I'm curious if anyone knows the answer to this.
I was told recently that EMD sized the Blomberg B trucks such that only EMD traction motors would fit in them in an effort to make it harder to switch to another manufacturer.
Is this true? And if it is true, how did those railroads that used Blomberg Bs under their Uboats accomplish that? I assume they still used GE traction motors.
Further, I've been given to understand that MPI/MK actually stretched the Blomberg M-2 (leaf spring) to match the AAR truck size and offers it as an option on their locos. What is the purpose of that?
I remember the old member Boagie engineer saying that the Outside swinghanger Blomberg and was far to complex a design for modern apps and needed to be replaced. I had thought that they were no longer being made, but apparently MPI is having them made.
Can anyone illuminate?
The EMD DC traction motor was descended from a GE traction motor that they sold to EMC before GM bought EMC. i used to know the model but I've forgotten. For a while GE parts would fit in the EMD motor, but eventually the design evolution took that away. That motor was physically a wee bit smaller than a GE752, but not so much so that some judicious machining wouldn't make a 752 fit. So, yes, GE locomotives with Blomberg trucks had GE traction motors.
I'm not a truck expert so I'll let those who are comment on the mechanical issues. We've all heard the anecdotal stories of how much better a Blomberg truck rode than an AAR or FB-2, but I've also heard that later FB-2's with upgraded snubber installations were considered a match. Again, I'd like to hear from an unbiased expert (if such a person exists )
As I've read and heard the GEs with blombergs use the EMD traction motor which is potentially the worst of all worlds. The MPI truck allows the good riding Blomberg to fit the larger 752 from GE which is nearly indestructible which is why GE was loathe to switch to AC traction as the 752 had so much life left in it. The EMD motor is notorious for squirrel caging during a wheel slip although I've never hadit happen to me.
Not sure about ride quality, as I haven't been in anything but GP swing hanger equipped engines.
I do know that GP trucks are much easier to service the brakes on. Just try changing the inboard brake shoes on an ALCo truck, without a pit.
Mike WSOR engineer | HO scale since 1988 | Visit our club www.WCGandyDancers.com
Speaking of Blomberg trucks, is there a source for accurate drawings of the original two axle and three axle trucks? Original drawings would even be better. Yes, I have googled, but no luck so far. My interest is in drawings for the F's and E's, FT through E9.