The PLM assigned four-cylinder compound locomotives with a 4-4-0 wheel arrangement to class C, of which the numbers 61 to 180 were also called “heavy C”. They had air cutters on the smokebox, chimney, Belpaire firebox and cab, hence the nickname “Coupe-Vents”. They pulled the most important express trains and could travel continuously at 90 km/h with 300 tonnes. Only when two coupled axles were no longer sufficient for the heavier trains were they initially replaced by locomotives with a 4-6-0 wheel arrangement on hilly routes and soon had to pull slower trains as well. Although the locomotives were retired between 1929 and 1936, they formally received new numbers when the SNCF was founded in 1938. 