CC14100 with Uckange. Whereas the rebuildings are hardly completed, the SNCF wants to undertake the realization of a vast programme of modernization of the principal arteries of the Alsace-Moselle area. Indeed, in a little more than two years, the framework of ex-network Al is equipped with a new system of electrification using a tension raised to 25000 V under 50 periods an industrial frequency. The choice of the artery of 281 kilometers linking Valenciennes in North in Thionville, via Audun the Novel and Fontoy, is notified in the current of the year 1951. This transversal connects two zones to strong industrial merger which generate a daily heavy traffic of an about sixty trains of 1000 tons each one; it is traversed only by some express train broad outline, of which some convey cars for Switzerland and Italy. Traced far from the capital, it does not have any rail junction with complex work; it is, according to the decision makers, the ideal test bench for an experimentation in commercial situation of the new system 25kV-50Hz.