[PRCo] Re: Clark__B2B__Trucks__ (&--B2A)

[Jim Holland]

Good Morning!


> Fred Schneider wrote:

> B2 and B2b trucks all came from Clark Equipment Co.,...
> The B3 was a Saint Louis Car Co. design.


	Had thought of mentioning these trucks in the discussions on the
B3 but forgot!


	The B2B  *might*  be considered a blend of the B2 and B3.

	((Photo on top of pg.128 in  *PCC Car That Fought Back*))


	The  B2B  utilized the B2 spring equalization with torque arm
between the axles under the tubular frame,  *But* the swing link
on either side of the bolster was replaced with a rubber spring
not unlike the B3 spring pot.    This was mounted to the inside
of the tubular frame so the distance from kingpin to spring
centers was considerable less than the similar distance on the B3
to the spring pot which means the trolleycar has more leverage
giving a softer ride.

	The rubber springs probably contribute to that softer ride as
well.    This is where the description of 
*Riding__On__A__Cloud*  is  MOST  Apt!    Motormen claimed that
it  *felt*  like the car was getting lighter as it gained speed
and they feared it would float off the track like a feather!

	If the trolleycar hit a dip in the track it seemed that the car
would move on about a car-length before it would 
ultra-super-slowly  lean into the dip and then right itself.   
In heavy traffic where the motorman would goose the power pedal 
--  on and off the power  --  the car would  Very--Gently--Lift 
with each power application and drop ever so slowly when power
was released.

	While I was born at Pgh.-General and lived on Race street, a
couple blocks from the Homewood yards, we soon moved to Dormont
in the South Hills.    With 25--1700-series cars for interurban
service, SHJ received only 1763--1769  *Originally*  (7-cars) for
city service.    It was a treat, therefore, to ride a city-17!   
Our summer School Picnic was at Kennywood and TrolleyCars where
chartered for the purpose.    About a dozen charter cars came
outbound on the 38-line, one of them a 1700-city car.    We
boarded at the Presbyterian Church opposite Bower Hill Road.    I
hoped for and received my wish of riding on that City-17!    I am
chided for that, even by railfans, because of the sealed windows,
but those B2B trucks were absolutely fantabulous.

	We headed inbound on the 38-line, out Carson, across the Mon to
Forbes and out the 68-line to Kennywood.    That last stretch of
prw really caused the B2B to perform the the Girls were screaming
(with Delight, I hope!) as that car rocked and rolled ever so
gently as we neared the Park.

	Don't Remember Nuttin' about Kennywood that day and would have
preferred by  FAR  to remain on that City-17, but alas and
alack.......


	Was it one  *Fwed*  Who  Said  that railfans ain't interested in
trucks?!?:)    This one is!!    When I joined Uncle Sam's Canoe
Club I wrote to Both Clark and St.Louis who graciously sent me
plans for all the PRCo trucks and PRCo PCCs.    PCCs are
3/4"_==_1'0"  and truck drawings are 1/4-size!    The Clark
Trucks show parts and stock-numbers.


	In 1960, I went to the Shrine convention with my Grandfather in
Toronto.    I nearly had a heart-attack when I spied a PCC rise
and gently settle as the motorman goosed the power on a PCC.   
Chased that car down for a ride.


	Only 125-PCCs utilized the Clark__B2B:

		1.>--	PRCo 1725--1799
			Last PCCs for PRCo.

		2.>--	TTC  4500--4549
			Last  NEW  PCCs for TTC.


	As the trucks aged the cars would lean excessively and PRCo must
have removed or otherwide disabled the rubber springs on the
bolsters.    This happened over time but was well underway by the
time I went to Toronto.    TTC eventually did the same.    I
thought it was because the rubber got softer but two independent
sources said the rubber actually gets harder.    John Bromley
inquired about the TTC B2Bs for me and found the same results.   
At any rate, the super ride of the B2B was gone about 15-years
after they debuted.


	The Clark__B2A was a forerunner of the B2B and this is a quote
from Pg.127 of above mentioned book::

	"""...the first being a pair designated the B-2A for tests in
Pittsburgh.    The conical journal springs were replaced by
rubber sandwiches on either side of the hournal which were soft
vertically and horizontally, but quite stiff longitudinally.   
The torque arms were no longer needed to keep the axles parallel
and the weak link of the rubber bushing was removed.    Rubber
sandwiches lying on their sides carried the bolster.    Soft in
the lateral direction, they provided cushioning for lateral track
irregularities and eliminated the lubrication needs of the swing
link bearings."""

	Note #9 under  *Pittsburgh*  on Foldout #2 in the pocket in the
back of the book lists 1644 as being equipped with the
Experimental  Clark__B2A  trucks in 1946 and then being equipped
with B3 trucks in 1948.    But by 1950, 1644 reverted to a city
car and remained so unitl its demise.


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Waiting for a bus is as thrilling as fishing,
    with the similar tantalisation that something,
        sometime, somehow, will turn up. 
            George Courtauld

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James B. Holland

• Holland  Electric  Railway  Operation....... 
  "O"--Scale St.-Petersburg Trams Company (SPTC)
	Trolleycars and "O"--Scale  Parts
		including Q-Car
	mailto:pghpcc at pacbell.net

• Pennsylvania Trolley Museum
	http://www.pa-trolley.org/
• Pittsburgh  Railways  Company  (PRCo),
	1930  --  1950
• N.M.R.A.  Life member #2190;
	http://www.nmra.org

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