[PRCo] Re: Fineview___PCCs

[Fred Schneider]

Tony never worked at Homewood Shops, only in carbarns where the object was fix
something simple or call Homewood to send out a runner to get the car.
According to Tony, barn men were not used to run lame cars to Homewood.

Boris Cefer wrote:

> From: "Fred Schneider" <fschnei at supernet.com>
> Subject: [PRCo] Re: Fineview___PCCs
>
> > If you are suggesting Tony DeSensi at Arden ... he was a parts replacer
> who
> > could get a car moving.
>
> But he should know particular parts and how the assembly works. When
> electric brake actuators are adjusted at shops (heavy maintenance), they use
> a dynamometer to adjust them at 55 kilogram pull. Don't know exact value in
> lbs required by WABCo specification.
>
> > 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 don't know much about GE, but Westinghouse equipped PRCo 1700s had their
> drum brake control circuits designed so as to obtain 3 different braking
> rates. Wiring diagram shows it clearly. And we had the same arrangement on
> earlier equipment.
>
> > 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?
>
> GE policy? Why not. But again - I don't know GE. Westinghouse 1700s had 4
> (F-O-U-R) rates of track brake actuating. Gives sense to you?
>
> > 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