Third rail
The Chemins de fer de l'Ouest had hoped to electrify parts of its lines to Saint-Germain and Argenteuil as early as 1908. Many of the construction work on the lines were initiated to alleviate operational issues but steam traction meant that without remote driving or the locomotive, engines had to be turned around the train at termini. Third rail electrification had been applied to Paris' underground and the Chemin de fer de Paris à Orléans's line from Les Invalides with success.