<html>
<head>
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
</head>
<body>
<font face="Calibri">Yawh; I know Daria ...<br>
<br>
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. <i>Howsomeever</i> -- 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.<br>
<br>
PRCo Orders 1948.05.07 written <b>to equip PCC 1645 As
Interurban, B-2B trucks [from 1644]</b> 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!.)<br>
<br>
Framing of ALL B-2 Trucks might 'simply' be described this way:<br>
</font>
<ol>
<li><font face="Calibri">"H" Upper frame, tubular by design,
extending over the Axles</font></li>
<li><font face="Calibri">Rectangular Lower Frame including axles</font></li>
</ol>
<font face="Calibri">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.<br>
<br>
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).<br>
<br>
The B-2A(B) differs from the plain B-2 in at least 2+Very distinct
ways:<br>
</font>
<ol>
<li><font face="Calibri">The Bolster swing links are replaced with
rubber springs (Shades of the B-3 within the B-2B!)</font></li>
<li><font face="Calibri">Coil springs at 4 corners of the trucks
are replaced with Rubber Springs Which Are:</font></li>
<ol>
<li><font face="Calibri">Soft Vertically.</font></li>
<li><font face="Calibri">Hard horizontal movement which keeps
axles parallel thus eliminating 'this need' for torque arm.</font></li>
</ol>
</ol>
<font face="Calibri">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.<br>
<br>
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.<br>
<br>
<i><font size="+2">Asides:</font></i><br>
<br>
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.)<br>
<br>
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.)<br>
<br>
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.)<br>
<br>
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.<br>
<br>
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.<br>
<br>
(ALL PRCo B-2B trucks had stamped torque arm and track brakes
suspended with compression springs.)<br>
<br>
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.<br>
<br>
</font>
<blockquote type="cite"
cite="mid:03c201d75e17$09f83840$1de8a8c0$@normanspaulding.com">
<div class="moz-cite-prefix"><font face="Calibri">On 2021-06-10
12:38, <b><font size="+1">Norman E. Spaulding</font></b>
wrote: <br>
</font>
<blockquote>
<blockquote><font face="Calibri"> Date: 06/10/21 07:10<br>
Re: PCC Cars in Pittsburgh, PA and San Francisco, From A
Friend<br>
Author: dariaphoebe<br>
</font></blockquote>
</blockquote>
<font face="Calibri"><font face="Calibri">Greetings: In
September 2018, I made a lengthy post on Trainorders that
was actually your post. Now comes someone today, who has a
question:</font>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<br>
</font></div>
</blockquote>
</body>
</html>