White Star Line "Olympic" class were to be the biggest and most luxurious ships in the world. The "Olympic" was the only ship of this class that was profitable for White Star. "Titanic" sank on her maiden voyage, while "Britannic" was requisitioned by the British government before she was fully fitted, and used as a hospital ship during World War I. "Britannic" hit an underwater mine, in the Kea Channel off the Greek island of Kea, and sank on the morning of 21 November 1916. Like many other shipping lines, the White Star Line suffered heavy losses during the First World War which
Sister ship American sister ships and , and the German Hindenburg class airship's "Hindenburg" and "Graf Zeppelin II". The generally accepted commercial distinctions of a "sister ship" are the following: The critical overriding criteria are the same hull design. For example, the popular TESS-57 standard design built by Tsunishi Shipbuilding are built in Japan, China, and the Philippines. All the ships of this design are classed as "sister ships". The International Maritime Organization defined "sister ship" in IMO resolution MSC/Circ.1158 in 2006. Criteria included these: Sister ship A sister ship is a ship of the same class or of virtually identical design