Paul MilenkovicI think the P-motors were nose-suspended
To my knowledge they were NOT quill-drive.
There should be enough construction pictures and diagrams here and on the MR forum (courtesy of Ed, 'gmpullman') to determine precisely how the motors were provided, and what changed when they were swapped out in the 750V conversion.
Naturally the motors were different, and I believe so were the drives (the GG1 twin 'universal' motors were capable of operating on DC, but of course PRR did not operate them that way). GG1 had fairly good quill drive; I think the P-motors were nose-suspended (original motor 278C, rebuilt motor 755A for those who want to look up motor data).
[/quote]
Were the GG1 electric motors capable of running on DC?
Yes, the were DC-style commutated series-ound motors, but doesn't the inductance of their windings limit current when fed (even 25 Hz) AC? If you fed them DC, could they not overload?
Now don't tell me to post this at the Classic Toy Trains forum, but can you run a Lionel or American Flyer motor on DC? They are, series-wound commutated motors, by the way.
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
Not too surprising about the tenders. There was a former PRR coast-to-coast tender at 18th Street in Chicago into the 1980's.
Erik_MagI've heard conflicting stories about Kapton for aircraft wiring, it's flexible but also more prone to wear than other insulators.
In my opinion, the difficulty is less 'wear' per se than that the insulation is relatively soft and pressure tends to distort it. So pressure at an 'edge' can cause cold flow ultimately resulting in exposure of point contact if the edge is conductive or coupled to some ground reference.
Some of the usual methods for mechanically or chemically hardening the material surface to 'preclude' this sometimes founder because the underlying plasticity, at required thickness for "cost-effectiveness", makes the applied coating fail in strain as the substrate yields. This is not dissimilar to what is seen in some hard-coating failure in bearings where deforming of the underlying surface is often the 'proximate cause' .
In my opinion, the difficulty is less 'wear' per se than that the insulation is relatively soft and pressure tends to distort it. So pressure at an 'edge' can cause cold flow ultimately resulting in exposure of point contact if the edge is conductive or grounded to some reference.
I've heard conflicting stories about Kapton for aircraft wiring, it's flexible but also more prone to wear than other insulators. One advantage for aircraft is that Kapton maintains its flexibility to (or almost to) liquid helium temperatures.
For motors, Kapton has the highest operating temperature of any common polymer and has a very high dielectric strength (i.e. hih breakdown voltage for a gien thickness). The high temperature allows for more current in a given winding and the high dielectric strength means that the insulation could be made thinner, which allows for more copper and also promotes better heat transfer. Both mean more currnt and thus more power out of a motor.
The NYC P motors were designed for short trips with fast acceleration, so GE may have tweaked the motors for ability to handle large overloads.
About Kapton insulation. Some time in the 1970 - 1980s (?) the FAA came out with an airworthiness directive that all replacement wiring on aircraft would be kapton. You could still splice onto the older ( May have changed ) but you can imagine the problems especially cable mining when feasible.. Replacement wiring all has to have a unique identifier stamped on the wiring that original had or did not have.. As well sometiimes color coding for the various guages. Interesting machine to stamp the identifier.
Overmod:
An eight axle P-motor would have been good for 4/3rds the power of the P1. The 6 axle design looks to be the better choice as it allows a 1/2/3 progression of running speeds versus the 1/2/4 progression with 8 axles. The three field strength options gave a total of 9 running speeds, which is pretty flexible for a non-chopper equipped DC locomotive.
The motors were designed for 1500V, and probably would run well at 1750V which would increase the speed for a given T.E by 10%. The 1969 era GE-750 motors that would have been used on the C-C's proposed to the Milwaukee were good for a continuous output of 900HP per motor, with short term ratings of maybe 1200HP per motor.
An aside about motor ratings. The voltage limit is imposed in part by the insulation of the wiring, although this has more of an effect when running two 1500V motors in series for operation on 3000V. The more important limitation is the commutator, where more than 20V between segments is almost guaranteed to cause problems (flooding the commutator with SF6 might help). Long term power ratings are set by thermal limits, particularly so in the days before silicone and polyimide (Kapton) insulation - these ratings are related to current, varying little with voltage. Short term power rating are often limited by commutation (even for interpole motors), excessive current on the armature can cause magnetic field distortions at the pole faces leading to excessive sparking at the commutator and potential for ringfire. This problem is often made worse with field shunting.
The P-1's were somewhat less powerful than the Westinghouse "Quills" on the Milwaukee, though more flexible and presumably less of a maintenance headache. The Quills also had regenerative braking, which was not strictly needed for the P's.
Thanks, gmpullman, for going through the trouble to put online the diagram for the P-1a motor; I certainly enjoyed studying it.
Also, the photo of SHRT 53 & CUT 214 is impressive and makes me envious.
You really have brought the good stuff to our party!
Erik_MagNice! From "0006", with the controller in the last notch (3 sets of 2 motors in series and FS-3), the P-1 was developing ~4,100 DBHP at 37.5mph and a bit over 1,200 DBHP at 62.5mph. Not quite Little Joe power levels, but still respectable.
From "0006", with the controller in the last notch (3 sets of 2 motors in series and FS-3), the P-1 was developing ~4,100 DBHP at 37.5mph and a bit over 1,200 DBHP at 62.5mph. Not quite Little Joe power levels, but still respectable.
One wonders what the P architecture taken up to eight axles might actually produce.
If anyone doubts the effectiveness of series-parallel transition, consider the TE at speed improvement just in going from groups of 3 motors to groups of 2. (I am tempted to say 'what is the extrapolation if you nominally run all the motors in parallel' but they're likely not insulation-rated for full line voltage...)
Someone find the equivalent curves for the locomotive after it was converted for low voltage, and the motors nominally uprated in achievable shaft power and instantaneous/hourly rating.
Nice!
NKP guyDo any photos exist of the interiors of the P class? Allow me to urge you to get a copy of the interior diagram posted here.
CUT_P1a_cover by Edmund, on Flickr
Oh what I wouldn't give to poke around under the hood...
P-1a_General Apparatus by Edmund, on Flickr
P-1a_General Connection by Edmund, on Flickr
CUT_P1a_layout_0006 by Edmund, on Flickr
CUT_P1a_layout_0005 by Edmund, on Flickr
Have Fun! Ed
Erik_MagIf I recall correctly, the Shaker Heights transit line also terminated at C.U.T.,
Just having some fun here:
IMG_5616_fix by Edmund, on Flickr
An unlikely pairing —
I lived at the end of the "Green Road" line and frequently rode the yellow PCC cars into C.U.T. Those were some fun times.
If you would like to read further about the Van Sweringen brothers planned empire I suggest this book:
https://www.amazon.com/Invisible-Giants-Clevelands-Sweringen-Brothers/dp/0253341639
Cheers, Ed
Ed,
I did see the album after clicking on the picture this morning, and many thanks for scanning and uploading to Flickr.
I remember my mom telling me about the electric operation at C.U.T. (she grew up in Lakewood). If I recall correctly, the Shaker Heights transit line also terminated at C.U.T., and I imagine my mom would have made use of that to visit her aunt living on Shaker Heights (about a 1,000' from one of the stops).
OvermodI don't know why the seller decided to use a photo of an NYC R motor to promote a C.U.T. DVD video...
I should have verified it.
T-3_275 by Edmund, on Flickr
His photo is of a model of an NYC T-3a
NYC_T3a_0001 by Edmund, on Flickr
Next time I'll make sure before I reply
Regards, Ed
gmpullman Overmod ... but does anyone else believe the picture in that listing isn't a model?
Overmod ... but does anyone else believe the picture in that listing isn't a model?
I don't know why the seller decided to use a phoro of an NYC R motor to promote a C.U.T. DCD video. I bought the DVD from him some years ago and he was using the other photo in the listing (with the wrong location, that is the P-1a shed, not Erie).
Still, for $10. it is a very worthwhile DVD. (I seem to recall there is a brief shot of the PRR Baldwin Centipedes in the film, too, at the old Cleveland Lakefront Depot).
Erik_MagI liked the link to the scan of the GE publlication on the C.U.T. electrification, had many details that I haven't seen before.
I have the entire GE publication in the Flickr album where the other photos are also residing:
https://www.flickr.com/photos/gmpullman/albums/72157695368994204
CUT_GE_1930_01_crop by Edmund, on Flickr
Cheers, Ed.
I liked the link to the scan of the GE publlication on the C.U.T. electrification, had many details that I haven't seen before. The use of the auxiliary messenger as a feeder and the circuit breaker stations reminded me of the description of the IC suburban electrification described in CERA bulletin 116 "Electrification by GE".
Incidentally, two of the M-G sets used in the C.U.T substations spent more time in use on the Milwaukee than on the C.U.T.
gmpullmanThere is an eBay seller that has a DVD available of some 16mm film of a cab ride in a P-1a in Cleveland. Worth every penny, some rare footage indeed. I'll send a link if he is still around*. * https://tinyurl.com/y3rab2b9
This is a good reference ... but does anyone else believe the picture in that listing isn't a model? (Granted, a very good one, with the headlight in particular being well-done in the picture, but...)
Look at the drivers, all common in the wrong color with strange flanges and wide tread. Look at the leading-truck wheels, too. The glazing is too deeply set and the paint thickness is too large on at least the near-side front window and the side window. I'm sure others can spot details that are 'optimized for smaller scale'.
I'm not savvy to any information regarding plans for the "P-1a Shed" at Collinwood. I don't have any CSX insiders. My nephew was inside there a while back and it is a beautiful facility:
P1A_shed by Edmund, on Flickr
Here's an earlier view:
CUT_P1a_shed by Edmund, on Flickr
NKP guyDo any photos exist of the interiors of the P class?
None that I recall seeing. Nor have I seen any during construction before the carbody was put in place.
CUT_GE_1930_04 by Edmund, on Flickr
Thank you for the link! I grew up on Eddy Road closer to St. Clair but those photos sure look familiar to me. The East Cleveland (Superior) station was still standing when I was hanging around there. Great photos and story.
There is an eBay seller that has a DVD available of some 16mm film of a cab ride in a P-1a in Cleveland. Worth every penny, some rare footage indeed. I'll send a link if he is still around*.
* https://tinyurl.com/y3rab2b9
Thanks, Ed
gmpullmanI'm a little late to the party here but I bring good things with me.
I'll second that! Great photos! I've never seen these before and they fill in a number of blanks when it comes to these locomotives. Many thanks!
Since you seem to live in Collinwood, let me ask if you know what plans CSX has for the old electric shops building on the south side of the yard (west of E. 152nd St.)? When I saw it in April it was boarded up.
Do any photos exist of the interiors of the P class? Allow me to urge you to get a copy of the interior diagram posted here.
(I sent you a link you might enjoy. Please check your messages/mailbox here.)
Hi,
I'm a little late to the party here but I bring good things with me.
CUT ad merge by Edmund, on Flickr
C.U.T. P-1a-1929 Data by Edmund, on Flickr
Somebody hosed down the front of the carbody for this shot, taken in the coach yard behind the passenger platforms proper:
CUT_p1a by Edmund, on Flickr
Looks like a three-chime whistle there:
P1A_1050_roof by Edmund, on Flickr
CUT_1050crop by Edmund, on Flickr
Forgive my bias but I like to roll-out the photo of this P-1a pair:
IMG_6782_fix by Edmund, on Flickr
Both Overland HO models.
I have an operating manual for the P-1a that I really have to sit down and scan one day. It has the only "floorplan" of the interior equipment I've ever come across. Maybe this thread will motivate me?
The GG1s don't forget had two traction motors per axle driving the quill shaft unlike the P1a which was geared more like a usual diesel traction motor.
Jones1945I believe (not base on research or historical fact) the NYC P motor and the PRR GG1 actually inspired the design of the Japanese JNR EF-48:
Looking at the sideframe construction this is FAR more likely a derivation of the older 'built up' construction of earlier GE locomotives, particularly those built from after WWI through the latter '20s -- some of which pioneered the use of twin motors as used on the GG1s (but not the P-motors). Seems to me that the NH Tiger motors, in particular, are far more like these than anything with a full cast Commonwealth set of frames. Even the pilot trucks are lightweight.
I believe (not base on research or historical fact) the NYC P motor and the PRR GG1 actually inspired the design of the Japanese JNR EF-48:
Jones 3D Modeling Club https://www.youtube.com/Jones3DModelingClub
NKP guyWas the paint job always NYC black?
As I remember on the NY suburban lines in the mid 60s, the P motors were grey. They may have been transitioning from lightning stripe to cigar stripe.
Overmod Yanking this up because the subject of the conversions has been broached on the NYC groups.io page. Started with this picture, of the units as received at Erie (picture nominally in 1954) to be converted: https://groups.io/g/NYC-Railroad/attachment/31443/0/NYC-P_electric_locomotives_at_GE_Erie_1954.jpg
Yanking this up because the subject of the conversions has been broached on the NYC groups.io page. Started with this picture, of the units as received at Erie (picture nominally in 1954) to be converted:
https://groups.io/g/NYC-Railroad/attachment/31443/0/NYC-P_electric_locomotives_at_GE_Erie_1954.jpg
Thank you, Overmod! Even at Erie awaiting gender reassignment surgery, as it were, these P motors have a countenance of supreme dignity and many more years of useful service left in them.
Since you belong to the NYC group and I don't, can you tell me where I can find a link that would have a diagram of the interiors of the P motors? How large was the cab? What did firemen on such locomotives do? Was the paint job always NYC black? Was the whistle (admitedly seldom used) just a single note? And why was there room enough to set up a card table and chairs? What was the purpose of such a large deck?
Though a Clevelander, I never saw these great locomotives in service there. But I did see them on the Hudson River line in 1971 & 1972, the last time being on the scrap line at Harmon. Even there, even in death...dignity.
One major problem according to my PRR relative who was an engineer and had GG-1's for years was that they were very noisy. (He did have hearing problems.) I suspect they wouldn't meet today's OSHA requirements without some type of hearing protection for the engine crew.
Our community is FREE to join. To participate you must either login or register for an account.