The Interpretation of the Evidence and Visualisation of the Sinking of HMAS Sydney II

On the 19th of November 1941, the Royal Australian Navy Modified Leander Class light cruiser HMAS Sydney II, en route to Fremantle, intercepted the disguised German raider, the HSK Kormoran, about 100 nautical miles west of Steep Point off the coast of Western Australia. In the ensuing battle, Sydney was sunk with the loss of the entire crew of 645 men. Kormoran was subsequently scuttled with the loss of 81 men. Following the discovery of the wrecks of Sydney and Kormoran in March 2008, the Defence Science and Technology Organisation (DSTO) in collaboration with the Australian Division of the Royal Institution of Naval Architects (RINA) were appointed to provide expert advice and opinion into the sinking of Sydney. The evidence from the wreck site of Sydney and the debris field on the ocean floor was extensively evaluated and interpreted using several advanced computer analysis techniques. Historical records and documents were also studied and evaluated to complement the computer analysis to determine the underlying cause of the sinking of Sydney. The analysis provided a scientific insight into the battle sequence, what it would have been like to be on board and why there were no survivors. DSTO also produced a highly realistic animation of the battle in order to show the probable sequence of events and to visualise the scientific findings. In essence, DSTO and RINA analysed the survivability of Sydney against the Kormoran. This paper takes the evidence of the weapons damage to Sydney and presents the interpretation of that evidence. It explains how and why Sydney sank, why there were no survivors and presents a visualisation of the engagement.