The CC 72000 locomotive has long represented the ultimate in French diesel traction. Built by Asthom in 92 units between 1967 and 1974, its aesthetics close to that of the CC 6500 earned it undeniable popularity among enthusiasts and railway workers. The CC 72000 locomotive was the result of the SNCF's desire to have powerful diesel engines in order to take over from the last steam engines built, namely the 141 R and 241 P. The speed, initially set at 140 km/h (CC 72001 at 20 with the exception of the CC72017) will be increased to 160 for the CC 72000 with higher numbers after fitting anti-swing dampers and reboring. There is no doubt that the noise, so characteristic and so dear to the ears of enthusiasts, was the result of these two turbos working at full power. The cooling system consisted of unified elements already used on the BB 67000 and 68000. The fuel tank had a capacity of 5500 liters and was placed under the body. Electric transmission: The alternator, via a silicon rectifier bridge, supplied the two traction motors coupled in parallel as well as the train heating system. The TAO 656 B1 traction motors were identical to those of the BB8500 and BB25500. A specific assembly of the electrical equipment power supply that Alsthom called "hyper-adhesion" ensured improved starting performance of 15 to 20%. The body, a steel monocoque, had strong similarities with the CC6500 which was then only under construction. The aim was to seek a thorough unification with what was to become the most powerful French electric locomotive of the time. Like the latter, the CC 72000 locomotive had a nose with a reinforced structure to ensure the protection of the driving team. In addition, the head crossmember supported hydraulic shock absorbers and had been designed to accommodate an automatic coupling at a later date. Note that the first "broken noses" were the CC 40100s released a few years earlier. The body rested on rubber blocks forming a pendulum suspension. Built in 92 units, the first of which was delivered for testing in November 1967, this series marked the history of diesel traction by its performance but also by its line that we owe to Paul Arzens. The livery used two tones of blue with white stripes on the side and end faces without forgetting the final touch that was its characteristic arrow. During general revisions, new liveries appeared as is the case for this magnificent CC 72006 locomotive proudly displaying the multi-service livery in Isabelle blue. More or less successful liveries were applied to certain machines, notably in green and grey for Freight and with the "En voyage" brand for the 72100s of the East. The CC 72000s made their debut in the West by providing relays for trains on the Paris-Nantes-Le Mans route. Assigned to the Rennes depot, they gradually extended their range to Croisic, Brest and Quimper as deliveries were made. They would later have the honour of operating trains from Montparnasse to Nantes without relays at Le Mans, as the electrics had to do. Towards the South, they would even go as far as Toulouse to compensate for the lack of electrification between Bordeaux and Montauban. The South-East also quickly benefited from the contribution of the 72000s which were assigned to the Vénissieux depot. They provided rapid and express services on Paris-Clermont-Ferrand and on the Alpine lines. Finally, it was the Chalindrey depot that received them to put them into operation on the Paris-Basel line. The oil crisis of 1974 dealt a severe blow to diesel traction and put an end to orders for this category of machines. Despite everything, the CC 72000 locomotives continued to crisscross most French regions for many years at the head of passenger or freight trains. They were even seen pulling TGVs on the Sables d'Olonne route. A modification of some of them to CC72100 extended their lifespan by benefiting from a less energy-consuming and more environmentally friendly engine. Those who have not seen this wonderful machine in operation can still go and discover it at the Cité du Train in Mulhouse and admire what was, at the time, the most powerful single-engine diesel locomotive in Europe.