From October until December 2015, FRET SNCF is testing a series of 12 1 000-metre long train services between the railway sites of Somain in Nord and Woippy in Moselle.

The first experimental test in Europe was organised in January 2014 on the occasion of the European Marathon project. At that time, SNCF and RFF (now known as SNCF Réseau) carried out the first use of a 1 500-m long train between Lyon and Nîmes, with the help of 14 partners.

Following this first success, FRET SNCF wished to launch a study into the commercial service of double trains of 1 000 to 1 500 metres long. The tests currently underway are important for checking the procedures for coupling/decoupling the trains under real conditions. Technically, the innovation being tested during the Marathon project was a radio system allowing the sole train driver in the locomotive at the front of the train to remotely control the traction and braking of a second locomotive located in the middle (or at the rear) of the train. The current phase of testing is carried out using trains with locomotives that are not yet equipped with radios; there is therefore a driver in each locomotive.

(Source: SNCF)