Will Davis Interesting developments. It sure seems to be getting clearer that ALCO was able to offer the 12-251 up to 2500 HP for traction, given the spec for the diesel-hydraulic (I sent an email asking to see the specification) and this vague reference to a supposed twin-block single-alternator machine. For whatever it's worth, that just sounds like a really bad idea to me. You're guaranteed that if one engine fails, the whole locomotive goes down. The reference in that description exactly describes the effect of Performance Control / Automatic Power Matching, albeit very roughly. What is the nature of the representation in the quoted railfan ALCO book? I'm not quite clear on it. Was this written by someone who was present at an ALCO sales pitch to the Milwaukee? Also interesting is the verification that the spotted reference was actually to an eight axle C-860. Now, does anyone have a surviving specification or ALCO sales book? If so that would be great. It also sounds like ALCO had not completely updated its sales book, still listing the C-855 at one place while listing a C-860 at another and having a penciled in reference to the higher output by the C-855 entry. I myself have some sales materials with some penciled-in notes, but these have not so far been anything revelatory. -Will Davis
Interesting developments.
It sure seems to be getting clearer that ALCO was able to offer the 12-251 up to 2500 HP for traction, given the spec for the diesel-hydraulic (I sent an email asking to see the specification) and this vague reference to a supposed twin-block single-alternator machine. For whatever it's worth, that just sounds like a really bad idea to me. You're guaranteed that if one engine fails, the whole locomotive goes down. The reference in that description exactly describes the effect of Performance Control / Automatic Power Matching, albeit very roughly.
What is the nature of the representation in the quoted railfan ALCO book? I'm not quite clear on it. Was this written by someone who was present at an ALCO sales pitch to the Milwaukee?
Also interesting is the verification that the spotted reference was actually to an eight axle C-860. Now, does anyone have a surviving specification or ALCO sales book? If so that would be great. It also sounds like ALCO had not completely updated its sales book, still listing the C-855 at one place while listing a C-860 at another and having a penciled in reference to the higher output by the C-855 entry. I myself have some sales materials with some penciled-in notes, but these have not so far been anything revelatory.
-Will Davis
I don't own the book (I am hoping to acquire a copy in the near future).
I have found Withers Publishing (the publishers of Diesel Era Magazine) to be fairly accurate in the research for their various publications...
I did ask anyone on the tread who does own the book to crosscheck it...
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
Since this thread has been inactive for so long, I have looked for more.
The SD39 and GP39 were built with alternators, but generators were offered. Two "GP39DC"s were built, but no "SD39DC"s were. I won't add this to the list, as GP39AC and SD39AC were not actual model designations.
NorthWestTwo "GP39DC"s were built, but no "SD39DC"s were. I won't add this to the list, as GP39AC and SD39AC were not actual model designations.
Please don't use that convention. "AC" appended to an EMD designation means AC traction motors. Confounding that with the type of main generator is only going to produce pain, confusion and delay.
If you must come up with a railfan distinction, I suggest appending the main generator/alternator designation to the unit type (e.g. D-32 or A-11, or whatever is appropriate for the units in question; I am not at nit-pick OCD knowledge status for models historically used!).
For current EMD products, AC does mean AC traction motors, but for the 38/39 models, AC or DC would refer to a traction alternator or generator respectively. There was no way that any EMD of that era would have been built with AC traction motors.
- Erik
Using the AC or DC at the end of the GP/SD38/39 models is the practice I have seen in most books, and so I used it.
But, technically, yes, you are right in that it is not the modern nomenclature and thus may be confusing.
Not having any official EMD paperwork, I am unable to determine if such things as SD38AC were actual model designations, or a railfan invention. I suspect it was simply an option, and EMD didn't create any special model name for the generator to alternator change.
Railroad Locomotives - My Blog
Thanks, Will.
Happy New Year to all.
I have changed my mind, and will add it to the list.
The List
GE
B18-7
U33CG
U18C-North American extension of the U18B
U56
U18BT
U15BT
B40-8(B)
C23-7
B28-7
C28-7
B23-8
B33-7
C33-7
EMD
DD40A
SD39-DC
SD55
AMT-125
RB3600
GMDH-2
SD40-2B
GP2000
SD39-2
SDL39-2
SD59
SD49
TR12
F45B
TR9
M-K
MK5000AC
MK6000AC
F-M
CFA-24
CFB-24
CPB-20
CPB-24
ALCO
PA-3
FA-4
C428
C620
C624
C636F
C636P(A)
C636P(B)
C650DH
RSD-33
Ingalls
3-S
16-S
5-S
17A
MLW
RSC-23
RS-13
RS-24
Bombardier
HR416
HR618
HR406
Lima
800 HP BB road switcher
1600 HP center cab C-C road switcher/transfer
2400 HP center cab C-C road switcher/transfer
3200 HP CC cab unit powered by 6 free piston generators powering a turbine.
1600 HP Switcher Combo
2400HP Switcher Combo
Baldwin
1000 HP C-C Road Switcher
1500 HP C-C Road Transfer (streamlined car body)
3000 HP A1A-A1A Road Locomotive
You are forgetting some of the most prolific builders of engines I. E. the dinkies and swithers such as whicombs and others. they are more of these types than ever were made by road diesel manufactures. some are in museums and some are just memories? any takers 4 the next list. think Pa. the standard railroad 4 the world. now think 2 the other end of the locomotive world?
RBANDR, I am having extreme difficulty understanding your post. I do not know of any small locomotives not built, and restored ones are not the purpose of this thread, which is not built yet catalogued diesel locomotive models. Do you have anything on this topic to contribute?
Think he means Whitcombs and co should be included, even tho they generally never proposed a new design and it not get built....
ML
I mean the smaller builders that were the backbone of the switching railroads bread and butter. think whitcomb and there salesman who went door to door with a book and an order pad I. e. ge 44tons or less? get it now. u have been thinking only of the major and gone makers. in steam days it was porters and even davenports?
Okay, I understand now. I'll look through the smaller units and see if I find anything.
I didn't find any, but others are encouraged to find diesel models fitting this thread, whatever the size!
Will DavisYou will in fact find EMD manuals with model designations on the cover such as "GP38-AC" - the company did in fact append some model designations with letters indicating use of optional transmission. Now, exactly when this started or how long it ran I have no idea; whether this was referred to in advertising or on locomotive specifications I also cannot tell you right off the top of my head. Note the hyphen in the EMD designation.
This is interesting because NS in my area runs GP38-ACs and indicates this on the cab sides. I don't remember them using the hyphen -- but this gives me an excuse to go down to Forrest Yard and see... ;-}
I think erikem is exactly right regarding the purpose of the DC/AC in this context, and I stand corrected.
Happy New Year... and Merry Christmas, too; it has today and tomorrow still to run...
I'm a diesel geek and have found this discussion to be absolutely fascinating!
HAPPY NEW YEAR!
The GP-38 was in a transition era. By AC did they mean just an alternator instead of a dc generator or alternator and ac traction motors, which is what an ac unit is today?
Something I once knew and now cannot remember. Help!
daveklepper The GP-38 was in a transition era. By AC did they mean just an alternator instead of a dc generator or alternator and ac traction motors, which is what an ac unit is today? Something I once knew and now cannot remember. Help!
Dave,
Your memory is better than you think (no pun intended).
The "AC" designation on some of EMD's 60's/70's roadswitcher and switcher models is an identifier that the locomotives were equipped with an alternator rather than a generator...
Models in addition to the GP/SD38ac include the MP15ac and GP15ac...
Building on Carnej1, the units with AC labels before the 60 series had alternators, but DC traction motors.
The GP/SD/DD40 series were all equipped with alternators as the traction generators on the GP/SD/DD35's were pushing the limit with 2500HP available for traction. Presumably EMD put traction generators in the '38s and '39s because the generators could handle it and saving development to get the alternators to work correctly with less than 3000HP.
Erik, I think you are right. The other reason may have been EMD conservatism, if the 40s failed, then they had a backup with the 38s and 39s.
Now, anyone have any more non-built models?
The alternators worked fine with less than 3000 HP; the first notch in a GP40 is only about 200 HP or something like that. Moreover, a GP40 power limits to 2000 HP up until about 11.5 MPH, whereupon it begins to linearly increase horsepower output with speed up to about 19 MPH where it's finally developing its full rated 3000 HP. So there was no issue with getting the alternator to work with less than 3000 HP.
(The Performance Control can be adjusted for a wide range of minimum continous speeds, by the way.)
Use of the D32 in the GP38 meant that you still had complexities of a big DC generator that the alternator didn't have and also had to have the transition program switch with multiple small stages of field shunt -- a device that had been troublesome in the 30 and 35 series units. Going to an alternator/rectifier drive increases first cost but lowers maintenance cost and increases reliability in this case.
The 39 didn't initially appear in the product catalog when the rest of the 645 line appeared.
The GP40 did have a number of problems initially, but EMD kept with it and refined the product until it worked. Among other things this led to the development of IDAC wheel slip control. That's right - the IDAC DID NOT appear along with the 1966 line of 645 engined locomotives. It came later.
Now back to things NOT built...
A couple more things.
Quarters cab offered on all GE-7 models.
GMD may have proposed a cowl version of the GP59 as the GP69? Anyone have more information?
Wouldn't theGP59 cowl unit be a F59?
GDRMCo Wouldn't the GP59 cowl unit be a F59?
Wouldn't the GP59 cowl unit be a F59?
Yes, I'd agree, and I see little if any meaningful difference between a 'cowl GP59' and a cowl GP59 built with HEP (which of course was built as the F59PH)
Wouldn't a "GP69" be a twelve-cylinder version of a GP70 (which I think we have concluded was offered but had no 'takers')? With the appropriate derating? (And with a cowl version being F69 anyway?)
An F69 of sorts was actually built. Two F69PHAC's, lettered as Amtrak 450-451, were built as AC motor test beds and tested on several Amtrak routes, primarily on the Empire Builder.
Overmod and GDRMco, that is what I would think as well. I found this in a DSG, but I can't find a second source.
I'd call this proposal a GP59F. (Like SD50F).
Were the GP70 and GP69 ever offered by EMD? Would that also mean that a SD69 was also available?
I must admit that with the more modern EMD units I'm a bit out of my element, but I have also not lived in a cave for the last 20 years either.... I was under the impression that after the GP59 and GP60 that EMD did not offer any further four axle freight locomotives in parallel with the SD series developments such as SD70 / SD75 / SD80MAC / SD90MAC and so forth. The EMD site only shows present models, at least so far as a cursory look determined. I'm not going to do a web search because I'll turn up a pile of imagineered stuff that isn't true. So...
Who can provide an actual product announcement in a trade paper, a product catalog reference, or an issued (published) specification for a four axle EMD freight locomotive higher horsepower and later than the GP60?
I read somewhere ATSF originally wanted their GP60Ms to have a full body cowl, but had to settle with only a wide-nose safety cab when EMD told them a full cowl would have added too much weight to the 4 axle GP60M, which had smaller-size fuel tank to reduce weight.
they hated anything not standard. a easy fix would have been a A-1-A BB. fust the opposite of the ones for the electric/diesel for McGuiness.
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