The Réseau Guerlédan was 5 kilometres in length, laid to a gauge of 310 mm, it ran along an abandoned metre gauge trackbed of the Réseau Breton (RB). Statutory powers to operate the line were inherited from the RB because lengths of rail had been left in place where there had formerly been level crossings. A fleet of British built steam locomotives, based on famous narrow gauge designs were produced for use on the line, however only two steam locomotives saw service on the line.

The reason for the railway's closure was the occupation of the station at Caurel by the local mayor who subsequently let the facility to a member of his family. This seriously compromised the railway operation and as a result, the railway was cut back to terminate one kilometre from Caurel.