[PRCo] Re: Interurban PCCs ???

Mon Mar 28 12:53:30 EST 2005

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.
>> >>>>>>>
>>
>>
>
>