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

[Jim Holland]

Herb Brannon wrote:
.
> Maybe it was just a bad dream then. I know, I was there in the 
> operators seat. Whatever the trucks, the specs, the engineers 
> drawings, the claims of Transit Reserarch Corp., etc. the brakes 
> failed and the car glided (it was not a 50mph runaway) all the way to 
> the bottom of the hill. It was then pushed around downtown and back to 
> SHJct by another car. But then 1727 should not have crashed either. 
> That car was heading for disaster almost a decade before it finally 
> did itself in. The cars had all seen heavy usage and PATransit was 
> trying to keep them going as long as they could. SKYBUS was a dead 
> subject and the cars had to keep operating. Many modifications and 
> "experiments" along with rebuilds (mostly "cosmetic", but "mechanical" 
> to the point that the operation of the vehicle might have been 
> changed) caused many strange mechanical happenings that were never 
> fully discussed with the general public, the press, or the railfans. I 
> remember that incident quite well, it was the
> only time I came close to being scared. I don't scare easily, believe 
> me, I don't. That trip down the hill was as close as I have come to 
> being really scared.
.
You have some Vivid Dreams, Herb!!!    Possibly what Boris suggested --- 
air pressure insufficient for complete release of drums and they wore 
out --- track brakes should have helped and even stopped the car.
.
Since this Is an ImPerfect World we shall  *_Always_* have accidents --- 
they can't be avoided even with the Bestest of Planning!!!
.
1727 may have been a problem car but *_The__Problem_* which caused the 
accident has been positively identified and is most probably totally 
unrelated to other problems the car had.  Only time I experienced 
anything similar to non-responsive braking was an SF Baby Ten  
(Westinghouse, B3 like PRCo Interurbans)  was a car giving an operator 
trouble on pullout and since I was working the line closest to the barn 
it was traded to me for pull-in.  The car wouldn't take power 
immediately but when it did come on it came on with a real Bang!  Very 
similar for braking.  Just cleared the K-line loop at Phelan so was off 
revenue trackage and on pull-in trackage when the car locked up --- 
Battery low which means drums won't release.  Battery drives pilot motor 
and possibly explains the slow response and Banging on both acceleration 
and braking.  I could go back through my files and pull up the car 
number but that takes time.
.
The ex-SLPS cars in SF Muni 1101 series  (GE!!)  were prone to Total 
Brake Failure --- something in the KM switch group failed as I was 
told.  Had that happen Many Times --- hate those cars!  Can't compare 
these cars to others because they are early All-Electrics and SLPS was 
the experimental property for All-Electrics.  Acceleration worked much 
differently from the Baby Tens --- rough on the SLPS cars --- donut know 
if that was a GE type problem or just the unrefined experimental nature 
of these All-Electrics.  While I did not like PRCo 1725-1799 GE 
ALL-Electrics, the acceleration was not noticeably different from the WH 
cars, 1700--1724, so I suspect that the problems with the SLPS cars are 
from the earlier phase electrics.
.
.
.
JBH
.
.
.
> Jim Holland <PRCoPCC at P-R-Co.com> wrote: Herb Brannon wrote:
> .
>> When mechanical 'things' (in this case a 1945 PCC streetcar, still
>> operating in 1975-76) get to a certain age, like humans, they start to
>> fall apart. Yes, it was the "Spirit of '76" car, and it had a bad air
>> leak. It would not have mattered if it would have had every type of
>> air applied brake known to mankind, it still would not have stopped
>> without any air pressure to apply the brakes. That brake system (air
>> applied/spring release), in my opinion, was one of the more stupid
>> systems devised. Couldn't at least one of the scores of engineers
>> working on the PCC project thought far enough to realize that a spring
>> applied/air released system would have been safer ???? They thought
>> enough to put a 'hand brake' on the car, why not a "fail safe" braking
>> system?
> .
>> Boris Cefer wrote: Are you sure, Herb? 1776 was
>> formerly an interurban car with B-3 trucks and spring-applied drum
>> brakes with air actuators (pressure-releasing).
>>
>> B
> .
> 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
>
>
>
>
> Rise Up -- Go Cavs
> Herb Brannon
>
>
>
>