• U.P. what if?

  • Discussion of General Electric locomotive technology. Current official information can be found here: www.getransportation.com.
Discussion of General Electric locomotive technology. Current official information can be found here: www.getransportation.com.

Moderators: AMTK84, MEC407

  by Allen Hazen
GE locomotive fans can't help somewhat mixed feelings about the U50C: impressive size (& a bit more imagination in the approach to twin-engine locomotive design than the competion), but disastrous!
Still, the fiasco wasn't entirely GE's fault: the customer wanted twin-engine units.
Suppose, however, that the customer HADN'T had that particular bee in his bonnet. (I've seen suggestions in print that Neuhart didn't understand the maintenance-cost statistics his own railroad had compiled, and that his double-diesel enthusiasm was based on this misunderstanding... take this as QUESTION #1 if you know more about this episode.)
Suppose that, instead of 40 U50C, U.P. had bought 60 U33B. This would have been, en masse, very nearly the same amount of GE locomotive: same number of cylinders, same number of axles & traction motors, 99% of the horsepower. (If you want to make the horsepower come out closer, change the order to 53 U33B and 7 U36B, but I don't think the maintenance people would thank you!)
It would be more in some respects: 50% more carbodies, trucks, couplers, etc. And it would take up more track space: a U50C was only 79 feet long, whereas one-and-a-half U33B would be 90 feet 3 inches. On the other hand, it would save 20 generators and electrical cabinets and smokestacks....
It would probably have served U.P. longer: Conrail retired its ex-PC fleet in 1983-1985, but only because the locomotive builders offered them VERY generous trade-in deals to keep their production lines open during a depression. CSX kept at least some of their ex-SCL fleet going into the 1990s.
QUESTION #2: any reason this wouldn't have served U.P.'s operational needs just as well? (Even assuming the U50C had worked properly!)
QUESTION #3: What about the cost? I assume that in @ (in the ACTUAL history, as oppose to the alternative I'm asking about), U.P. got a bit of trade-in credit for the trucks from Big Blow turbines that were re-used on the U50C, but also had to pay a premium for the special engineering on non-standard units. Does anyone know (a) what U.P. paid for its U50C and (b) for comparison, what S.C.L. paid in the same time period for U33B and U36B?

  by *istDS
1) The UP did not purchase any significant quantity of high hp B-B locomotives.

2) The U33B model would not have been suitable for the type of grades that are characteristic of UP. The design was not intended for drag freight service. Think PC,SCL & RI.

3) Think about it-the U50C was in many respects, two complete locomotives above the platform. $$$$$

4) The guy who spec'ed them, Dave Neuhart, was thinking in terms of Challengers and Big Boys.


  by byte
I don't think it was just the turbine trucks that the U50s were built on - IIRC, it was the frame as well (although presumably not the carbody frame, as the two locomotives were very different in that respect). So that would probably have dropped the cost a bit.

  by Typewriters
In point of fact, the horsepower per axle of the U50C and U33B was practically identical. The question is then (on the basis of horsepower per axle) relevant, since with the U33B the technology and application would have been entirely conventional.

{Allen notes that GE had a bit more imagination in its second twin-engined design for Union Pacific, although it should be noted that both designs considerably increased output per ton of locomotive weight. General Electric ended up producing units of the same horsepower it had with the U50 but greatly reduced the weight, whereas Electro-Motive only slightly changed the weight but greatly increased horsepower. Thus, improved productivity (theoretically) in both of the later designs. Again, though, note that in the EMD units and in the GE units the horsepower per axle was roughly the same (which as I noted is the same as the U33B.) }

Taken on the balance, then, if we look to the normally printed reasons for taking the U50C units out of service (electrical fires in the alumimum main cabling and cracked truck frames) you would have to automatically assume that better availability would have been obtained through the purchase of U33B units over the U50C units. I should point out though that around this time, Union Pacific was beginning to purge all of its low-availability high-cost-per-mile units, including the ALCOs, so it might not look so bad for the U50C units in that context. (Not to say they were NOT bad. Just offering perspective.)

The U33B, whose design, development and construction are fairly well covered on my website, was fitted as standard equipment with control system features that enhanced drag speed performance and allowed compatible operation with units of lower horsepower per axle. This equipment functioned somewhat like EMD's Performance Control through limitation of excitation in the lower speed range, below minimum continuous but above about eight MPH for standard gears. Penn Central did in fact operate U33B units in mountainous territory, although I'm sure LCJ will have plenty to say about that. The point here is that operation of the U50C and of the U33B in such conditions would be the same as conditioned by this control system feature, so that operation of the two different types in identical terrain would not be an issue.

Interesting question, and I would bet that many on UP wished that conventional locomotives had been purchased -- which, for example, could have operated freely in pool service.

-Will Davis

  by *istDS
As an overarching statement, I think it is dangerous to draw conclusions about the performance of a given locomotive design based upon the builders' literature. The field separates the contenders from the pretenders.

Furthermore, back in the day, the railroads were still on the steep side of the learning curve with respect to high HP B-B's and C-C's.

I note that the GSC swing bolster truck was probably way out of its element when applied at 825 hp/axle. This truck design was descended from the MCB (trolley) truck of 1898 !!! Alco seemed to be aware of this back in 1967 when they fielded the Hi-Ad truck design. That was at 750 hp/axle.

Believe that the std. gearing on U33B's was 81:22, which equated to 75 mph top speed and a higher MCS than the U33C. The U33C also benefited from an additional axle load of 5 tons per axle and a modern (for the time) truck design.

GE's own application studies, which were done before the order was even signed, indicated that the U33B was intended for high speed freight service
on properties such as the NYC's NY to CHI line-the Water Level Route. The NYC was an early proponent of high speed intermodal freight-yes ?

There is ample testimony (in the form of retired operating types) that a four unit set of Alco road freight units could dig in and drag for hours on the worst grades found on the B&A. The same men will tell you that a three unit set of U25B's-which offered an additional 1500 hp but approximately the same TE-could not do the same job-without slip.

Don't think that PC could be cited as a sterling example of either proper locomotive application or maintenance. At the onset of Conrail, there were a large number of locomotives running with one or more traction motors cut out. I believe CR took the draconian step of cutting out the TM
CO switch so that defective locomotives got red tagged and went to the shop for repairs.

Seems to me that the GP-40 and SD-45 were the gold standard in their respective categories. IDAC was seen as far superior to GE's ALDAC-so much so that GE went to CMR. I wonder why EMD eschwed more than 750 hp/axle on a B-B until they developed a new concept in slip control-Super Series.


  by Typewriters
Interesting and true, although it does expand the discussion considerably beyond the limits of Mr. Hazen's original question.

I should note here that the top speed of the U50C is given as 85 MPH, and that of the DDA40X as 90 MPH; these units were not originally intended for operation in only drag service. It is true that power matching on the GE units allowed a minimum continous speed of 14.7 MPH, and that of the EMD units 11.25 MPH (correlating well to the U25B in the first case and very many kinds of EMD units in the second) although this was likely only to allow compatibility with older units and not directly to allow these units to operate in drag duty. (Nobody thinks of the Challengers, the Big Boys, or any of the Gas-Turbine-Electric locomotives which preceded these types as drag units, it is worth noting.)

The original question regarding comparison of U33B and U50C units is perfectly valid considering the facts that the horsepower per axle was roughly equivalent, and that the weight per driving axle of the U50C was actually significantly higher. It could be successfully argued then that were one to attempt to construct a fully equivalent unit to the U33B but with six driving axles, he would arrive at something quite like the U50C turned out to be. (U33B, approx. 275,000 lbs / 68750 lbs per axle, and U50C 442,660 lbs / 73777 lbs per axle.)

The comparison of four ALCO-GE units to three second-generation GE units on the former B&A is well supported, however, and easily understood when one considers that the four-unit set of older units had a weight on drivers of over one million pounds, whereas the three unit set of GE units weighed something under 800,000 pounds and was distributing 7500 HP through twelve axles (instead of 6000 to 6400 HP through sixteen.) Time and again this case was tried and retried in many "courts of opinion," especially at annual meetings of the Railway Fuel and Operating Officers' Association, wherein it was made perfectly clear that the vast majority of actual operating officers did not understand the true nature of the locomotives being offered by the manufacturers. Even as late as 1968, Mr. D. I. Smith of General Electric was forced to restate the fundamental differences in performance between the then-new U33B and U33C units as a direct result of a question from the floor as to the ability of the U33B. Most often the new units were simply overestimated and overloaded. Many times it was attempted to replace older units three-for-four, or similarly, with the expectation that the new wheelslip systems would allow acceptable performance. That they did not is at least partly indicated by the large turn to six-axle power (actually following a trend initiated by ACL in the middle 1960's and much debated and watched by many interested parties.) The drive to increase horsepower per axle was in step with, or responsive to, the desire to increase train speeds; this dictates higher horsepower per ton of train to be hauled, and the assumption that three second-generation four-axle units could outperform four older ones was valid only on level or mostly level profiles.

In point of fact, when two of the three experimental Krauss-Maffei diesel-hydraulic locomotives (model ML4000C'C') were loaned to the NYC for testing, they were assigned tonnage over the B&A based entirely on their horsepower rating and on the assupmtion that the units should theoretically have performed about the same as four GP-9 units. The facts that the units only weighed about 331,000 pounds each, and that they were derated for operation at altitude, were ignored with the result that the units slipped to a standtill on the main line of the Boston & Albany in a blizzard. Had the true knowledge of these units' merits and demerits (and capabilities) been available, such an event would not have occurred. Identical thinking was applied everywhere, in mountainous territory, that it was attempted to replace four older four-axle units with three new high-horsepower (four-axle) units.

Getting back to the original question, though, it is obvious that for whatever application the U50C was tailored to meet on the Union Pacific, the U33B would have filled the bill identically if assigned (evaluated) by axle count; it is quite nearly "apples to apples." The original question centered around the idea that it might have been more sensible to avoid dual-engine units and some new technology for this service, which as I've said, taken on the balance would probably have been better. Both types had roughly identical horsepower per axle and (less roughly) identical weight per axle, and both employed Power Matching so that in theory their employment would have been identical. It could be guessed at, and I do not have figures at hand, that the purchase of conventional U33B units might have been less expensive initially, but would almost surely have cost the railroad less in the long run.

Finally, it should be noted that the vastly superior and highly successful EMD DDA40X units were essentially identical in performance to two U33B units, even to the point of being rated identically in horsepower and horsepower per axle. Perhaps this does more than anything else to support the validity of Mr. Hazen's original question..... although we're all quite aware that the U33B was a poor comparison to the GP-40.

-Will Davis

  by Allen Hazen
I don't have much to add to Will Davis's comments.
It's certainly true that U.P. hasn't been a big purchaser of high-horsepower B-B units. (They got a few of the "GP49X" (prototypes for the GP50) -- I think these were the only units built with the high adhesion B truck EMD experimented with in the late 1970s -- but didn't come back for production units.) This just makes their repeated purchase of "double-diesels" -- units with the horsepower/axlecount ratio of the highest h.p. BB units of their time -- seem all the more anomalous!
*istDS makes the point that the drop equalizer trucks standard on a U33B are a very old design, and perhaps do not offer good adhesion at high power ratings. (The GE FB-2 truck apparently offers somewhat better adhesion, perhaps at the cost of ride quality, but the period of U50C production is just too early for it. U.P. COULD have bought U33B with Blomberg trucks, as S.C.L. did, but this would probably have been an extra-cost option. Since Alco had just exited the locomotive business, one can fantasize about U.P. purchasing the patent for the Alco 2-axle Hi-Ad truck and ordering U33B with these trucks -- which, when wheelslip detection systems were fine-tuned to go with them, apparently DID give improved adhesion, but that is wild fantasy: alternative histories where that happens are more farfetched(*) than those where U.P. buys U33B with drop equalizer or Blomberg trucks.)
The trucks used on the U50C date from the late 1950s: do you know that they gave better adhesion than conventional trucks of the time, *istDS, or is that just a guess?
Finally, I'm not sure U.P.'s mountainous track profile should have ruled out high-power BB units. W.P. stuck with BB units -- GP40 and U30B -- even after testing CC demonstrators.
(*) "Farfetched" is used almost as a technical term by the late American philosopher David Lewis in his book "Counterfactuals." His idea was that to evaluate a counterfactual, like "IF U.P. had bought U33B instead of U50C, they WOULD HAVE gotten better value for their money," you consider the LEAST far-fetched alternative history in which the IF half is true and see if the THEN half is true their too.

  by thebigc
Allen Hazen wrote:I don't have much to add to Will Davis's comments.
It's certainly true that U.P. hasn't been a big purchaser of high-horsepower B-B units. (They got a few of the "GP49X" (prototypes for the GP50) -- I think these were the only units built with the high adhesion B truck EMD experimented with in the late 1970s -- but didn't come back for production units.)
For the record, those were GP40X's. Both UP and SP GP40X's were equipped with the HTB truck.

  by Allen Hazen
Thanks for correcting the typo! GP40X.
And thanks, also, for the note on SP's GP40X: I'd forgotten them! (Santa Fe and Southern also got GP40X, but with Blomberg trucks.)
On the BB vs. CC issue: in the late 1970s there seems to have been a renewal of interest on the part of the railroads in high horsepower BB units: maybe faith that the new wheelslip control systems introduced by both builders would solve the slipperiness problem, but perhaps also in part because the highly publicized derailments of Amtrak's SDP40F made people worry about the tracking qualities of CC units.
Southern Pacific, after purchasing hundreds of high horsepower CC units (SD45, SD45T-2, U33C) seems to have looked into a variety of ways of getting new 4-axle power: in addition to the GP40X, they had a small number (4, I think) of U25B reengined with Sulzer engines and (showing MUCH better taste (grin!)) ordered some B30-7, four of which were actually B36-7 prototypes. From the point of view of the question about the applicability of high-h.p. BB units in mountains, this raises a
QUESTION #4: Did S.P. make a concerted effort, between 1979 and their absorption into Big Yellow, to keep high-h.p. 4-axle power on their more easily graded routes, or did they dispatch them over the Sierras on a regular basis?

  by *istDS
AFAIK, most of the high HP B-B's purchased by the SP were lettered "Cotton Belt." A brief viewing of various railroad picture sites seems to indicate that they ran everywhere on the system.

Herein lies the rub I was aluding to previously: there was nothing to stop to the railroads from applying diesel locomotives in a manner than the builder had NOT intended or even recommended.

In contrast, I don't recall ever seeing a NYC Hudson on a local freight or a Big Boy working the hump.

BTW, another issue that never even mentioned was dynamic braking-which is of no small import to the Western roads. Strictly speaking, C-C units have more dynamic braking capacity than B-B's. Usually, the timetable or special instructions would call out the number of axles for a certain train or route. I'll leave this for the operating types to elaborate upon.

With all due respect, I find your scenario to be pure fantasy. For one thing, Mr. Neuhart set UP motive power policy for a number of years. The 'double diesels' were but one manifestation of this policy. I note that his successor, Frank Accord, was responsible for the switch to SD40's and U30C's.

Additionally, there was no comparison (in terms of reliability)between any EMD and the equivalent GE model of the period that you are speaking of. The GE's were junk-plain and simple. The FDL engine of the last few years can and should be be viewed as a total re-design of the variant found in U33's. The old Elliot turbo, which was problematic, is long gone.
The main frame of the engine was not 'happy' at 3300 hp-and many of them cracked. PC developed a special technique to repair the frames-which were made of a cast iron alloy. Not an easy thing to do-welding on cast iron. The power assemblies went through a complete re-design.
And so on.

That said-wouldn't you think 'bad news' re: GE U-series traveled between the mechanical officers of various railroads?

I note that the WP considered their U30's a poor second to the GP-40's on their roster. Why do you suppose the WP's CMO at the time-Cuyler (a former EMD guy) even OK'ed the purchase of GE's ?

Finally, your question discounts the essential difference in the wheel-rail interaction in high HP B-B's and and C-C's of the 1960's. EMD did much in the way of instrumented testing to confirm this point. Hence the need for performance control circuitry, new truck designs and the like.

The mfrs. marketing and sales literature is nothing more than fools' gold with respect to how the actual locomotive behaved in the field.


I note that GE had done some application studies claiming that a B40 could replace SD40's one for one in a certain application. I wonder if there are any working railroaders who could testify as to whether or not this ever happened.

  by Typewriters
I think we're getting off topic here. Nobody claimed:

1. That General Electric units of the time period in question were more reliable than Electro-Motive units;

2. That four-axle locomotives could do the job of six-axle locomotives;

3. That the question and scenario at hand were anything but pure speculation and perhaps slightly fantastic although worth considering;

4. Anything at all about manufacturers' sales literature whatsoever.

What we DID do was:

1. Speculatively consider the U33B as a better buy than the U50C given the problems specific to and inherent in the U50C;

2. Incorporate information from actual meetings involving both locomotive manufacturers and railroad operating officers;

3. Indicate the fact that IN THEORY the U33B (if one were inclined to purchase GE locomotives over EMD) would in fact have been applicable to UP's operations based upon many factors, both comparative with the actual U50C and DDA40X units purchased.

We are all well aware of the fact that General Electric locomotives were poor seconds to EMD locomotives of the time period, although it should also be noted too that General Electric spent many years and millions of dollars to address these problems, and the evidence of this can be seen not only in the lectures and Q&A sessions of the RF&OOA meetings but also in GE's placement in orders received over the years.

ONCE WE GET PAST THAT, though, it is STILL fair to consider whether or not a conventional locomotive (off the shelf, so to speak) would have been better than an unconventional one tailored to specific requirements, no matter the source of those requirements. Taking all things into account, it is hard to believe that U33B units would have been LESS reliable than the U50C units actually were, and so from solely a reliability standpoint, the U33B would have been a better buy. The improved traction of the U50C (higher weight per axle, six axle trucks) whether real or perceived was nullified by their tendency to remain out of service; a U33B with less than ideal trucks, out on the road generating gross ton-miles per train hour is better than a theoretically superior U50C parked next to the locomotive shop.

It is on that basis alone that the comparison can initially be considered as valid. We have already established that the units (again, only the U33B and U50C) were comparable in horsepower per axle and weight per axle, so that consideration by axle count (mentioned in the previous post, by the way) would have been relevant as well. (It is also my recollection that dynamic brake effort per axle, comparing four and six axle units of the same series --- that would be GP-40/SD-40 or U33B/U33C --- was usually roughly the same, so that dynamic braking ability per axle would be comparable again between U33B and U50C.) The Power Matching equipment was adjustable on these units to allow variation in minimum continuous speed so as to allow operation at quite low speeds at greatly reduced horsepower; this is the same 'great equalizer' that EMD employed initially with its GP-30 and applied to everything with more than 500 HP / axle following that time. Again, if one WERE inclined to purchase GE units at that time, this feature would have been -- how shall I put it -- necessary and 'in play' with such units. (And WAS with the DD-35, DD-35A, U50C and DDA40X units actually constructed.)

Having been a nuclear engineer I am quite familiar with the fact that equipment does not always perform at or near the level originally specified by manufacturers' information. What is unfortunate in this hobby is that the manufacturers' information, and side of the story, is often omitted or misrepresented. This is why I incorporate information from this source in my website -- but I also incorporate information from the field to give a complete picture. There are plenty of places -- these forums for instance -- where one can search for the phrase "old GE's are junk" and come up with hit after hit after hit after hit after hit. That's old news; everyone knows it.

(Of course, information from EMD is often OVERREPRESENTED because, as many EMD fans will tell you, EMD "won out." So every time Dick Dilworth made himself a ham sandwich for lunch, we all have to read about it.)

I usually make a rule not to get involved in imaginary topics on these forums, although it is only due to the fact that there's so much interest in reality that imagination isn't needed -- but in this case I made an exception because the premise of the question was, in all likelihood, something nearly exactly the same as something considered by UP officials about the very locomotives in question following their purchase. I will add as a final note that a reference has been made in print to the fact that if the original U50 units had proven unsuccessful, the Union Pacific had a reserved option to convert its order to a proper number of U25B units. It is again speculative, but one wonders if UP wouldn't have been better off to experiment with a small number of U50C units and require provision of this same kind of clause with General Electric before taking delivery of all of the U50C units as fast as they could be built.

-Will Davis

  by Allen Hazen
*istDS --
Once again, Will Davis's comments leave me with little to say: maybe a question. So...
You wrote
"Finally, your question discounts the essential difference in the wheel-rail interaction in high HP
B-B's and and C-C's of the 1960's."
QUESTION #5: Can you elaborate on this?
I have seen (*) a story that, when EMD was testing the prototype of the SD truck, they were astonished by the good adhesion obtained. Is there some general fact about truck designs from the 1940s-1950s-1960s that gabe C trucks better adhesion than B trucks? (Perhaps -- this is sheer guess -- inter-axle weight transfer is less with the three-axle designs?)

On a more trivial note, you wrote
"I don't recall ever seeing a NYC Hudson on a local freight." Actually, one of Alvin Stauffer's books (probably "Thoroughbreds," but maybe one of his two more general volumes on New York Central power) DOES have a photo of a Hudson on a local freight! (The caption suggests this was probably a break-in assignment after shopping: so not really counter to yourmain point.)


(*) I thought it was in "The ML-2 Story" by Peter L.Bermingham, though I couldn't find the passage just now. ... This book is a history of the B-class locomotives of Victorian (Australia) Railways: the double-ended F-units on SD trucks. The SD-7 demonstrator was released six months before the first ML-2 was delivered to V.R., but Bermingham suggests that the original impetus for the development of the Flexicoil C truck was the Australian request, and apparently the export truck was tested before the domestic SD truck.