Hanscotte centre-rail system

The engineer Jules Hanscotte [fr] developed the system while working for Société de construction des Batignolles (SCB), Paris, in about 1904.

[2] By placing the opposed pairs of horizontal wheels at the ends of the locomotive, rather than close together, Hanscotte ensured that they were less likely to drop contact at small gaps in the central rail and so fail to maintain traction—on the Chemin de Fer du Puy-de-Dôme line narrow gaps in the centre rail were permitted at level crossings.

[2] SCB's main interest was reliability in braking heavy trains and keeping vehicles on the track in mountainous routes prone to high winds; the company declined to extend development for traction on steep gradients.

The enterprise was successful, and Claret used Hanscotte-equipped Fives-Lille steam locomotives for his ambitious project of a tourist light railway from the centre of Clermont Ferrand to the summit of the spectacular Puy-de-Dôme.

For the first 2.5 kilometres (1.6 miles) from the city centre as far as Les Quatre Routes, Chamalières, conventional two-rail track, (electrified in 1911) was used.