HMCS Protector was a large flat-iron gunboat commissioned and purchased by the South Australian government in 1884, for the purpose of defending the local coastline against possible attacks in the aftermath of the 'Russian scare', of the 1870s. She arrived in Adelaide in September 1884 and served in the Boxer Rebellion, World War I and World War II.

Sir W G Armstrong Whitworth & Co Ltd was a major British manufacturing company of the early years of the 20th century. With headquarters in Elswick, Newcastle upon Tyne, Armstrong Whitworth built armaments, ships, locomotives, automobiles and aircraft.