U30B Vs. SD45

[Anonymous]

I read where the WP test operated the SD45 back in the 60's and liked it. However it was determined that it was going to be too rough on the rails. Disapointed they were. Enter GE with the U30B which they claimed pulled as hard as the SD45 and wasn't going to be hard on the rails. Hard to believe, however, the WP didn't find the U boat all that bad. I find this interesting. Any comments?

[Anonymous]

I do NOT want to get another "Ford vs Chevy" type of discussion started, I'll just speculate that with the many sharp curves on the WP, they favored the 4 axle units. Of course, now almost all the UP power traversing these rails are big 6 axle units.
Todd C.

[Anonymous]

Hello Powerdesk,

I seem to recall that the WP train crews hated the U-boats. As to GE's claim that the four-axle U30B generated as much tractive effort as the six-axle (and far heavier) SD45, I find that hard to believe. I'd be happy to see any TE figures for comparison should someone know where to dig them up. A nominal guess would be that the SD45 generated about 100,000-plus pounds of TE at 11 mph, while the U30B at most would deliver 84,000, and probably less because it lacked two additional axles.

Please chime in, anyone with more information!

Paul Schmidt
Contributing Editor
Trains.com

[Anonymous]

You are right. The WP crews hated the GE's.

[Anonymous]

I read in a couple of books that WP had a lot of trouble with their U30Bs. After the merger with UP, all but one was scrapped. The one remaining U30 is in a museum.
I've seen a few photos of WP U23Bs leaking something around the long hood, but UP kept those, so I assume they weren't too bad.

[oltmannd]

What limits the max TE on both units would be the wheelslip control system. The state of the art in the 60's for both GE and EMD allowed "all weather" adhesion of about 18%, so that would mean about 70,000# for the SD45 and about 50,000# for the GE. Under ideal adhesion conditions, the GE traction motors had a somewhat higher thermal capacity than the EMDs, so under the right circumstances, the gap may be smaller, but there is now realistic way GE could claim equality. Hard to believe you could count on good rail conditions headed east up the Sierra's, also.


Now, what GE might have been selling was that over the normal speed range, the difference in TE between a 3000 HP loco and a 3600 HP loco was minimal. Or, more likely, the case was based around buying 4 U30s for the price of 3 SD45s and having the same total TE and slighlty higher total HP.

-Don

[Anonymous]

Paul,
GE Transportation Service web site has tractive efferts adn a lot of other stuff. I think the "Right on rails" area is where you need to go.

[Anonymous]

Thanks, Powerdesk, I'll check that out.