I saw Denver Zephyr’s post about U50s, and remembered this:
I’d been looking through the 1966 Car and Locomotive Cyclopedia, and in the GE section, right next to the U50, is the U56. It’s apparently a U50 carbody with two 2800 horsepower engines. Same dimensions, only a difference in engines.
So did the U56 ever become a test bed or was it just a concept?
Neither was built even to test – and there would have been little point in a demonstrator as the locomotives would just be ‘higher horsepower’ versions of the U50Bs already running, and the implications of ‘overclocking’ the FDL-16 were well-established in single-engine versions…
Some reference to it here:
Pretty clear that it would have been two 2800 (slightly increased governor settings over what was in the U50, I believe) engines, probably in the B+B-B+B frame configuration – you would want the extra TMs and axles at the higher HP…
Presumably the version with AC (main alternator) would have been U60
RME
Yep, it was on the B-B+B-B frame. I don’t know about the modifications, but they definitely were U28 engines.
I just looked through the Cyclopedia again and found another odd duck - the EMD DD40A. Not the famed Centennial, but a 6000 horsepower test bed with a standard EMD cab on a comically long body. Very similar to the DD35A, just with 1000 extra hp. Specifications list two 16-645E engines. I do know at least one test bed existed - found a picture of it in EMD livery.
I feel that some forumers will think I’m lying.
While you are not lying, you aren’t correct either…
No DD40A or DDA40 was ever built.
However, the DDA35 (or DD35A) which was built at the end of 567D3A production was visually very similar to the proposed DDA40 including the angled radiator intake grilles later used on the SD45. The visual difference between the “35” and “40” was the radiator fans, two 48" and one 36" per engine on the DDA35 and three 48" per engine on the DDA40.
I believe photos of a UP DDA35 were retouched to show the EMD demonstrator livery of silver and blue to represent the DDA40. The radiator fans are not obvious in a ground level view.
M636C
Very Interesting…
I wonder if GE pitched this to UP, if they and/or SP had ordered units I guess the next step (circa 1967) would have been a U60.
However, I would hazard a guess that the U50C frame would have been too short for 2 16 cylinder engines so thus the twin FDL-12s.
I wouldn’t have been surprised if GE designed this just for UP. It would’ve been interesting to see GE’s answer to the DDA40X…
IIIRC,the U50C came about because UP was trading in it’s fleet of 8500 HP gas turbine electric locomotives and the U50 series design was adapted to re-use the CC trucks from those retired units just as the UP U50s had used trucks from the earlier turbines…
The picture in EMD livery is probably a retouched DD35A. The DD40A was included in the catalog of the original 645 line announced in 1965 (See July 1965 TRAINS). The first 645 line included nine models, SW1000, SW1500, GP38, GP40, SD38, SD40, SDP40, SD45 and DD40A. No DD40A’s were ever ordered or built and it was quickly dropped from the catalog.
The U56 was more than a concept. Union Pacific U50 #52 was rated at 5600 horsepower for test. The unit was delivered with a Cummins PT fuel system. The unit was rebuilt with a standard fuel system and rerated to 5000 horsepower in October 1966. A 1969 GE proposal to upgrade the UP U50s to 5600 horsepower was declined. Data from Paul Withers’ article Union Pacific U50s in Diesel Era Volume 20 Number 4 July/August 2009 see pages 22-23.
Hello! Earlier in this string, a link was given to a site which read as “Davis FDL 3.” I’m the person who wrote it.
The U56 was, as I said on the site, announced to the trade on or about October 1, 1965 in a rather brief way. More detail is found in GE sales brochure GED-5340, printed 8-65 which depicts and describes the U56 along with what was loosely elsewhere referred to as the “1966 line.”
The U56 differed from the U50 in the ways the U28B differed from the U25B in the engine, regarding horsepower output, and the application of 75 MPH gearing as standard, giving a continuous effort for the U56 of 108,200 lbs. Weight is listed as 536,000 to 560,000 lbs. Layout of the locomotive is however completely unchanged from the U50; no attempt was made to relocate either the equipment blowers or the dynamic brake grids and blowers.
The weight listed for this unit is heavier than that given in the specification book for the ALCO C-855, directly comparable in many ways to the U56. The ALCO specification lists basic weight for A and B units as 528,000 lbs, with optional ballasting to 544,000 lbs. Interestingly, the standard gear ratio for the C-855 was not the 75 mph ratio standard for the U28B and U56 of comparable horsepower per axle, but rather the usual 74/18 for a 70 MPH top speed.
The brochure also shows (of course) the U28B and U28C, as well as the U28CG - all of which were actually built. That said, there’s nothing at all that would have prevented the U56 from being built immediately - no additional engineering would have been required.
I noted a quote earlier in this string about the single Union Pacific unit which was fitted with a Cummins PT pressure-time fuel injection system, and would just note that the entire wording, exactly, for that information appears to have been lifted from the George R. Cockle book “Giants of the West,” from some years back which is a treasured pa
So would a Dash 7 version of GE’s double diesel had been called a BB60-7 had UP’s double diesel craze lasted into the late 1970s or early 1980s?
And I guess the EMD equivalent would have been a full fledged dash-2 version of the DDA40X, or even a conjectured DDA50.