This is the first test operation of a 1500m-long freight train in Europe and was achieved by reforming three of Kombiverkehr's regular Germany – Spain intermodal trains into two 750m-long consists, which were coupled together at Sibelin yard to form a 4100-tonne 70-wagon train. This was hauled across France by two Alstom class 37000 electric locomotives operating in distributed power mode.

SNCF says the trial run was preceded by two years of preparation and testing.

Marathon is a €4.4m collaborative project co-founded by the European Commission through its 7th Framework Programme for Research and Development. The three-year project was launched in April 2011 and aims to demonstrate the effectiveness of operating longer, faster, and heavier freight trains on selected routes in Europe.

Other partners in the Marathon project include Swedish infrastructure manager Trafikverket; suppliers Alstom, Vossloh and Faiveley Transport; and industry bodies including the International Union of Railways (UIC) and the European Rail Industry Association (Unife).