Tavannes–Noirmont railway line

TT freight train hauled by locomotive no. 2 in Tramelan in about 1910.

The first railway lines in the Jura were built to connect Switzerland with France. Afterwards efforts were made to connect areas that were not yet developed with Lokalbahnen ("local lines") to the main lines.

The metre-gauge Tavannes-Tramelan railway was opened as a branch line on 16 August 1884 by the Tramelan-Tavannes Railway (TT) (French: Chemin de fer de Tramelan à Tavannes).[2] The 9 km-long line connected Tramelan with Tavannes, which lay on the existing standard-gauge Sonceboz-Sombeval–Moutier railway opened on 1874. The railway was, after the Lausanne–Echallens (1873), the Rigi-Scheidegg (1874), the Herisau–Urnäsch (1875) and the Waldenburg (1880) lines, one of the first Swiss narrow gauge railways and served as a model for many similar operations.

The railway was initially operated with two class G 2/2 two-axle tender locomotives. A third locomotive was acquired in 1891. A very high level of performance was required for the steam locomotives as the line had gradients of up to 4.0 percent. Shortly before the electrification, the locomotives were equipped with new boilers.

Tramelan station after the electrification of the TT and the opening of the TBN.

Electrical operations at 1200 volts DC commenced on 15 November 1913. The reason for the electrification was the opening of the meter-gauge, electrically operated Tramelan-Breuleux-Noirmont Railway (TBN).

For electric operations, the TT procured two BCe 2/4 railcars (nos. 60–61) and a two-axle locomotive of class Ge 2/2 (no. 4). Both types of vehicles had the same electrical equipment. The three units were identical to the two railcars, 70–71, and the Ge 2/2 locomotive no. 5 of the TBN. While the railcars were procured for passenger trains, the two locomotives hauled freight trains and were used when double-heading was needed.

The electric supply to the catenary of the two lines was carried out through a substation in Tramelan, which was equipped with backup batteries.[3]

The TT mainly served passenger traffic. At times it was able to pay a modest dividend. Investment in catenaries and new rolling stock were necessary for the electrification in 1913. The First World War led to additional revenue from both passenger and freight transport. In 1917, the railway had the best operating result in its history. Thereafter, however, sharply rising operating expenses affected the balance sheet.[4]

Railcar BCe 2/2 of the TBN on delivery.

Advances in electrical engineering enabled the continuation of the narrow gauge line from Tramelan through the heights to Les Breuleux and Le Noirmont to connect to the Saignelégier–La Chaux-de-Fonds railway (SC) (French: Chemin de fer Saignelégier–La Chaux-de-Fonds). The Tramelan-Breuleux-Noirmont Railway (TBN) was operated at 1200 volts DC from its opening on 16 December 1913.[5]

Ge 2/2 of the CTN in Tavannes. Railcar BCe 2/4 no. 70 is visible behind.

As already mentioned, the TBN procured two BCe 2/4 railcars (70–71) and Ge 2/2 locomotive (5).

The outbreak of the First World War in 1914 led to increased traffic at the TBN and led to financial relief. At the beginning of the 1920s, declining income from passenger transport increasingly led to financial difficulties.[6]

The TT and the TBN, which opened in 1913, formed a joint operating arrangement and operated the line with the electric rolling stock running through from Tavannes to Le Noirmont. The Saignelégier-La Chaux-de-Fonds Railway (SC) continued to use steam locomotives on the line from Le Noirmont to La Chaux-de-Fonds which made through running difficult.

Since 1 May 1921, standard gauge freight cars have been loaded on transporter wagons in Tavannes, so that they can be carried on the narrow gauge line to Le Noirmont.

On 1 January 1927, the two electrically operated railways TT and TBN, which previously formed a joint venture, joined to form the Tavannes–Le Noirmont Railway (French: Chemin de fer Tavannes – Le Noirmont). But even after the merger, the operating results remained modest and the infrastructure became obsolete.

The Tavannes–Noirmont Railway was merged on 1 January 1944 with the SC and two standard gauge railways, the Régional Saignelégier–Glovelier (RSG) and the Régional Porrentruy–Bonfol (RPB) to form the Chemins de fer du Jura (CJ).

Railcar CFe 4/4 601, which was built at the beginning of the CJ, in Le Noirmont.

Waste train with an ABe 4/4 railcar from the Arosa Railway in Le Noirmont.

With the merger of the four railway companies in the then Bernese Jura, the foundation was laid for a comprehensive technical renovation. The CJ has operated its entire metre-gauge network with 1500 volt DC since 4 October 1953. For this purpose, the overhead line voltage was increased from 1200 to 1500 volts DC. The converter plant in Tramelan was replaced by three rectifiers in Orange, Les Reussilles and Le Noirmont. The rolling stock was almost completely replaced by new vehicles. No changes were made to the existing locomotives.[7]

A train carrying railway staff crashed into a train carrying train axles at Orange between Tramelan and Tavannes on 27 October 1953. Two railway employees were killed by axles flying off a flatcar hauled by Ge 2/2 5. The railway staff train had not waited in Orange to allow the trains to cross.[8][9]

The 246 metre-long Tavannes viaduct was opened in 1966 to separate the railway from the road in the village of Tavannes.