This new book tells the story of the Ocean class of standard cargo ships, their design, building and careers, and the author places them firmly in the context of the battle of the Atlantic which was raging at the time of the first launchings. They entered the vanguard of the Allied shipping effort at a time when the German U-boat threat was at its most dangerous, and British shipping resources were stretched to the limit. They were deployed in the North Atlantic, on the long supply routes around Africa to the Middle East, in the Russian convoys, in operations in support of the invasions of North Africa and Italy and the land campaigns which followed, in the D-Day landings and later amphibious operations on the south coast of France. Finally, some of the class joined an invasion force making its way towards Malaya when Japan surrendered in August 1945\. The Oceans paid a heavy price for these accomplishments, one third of the class being lost to torpedoes, bombs or mines in places as far apart as the Florida coast, the Norwegian Sea, the Bay of Algiers and the Gulf of Oman. While these achievements alone would merit an important place in histories of the war at sea, the impact of the Oceans stretched far beyond the direct contribution of the ships themselves. The yards where they were built also served as models for a series of new American shipyards, designed to mass produce cargo vessels with such speed and in such volume as to completely reverse the mathematics of attrition, which had run so badly against the Allies into 1942\. Even more important, the Oceans' blueprints were used as the basis for the American Liberty ship, the 2,700-strong fleet which finally tilted the balance of the war at sea decisively in the Allies' favour and went on to underpin the post-war renewal of the world merchant fleet. This comprehensive new history, based on extensive archival research and lavishly illustrated with contemporary photographs, restores the Oceans to their rightful place in history. The ships' design antecedents are explained, and their ordering, financing and construction analysed in full. Wartime operations are covered in depth, by theatre and with full details of war losses and other casualties. The book concludes with an assessment of their subsequent peacetime careers and a comparison to other war-built designs. This is a model history of a highly significant class of ship.