[PRCo] Re: Fineview___PCCs

[Boris Cefer]

So somebody will have to visit the library at Arden with a doodlebug in his
hands.
Don't look at me, I cannot spend three months overseas!

From: "Fred Schneider" <fschnei at supernet.com>


> 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>
> >
> > > 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
>
>
>
>