The SNCF BB 16000 are a class of 25 kV 50 Hz AC electric locomotives produced by MTE. They are the AC version of the BB 9200. Description This class of 62 locomotives was ordered in 1958 in order to equip the north east network with high speed locomotives capable of running at under 25 kV-50 Hz single-phase catenary. They are part of the large family of locomotives nicknamed BB Jacquemin, of which the BB 9200 were the first versions produced for 1.5 kV direct current operation, and developed using the results of speed tests carried out on the prototype series BB 9001-9002 and BB 9003–9004. During the development of the BB 16000, test runs at were carried out to check the behavior of the AM 11 single-arm pantographs. Design The electrical power equipment is directly derived from the first machines using Jacquemin concepts, the BB 12000: 25kV / 15kV auto-transformer, auxiliary transformer and traction transformer, rectifiers with ignitrons, later replaced by silicon diodes, and smoothing chokes, shunt resistors on the inductors of the 4 traction motors, and Arno three-phase converter to supply hotel power. The interesting improvement concerns the replacement of the mechanical camshaft controllers, as used on the BB 12000s, by Jeumont-Heidmann servomotors. The first 34 BB 16000s had provisional support for the AM 11 single-arm pantograph, similar to that fitted to BB 9400, except that the insulators are different for a single-phase machine. From BB 16035, the new reinforced support was installed, as used by BB 16500. BB 16001 to 51 were delivered with a body similar to the first 21 BB 9200 locomotives, with short louvres. From BB 16052 the louvres were lengthened. There were some minor differences between the two sub-series, concerning the weight and the electrical equipment. BB 16012 had additional ventilation louvres, which were provisionally installed to test the new silicon diode rectifier blocks. These were retained after the tests were concluded. BB 16050 was the only push-pull fitted member of the class allocated to Corail never to have sported the Corail livery. It was fitted with the control cables and equipment while it was still in the mid-1970s green livery which it retained. 15 members of the class have been converted to class BB 16100 to operate VB2N sets in push-pull mode. Service history The BB 16000s during their very long career have hauled most of the fast and express trains of