On the 19th of November 1941, the Royal Australian Navy Modified Leander Class light
cruiser HMAS Sydney, 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 Chief of the Defence Force, Air Vice-Marshall A. G. Houston AC, AFC, established a Commission of Inquiry (COI), charged with the following Terms of Reference: To inquire into and report upon the circumstances associated with the loss of Sydney in November 1941 and consequent loss of life and related events thereto
In support of these Terms of Reference, the Defence Science and Technology Organisation
(DSTO) of the Department of Defence in collaboration with the Australian Division of the Royal Institution of Naval Architects (RINA) were appointed to provide expert advice and opinion. The wreck site of Kormoran and Sydney were extensively surveyed by SV Geosounder. The footage was extensively analysed by DSTO and RINA to assess the extent and type of damage to both Kormoran and Sydney. The analysis of the action between Sydney and Kormoran was bound by a number of assumptions concerning the battle sequence, the environmental factors and other operational aspects. These assumptions were provided by the COI.
In the provision of expert advice and opinion, DSTO and RINA used a number of scientific analysis tools. Aside from the physical examination of the video imagery, and a large number of historical documents, photographs and other publications, the analysis utilised modern computer codes. More importantly, advanced analysis techniques including a series of visualisations which have been included as Appendix C, have been used to determine the effects of the weapons damage on Sydney. Naval architectural assessments have been made to determine the probable final demise of Sydney. The evidence from the wreck site of Sydney has been interpreted using not only factual evidence from the wreck but also from a consideration of evidence from similar events to other ships. Observations made from the Sydney wreck site confirm Kormoran survivors’ accounts of Sydney being hit in the bow by a torpedo and peppered with a large number of shells to both the port and starboard sides of the ship.
Observations of the footage of the wreck site of Sydney identify 87 individual 15 cm shell hits. Each of these shells weighed 45.3 kg, which represented a total weight of 3900 kg hitting Sydney. Each of these shells is designed to splinter on impact, cumulatively generating a minimum of 200,000 individual steel fragments and thousands of secondary fragments as they smashed through Sydney. It is reasonable to suggest that a significant number of hits to the Upper deck regions cannot be identified due to the condition of the ship in its present state, so these numbers should be viewed as conservative. It was not possible to identify the damage to Sydney from the smaller calibre shell impacts from the photographs. However, Kormoran’s survivors’ accounts state that both the 2 cm and 3.7 cm guns peppered the upper decks and the bridge structure of Sydney. Kormoran could bring to bear three of her five 2 cm guns at a time, each with a conservative firing rate of 100 rounds per minute (its design firing rate is stated as 240 rounds per minute). It would be reasonable to suggest that they would have sprayed Sydney with between 500 to 1000 rounds per gun during the encounter. These rounds would have been directed towards the exposed personnel and equipment on the upper
decks. Kormoran’s survivors have also stated they fired their 3.7 cm guns towards the bridge and superstructure regions. This gun had a more effective range than the 2 cm gun and had a rate of fire of 80 rounds per minute for the 0.7 kg AP shell. It is reasonable to suggest that Kormoran may have hit Sydney at least 400 times during the encounter, which would have added another 300 kg of steel fragments distributed around the upper decks and further added to the number of personnel critically wounded.
The battle between Sydney and Kormoran was a unique sea battle in that Sydney was not
only hit by a torpedo, but was also pounded by accurate and sustained gun fire from close
range for an extended period of time. Other World War II (WWII) ships had survived
torpedo hits and others had survived shell hits from larger calibre shells. However, Sydney had to endure the sustained attack at close range from 15 cm shells smashing into the sides of the ship, raking the upper decks with 20 mm shells at a rate of fire of more than 100 rounds per minute and sustained shelling with 3.7 cm guns. As Sydney sustained hit after hit, the damage to both equipment and crew multiplied along with the loss of numerous capabilities. Figures presented propose that at least 70% of the crew were incapacitated or trapped in spaces due to fires and escape passages being blocked. Fires broke out in many areas of the ship and choking smoke and toxic gases engulfed the upper decks and was drawn into the lower decks. The torpedo hit to the bow resulted in extensive forward flooding. The loss of the ship’s electrical power and the physical blockage to passageways for egress would have made any damage control operations extremely difficult to conduct. Firemains and Main Suction lines would have been significantly damaged and the ability to pump water to fight the fires would have been further limited due to the lack of electrical power. This is particularly true for all areas forward of the machinery spaces. Although the initial action resulted in damage to the port side of Sydney, the turn to port after 5 minutes exposed Sydney to shelling on its starboard side and magnified the damage with as many shell hits on the starboard side as the port side. The boats and Carley floats on port and starboard sides were either blown overboard or were directly damaged by shells or the thousands of fragments that were spraying around the upper decks. The boats and Carley floats were rendered useless for evacuation or lifesaving. Given the torpedo strike to the forward part of the ship, the extensive weapons and fire damage to the midships and aft regions of the ship, it is highly likely that the only survivors were in the stern of the ship and possibly the aft engine room. The remaining crew would have been trying to save the ship by bringing it under control and possibly trying to carry out limited damage control. The surviving able bodied crew were likely to have been attempting to control the ship from the machinery spaces and steering compartments, provide electrical and fire fighting services, as well as assisting and treating the injured.
After the engagement the sea state increased as Sydney travelled to the south east at
approximately 5 knots. At this time Sydney was severely damaged, with a very large
number of casualties, several major fires, many small fires, much of the upper and lower
decks filled with smoke, flooding occurring in the bow area and electrical power gone for
much of the ship. The weapon holes were fuelling the fires by allowing air to ingress from outside. The damage control crews would have been overwhelmed at this stage and any damage control that was being conducted was simply to try to save the ship.
Any slight deviation from the beam-seas heading would have significantly changed the
time the vessel remained afloat. As the sea conditions deteriorated to sea state 4, Sydney began to roll and more water flooded in through the weapons holes in the hull and deck openings. It is probable that the roll became significant and increased with flooding and increased sea state, rolling from 15° up to 40°. At these roll angles, immersion of the edge of Sydney’s deck was likely and any attempt at damage control operations or movement around the ship would have been virtually impossible. Any survivors trapped below decks would simply have been trying to stop being thrown around. Eventually Sydney is likely to have rolled to an angle beyond which she could not have recovered, lost buoyancy and sank rapidly. It is possible that this process was also accompanied by the sudden collapse of one or more watertight bulkheads which further contributed to the sudden and catastrophic loss of buoyancy and sinking. For the damage extents considered,
the analysis indicates that for all other headings considered, the time after the battle that Sydney could potentially remain afloat was somewhere between 2 to 4.5 hours. This is consistent with reports that the glow on the horizon from the fires onboard Sydney disappeared approximately 4.5 hours after the battle. As Sydney sank the weakened bow was violently torn off and plunged towards the sea floor. It is not possible to factually state that there were any survivors from Sydney that entered
the water. However, it is possible that some crew from Sydney entered the water at some
stage during or after the engagement. Those during the engagement were likely to have
been blown off the deck as a result of blast or fallen overboard. Those after the
engagement were possibly swept off the decks when Sydney went down or entered the
water if an abandon ship order was given. There is no evidence to support any of these
statements and they must be seen as supposition. It should be noted that any survivors that did make it into the water would most likely have been affected by injuries, shock, burns and possibly the effects of smoke and/or inhalation of toxic fumes. There is little doubt that the ship’s boats were either damaged or were not able to be lifted off Sydney due to the aircraft crane being damaged. The Carley floats would have been either blown off during the engagement or damaged with shell hits, fragments or fire. They would have been of little use. If any Carley floats did survive and floated, then it is possible that some survivors may have reached a float. Any other survivors would not have had anything other than their life belts to help them survive. The survival time of someone wearing a life belt was hours. Although the Carley float provided a degree of survival capability, Royal Navy data suggests that a person in a Carley float would only survive for 3 to 5 days. Contemporary data and modelling on survival of people at sea show that at a water temperature of greater than 20 C, hypothermia is not a critical factor. Data suggests that a person can survive for greater than 12 hours at 25 C and possibly up to 40-50 hours. It should be noted that none of this data can be validated. Since neither Sydney nor Kormoran were accompanied by any other ships, nor were there any other ships in the immediate vicinity which were aware of the encounter, there was little possibility of survivors being picked up quickly. Once in the water the major problem for survivors was drowning, dehydration and the presence of sea creatures particularly sharks. The water temperature in this area was approximately 23-24 C, so hypothermia was not a significant factor in survival. If the survivors were supported only by a life belt, then the constant breaking of waves over the head could result in the ingestion of salt water leading to drowning. During the battle and the sinking of Sydney the sea states were 3 to 4. Given the limited support and buoyancy of the life belts, any survivors would most likely to have drowned and their bodies would have sunk. As a body sinks into deep water, the pressure of the water tends to compress gases in the
abdominal and chest cavities with the result that it displaces less water as it sinks deeper and consequently becomes less buoyant. Once a body sinks, it also commences to decompose due to the action and growth of anaerobic gas forming organisms in the intestines. The growth of these organisms causes the abdomen, followed by the whole body, to bloat and to swell with gases. The critical factor in this process is the water temperature. The lower the water temperature the slower is the rate of putrefaction. Once the body swells, it then rises to the surface where it floats. Typically, the time for a body to
rise is between 3 and 10 days but can take much longer in cold waters and never at all if the water is very cold and/or if the body is lying at a great depth. In this case the
survivors from the encounter would have sunk to a depth of approximately 2500 m. Given
the significant water pressure on the body at this depth, it is likely that the putrefaction process would not result in enough gas generation to make the body buoyant. If, however, any bodies did rise to the surface, given the water temperature at 2500 m of approximately 2.5 C, they would have taken longer than the typical 3-10 days to rise. Based on this scenario, the searchers would not have found any bodies as they would not have risen to the surface, if at all, during the search period. This report describes the technical findings of the battle and sinking of HMAS Sydney and HSK Kormoran based on historical and archeological evidence. The battle occurred on the 19th of November, 1941 off the West Australian coast. The wrecks of the two ships were discovered in March 2008 and their subsequent underwater exploration has shed light on the events that took place during and after the battle. This report was presented to the HMAS Sydney II Commission of Inquiry by the Defence Science and Technology Organisation (DSTO) and the Australian Division of the Royal Institution of Naval Architects (RINA) in January 2009. N/A