Alco FA-'s are still being operated on the Grand Canyon Railroad, although not exclusively, between the steam power and the F-40’s. The Napa Valley Wine Train also operates FA-'s that I believe have been converted to operate on compressed natural gas.
“ALCo” was the “American Locomotive Company”. “ALCoa” is an aluminum manufacturing company (Aluminum Company of America, iinm). So, the proper plural of “ALCo” is “ALCos” Blue Streak gets a Blue Smudge on this one.
The Grand Canyon Railway operates ex Canadian National Alco FPA-4 locomotives equipped with an Alco 251 V-12. Last I knew they were running on Propine instead of diese. The FPA as the passenger equipped version of the freight only version the FA FB.
The Alco 251 engine was the engine that replaced the 244 and is still in production to this day. Fairbanks Morse purchased the right tools and dies for it and can make any part required just have a deep pocketbook. Many ships, power plants still use the Alco 251 today as do a number of short lines Alco diese locomotives have always had a good reputation as a puller and a very economical locomotive with a slightly higher maintenance program required.
You know, the ALCO RS-3’s were considered by some to be ugly locomotives, but I kinda like the look of 'em. Can’t tell you why. “Beauty is in the eye of the beholder.”
Most of my RS2/3’s came in maroon, gray and yellow with a few others tossed in. They handled local service on EL, transfers and commuters on RI, and general service on Monon (including the “Thoroughbred”).
Most interesting were the re-powered RS2/3’s on Rock Island (RI 450-454 and 456). They lasted until the demise of the Rock in 1980.