Nord 4.001 to 4.075 and 4.636 to 4.990

Nord 4.001 to 4.075 and 4.636 to 4.990, also called 180 unités, were 0-8-0 locomotives for freight traffic of the Chemins de Fer du Nord.

Construction history
The locomotives were built in several batches by various manufacturers. Starting with 1879 a Belpaire firebox was installed in the newly built machines, and beginning with 1890 the locomotives were equipped with a cab.

In 1921 the remaining machines were renumbered as follows:
 * 4.001 – 4.075 became 4.601 – 4.674 (4.005 was written off in 1908)
 * 4.636 – 4.800 became 4.702 – 4.853
 * 4.801 – 4.850 became 4.856 – 4.878
 * 4.881 – 4.919 became 4.881 – 4.930
 * 4.954 – 4.990 became 4.931 – 4.954