In 1944, the railway was merged to form the Chemins de fer du Jura (CJ), which electrified it at 1500 Volt DC in 1953.

The then Saignelégier–La Chaux-de-Fonds Railway opened its metre-gauge line from Saignelégier via Le Noirmont to La Chaux-de-Fonds-Est on 7 December 1892.

The extension to La Chaux-de-Fonds on the Jura–Simplon Railways had to wait until 28 November 1893, when the Hotel de Ville rail and road bridge was finished.

In 1904, the Régional Saignelégier–Glovelier (RSG) took over operations, creating an important connection to the Basel–Delémont–Glovelier–Porrentruy main line, which continued to France.

Nevertheless, the Saignelégier–La Chaux-de-Fonds Railway provided PCS services after 1 July 1913 when the Jura neuchâtelois (JN) was nationalised and incorporated into the SBB.

Because unlike the SC, the TBN has been electrically operated since its opening, continuous services between La Chaux -de-Fonds-Bahn and Tavannes were limited.

The TBN and TT were merged in 1927 to form the Tavannes–Noirmont Railway (Chemin de fer Tavannes-Noirmontm, CTN).

To enable a thorough renewal of the line, it merged with the RSC, the CTN and the Régional Porrentruy–Bonfol (RPB) to form the Chemins de fer du Jura (CJ) in 1944.

In La Chaux-de-Fonds, the CJ and TRN catenaries can be interconnected via a coupling switch to provide power to the neighboring railway in case of emergency.

The Marché-Concours national de chevaux horse race takes place in Saignelégier in August.

[4] The 27-kilometre-long line connects Saignelégier in the Canton of Jura with the watchmaking town of La Chaux-de-Fonds in the Neuchâtel.

Shortly after leaving Saignelégier, passengers see the deep valley of the Doubs and behind it the high plateau of Maîche, which is in France.

Passing the small towns of Muriaux and Les Emibois, the trains reach Le Noirmont, where the line from Tavannes joins on the left.

With the electrification of the Chemins de fer du Jura, locomotive 9 became surplus and was scrapped in 1956.