RME Firelock76 Considering it was the 1920's I assumed "oil-electric" and "diesel-electric" were interchangeable terms, as is usually the case when a new technology comes along and is finding a niche or a name for itself. I have not studied this carefully -- but wasn't "Diesel" a proper noun when used for engine technology well into the Thirties and perhaps beyond?
Firelock76 Considering it was the 1920's I assumed "oil-electric" and "diesel-electric" were interchangeable terms, as is usually the case when a new technology comes along and is finding a niche or a name for itself.
I have not studied this carefully -- but wasn't "Diesel" a proper noun when used for engine technology well into the Thirties and perhaps beyond?
The problem was that Diesel's patent was for compressed air injection of fuel, originally pulverised coal, into a compression ignition engine. When Maschinenfabrik Augsburg Nurnberg tried to get it to work, they made numerous changes including changing to oil fuel and various types of precombustion chambers to get it to work.
The British in particular weren't impressed because they pointed out that an Englishman named Ackroyd-Stuart had built a working oil fuelled compression ignition engine some time before MAN managed to make anything out of Diesel's ideas. Some small narrow gauge locomotives built for the British Army during WWI actually used Ackroyd-Stewart engines.
In Britain at least there was a desire to avoid the use of Diesel's name for the two reasons that he wasn't the first and his patent didn't work. British industry published an annual catalogue of "Oil Engines", and I don't think they used the word Diesel until about 1956.
To return to the subject of the thread, surely one reason the GG1s were so long was that they effectively had twelve traction motors arranged two per driving axle. I know that these were regarded as a single motor with two armatures, but it is effectively 50% more motors than a DDA40X...
M636C
Apparently all were built with boilers; some of the lower-geared 'freight' motors used them for special moves (e.g. football trains) after the locomotives were not needed for the decreasing number of passenger trains in the latter '50s -- I think the boilers in the freight-only series were removed in the late '50s to early '60s (4800 lost hers in 1960).
Off the top of my head, the capacities were 3000lb oil, 23000lb water. That translates into something like 425gal and 2750gal respectively. This is reasonably proportional for the ratio of combusted fuel to generated steam mass at 200psi output pressure for an OK-4620, so you would service the oil and water roughly at the same time.
If diesels were drawing the steam-generator fuel from the main tank, the amount of 'water servicing' would be proportional to prime-mover fuel consumption, outside temperature, and whether or not the train used an undue amount of steam (e.g. due to poor maintenance or leaking steam-line seals). It is also possible that the actual water reservoir capacity on some diesels was weight-limited or restricted by packaging (note for example where some of the early F units put the SG reservoir) and in the absence of the ability to scoop from track pans* this would produce shorter range between 'water stops'.
*I say, I say that's a joke, son.
ndbprr. If GG1s had HEP heat it would fail if the power was cut off for any reason. While the G would die at least it could keep the train warm awaiting rescue.
The problem there is that a Vapor-Clarkson steam generator requires a fairly hefty blower and modulated spark ignition to run -- it's a monotube, similar in operating principle to what's in a Doble automobile. I do not know whether (or how long) you could run one of these on a 'dead' electric (which doesn't need the substantial battery capacity a diesel-electric passenger locomotive would have for starting, so has very little effective onboard power storage).
M636CTo return to the subject of the thread, surely one reason the GG1s were so long was that they effectively had twelve traction motors arranged two per driving axle. I know that these were regarded as a single motor with two armatures, but it is effectively 50% more motors than a DDA40X...
But you forget that a defining characteristic of the GEA-627-A1 was that it fit reasonably well inside a 57" wheel, so little if any extra length in the chassis was produced. Less, in fact, than if the same size motor had been mounted with nose suspension in the 'normal' alignment.
I am trying to find a picture of how the 428-A motor fit in the DD2 chassis (which used a larger driver diameter). Permutations of this were very likely what the 'wartime' plan for electrification from Harrisburg to Pittsburgh would use (the horsepower numbers for the different wheel arrangements match),
To an extent, the chassis was long because the driver diameter was relatively large, but it might be noted that the diameter of the AEM-7 driver is almost identical and even a "one-and-a-half-toaster" B-B-B version wouldn't be terrifyingly long. Much of the length came in the use of pony trucks at both ends and the extended tails for the articulation hinge between the cast underframe halves. It might be noted that a 'revolution' of sorts in secondary suspension made possible a high-speed configuration with large wheels, and good guiding without the four-wheel pin-guided lead -- similar observation for the V1 (and early TE-1) chassis that was 2-D+2-D or for the Centipede underframe, vs. good swing-hanger of 'flexi-float' trucks.
I had been told that one reason the Sante Fe used steam-ejection air-conditioning is that thermostatic control could automatically switch the device from cooling to heating and visa-versa. This was important, because of great temperture swings encountered by passenger trains on a normal run on that railoroad. When you have seperate systems, steam heat and eletto-mechanical air-conditioning, some operator intervention for the switch is usually required.
The GG-1 was not alone in its length. The New Haven 4-6-6-4 EP-3 (box) EP-4 (streamlined) and EF-3 (some equipped with boilers and the preferred power for Penn Sta. trains) and the EP-2 2-6-2+2-6-2 were approximateloy the same length as the GG-1. And the Little Joes, possibly a bit longer.
As far as I know, the big DC motor of each half of a DD-1 was within the carbody, not between the wheels.
daveklepperAs far as I know, the big DC motor of each half of a DD-1 was within the carbody, not between the wheels.
RME M636C To return to the subject of the thread, surely one reason the GG1s were so long was that they effectively had twelve traction motors arranged two per driving axle. I know that these were regarded as a single motor with two armatures, but it is effectively 50% more motors than a DDA40X... But you forget that a defining characteristic of the GEA-627-A1 was that it fit reasonably well inside a 57" wheel, so little if any extra length in the chassis was produced. Less, in fact, than if the same size motor had been mounted with nose suspension in the 'normal' alignment. I am trying to find a picture of how the 428-A motor fit in the DD2 chassis (which used a larger driver diameter). Permutations of this were very likely what the 'wartime' plan for electrification from Harrisburg to Pittsburgh would use (the horsepower numbers for the different wheel arrangements match), To an extent, the chassis was long because the driver diameter was relatively large, but it might be noted that the diameter of the AEM-7 driver is almost identical and even a "one-and-a-half-toaster" B-B-B version wouldn't be terrifyingly long. Much of the length came in the use of pony trucks at both ends and the extended tails for the articulation hinge between the cast underframe halves. It might be noted that a 'revolution' of sorts in secondary suspension made possible a high-speed configuration with large wheels, and good guiding without the four-wheel pin-guided lead -- similar observation for the V1 (and early TE-1) chassis that was 2-D+2-D or for the Centipede underframe, vs. good swing-hanger of 'flexi-float' trucks.
M636C To return to the subject of the thread, surely one reason the GG1s were so long was that they effectively had twelve traction motors arranged two per driving axle. I know that these were regarded as a single motor with two armatures, but it is effectively 50% more motors than a DDA40X...
Looks pretty much like a GG1 to me...
http://prr.railfan.net/diagrams/PRRdiagrams.html?diag=dd2.gif&sel=ele&sz=sm&fr=
M636C Looks pretty much like a GG1 to me...
Yes, the layout is the same, as is the operating and 'transmission' principle. Note two things from the diagram: the larger motor diameter, and the increased axle spacing (probably for weight distribution, although I do not know if overall length was dictated by packaging of things like the main transformer within the carbody).
I would note that some of the same problems encountered by the T1 regarding slipping might be found in this design, with fewer axles supporting both higher peak torque and higher available horsepower per axle. What looks like a good idea to reduce brakeshoe wear, number of wheels, etc. might not be so good, in the absence of really good and positive slip control, and this might explain why the actual wartime electric purchases were 'more GG1s' while the contemporary (actually, I think, started before that wartime order was placed) expansion plans called for 428-A equipped locomotives of several potential sizes, only the smallest of which was comparable to the DD2.
Likewise I'd expect point loading and 'beam deflection' in the rails to be bad for the DD2 as it was for the P5s. I would be very interested in seeing any test reports -- scientific or anecdotal -- about the ride quality and performance of the DD2, and any maintenance issues it had. (I would NOT think it was an optimal configuration for a freight-only locomotive, and I'd also not think the 'best' place to use it would be as the Baltimore tunnel helper... but it certainly had a long life for a singleton locomotive with what turned out to be singleton motor utilization, once the decision was made in the late '40s not to proceed with any substantial electrification west of Harrisburg.
The only 'test' picture I can find that shows the 'original' DD2 is this:
Note the nose styling (and compare it to other 3/4 shots of the locomotive, which give it a strong 'family' resemblance to the stillborn V1 turbine). Now look at the appearance of the locomotive in this picture:
which appears to show a much more 'streamlined' nose profile and headlight surround, perhaps indicating that the appearance was modified at some point in the engine's life. Would this engine have been lettered in Futura when built, or was it always in Clarendon?
What I was hoping to see was detail photographs of the DD2's underframes, perhaps with some technical description of the suspension arrangements and physical weight distribution. The diagram as given is interesting and useful, but doesn't contain much of the needed documentation of the detail design.
RME,
Check out:
https://en.wikipedia.org/wiki/File:PRR_DD2.jpg
This shows that the DD2 only had one configuration: rounded streamlining but with a crease line at the centre. The compression effect of the distant photo flattens the appearance of the nose, combined with the edge on lighting.
The Wikipedia photo shows Futura lettering, but it is a matt finish works photo.
The DD2 combines the worst features of the GG1 with the worst features of the R1. The axle load is shown as 71 000 lbf, ten tons more than either a GG1 or an R1. Running a load like that on jointed track is asking for trouble with both the track and locomotive.
Incidentally, I have an ASEA brochure illustrating a "one and a half Toaster" in SJ livery. It was a serious proposal for the Narvik iron ore services, but the decision was taken to run three Rm class (regeared Rc type) rather than two Bo'Bo'Bo' units. These Rm ended up later in normal service after AC traction units took over.
M636CThe DD2 combines the worst features of the GG1 with the worst features of the R1. The axle load is shown as 71 000 lbf, ten tons more than either a GG1 or an R1. Running a load like that on jointed track is asking for trouble with both the track and locomotive.
In my opinion this is an attempt to increase the effective FA for the same general purpose as doing so with the T1, looking to decrease slipping but actually increasing some of the physics that lead to it.
It does have to be said that I don't think either the GG2 or the four-drive-axle chassis helpers/snappers (hard to say what their wheel arrangement would actually have been) called for in the early-Forties electrification plan would have had the 'extended' axle spacing, although I do suspect they would have had the high axle load. We should get Dave Klepper to explain how to implement 'electrical' detection and quick prevention/remediation of slip on a locomotive with 428-A motors, especially if these differ electrically from the 627-A1 specifically because in the PRR application they would not be expected to run on 600VDC as the New Haven twin-motor locomotives were.
I've always been fascinated by how disastrous most of the PRR electric-locomotive engineering and design work actually turned out to be, whether before or after the GG1. It's fun to look at some of the speculative designs, like Steins' little oil-fired steam switch engine, and guess whether they'd show 'genius' or 'more of the same'...
I have to make the point again that any 25Hz COMMUTATOR motor, even if not specifically designed to run on DC, with run efficiently on DC. This definitely includes the GG1's motors.
And I again just wish that someone would buy up opr has bought up all the electricals, minus the mjotors, of thre AEM-7's, to restore a GG! to operation under any NEC catenary. The 25x2 Hz (cps) growl would be missing, but an efficient excursion locomotive would be a result. Should have a matched set of restored Congressional/Senator Budds to haul of course.
daveklepperI have to make the point again that any 25Hz COMMUTATOR motor, even if not specifically designed to run on DC, with run efficiently on DC. This definitely includes the GG1's motors.
But can you confirm that the 428-A as installed in the DD2 had that capability? (I ASSume it, but I don't know specifics)
If the motor is a commutator, armature, field coil single-phase 25Hz motor of any type, it will run on DC. If it uses slip rings and/or an induction cage it will not runj on DC. I suspect it is the former.
You are talking about the commutated "universal" motors used in the GG-1?
In theory, such a commutated motor (with laminated iron to make the eddy current losses tolerable when supplied AC), if it runs on AC, it will also run on DC.
But -- the control of motor current when supplied with AC may depend on inductance, which will not have an effect limiting the current when supplied with DC. Supplying the motor with DC without taking this into account could burn the motor out.
It is the same thing with AC solenoids of the type of "buzz" open security entrances. That "buzz" when you "buzz" someone entrance into your security apartment is from the AC. You cannot actuate those solenoids with DC without providing a way to regulate the current flow so you don't burn them out -- the inductance in the solenoid is limiting the current when supplied AC of the rated voltage.
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
This was equally true of the straight dc motors used for years on everything from streetcars to Little Joes. The classic way to limit the current was by use of reistors in steps and changing from series to parallel as speed increased. This was insistuted with the original Sprauge Ricihmond electrification up to the DC controls for the NYNH&H EP-4 streamlined electrics when running on DC. The AC side, as in the GG-1, used a large multitap transformer, which is not possible on DC. The last DC development, before going to AC non-synchronous induction motors, was electronic control of one type of another, chopper control with smoothing is one example. That is why I am hoping that someone will save the electricals sans motors of three DC AEM-7s to put a GG-1 back to life with the original motos but controlled by adapted and modified AEM-07 electricals.
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