In this heavily industrialized area of the country with steep grades, the railway would pull heavy freight trains along the North-East line using
SNCF 150.X steam locos, often requiring pusher locomotives to help move the trains along. The SNCF wanted to use only one locomotive on these trains and began studying the use of electric locomotives on the line.
25 kV 50 Hz electrification Around 1950, France began a program of electrification with 25 kV at the 'industrial' frequency of 50 Hz. An experimental program was begun with four similar locomotive designs, one from each maker of electrical equipment, to find the best system. Investigating the electrification of the Lille – Thionville line, the CC 14000 were part of an order for 85 electric locomotives in 1952, each using a different system: five BB 12000 in a mono-continuous format with
ignitron rectifiers, fifteen BB 13000 with direct motors, twenty four-phase CC 14000 and sixty-five CC 14100 with single phase-continuous rotating units. The project was very successful, with 150 locomotives ordered in 1954 amongst the BB 12000, BB 13000, CC 14000 and CC 14100 series. The various locomotive types were used in experimenting with different ways of transforming current flowing from the traction network through transformers and rectifiers to the traction motors. As a result, the success of this trial led the SNCF to electrify its remaining lines, decided as being both economical and future-friendly. The 14000s used a rather complex electric motor, prone to a multiplicity of various (mostly minor) breakdowns, yet frustratingly difficult enough to repair (one author explaining the breakdowns were suicide-inducing). In 1952, orders for 85 locomotives were placed: five BB 12000, fifteen BB 13000, twenty CC 14000, sixty five CC 14100. == Design and Technical Details==