RMS Mauretania (1906) launched by the Duchess of Roxburghe. At the time of her launch, she was the largest moving structure ever built, and slightly larger in gross tonnage than "Lusitania". The main visual differences between "Mauretania" and "Lusitania" were that "Mauretania" was five feet longer and had different vents. "Mauretania" also had two extra stages of turbine blades in her forward turbines, making her slightly faster than "Lusitania". "Mauretania" and "Lusitania" were the only ships with direct-drive steam turbines to hold the Blue Riband; in later ships, reduction-geared turbines were mainly used. "Mauretania"s usage of the steam turbine was the largest application
German submarine U-309 German submarine U-309 German submarine "U-309" was a Type VIIC U-boat of Nazi Germany's "Kriegsmarine" during World War II. The submarine was laid down on 24 January 1942 at the Flender Werke yard at Lübeck, launched on 5 December 1942, and commissioned on 27 January 1943 under the command of "Oberleutnant zur See" Hans-Gert Mahrholz. She sailed on nine combat patrols, but damaged only one ship, before being sunk off Scotland on 16 February 1945. German Type VIIC submarines were preceded by the shorter Type VIIB submarines. "U-309" had a displacement of when at the surface and while submerged. She