[PRCo] Air Brakes - CERA Trolley Sparks 85

[Fred Schneider]

This is an open letter to Mark Maguire and to anyone else who cares  
to read it.

To Mark because he once asked me to try to teach him about streetcar  
control.

Central Electric Railfans Association (CERA) published a bulletin in  
1949 authored by David G. Blaine, who worked for Westinghouse Air  
Brake and is probably long since pushing up daisies, on the subject  
of streetcar air brakes.   I just now found a xerox copy that I had  
filed in my desk drawer at home.  Ed Lybarger cleaned that drawer out  
and it was in a box here.   I think I also have an original copy of  
the book at home that the princess is holding hostage as part of the  
divorce.   They may still be there five years from now in the same  
boxes rotting in the garage.

At any rate, if someone wants to find an original in a used book  
collection, you are looking for CERA Trolley Sparks, Bulletin 85,  
June-July-August 1949.

This particular booklet, 17 pages in length (some pages must be  
missing in the xerox) deals only with straight air systems.       My  
copy has two piping drawings.  One shows a type SME (Straight Air -    
Motor Car - Electric) for a motor trailer set.   The second drawing  
is for safety car control but only a single-end car.

He mentions several later improvements, including relay valves, self  
lapping brake valves and variable load valves but does not include  
piping diagrams or drawings.   The relay valve is a separate valve  
mounted on or close to the brake cylinder which controls the actual  
air application.   It is actuated by a small diameter pipe from the  
motorman's valve.   Because only a small amount of air moving through  
a very small diameter pipe from the platform valve is needed to make  
it work, it permits much more rapid applications and release.   As an  
aside from Fred, the Melbourne, Australia, cars which Gomaco has  
scrapped in order to produce the pseudo Birneys for Little Rock,  
Memphis and Tampa had relay valves.   Therefore those new so called  
"Birney cars" in the U. S. have relay valves and the brakes are very  
fast acting compared to cars made between 1916 and 1930.   (Mark:    
Now that you have run PST 78, you need to go over to Tampa and  
observe just how fast the brakes on those cars apply and release.)

Dave Blaine also mentions the West Penn track brake technology and  
PCC air brake and dynamic brake technology.

I think that there was a subsequent CERA booklet covering AMUE  
designs (Automatic, Multiple Unit, Electric)

Blain also provides an appendage of Westinghouse apparatus ...  
compressor stock number and how to decode them (i.e. what AC, A, AA,  
B, BB, C, D, DH, UH meant and what the numbers afterward meant.    
DH-16 for example was a bungalow compressor putting out 16 cubic feet  
of air per minute.   He also decodes the mysteries of all the brake  
valves.

What he does not do, very sadly, is comment on the competitor's  
products.   If you see a CP-27 compressor, it was made by General  
Electric.   He does not mention that General Electric was even in the  
business.   David worked for Westinghouse Air Brake.

I WILL LEAVE THIS LAY ON THE DINING ROOM TABLE FOR A FEW DAYS.   IF  
ANYONE WANTS A COPY, I'LL TAKE IT TO OFFICE DEPOT AND RUN IT ACROSS  
THEIR MACHINE.   WHOEVER WANTS IT PAYS WHATEVER IT COSTS ME.   SEND  
MAILING ADDRESS.   AND REMEMBER, YOU'LL BE GETTING A COPY OF A  
XEROX.   WILL NOT BE AS SHARP AS A FIRST GENERATION COPY.

Next time I go to PTM, it goes to the library and you've lost the  
opportunity.

Fred Schneider
EMail or 717 560-2091