Since the first diesel locomotives of the SNCF were not powerful enough to replace the largest steam locomotives in express service, Alstom developed the CC 72000 as six-axle diesel-electric locomotive that was also suitable for freight service. The body was designed by Paul Arzens and featured the “Nez cassé” also found on other French locomotives. Like its electric sisters, it also had bogies with a single traction motor that transfers its power to multiple axles via a two-stage gearbox.
Top speed in low gear was 85 km/h, while the high gear was set for 140 km/h on the first 20 locomotives and 160 km/h on the other 72. Power came from a 2,650 kW (3,555 hp) SACM AGO V16, with 2,250 kW available for traction. CC 72044 and 72075 were equipped with a 3,530 kW (4,735 hp) Pielstick engine in 1987, but no others followed. More successful was the rebuild of 30 others between 2002 and 2004, which received a more modern Pielstick engine with the same power as the original one and were designated CC 72100.
In their best years, they were used for long-running express trains, some of which were international, also including the TEE. After all major lines had been electrified, they were increasingly used in freight service. Their low gear with a top speed of 85 km/h ensured a high tractive effort, but in the 21st century this became even too slow for freight trains. In their last years they were also used for commuter trains on non-electrified lines, but their missing compliance with new emissions standards meant that they had to be replaced by modern DMUs. So the last commercial services ended in 2009 and today there are only three remaining in service with STF Infrarail. Six had been sold to Morocco in 2007.
