The BLH RS-12 was a class of 1,200 hp (895 kW) diesel-electric road switcher locomotives configured with an AAR type B-B wheel arrangement.

There was still one outstanding order for Lima A-3174s but the customer, New York Central Railroad agreed to receive RS-12s instead.

One RS-12 is preserved in operational condition in the "Skunk Train" livery of California Western 56 (Locomotive) at Travel Town Museum in Griffith Park; another #300[2] is owned by and occasionally used on the Escanaba and Lake Superior Railroad, with others owned by the same railroad held in non-operational condition.

Escanaba and Lake Superior 207 was leased to the Nicolet Badger Northern Railroad for a short time in the 1990s and was later returned to the Escanaba and Lake Superior where it now remains in storage in Wells, Michigan.

Escanaba and Lake Superior 209 was used for ballast and general freight until the late 1980s when it was put in storage.