SD70, RS3,....

Hi, I´m Christian from Germany,

can anybody say me what for a enginetype with

buildername are in a SD70, AC4400, RS3, GP35, C44Dash9W and F40PH.

Thanks forward!

E, F, BL, SW, NW, SD and GP engines are EMD (F7, SD70, GP-9).

U or C engines are GE (U30C or C44-9).

except …

FA, PA, RS or C engines are ALCO (FA-2, RS3, C628). The ALCO C’s have a 3 digit number (axles, hp).

H series are usually Fairbanks Morse (H-24-66).

Usually, the letters are a serices name, and the numbers are ether a horspower rating, or representative of the where that engine lands in it’s series.

SD is usually “special duty” or something along those lines. EMD usually numbered by 5s or tens, so an SD70 would have been near the 7th style of locomotive in the SD series. (Reality is that several #5s existed, and skewers this)

AC in this case breaks the rule, and stands for alternating current, used by the traction motors?

GP is General Purpose, also belonging to EMD, and follows the SDs

RS is Alco, and I believe stood for rural service. Someone else would need to fill you in on what F40PH was, and the C44. I do kbnow that Dash-9 was another series name, and the W refferred to Wide cab

Yup, when the train approaced a big city, they had to stop the train at the city limits and change to a different engine. [:)]

RS means “Road Switcher”, that is, a diesel that could pull a train on the mainline, but could also stop and do switching work to pick up and set out cars. Early road diesels like GM’s F-units weren’t really designed for way freight service, as visibility was limited. Baldwin used “DRS” for some of their engines, indicating “Diesel Road Switcher”. In their system a DRS-6-6-1500 was a Diesel Road Switcher with 6 axles, all 6 powered, and 1500 horsepower for example.

GP does mean “General Purpose” and SD “Special Duty”. The SD’s had six powered axles instead of the GP’s 4 axles, and were designed more for slower heavier trains.

Early unit name/numbering often related to something like horsepower etc, but really EMD’s numbering system just indicates which model follows which. F units came in FT, F2, F3, F5 (an unofficial designation) F7 and F9. Since GP’s and SD’s were introduced in 1949, the same year as the F7, they started with the GP7 and SD7 respectively. These were followed by the F9, SD9 and GP9 in the 50’s. Then there were GP18s, GP20s, GP30s, GP35s etc. usually with matching SD units.

EMD tended to replace units with the new one, i.e., you might order an SD-7 and get and SD-9 if they were in production by the time the order was filled. On the other hand, Alco tended to keep the old engine in their line, so their RS-1s were made from 1941 until about 1960.

That, does make more sense. But then again, EMD did have the “Branch Line” engines.

I would be careful With Alco. They stopped RS-1 production in America in early 50’s but kept making RS-1’s in Canada up to the introduction of the Century (C415, C420, C424, C425, C430, C628, C630) series in 1963 or so. The Century series ended around 1970ish with the end of Alco locomotive production. The National Train Museum here in Green Bay has 2 BL2’s, although they are NOT kept on museum grounds. Just drove by them today in fact. One is a Bangor & Aroostok, the other I forgot but something like Manchester & Southern. I can drive by tomorro and try to get some pics.