The SNCF BB 16500s were a class of SNCF electric locomotives operating at a supply voltage of 25 kV single-phase 50 Hz AC. Ordered from 1954 as part of the electrification of the radial lines from Paris to the north and east of France, a total of 294 locomotives were delivered between 1958 and 1964, which made them the most numerous class of electric locomotives put into service by the SNCF. These versatile machines operated over all the lines of the north-eastern quarter of France at the head of regional passenger trains or freight trains, descending as far as the Jura, Dole-Vallorbe, or venturing to the Channel coast at Cherbourg or Le Havre. Some locomotives also operated on the northern and eastern suburban lines of Paris. Eventually competition from more modern classes and the discomfort of their driving cabs, led to the locomotives all being withdrawn between 2001 and 2011. Genesis of the class In the second half of the 1950s, the Paris–Lille line was electrified with single-phase alternating current. The radial routes, from Paris to the east of France, were also electrified. The original fleet of locomotives was made up of BB 16000s , a synthesis of the driving qualities of the BB 12000s put into service between Valenciennes and Thionville in 1954 and the bodies of the BB 9200s , the first of which had been operating since 1957 on the lines linking Paris to Lyon, Toulouse and Bordeaux. In 1954, studies for the design of a locomotive dedicated to mixed traffic service, passenger and freight, were launched under the direction of Louis Armand and Fernand Nouvion . The specifications stipulated that these 2,000 kW locomotives would have a weight of approximately , that they must only be equipped with one motor per bogie and have a double gear ratio limiting the speed to depending on the use of the machine. Alsthom 's design was finally chosen, in preference to that of MTE, manufacturer of the BB 16000s. A first sketch, not proceeded with, gave the locomotives an appearance quite similar to that of the BB 12000, with a single cab framed by two engine cowls of different lengths, giving the locomotive a total length of . However, the single-cab formula, though it simplified the wiring of the locomotive, prohibited operation in multiple, so the BB 16500's final design would be a locomotive of a more classic configuration