[PRCo] Re: Fineview___PCCs

[Fred Schneider]

If you are suggesting Tony DeSensi at Arden ... he was a parts replacer who
could get a car moving.
Regarding variable rate drum brakes:  drums were generally used only in
conjunction with extended dynamic brakes in North America, which extended the
dynamic brake capability down to about 1 mph or about 1.5 feet per second.
Given a normal braking rate of around 4 miles per hour per second, the car is
going to stop in about 4/10ths of one second after the drums come on, which is
faster than any operator could adjust the pedal depression to change a braking
rate.  Regardless of such reality, General Electric did build variable rate drum
brakes which, to me, seems somewhat lame.

I was not aware that anyone had variable track brakes.  The general principal
here is that you simply don't use them in normal service because they cause
excessive rail wear, particularly at stops.  A good operator simply doesn't push
the pedal more than half way down.  We also don't want the passengers to be
alarmed by hearing the emergency buzzer.  And when you need them in an
emergency, graduation of the braking rate is the last thing you think about ...
at that point you want the car to stop yesterday.   But given the the propensity
of  car owners to dream up something that distinguishes their cars from everyone
else's, I don't doubt that it happened.  I recall questioning a control engineer
from General Electric  about all the various control and motor designs for
PCCs.  I was bewildered.  His answer was simple.  GE wanted to make money and if
the customer didn't like the off the shelf product, they would change it to get
the money.

Make sense?

Boris Cefer wrote:

> Wasn't the problem of all-electrics in lack of drum brake adjustment? Maybe
> no. The soft adjustment of standard all-electric drum brake would provide
> very long stopping distance on steeper downgrade and the shoes would suffer
> heavy wear.
>
> Maintenance specification we use here for drum brake says that each car must
> be tested by removing of drum brake fuse and pressing power pedal to reach
> starting current of 290 Amps - drum brakes must hold the car (on dead level
> track). 290 Amps cause approximately the same traction effort as 9.5 %
> downgrade. Sometimes we experience drums which are sufficient to hold the
> car at 350 Amps, which would be about 11.5 % downgrade, but this is with new
> brake shoes and freshly adjusted brake. I think there is no considerable
> difference between WAB brake and our CKD product, as for the braking
> capability.
>
> But if you find any drawing and cpecification for WAB drum brake and
> actuator at Arden (that would need some work - consign it to limbo), I can
> easily made a calculation and answer the question of maximum grade which
> allows drum brake operation.
> Or you can ask Tony, I think he has some experience with 1700s. I am curious
> what he knows about drum brakes.
>
> B
>
> ----- Original Message -----
> From: "Fred Schneider" <fschnei at supernet.com>
> To: <pittsburgh-railways at dementia.org>
> Sent: Thursday, March 11, 2004 11:32 PM
> Subject: [PRCo] Re: Fineview___PCCs
>
> > The 1600s did not have spring applied drums ... they had air brakes.  It
> was my
> > understanding (correct or incorrect) that the cars used on Fineview were
> set up
> > for higher brake pressure.  Extended dynamic braking would not have been
> > significant because the cars would stop automatically ... they faced
> forward
> > uphill.  The problem was holding the cars on a hill.  I can assure you
> that
> > all-electrics would not hold on Henderson Street without also using track
> brake
> > shoes.
> >
> > Boris Cefer wrote:
> >
> > > I know about 1689, 1690, 1695 and 1697. What else?
> > >
> > > But my opinion is that it had nothing to do with dynamics. The problem
> was
> > > in drums which were not sufficient to hold the car on a steep grade or
> make
> > > a rapid stop.
> > >
> > > Boris
> > >
> > > ----- Original Message -----
> > > From: "John Swindler" <j_swindler at hotmail.com>
> > > To: <pittsburgh-railways at dementia.org>
> > > Sent: Thursday, March 11, 2004 10:37 PM
> > > Subject: [PRCo] Re: Fineview___PCCs
> > >
> > > >
> > > > Correct Jim.  Not gospal - just something once heard - or read.  And
> the
> > > > recollection is that it wasn't the entire 1680s.  Had to do something
> with
> > > > extended braking - which sounds like something for Fred the third to
> clear
> > > > up.
> > > >
> > > > Wish I'd paid more attention back then.
> > > >
> > > > John
> > > >
> > > >
> > > > >From: Jim Holland <PghPCC at pacbell.net>
> > > > >Reply-To: pittsburgh-railways at dementia.org
> > > > >To: pittsburgh-railways at dementia.org
> > > > >Subject: [PRCo] Fineview___PCCs
> > > > >Date: Thu, 11 Mar 2004 13:06:06 -0800
> > > > >
> > > > >Good Morning!
> > > > >
> > > > >
> > > > > > Fred Schneider wrote:
> > > > >
> > > > > > Was 1699 one of those cars altered to run on 21 FINEVIEW?
> > > > >
> > > > >Fred  --  wouldn't your car-cards give us this info?
> > > > >
> > > > >
> > > > > I was told it was the 1680s modified for Fineview.
> > > > >
> > > > > This is  *White--Flagged*  information which means
> > > > >it is the best information so far but unconfirmed.
> > > > >
> > > > > John Swindler told me this in the 1960s.     John
> > > > >never said this was Gospel  --  it was just what he had
> > > > >heard and thus shared with me.
> > > > >
> > > > >
> > > > >
> > > > >
> > > > ><><><><><><><><><><><><><><><><><><><><>
> > > > >
> > > > >Jim
> > > > >
> > > > ><><><><><><><><><><><><><><><><><><><><>
> > > > >