French Southern Railway E 4601 to 4650

The second generation of electric locomotives known as “BB Midi” consisted of the E 4100 and the E 4600. The E 4600 was intended for passenger service and had a longer gear ratio than the E 4100. It was therefore mostly used for passenger trains on the lines in the Pyrenees. They were designated BB 4600 by the SNCF and in the fifties, their number grew when a greater number of BB 4100 was rebuilt into the BB 4600 to use them for fast freight service. But after running fast with heavy trains had resulted in damage, some original or rebuilt BB 4600 were rebuilt back to BB 4100 to be used for slower freight trains. The last ones were retired in 1984.