (voltage on each
motor 275)
     3.  All motors in parallel (voltage on each motor would be 550).  
> 
> 
> Group--24  4250--4299 GE 3-sp. control.
> 
> Group--25  4300--4349  BE 3-sp control.
> 
> Group--26  4350--4399  HL & K-35 control.
> 
> Group--27  4400--4411  WH 3-sp. control.
>         All these cars scrapped by 1942.
> 
> Group--28  4420--4423  Jones 3-sp. control.
>         Former trailers.
> 
> Group--29  4700--4799  K-35 control.
> 
> Group--30  4800--4824  K-43 control.
> 
> Group--31  4825--4864  K-43 control.
> 
> Group--32  4865--4939  K-43 control.
> 
> Group--33  5000--5099  HL control.
> 
> Group--34  5100--5159  HL control.
> 
> Group--35  5200--5282  HL control.
> 
> Group--36  5400--5464  K-43 control.
> 
> Group--37  5500--5549  K-43 control.
> 
> James B. Holland
> 
>         Pittsburgh  Railways  Company  (PRCo),   1930  --  1950
>     To e-mail privately, please click here: mailto:pghpcc at pacbell.net
> N.M.R.A.  Life member #2190; http://www.mcs.net:80/~weyand/nmra/