[PRCo] Question For You To Answer

[Holland, James B.]

Yawh; I know Daria ...

View Any B-2B truck, PRCo 1725-1799 / TTC 4500-4549 (only PCCs to use 
Clark B-2B) and you see B-2A. Note: These cars All+Electric; PCCs 1644 & 
1645 Air+Electric. Rare Pics foggy; B-2A appear as Any Clark B-2 w/drum 
brakes, torque arms. PCC 1644 had short Interurban life: CVI 1947.05.02; 
CV CITY 1949.05.19; Essentially, B-2A and B-2B look identical. 
/Howsomeever/ -- Some / Many / Most could not tell difference between 
'plain' Clark B-2 truck and B-2B let alone between B-2A and B-2B. 
Additionally, as trucks often 'rotated' to other equipment, simple even 
foggy pics do not tell us exactly what IS under the car.

PRCo Orders 1948.05.07 written *to equip PCC 1645 As Interurban, B-2B 
trucks [from 1644]* to be applied. (Purchase order Not known for another 
set of Air+Electric B-2A(B) trucks; those on 1644 presumed source for 
1645, especially since 1644 "demoted" from Interurban to City status!.)

Framing of ALL B-2 Trucks might 'simply' be described this way:

 1. "H" Upper frame, tubular by design, extending over the Axles
 2. Rectangular Lower Frame including axles

Lower frame has dual spring pots mounted over axle, one spring forward, 
other aft of axle. Thus four, dual spring pots at 4+corners of truck. 
Torque arms mounted between axles to keep axles "parallel". This arm 
solidly bolted to axle closest to gear house; other end of arm is 
flexible for uneven track. Bolted arm is 2nd and 4th axle on door side 
of PCC, 1st and 3rd axle on 'blind' side.

Upper "H" frame are two tubes, one each side of truck, from which 
Bolster is hung through swing links. "H" frame set over axle spring pots 
and secured in place. Motor mounts welded to tubes on both sides. As 
1601s Only in consideration, friction brakes are drums mounted at motor 
on drive shaft; Track brakes suspended from torque arms with extension 
springs (soon changed to Compression Springs).

The B-2A(B) differs from the plain B-2 in at least 2+Very distinct ways:

 1. The Bolster swing links are replaced with rubber springs (Shades of
    the B-3 within the B-2B!)
 2. Coil springs at 4 corners of the trucks are replaced with Rubber
    Springs Which Are:
     1. Soft Vertically.
     2. Hard horizontal movement which keeps axles parallel thus
        eliminating 'this need' for torque arm.

B-2A presents dual action as Both Spring / Torque arm (Hard horizontal 
movement) rendering usual torque arm obsolete except for need to mount 
Track Brakes! Production B-2B trucks retained normal springs at 
4+corners and retained original torque arm because of Need to attach 
track brakes! Rubber sprung bolster is retained on the Production B-2B 
trucks.

Operators introduced to many features of new PCCs for Interurban service 
- significant is how to secure car if disabled and how to prepare for 
being pushed / towed, etc. Noted is Each and Every Operator of 1644 
(1645 after converted) Without Exception reported back at exceptional 
ride on B-2A / B-2B trucks, a shadow of things to come in 1949 where 75 
All-Electrics arrive with B-2Bs.

/Asides:/

No record 'known' to reveal how long B-2A(B) remained under 1645; she 
had standard B-3 during most of 1950s until her end. One of a kind units 
rarely last long. (PCC Interurban 1645 scrapped 1967 as result of 
collision with 1261 on 38A, nachod failure.)

ALL PRCo 1601s arrived from St.Louis With B-2 trucks With Drum Brakes; 
None had wheel tread brake shoes as ALL air cars before did (100; 
1000-1299; 1400-1564). Many 12s and 14s had wheel tread brake shoes 
removed and replaced with drum brakes but only 6+cars of the 15+series 
were modified, 1500-1505 (with 1505 renumbered from 1547 - the original 
1547 was all painted for PRCo but sent to TCRT; the replacement 1547 was 
built 'with the 1601s and delivered with drums but otherwise appeared 
like 1500s. As 1500-1504 were converted drums, PRCo traded numbers on 
original 1505 and replacement 1547 to keep drum equipped cars within a 
set of the 15s.)

Interurban routes / Operators wholly separate from City Lines until 
1955, both at South Hills Car House; in spite of truncating lines within 
Allegheny County in 1953, Interurban PCCs strictly set aside for 
Interurban use until early 1970s. Occasional exceptions exist, but that 
was the rule. PCCs came to Pgh. 1936 with steady new deliveries every 
couple years. Year+1946 saw dedicated use of PCCs on Washington 
Interurban first. (Rush Hours saw 12--d & 1400s PCCs used locally on 
Overbrook through Castle Shannon to West Library, even to Riverview on 
occasion. Some 1200 series PCCs participated in B-3 Truck testing.)

On delivery of 1601s, Track brakes mounted on Cast/forged Torque arm 
with Extension Springs but these cars quickly received a change to 
'stamped metal' torque arm with compression springs for track brakes. 
ALL previous Air Electric Cars had Extension Springs on track brakes, 
forged torque arm.

The 1601s "Already Modified" and In Service as Interurbans on Washington 
line received their roof lights about 1949 (with which 1700-1724+series 
were equipped on arrival, same year). The one exception is 1644: it 
seems she never received the roof light.

(ALL PRCo B-2B trucks had stamped torque arm and track brakes suspended 
with compression springs.)

Often I wrote about the superb ride qualities of B-2B on Pgh. list to 
find myself talking to a Cement Wall -- NO ONE else ever wrote anything 
that reflected knowledge let alone experience with riding a B-2B 
equipped car, Not Even THE Experts. As Bolster springs aged car often 
leaned distinctly into turnouts, especially narrow ones, forcing trolley 
wheel onto wrong wire and dewirement. Very late 1950s, early 1960s I 
noted soft ride disappeared on many, eventually, ALL 75 17s. No one on 
list knew what I was talking about. It was 2011 when esteemed visitor 
Mr.Cefer found in PTM archives that shock absorbers on Interurban B-3 
trucks were to be removed and installed on 1726-1799. Of course, some 
shocks bought new as only 37-38 PCCs equipped with B-3s.

> On 2021-06-10 12:38, *Norman E. Spaulding* wrote:
>
>         Date: 06/10/21 07:10
>         Re: PCC Cars in Pittsburgh, PA and San Francisco, From A Friend
>         Author: dariaphoebe
>
> Greetings:  In September 2018, I made a lengthy post on Trainorders 
> that was actually your post. Now comes someone today, who has a 
> question:Worth asking, and this seems like as good a place as any: do 
> any of you know of pictures of the experimental B-2A trucks that were 
> under 1644 briefly? Norm
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