Thirty five type 1 locomotives were built by the Société Anonyme la Métallurgique at its Tubize factory. They had a high degree of superheat, and a firebox that was so wide, it had two firehole doors.
The members of the class were retired in 1962.
One locomotive, no. 1.002, has been preserved by the NMBS/SNCB. It is displayed at the Treignes railway museum of heritage railway CFV3V (Chemin de fer à vapeur des trois vallées) in the far south of Belgium.