Known to the SR’s traffic department as “The Dunkerque”, it provided the only through passenger coaches between Britain (London Victoria) and mainland Europe to Paris (Nord), later to Brussels, for a brief period to Basle. It was the only CIWL operated service in Britain composed by Wagons-Lits sleeping cars,. It was also the only train specially built for the purpose with docks and ships built for its exclusive use. For a certain period it was the only train operated by British staff on a train in a foreign country, had the heaviest timetabled passenger working and with 400 to 600 Tons was one of the greatest loads of any train running in Britain.

Travellers found the novelty and excitement of the journey emotionally moving. At long last the comfort, convenience, elegance, allure, and above all safety and privacy of international overnight rail travel by Wagons-Lits “Grand International Express” extended to England. No sleeping cars belonging to the Company had run there since 1875, and only one, a hideously uncomfortable vehicle (No. 42) with beds against the draughty doors, ever did so. In 1936 nobody remembered it.

In the 1930’s the Great European Expresses were the accepted ways of European travel. From Calais sleeping-cars departed nightly for Istanbul, Berlin, Rome, Trieste, San Remo, Monte Carlo, Nice and Cannes and Bucharest. Trice weekly they ran to Karlovy Vary (Carlsbad) and Niegoreloje (beyond Warsaw, on the then Russian border), to Chur for St. Moritz, to Interlaken for Wengen and Grindelwald, to Brig for Zermatt, to St. Gervais-Le Fayet for Chamonix. But what a hassle to attain them.

Mountains of registered baggage to be moved, hand-baggage galore to be carried by the railway porters and the ship’s stewards, whilst the priviledged passengers showed their papers at Dover, or walked, disdainfully, direct to their sleeper compartments at Calais.

So what a thrill to step aboard in London ! To see the same glamorous blue and gold cars with their foreign French wording drawn up at Victoria made many rub their eyes in disbelief. On the waist, at one end, were the words “Voiture-Lits I-II Classe”, at the other : “Sleeping-Car I-II Class”, while above the windows were the proud words : “Compagnie Internationale des Wagons-Lits et des Grands Express Europeens”. To find one with “International Sleeping Car Company” you had to go to China or Palestine, both countries where CIWL ceased to run after WWII.

The first train ferry in Britain was built 1849 and, in 1872 and again in 1905. In 1917 a goods train ferry existed from Southampton to Dieppe. In 1930 after one of the perennial rejections of the tunnel proposal the Southern Railway general manager Sir Herbert Walker determined to promote a through London-Paris night service using a ferry.

A special SR board meeting was called for 19 October 1932  solely to consider the train ferry proposal and, in the face of the French threatening to support a Calais-Harwich service unless they obtained an assurance about the SR plans, the board agreed a train ferry operation between England and France should be established by the Southern which would supply ferry boats and a terminal at Dover. A month later Dunkerque was first mentioned and authority was given for a public announcement to be made and tenders to be invited.

Twelve Wagons-Lits sleeping cars were designed in 1933 and constructed by Ateliers de Construction du Nord de la France Blanc-Miseron, between November 1935 and May 1935 carrying numbers 3788 to 3799 and known as type F (for ferry). They were, of course, specially built for the British loading gauge, smaller in width, length and height than normal continental stock that was built to the Bern loading gauge although not prohibited from working elsewhere on the continent.

The tire inclination was maintained at 1 in 40 (vis a vis 1 in 20 in Britain) to afford a smoother ride on the continent.