[PRCo] Re: Interurban PCCs ???

Mon Mar 28 13:34:37 EST 2005

There are some differences in the balancing speed, result of different body
weight. In addition to that, some cars are equipped with different motors,
which also results in changes of the balancing speed (e.g. cars for German
cities which operate trailers).
And there are also another source of differences: several different gear
ratios, which affect the balancing speed. The most common gear ratio is 52:7
(= 7.43), then 7.366 and also 9.36 ("mountain gear") and 8.775.
Unfortunately, the manufacturer did not provide any accurate (if any)
tractive diagrams nor exact motor curves, so I don't know any particular
figures.
For T1, T2 and T3 the balancing speed is roughly 65 km/h.

B

----- Original Message -----
From: "Harold G." <transitmgr2 at earthlink.net>
To: <pittsburgh-railways at dementia.org>
Sent: Monday, March 28, 2005 7:53 PM
Subject: [PRCo] Re: Interurban PCCs ???

> Boris
>
> Interesting emails.  thanks for your knowledge and to
> Jim also.
> Now a question..is the balancing speed of the various
> Tatra different?  T1, T2, etc.?   How about the artics?
>
> Harold Geissenheimer
>
> -----Original Message-----
> From: Boris Cefer <westinghouse at iol.cz>
> To: pittsburgh-railways at dementia.org <pittsburgh-railways at dementia.org>
> Date: Monday, March 28, 2005 2:23 AM
> Subject: [PRCo] Re: Interurban PCCs ???
>
>
> >My opinion is that the figure of 42 mph is related to the early PCCs
which
> >were lighter than the postwar all-electrics. Fred gave us an overview of
> >balancing speeds on various different track grades, which supposedly came
> >from a prewar PCC specification book.
> >Heavier postwar PCCs would have slightly lower balancing speed on dead
> level
> >track than their light predecessors built in 30s, but the difference is
not
> >big.
> >
> >B
> >
> >----- Original Message -----
> >From: "James B. Holland" <PRCoPCC at P-R-Co.com>
> >To: <pittsburgh-railways at dementia.org>
> >Sent: Monday, March 28, 2005 12:46 AM
> >Subject: [PRCo] Re: Interurban PCCs ???
> >
> >
> >> John Swindler wrote:
> >>
> >> > Concerning M11, Jim, the power pedal might have been to the floor,
but
> >> > at the balancing speed, that doesn't do any good - except to maintain
> >> > the car's speed at the balancing speed of the motors.
> >>
> >>
> >> Thank You for mentioning this, John  --  don't know how I could have
> >> missed this fact! :-D
> >>
> >> > It's not the car's that have a balancing speed. It's the motors.
> >> >
> >> > John
> >>
> >>
> >> Let me restate this to make my point clear    ----    After reading the
> >> books I was under the impression that  ALL  PCCs  were wired the same,
> >> thus their motors would deliver a maximum of 42-mph balancing speed on
> >> level tangent track, no // minimum load.       Thus  ALL  PCC  Cars
> >> would operate at the same speed.
> >>
> >>
> >> Jim
> >>
> >>
> >>
> >> >> From: "James B. Holland" <PRCoPCC at P-R-Co.com>
> >> >> Reply-To: pittsburgh-railways at dementia.org
> >> >> To: pittsburgh-railways at dementia.org
> >> >> Subject: [PRCo] Re: Interurban PCCs ???
> >> >> Date: Sun, 27 Mar 2005 01:14:38 -0800
> >> >>
> >> >> Well, Glory__Be!!!!!!!
> >> >>
> >> >> We thought slip/slide was something developed with the electronic
> >> >> revolution -- and here the PCCs had it 60-years ago.
> >> >>
> >> >> Whatever governors were on the lower series Air-Cars - 14s, 15s, 12s
> >> >> - didn't operate the same as on the 16s -- power never shut off on
> >> >> the lower cars and EveryThing was vibrating at speed! M11 took speed
> >> >> extremely well with little vibration, however -- rode a charter out
> >> >> on Library and the power pedal was flat on the floor unless it was
> >> >> absolutely necessary to brake. Very Interesting that the 17 on
> >> >> Library caught up to us at Castle Shannon Inbound -- motorman on the
> >> >> charter thought it would even though we were moving at break neck
> >> >> speed with M11.
> >> >>
> >> >>
> >> >> Jim
> >> >>
> >> >>
> >> >>
> >> >> Boris Cefer wrote:
> >> >>
> >> >>> Slippage, skid.
> >> >>> The slip relays provided protection of main motors against
excessive
> >> >>> speed due wheel slippage or they prevented creation of flat spots
on
> >> >>> wheels in braking.
> >> >>> In acceleration the relays inserted some resistance in the power
> >> >>> circuit reducing the motor torque. In braking they inserted field
> >> >>> shunts with the same effect on the main motors - reduction of
> >> >>> braking torque.
> >> >>>
> >> >>> By the way, it looks that Westinghouse 14s and 15s had SG (speed
> >> >>> governor ?) relays. But I can't find them in schematic diagrams.
> >> >>>
> >> >>> B
> >> >>>
> >> >>> ----- Original Message -----
> >> >>> From: "James B. Holland" <PRCoPCC at P-R-Co.com>
> >> >>> To: "- 1714 PRCo__WP__JTC -" <pittsburgh-railways at dementia.org>
> >> >>> Sent: Sunday, March 27, 2005 10:02 AM
> >> >>> Subject: [PRCo] Re: Interurban PCCs ???
> >> >>>
> >> >>>
> >> >>>> What is a Slip Relay, Please?
> >> >>>>
> >> >>>> Jim
> >> >>>>
> >> >>>>
> >> >>>> Boris Cefer wrote:
> >> >>>>
> >> >>>>> That's a good idea! Ed, can you hear us? Put on your overalls :-)
> >> >>>>>
> >> >>>>> At this point we don't know what field shunting equipment the GE
> >> >>>>> 16s and 17s had (unfortunately there is no GE car to look at :-(
> >> >>>>> ), but there is at least evidence that GE 16 had overspeed
> >> >>>>> protection. Now I see in the GE parts catalog that also GE 17s
had
> >> >>>>> overspeed relays! This "may" suggest that also GE cars were
> >> >>>>> capable of higher speed.
> >> >>>>>
> >> >>>>> Several PCC series had also slip relays (both W and GE 14s, 15s
> >> >>>>> and 16s), but it appears that they were removed or at least
> >> >>>>> deactivated.
> >> >>>>>
> >> >>>>> B
> >> >>>>>
> >> >>>>> ----- Original Message -----
> >> >>>>> From: "James B. Holland" <PRCoPCC at P-R-Co.com>
> >> >>>>> To: <pittsburgh-railways at dementia.org>
> >> >>>>> Sent: Sunday, March 27, 2005 9:05 AM
> >> >>>>> Subject: [PRCo] Re: Interurban PCCs ???
> >> >>>>>
> >> >>>>>
> >> >>>>>> Another clarification. As we are talking about only the
> >> >>>>>> 1700--1774 WH cars, the same holds for the 1600 and 1601--1674
> >> >>>>>> cars -- we do not know about GE in either series -- correct?
> >> >>>>>>
> >> >>>>>> Yes, PRCo trackage was rough relative to other properties, but
it
> >> >>>>>> was in the early 1960s when I experienced the governor cut-out
of
> >> >>>>>> power on both the 17s and 16s -- you could still get those cars
> >> >>>>>> rolling very nicely!
> >> >>>>>>
> >> >>>>>> Maybe Ed could check those jumpers on 1711 as Hands-On Training
> >> >>>>>> for his Electrical Engineering Degree!!!
> >> >>>>>>
> >> >>>>>> Jim
> >> >>>>>>
> >> >>>>>> Boris Cefer wrote:
> >> >>>>>>
> >> >>>>>>> But the earlier books appear more detailed.   There are
possibly
> >> >>>>>>> some data in GE wiring diagrams, but I haven't seen any except
> >> >>>>>>> for the early air cars (1000-1200 series), but they don't make
> >> >>>>>>> me happy because the early GE design was terribly complicated.
> >> >>>>>>> GE parts catalogs do not contain any useful data, these are
> >> >>>>>>> endless lists of parts with some pictures only.
> >> >>>>>>>
> >> >>>>>>> And an another question is still the Westinghouse 1700s. Their
> >> >>>>>>> equipment allowed to change the balancing speed by means of
> >> >>>>>>> higher field shunting. Only four small jumpers joined to the
> >> >>>>>>> field shunting resistors increased the balancing speed several
> >> >>>>>>> mph, but we don't have any evidence whether PRCo or later PAAC
> >> >>>>>>> did not dismantle them to avoid eventual accidents due
extremely
> >> >>>>>>> high speed over irregular track. Memory is sometimes very
> >> >>>>>>> delusive and some few can tell us what the top speed was 50
> >> >>>>>>> years back. Our friends at PTM would have to check whether the
> >> >>>>>>> jumpers on 1711 are in place...
> >> >>>>>>>
> >> >>>>>>> B
> >> >>>>>>>
> >> >>>>>>> ----- Original Message -----
> >> >>>>>>> From: "James B. Holland" <PRCoPCC at P-R-Co.com>
> >> >>>>>>> To: <pittsburgh-railways at dementia.org>
> >> >>>>>>> Sent: Saturday, March 26, 2005 10:17 PM
> >> >>>>>>> Subject: [PRCo] Re: Interurban PCCs ???
> >> >>>>>>>
> >> >>>>>>>> Time to speculate why GE was so Resistant to include specific
> >> >>>>>>>> information!! :-)
> >> >>>>>>>>
> >> >>>>>>>> Various PCCs had been *tested* for interurban service
according
> >> >>>>>>>> to that 1952 ERA type dissertation on the PRCo Interurbans as
> >> >>>>>>>> well as the Ira Swett article on Charleroi -- but they weren't
> >> >>>>>>>> specific about the tests and whether or not the PCCs were run
> >> >>>>>>>> beyond Library -- we know that they were used as trippers this
> >> >>>>>>>> far and even the PTM calendar shows an 1100 used for Fair
> >> >>>>>>>> Grounds tripper about 1949 or 1950.
> >> >>>>>>>
> >> >>>>>>>> With 1613 and 1614 converted for interurban Test service
within
> >> >>>>>>>> 6-months of delivery (at least for 1613) PRCo was *probably*
> >> >>>>>>>> considering PCCs for interurban service even as the 1601s were
> >> >>>>>>>> ordered. Guess we shall never know For Sure without something
> >> >>>>>>>> turning up in the archives.
> >> >>>>>>>
> >>
> >>
> >
> >
>
>