Locomotive N° 1 (of 2-6-0 T type, 1 pony truck leading axle, 3 driving axles) was built in 1906 in La Courneuve, near Paris, by the Corpet-Louvet company, one of the leading French builders of secondary railway locomotives. It was supplied to the Chemins de Fer Départementaux de l’Aisne (CDA) network, which later became the Régie des Transports de l’Aisne (RTA).

Withdrawn from commercial service in 1961, the locomotive was bought by a private individual who was hoping to create a museum in Verneuil (Marne). This project having failed, the CFBS bought the engine in 1971.

N° 1 was completely restored by the CFBS works between 1989 and 1992, and ran in regular service until 2001. By the end of that season however, the boiler (built almost 100 years earlier) was showing distinct signs of wear. It was decided to replace it with a newly-built boiler, with many other parts being replaced at the same time. The engine was returned to service for its hundredth anniversary and was the star of the 2006 Steam Gala.

In 2012, Corpet-Louvet N° 1 broke the CFBS mileage record, having travelled a total of 8963km (5600 miles) during that season!
 

Listed as a Technical Heritage Item

Some technical data:
- Empty weight: 19.170 t.
- Diameter of driving wheels: 1 m.
- Working pressure: 12.5 kg/cm2
- Surface of the grate: 0.71 m2
- Diameter of the cylinders: 0.300 m.
- Piston stroke: 0.450 m.
- Length: 7.700 m.
- Width: 2.200 m.
- Height: 3.300 m.