I have been going to post these questions for six months or longer!
I know that there were GP30s and GP35s that ran with AAR Type B road trucks; can anyone think of any examples of this truck being used under 40-Series locomotives?
The only GE units I can remember as using Blombergs were Auto-Train’s U36Bs; were there any others?
Western Pacific U23B’s, U30B’s and Chesapeake & Ohio U23B’s had Blomberg trucks. So did some of Seaboard Coast Line’s U18B’s and some Family Lines B23-7’s as well as the ever-popular BQ23-7. Also Maine Central’s U18B’s. And SCL’s U30B’s, U33B’s and U36B’s.
Looks like there were a few. With your info in mind I guess it would be feasible to buy a few Atlas U23Bs and B23-7s and use the AAR Type B trucks to repower some Atlas GP35s and GP40s and use their Blombergs to repower those U23Bs and B23-7s.
If you feel really ambitious, consider some of Rock Island’s FA1/FB1’s. They were repowered with 567 engines in the mid-1950’s. When RI ordered its first U25B’s, RI used FT’s for trade-ins but in order to provide GE traction motors for the trade-in credit, the Blomberg trucks on the FT’s were swapped with the Type B trucks from the FA’s. What you then had was a collection of repowered FA1/FB1’s running on Blomberg trucks with EMD traction motors.
I’m pretty sure that Atlas made it’s U23B’s and B23-7’s with the correct roadname-specific trucks under them. Proto 2000 put AAR type-B’s under the appropriate GP18’s & GP30’s. Athearn may have done the same thing with the current GP35’s.