DB Class V 51 and V 52

However such trouble free operation could not stop the decline of the Baden-Wuerttemberg narrow gauge lines, in 1964 the Federseebahn closed.

In 1970 both displaced locomotives went to the Biberach an der Riß-Ochsenhausen line to replace steam locomotives (99 633 from bad Buchau remained as a single replacement steam engine); at that time the line still had substantial freight operations; the refrigerator factory of the Liebherr Group in Ochsenhausen assured the continued operation of freight using (Roll-blocks) for almost 20 years after the end of passenger traffic and the closure (and removal) of the section to Warthausen.

However, there was no need for all three locomotives on this shorter route so in 1971 251 901 was sold to the Steiermärkische Landesbahn (StLB) in Austria and regauged to 760 mm (2 ft 5+15⁄16 in) Bosnian gauge.

There the locomotive remained in its original colour as "VL 21" in long term use up till 1999 when it was purchased by the Rügensche Kleinbahn[7] - (the narrow gauge railway of Rügen island) and re-gauged back to 750 mm (2 ft 5+1⁄2 in).

251 902 remained on the Warthausen-Ochsenhausen line after the official closure and continued work there under its new guise as the "Oechsle" Museumsbahn (heritage railway)[9] In 1996 the locomotive was withdrawn.

The two locomotives remained on the Mosbach-Mudau; being suited to freight work; and because of five manufacturing companies using the line at Sattelbach and Krumbach Limbach.

Both units rebuilt to standard (1,435 mm (4 ft 8+1⁄2 in)) gauge and sold to local private rail companies to recover the state grant which was used in their purchase.

[13] 252 902 was converted back to meter gauge (in which the original appearance was restored) and sold to the narrow-gauge Ferrovia Genova-Casella (FGC) (Genoa) in 1986, later in the 1990s work was undertaken on it to enable a snow plow to be fitted.

251 901 in May 2024 at Putbus. Note the front end that is different from 251 902's.