In order to be able to take traffic further into the center of Paris, the PO built a new line around 1900, some of which ran underground. Operation here was under 600 V direct current, partly via third rail and partly via an overhead line. In manufacturing the locomotives, support was sought from General Electric, which had already supplied technology for the Baltimore Belt Line.

The eight locomotives built first were of the steeplecab type with a central driver's cab. Seven of these were converted from 70 to 100 km/h in 1904. After further sections were electrified, a further five were built by 1912, which had two cabs and a central luggage compartment. After the 1,500 V system had established, they were converted to this system. Later, half of them were further converted into shunting locomotives with a top speed of 50 km/h and significantly lower power. Their withdrawals took place between 1965 and 1967.