The RMS 'Mauretania', 20th century. RMS 'Mauretania', sister ship of the Lusitania, was an ocean liner built by Swan, Hunter & Wigham Richardson at Wallsend, Tyne and Wear, and was launched on 20 September 1906. At the time, she was the largest and fastest ship in the world. Particularly notable was her steam turbine propulsion, which was a revolutionary development in ocean liner design.