[PRCo] Re: Drum__Brakes_--_All-Electrics,__etc........

[Boris Cefer]

I think the experimental trucks had air-applied brakes, except in the first 
stage - originally they had spring applied brakes similar to other 12s, but 
with an emergency release ratchet wrench and pull rod (not that emergency 
release air tank and valve like other 12s).

Is it possible that the brakes on 1776 II were worn due to air leak which 
did not allow proper release? Why did PAT scrap all air B-3 trucks???!!!

B

----- Original Message ----- 
From: "Jim Holland" <PRCoPCC at P-R-Co.com>
To: <pittsburgh-railways at dementia.org>
Sent: Sunday, May 27, 2007 11:17 PM
Subject: [PRCo] Re: Drum__Brakes_--_All-Electrics,__etc........


> .
> As Boris Mentioned, The Bicentennial Car 1776 is ex-1616 and is thus
> equipped with B3 trucks.  ALL  PRCo B3 trucks are *_Spring-Applied_*
> Drum Brakes so a loss of air pressure with 1776_ex-1616 should have
> caused the drums to set up automatically --- i.e., air pressure is Not
> Used to stop  ({[pat]})  1601s renumbered as 1776-1781 --- Springs apply
> the brakes on these cars!!
> .
> Chust as a reminder.......
> .
> .......This is an ImPerfect World
> .
> In Fact --- EVERYTHING and  _EVERYONE_ is Very Far From Perfect.
> .
> .
> That being said, the PCC is Still An Engineering Marvel and was Very
> Well Suited for the job it had to perform.  Even into the 1950s the PCC
> could outpace the average automobile on the road from a dead stop.  The
> PCC books indicate that the accident rate went way down with PCCs as
> compared to older conventional cars because of the increased performance
> and in spite of the Increased Speed of the PCC --- the standard PRCo
> low-floor cars had a top speed of only 25-mph until many were rebuilt
> for speeds comparable to the PCC.
> .
> .
> The Hand Brake was to compensate for the lack of Fail Safe as were the
> track brakes --- get the car stopped using track brakes // hand brake,
> pop the dead man to keep the track brakes applied, jump out of the car
> and chock it!  Loss of Air Pressure is an occasional & UnUsual failure,
> not routine, and the air gauge should give the op indication that a loss
> is occurring so he can Still Safely Stop The Car before total loss.  I
> rode the cars All The Time and Never experienced an air failure and
> remember Only One Operator mentioning such.
> .
> As Schneider mentions, the All-Electrics with spring applied drums are
> fail safe --- but  *_Apparently_*  Not All Of Them.  The ex-TTC, ex-KCPS
> cars that came to SF during subway construction were GE with GE brake
> actuators and am told that when the MG is shut off, so are the drum
> brakes and the car will roll on a hill.  Thus the flange marks on 30th
> from Judah to Irving where a dead car was spotted and ran away!  I
> operated these cars but never shut down the MG except in the yard so am
> not all that familiar with them.  They were Very Smooth Operating cars
> as compared to Muni --- brakes felt Very Soft and as if the car would
> never stop but they stopped Just As Fast as a Muni car but Much More
> Smoothly.
> .
> .
> PRCo:::::::
> .
> 100, 1000--1199 --- Air-Applied, Spring Released Wheel Tread Brake Shoes
> .
> 1200--1299 --- Spring-Applied, Air Released Wheel Tread Brake Shoes.
> Many 12s had brake shoes removed and drums applied.  Cars with drums had
> a tendency to roll back when stopping upgrade.  Thought Izzy Reichert
> was going to have an heart attack when that happened to him on the
> 42-Dormont!
> .
> 1400--1564 --- Air-Applied, Spring Released Wheel Tread Brake Shoes.
> Some converted to drums; these cars Not Plagued with slippage like the 
> 12s.
> .
> 1600 --- All-Electric
> .
> 1601--1699 --- __AS__DELIVERED__ Air-Applied, Spring Released _DRUM_
> brakes --- extended range dynamics.
> .
> ..........For Those 1601s Converted to Interurbans with B3s the Drums
> are Spring-Applied, Air-Released!  Remember___ 1613 and 1614 had
> experimental B3s --- believe that these were Spring-Applied - Boris??
> But Both 1613 and 1614 had B2s reinstalled in the 1950s and it is
> *_Presumed_* that they reverted to air-applied, spring released drums.
> .
> 1700--1799 --- All-Electric.
> .
> It always *_Seemed_* to me that the 1601-Interurbans were never going to
> stop but they did and probably just as good as any other car  (possibly
> not unlike the ex-KCPS cars in SF!)  But the 1601-City Cars *_NEVER_*
> gave such an impression --- they were peppy, powerful cars!!
> .
> .
> .
> Jim__Holland