Chemins de fer de ceinture No. 4001 to 4005
After the purchase of the 4-6-0T tank locomotives with the numbers 51 to 65, the Paris belt railway needed even more powerful locomotives which were primarily intended for freight service. The requirements included 550-tonne freight trains on one percent and 430 tonnes on 1.5 percent. At times of high passenger traffic volumes, additional passenger trains were to be hauled.