I've always admired the NYC's P motor class of electric locomotives. Although the GG-1 is probably considered by most people to be handsomer than the P motor, I think the P's just exuded a strength and masculinity (for lack of a better term) that compared very favorably with any others.
But what about power? Pulling ability? Efficiency?
Would anyone here care to enlighten me a bit by comparing and contrasting these two fine engines?
Thanks.
I loved the hell out of P-motors as a kid. They were by far the best motors on the still-exotic NYC line to Harmon. Especially splendid in lightning stripe (and I still don't quite understand why the last of those was scrapped without being offered for preservation...)
Article in Trains back lo! these many years ago that said about the porch on an SD-40 that you had 'room to set up a card table and deal'. Of course our high-school railroad club has the photographic proof somewhere that that comment is not hyperbole on a P-motor. (As long as you don't care about stuff impeding legroom under the table after you set it up!)
The GG1 was explicitly streamlined, and intended for much faster service than the P (either in Cleveland or Harmon service). There was, at least initially, more care to provide high-speed compliance in the suspension, and roller bearings on all axles (I don't think the P-motors had roller bearings even after the rebuild in the Fifties). Top speed, and I think it was a hard limit, was 70mph (GG1s could run far faster).
Someone here will have the actual instantaneous and hourly rating for these. In Cleveland (with the original 3kV setup) they had just over 3000 continuous horsepower; after the 660V rebuild this increased to over 4200, but this was still shy of a GG1. I do not know how arrangements for back EMF were handled and have never seen a speed-to-TE graph for those locomotives.
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).
I do not have a hard reference whether the rather-substantial weight reduction during the 'rebuilding' was done because the removed 3000V equipment was 'that much' heavier or because there were restrictions on the Park Avenue viaduct that had to be met. Someone out there will know.
The P motor was the first of the 2-C+C-2 wheel arrangements. Soon after, NH bought motors in that arrangement. PRR leased an EP-3 from NH to test it agains some other motors, eventually adopting the wheel arrangement for the GG-1.
Overmod Someone here will have the actual instantaneous and hourly rating for these. In Cleveland (with the original 3kV setup) they had just over 3000 continuous horsepower; after the 660V rebuild this increased to over 4200, but this was still shy of a GG1. I do not know how arrangements for back EMF were handled and have never seen a speed-to-TE graph for those locomotives.
Jack Grasso's book on the CUT states that the continuous rating at 3kV was 2,635hp, 1 hour rating at 3kV was 3,030hp. The book also states that the P's were good for 50,500 lb T.E at 35mph and 2.7kV, working out to 4,700 drawbar hp. This suggests they should be good for 5,200 drawbar hp with 3kV at 38.9 mph.
Erik_MagThe book also states that the P's were good for 50,500 lb T.E at 35mph and 2.7kV, working out to 4,700 drawbar hp. This suggests they should be good for 5,200 drawbar hp with 3kV at 38.9 mph.
But wouldn't this be motor-limited with the 278Cs?
For fun, go back and find the comparable numbers for the as-converted Ps on third rail, with the 755As (which apparently were much higher in power, perhaps due to lower insulation requirements, than the motors they replaced).
I do not remember when the third-rail voltage was increased, but if that were done in the era the Ps were running it would likely not compromise the insulation significantly but would produce a nifty boost in the achievable power...
Since hourly rating was barely over 3,000hp, the 5,200hp would be a short term rating (5 minutes or less). I would also guess that was with a shunted field.
When I worked on the NYC in 1967 and 1968, I commuted from the Greystone station in northwestern Yonkers. While waiting for my MU train into GCT, I would sometimes see through trains blasting through on the inner tracks. I noted that the front trucks of the P-2s often slapped back and forth between the rails. Rightly or wrongly, I attributed this to insufficient maintenance of the running gear. I had the opportunity to ride in the cab of a P-2 from GCT to Harmon and later in a (by then) Penn Central GG1 from Penn Station to North Philadelphia. I did observe that the GG1 seemed to ride more stably laterally than the P-2. It was surprising to me, however, how much more cramped the GG1's cab was than the P-2's. As far as power is concerned, the NYC diagram for the P-2 gave continuous ratings of 4243 hp at 39 mph (40,800 lbs. tractive effort) and 4262 hp at 55.5 mph (28,800 lbs. tractive effort).
Dick DawsonWhile waiting for my MU train into GCT, I would sometimes see through trains blasting through on the inner tracks. I noted that the front trucks of the P-2s often slapped back and forth between the rails. Rightly or wrongly, I attributed this to insufficient maintenance of the running gear.
I would agree with this, a further question being whether the observed truck motion were strictly lateral or had an oscillating component around the pivot (e.g. potential hunting). Someone with access to the drawings might look at the bolster lateral-accommodation methods and post something here; since this was a common occurrence, I'm hesitant to attribute only 'accidental' things like wear of wedges or broken springs as the cause.
I'd add that stiffer lateral on the lead trucks should be 'designed in', as the rigid wheelbase of the actual chassis half will likely have the same 'self-steering' action as a comparable steam-locomotive rigid wheelbase and the requirements for effective lead-truck guiding should be comparable.
I had the opportunity to ride in the cab of a P-2 from GCT to Harmon and later in a (by then) Penn Central GG1 from Penn Station to North Philadelphia. I did observe that the GG1 seemed to ride more stably laterally than the P-2.
A large part of this is likely the quill drive arrangement, which has a much smaller lateral unsprung mass (and at least the opportunity for much better lateral compliance control, if the spring arrangements in the quill drive are properly lubricated). P2s carry the weight of the drive much lower down, and the lateral is likely more highly constrained by the mounts for the nose-suspended motors.
It was surprising to me, however, how much more cramped the GG1's cab was than the P-2's.
Drafty, too, and hung so far out you almost have to guess the track you're going onto at crossovers.
As far as power is concerned, the NYC diagram for the P-2 gave continuous ratings of 4243 hp at 39 mph (40,800 lbs. tractive effort) and 4262 hp at 55.5 mph (28,800 lbs. tractive effort).
This adds useful information to the discussion. Thanks!
Dick Dawson ... I noted that the front trucks of the P-2s often slapped back and forth between the rails. ... I did observe that the GG1 seemed to ride more stably laterally than the P-2. ...
... I noted that the front trucks of the P-2s often slapped back and forth between the rails. ... I did observe that the GG1 seemed to ride more stably laterally than the P-2. ...
MidlandMikeCould it be that the P motors were designed for Cleveland Terminal service, and later went to NY terminal service, whereas the GG-1 was designed for mainline service?
I seem to remember they were designed for reasonably high top speed in Cleveland service, where the catenary wouldn't restrict speed as third rail does. And they were explicitly rebuilt at GE for 70mph speed.
Now, NYC is a little infamous for having operated electric power at wildly greater than posted speed -- ask Mr. Wilgus how those four-wheel trucks got shoehorned into the S-motors -- but I doubt the speeds in the PC era were greater than 70mph on the fastest part of the line to Harmon; I certainly don't remember them being (although the curve superelevation in the waning years of the P-motor 'experience' could be high enough to produce actual discomfort when stopped on it, I think something like 10.5 degrees in some places)
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.
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
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
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.
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.
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
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.
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.
Cheers, 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.)
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
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'.
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.
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.
gmpullman Overmod ... but does anyone else believe the picture in that listing isn't a model?
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
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).
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
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
Nice!
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.
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.
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.
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!
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