Nez Cassé

The Nez Cassé series of locomotives is a large family of electric and diesel locomotives intended primarily for fast passenger service on the French SNCF railway system. Produced by Alsthom for use under multiple electrification networks and unelectrified lines, they have been in widespread use from the 1960s into the 21st century. Classes produced in the main series were BB 7200/7600 and CC 6500 under 1.5 kV DC, BB15000 under 25 kV 50 Hz AC, BB 22200 (7200+15000) and CC 21000 under dual 1.5 kV DC and 25 kV 50 Hz AC, and the diesel CC 72000/72100.

The locomotive series was developed from the 1964 quadruple-voltage CC 40100, designed by Paul Arzens, which was mainly used for Trans Europ Express international service. The CC 40100 featured a forward-leaning nose and windshield that drew comparisons with a broken-nose facial profile ("Nez Cassé"). A greater emphasis on crash protection for engine drivers in the following series added depth to the nose and changed the broken-nosed profile.

The first versions for the SNCF that were introduced in 1969, the 1.5kV CC 6500 and the 1.5/25kV CC 21000, used a Co'Co' bogie arrangement on account of their substantial weight. The unique BBB 8000 used by Korail from 1972 used a Bo'Bo'Bo' bogie arrangement due to track loading requirements and Korean rail geometry requirements. The later BB 7200, BB 15000 and BB 22200 were substantially lightened, and could use a Bo'Bo' arrangement. These later series, introduced by the SNCF from 1971–1976, were also less costly to procure.