Did EMD ever produce a prdecessor to its GP7 and GP9(and GP8)
I never haveheardmention of one
But it seems possible
No the first ‘geep’ was the GP-7, three silver and blue demonstrator units were produced in 1949 and went out for railroads to test, with production models rolling out in 1950.
EMD’s F-units were the FT, F-3, F-7, and F-9. The F-7 was the current F-unit (think it was made 1948-54) in 1949 and since the new GP diesel had the same horsepower, same engine etc. as the F-7, EMD called the first GPmodel the GP-7 to match.
Earlier EMC engine’s were smaller, for switching - SW-1, SW-2, etc. Then passenger (E for Elecro Motive) E-1’s, E-2’s, etc. 'FT’s (Freight train) were origially for freight, as were 'F’s, and later FP’s were boiler equipped F’s . The idea of a non streamlined F7 for freight became the very successful (General purpose) GP-7.
ALCO’s RSD’s (Road switcher diesel) and later DL (Diesel locomotive) were 1800 - 2000 horsepower attempt’s to compete with Electro Motive’s (now EMD) 1500hp product’s, as were their PA-PB’s.
FAIRBANKS MORSE 's submarine motored HH (high hood) diesels were less succesful - as was their passenger attempt - for meeting the higher powered competition.
EMD did not really get into the ‘road switcher’ market until after WWII. They came out with some elongated switchers on road trucks(NW3/NW5) to match the popular Alco RS1, and then tried the BL2 to compete with the Alco RS2(the BL2 cost more to build than the current F3 at the time). They hit paydirt with the GP7. There was no GP1-6 - The GP7 was just part of the current ‘7’ line in 1949…
Jim Bernier
Exactly - the Also RS’s were not made to ‘catch up’ to EMD, Alco was the originator there. The GP-7 was EMD’s attempt to catch up (after the ridiculous BL-2 - with the RS-1 already successful, who came up with THAT thing? Must still work for GM - probably designed the Aztec [:D])
–Randy
You missed the F-2. It was sort of a cross between the FT and F-3, maybe a preproduction model.
Not that it’s important, or anything…
trainboy
The GP8 is not an EMD orginal. It’s a common designation for locomotives rebuilt from GP7 and 9s.
Nick Brodar
To answer the F2 question…
F2s were only built as F2As and were pretty much FTs that could be run with the 2 unit FT AB sets (FT AB sets could not be uncoupled from each other) in ABA combination, rather than have 2 FT AB sets in ABBA. Pretty much the RR’s wanted to use less HP on smaller train where ABBA sets weren’t needed. I think the Boston & Maine was one of the only F2 buyers.