They were equipped with the same boiler as the Nord's "Superpacifics" (3.1251 to 3.1290) They also had "Cossart" type rotary cam actuated valve gear.

The series were renumbered 2-141.TC.1 to 2-141.TC.72 by SNCF after its creation in 1938; the class was still in service until December 12, 1970, when the use of steam traction on the Nord commuter network had ended.

The 72 locomotives were built from 1932 until 1935 by seven manufacturers, including the railway's own workshops at Hellemmes, Lille From 1936, as an economy measure, the boiler pressure was reduced from 1.8 to 1.6 megapascals (260 to 230 lbf/in2), and the cylinder bore was reduced from 640 to 585 millimetres (25.20 to 23.03 in).

In 1935, the 4.1200s essentially provide commuter services at the head of push-pull trains composed of five to nine cars, up to 420 tons gross.

In addition to the commuter traffic, 4.1200's also take charge of the freight service between Persian-Beaumont and Luzarches with reversal at Montsoult.