GE U50

[MEC407]

(Moved from the "favorite GE locomotives" topic to its own separate topic)

GE built two different 5000 hp twin-engine diesels.
The first is the one Dutch Railnut describes: (16-cylinder) engines as in the U25B, built basically for UP (SP took three as a sample) in about 1963. This one had eight axles: four standard two-axle trucks (as on U25B), two on a span bolste at each end. (EMD's equivalent was the DD35, with a newly designed four-axle truck.)
The second was the U50C, built for UP alone in 1969-1971. By this time GE was able to get 5000 hp out of two 12-cylinder engines, allowing a slightly smaller locomotive on two three-axle trucks. (A GE drawing showed the unit on the FB-3 trucks used on U30C, etc, but all those actually built had drop-equalizer trucks from traded in "Gig Blow" gas turbine locomotices: perhaps unfortunately, as the very heavy U50C suffered truck-frame cracking.) They had design flaws-- the worst was apparently a prone-ness to electrical fires due to the use of aluminum wiring-- and were retired by the mid-1970s.

Apologies for resurrecting an old topic, but I searched the forum and (surprisingly) this was the only mention I found of the (in)famous GE U50.

I was uploading a photo to Railroad Picture Archives today, and as I was browsing other members' recent uploads, I came across this very nice photo of a brand new U50 in transit to Union Pacific. The photo was taken on July 18, 1964, and the unit was placed in service four days later. Check it out: http://rrpicturearchives.net/showPictur ... id=2299154

Union Pacific ran it for 10 years... which, if I'm not mistaken, is longer than they ran their H-engined SD90MACs.

[MEC407]

Here's another great U50 shot from the same contributor:

http://rrpicturearchives.net/showPictur ... id=2299106

[Allen Hazen]

MEC 407--
Thanks for linking those photos! I should try to see if I can find a dimensioned drawing: look how the U50 in the second photo seems to tower above the U25B coupled behind it. Were they really that much taller, or is it a trick of the perspective?
--
It's interesting that EMD designed an all-new 4-axle truck for their competitive model: GE seems to have found that standard B-trucks on span bolsters worked well enough. Still do: the 8-axle GE units on the Brazilian mining railroad still use span bolsters, with what look like FB-2 (probably a small-scale version of the FB-2, since these are meter-gauge units) instead of drop-bolster B-trucks.

[Allen Hazen]

Yes, they DO seem to have been that tall. "The Diesel Shop"
http://www.thedieselshop.us/GE%20U50.HTML#TechData
isn't always reliable, but they say the U50 was 16'3" from rail-head to top of engine hood (and 16'10" to top of cab, which may include horns or radio antennae, since the cab-roof doesn't seem much higher than the hood), whereas a U25B was only 15'3" to the hood roof (which probably includes the raised portion of the radiator housing, which is higher than the rest of the hood: height over cab is given as only 14'7"). Which makes sense: the U25B was designed to go all over the North American system, including low-clearance eastern lines, and the U50 for Union Pacific didn't have to be kept within that more restrictive envelope. And I suppose span-bolster trucks are a bit higher than ordinary ones. (Not to sully the precincts of the GE forum, but I think the competitor's DD-35 was a few inches taller than its GP-35, too.)

[MEC407]

More great photos at: http://rrpicturearchives.net/locoList.aspx?mid=284

[Typewriters]

General Electric sales brochure "General Electric Locomotives," GE publication number GEA-7842 with a publication date of 9/63 in our collection gives basic dimensions and specifications for the three GE road locomotives offered at the time; to wit, here are the indicated overall heights:

U25B 14 ft 7 in
U25C 15 ft 0 in
U50 16 ft 4-3/4 in

-Will Davis

[Allen Hazen]

Will Davis--
Thanks! Lord only knows where "The Diesel Shop" got its figures: their heith to top of cab for the U25B corresponds to yours for the height of the U25B.
I'm a bit surprised that the U25C is only three inches higher than the U25B: my recollection is that the deck height of GE's domestic six-axle models was five (five and a half?) inches higher than that of its four-axle models (until the introduction of the North American cab, which involved lowering the deck on the C40-8): is the above-the-walkway height of the superstructure on a U25C actually two inches less than on a U25B, or was GE measuring different things for the two models?
(The more I learn, the more I realize I still don't know!)

[Typewriters]

I'll have to check out those measurements, Allen...

One interesting fact is that the Specification for the ALCO C-855 (we have that here too) gives absolutely exactly the same overall height as GE gave for their U50. You'd have to think that's not a coincidence; it's probably UP's absolute maximum permitted height.

-Will Davis

[Mr.S]

Ah! The good old age of railroading, rail fanning and model railroading we had a nice variety of locomotives and railroads when I was growing up ,late 1960's1970's. For those youngsters "born late 1990's to present.. " I'm talking about those who are between 16-20 years of age.. "

Yes, people I was born in the early 1960's.

[Typewriters]

Well, here we go, from GEA-8080, 10/64 which is a sales brochure for the U25B and U25C.

Distance from rail head to running board height for the U25B: 67-5/8 inches.
Same measurement for the U25C: 75-1/4 inches.

GE fans might want to check out our blog - there's a fair bit of GE information on there now including a new post today.

-Will Davis

[Allen Hazen]

Thanks, Will!
I think those running-board heights stayed pretty much the same (I can't swear to the fractions of an inch) on later domestic GE 4-axle and 6-axle units until the C40-8W: to accommodate the large "North American" cab, GE redesigned the platform on their six-axle units to lower the deck height. Depth of the sideframe beneath the handrails alongside the long hood is the most obviously visible sign of this redesign, unless you are very confident of judging heights from a perspective!

[Allen Hazen]

Everybody else: DEFINITELY go check out the Railroad Locomotives blog that Will Davis and his brother have started: lots of GE infomation, lots of Baldwin information... Documented (unlike most railfan publications) from original (GE, BLH, etc) sources!

[Desertdweller]

I think the height difference between the early and late versions of the U-50 can be attributed to the span bolster arrangement on the earlier version.

The Alco C-855 used the same bolster arrangement, and was thus the same height as the early U-50's.

Les