[PRCo] Re: PCC__Handbrakes

[Fred Schneider]

Ed:

I had a hectographed page from the engineering office in Homewood (for those
who think it matters, it is not on company letterhead) that lists all of the
numerous variants in brake schemes among the Pittsburgh PCC cars.  I said a
page ... a whole page of different schemes and retrofits.  I have no idea where
it is today but you might look in all my left over files from the PCC books
that we moved to the library.

In general all-electric cars had spring applied, electrically released drums,
and the shoes could either be internal expanding or external contracting.  In
other words, any way it could be built, it was.  I have no objection to what
anyone posted here about air drums ... again, they could be internal or
external to the drum, and air applied / spring released or vice versa.
Whatever a company wanted to buy.  If you can find that sheet, you might have
proof that Pittsburgh did it both ways.

What I'm most curious about is Boris's picture showing the air cylinder next to
what looks like an air reservoir.   It appears that the air reservoir being
right next to the cylinder was an attempt to either give a bast apply or a fast
release by not having  100 feet of pipe to fill with air.  One of the problems
with some air-PCCs (the only one with which I have experience) is the slow
application time after the lockout relay commands a brake application.  It
takes time to charge all that pipe.  Therefore you tend to get a momentary
brake release when the dynamics fade and it takes a second or two for the air
to build up.  This may have something to do with my observing track brakes
being used on air cars as they came to a stop on a safety island in East
Liberty.  Perhaps the motorman was pushing the pedal to the floor to avoid
running off the end of the island, and getting track brakes.  My experience is
with Baltimore 7407.  I'm waiting to see if PRC 1138 behaves the same way.

For those of you totally oblivious to what I'm trying to say, with any air
brake system, the brakes will not apply (or release) until the pipes are filled
with compressed air or all the air is released.  Some of the newer Gomaco cars
are using relay valves to connect an adjacent air tank to an air cylinder, and
using very small diameter pipes to connect the relay valves to the motorman's
brake valves.  This appears to cut the application and release times down to a
fraction of a second.   This was not a problem with all-electric PCC cars
because ... think back to high school physics ... electricity travels at the
speed of light, or 186,000 miles per second.  If you all-electric car was
equivalent to a snake wrapped twelve times around the earth, then you would
have a similar delay.

So Boris ... you want to post a drawing to show us just how this works.  I can
see two valves.  One probably a magnet valve (the lower one) and the other
valve hand controlled from a pull / push rod.

fws

"Edward H. Lybarger" wrote:

> I don't think we have an interior view of a 10.  We have one of car 100,
> with the automotive-type handle-sticking-out-of-the-floor, and of course we
> have the actual thing in 1138.  Someone who is more into minutiae than I
> will have to answer this one.
>
> -----Original Message-----
> From: pittsburgh-railways-bounce at lists.dementia.org
> [mailto:pittsburgh-railways-bounce at lists.dementia.org]On Behalf Of James
> B. Holland
> Sent: Sunday, May 01, 2005 12:40 AM
> To: pittsburgh-railways at dementia.org
> Subject: [PRCo] Re: PCC__Handbrakes
>
> Hi Ed!
>
> Does it then follow that all the 10s and 11s have a wheel handbrake?
>
> The 12s did have  *opposite--working*  friction brakes from most
> Air-Cars  --  friction brakes on 12s spring applied so hand brake not
> needed to hold dead car.
>
> Jim
>
> Edward H. Lybarger wrote:
>
> > Our 1138 has the wheel; air cars 1400 and higher had the water pump.
> > 1200s didn't have a hand brake, did they?
> >
> > Ed
> >
> > -----Original Message-----
> > From: pittsburgh-railways-bounce at lists.dementia.org
> > [mailto:pittsburgh-railways-bounce at lists.dementia.org]On Behalf Of Boris
> > Cefer
> > Sent: Saturday, April 30, 2005 6:16 AM
> > To: pittsburgh-railways at dementia.org
> > Subject: [PRCo] Re: PCC__Handbrakes
> >
> >
> > 1440 at Seashore has the "water pump" hand brake lever.
> >
> > B
> >
> > ----- Original Message -----
> > From: "James B. Holland" <PRCoPCC at P-R-Co.com>
> > To: "- 1714 PRCo__WP__JTC -" <pittsburgh-railways at dementia.org>
> > Sent: Saturday, April 30, 2005 12:02 PM
> > Subject: [PRCo] PCC__Handbrakes
> >
> >
> >>>> PRCoPCC at P-R-Co.com writes:
> >>>
> >> >> Don't remember wheel to operate hand brake -- remember lever.
> >>
> >>
> >> > CRVLKOTULA at aol.com wrote:
> >>
> >> > Interesting.......I remember seeing one of these
> >> > hand brake wheels on a Washington PCC from
> >> > the 1938 group. ....A good view of the hand brake
> >> > wheel is illustrated in Fred Schneider's PCC book,
> >> > The Car That Fought Back, on page 142,
> >> > as it appears on a 1938 Philadelphia PCC.
> >>
> >> > Dick Kotulak
> >>
> >>
> >> Hi Richard!!
> >>
> >>
> >> Pg.159 shows PRCo 100 in top left photo with handbrake lever but what
> >> I really remember is the lever like on MBTA 3275 on the top
> >> right!       Don't remember any wheel handbrakes but they apparently
> >> lasted into my era. It is *possible* PRCo changed them to levers but
> >> do not know that for sure.
> >>
> >> I rode in 100 several times but don't remember anything about that
> >> lever -- just the inverted controller and how HOT it got!
> >
>
> Jim__Holland
>
> I__Like__Ike.......And__PCCs!!
>
> down with pantographs ---- UP___WITH___TROLLEYPOLES!!!!!!!