5. The Battle of Sydney Harbour

Australian ships included the cruisers HMAS Canberra and HMAS Adelaide, the armed merchant cruisers HMAS Westralia, HMAS Manoora and HMAS Kanimbla, and the destroyer HMAS Arunta. Other Australian ships included three corvettes; HMAS Geelong, Whyalla and Launceston, two anti-submarine vessels; HMAS Yandra and Bingera, five mine sweepers; HMAS Goonambee, Samuel Benbow, Doomba, Heros and Birchgrove Park, minelayer HMAS Bungaree, the barracks vessel HMAS Kuttabul and the examination vessel HMAS Adele.

United States ships in the harbour included the heavy cruiser USS Chicago with her protecting destroyer USS Perkins, the destroyer tender USS Dobbin and the destroyer USS J D Edwards. Additional naval ships included the Free French destroyer Le Triomphant which was being refitted, the Indian corvette HMIS Bombay, and the minesweeper HMIS Madras which had been recently launched and completed at Cockatoo Island. Two Dutch submarines, RNS K-9 and K-12 together with the Dutch anti-submarine escort HNMS Abraham Crijnssen were also in the harbour. (84) There is also evidence of a ‘Yankie’ cargo vessel fully laden with explosives on the ‘ammunition buoy’ off Rose Bay. (85)

This was a significant gathering of allied naval force – twenty-nine naval vessels plus the twelve Channel Patrol Boats of the Hollywood Fleet, a score of smaller Naval Auxiliary Patrol boats, and a cargo vessel fully loaded with explosives.

Many more merchant ships were moored west of the Sydney Harbour Bridge. Other ships were being repaired or were under construction at Cockatoo Island Dockyard.

The attack was audacious. (86) Using three midget submarines, the Japanese aim was to penetrate the harbour defences and attack the naval ships in the harbour - in particular the USS Chicago which the Japanese mistakenly believed was a battleship. The enemy wanted to inflict a killer blow on the allied fleet and halt the rise of the allied war effort in the Pacific.

Over several months, there had been numerous warnings of a possible attack that went unheeded.

Two days before the attack, the Japanese launched a seaplane from one of the fleet submarines. The plane flew unchallenged over the harbour and confirmed the size of the assembled fleet and the significant warships available to attack. As with the earlier warnings, no action was taken by the port commander, Rear Admiral Muirhead-Gould, to better guard against an attack.

During that day, the Japanese Third Submarine Company of five large I class ‘mother’ submarines assembled well off Sydney Harbour. These submarines which were 110 metres in length with a displacement of 2,550 tonnes, were some of the largest submarines of any of the world’s navies at the time. Three of the ‘mother’ submarines each carried a midget submarine on their rear deck. The remaining two each carried a small float plane, housed in a waterproof hanger on their foredecks, immediately in front of their conning towers.

This is an image of the type of Japanese midget submarine that attacked Sydney Harbour. (88) Each was approx. 24.5 metres in length with a diameter of 2 metres at midships and weighed between 40 and 50 tons. The conning tower rose 1.4 metres with an additional guard and periscope which could be raised and lowered. The midgets were fixed to the mother submarine with steel straps during passage to Sydney. Each had a crew of two and carried two torpedoes, each carrying 350kg of explosives. The torpedoes could run at about 44 knots. The bow guard and wire to the conning tower were installed after the attack on Pearl Harbor to enable the submarine to cut through anti-submarine nets. Each midget carried two self-destruction charges – one forward and one aft. The craft was powered by batteries driving a 600hp electric motor for the twin contra rotating 1 metre diameter propellers. The propellers were protected in a steel guard. Maximum speed on the surface was approx. 23 knots and 19 knots submerged. Running at maximum speed would exhaust the batteries in about one hour but at low speed, the submarines had an endurance of about 25 hours and a range of up to 200 kilometers. (89)

After sunset, the three submarines carrying the midget submarines closed the distance to within seven miles (11.2km) of the harbour entrance and launched their midget submarines. Each had a crew of two – Lieutenant Chuma (90) and Petty Officer Ohmori (91) in M14, (92) Lieutenant Matsuo and Petty Officer Tsuzuku in M21 and Sub-Lieutenant Ban and Petty Officer Ashibe in M24.

If one was to believe the official account of the war (93), HMAS Lolita played no part in the Battle. The official report of the Battle, by Muirhead-Gould makes no mention of HMAS Lolita’s action, (94) while today, the Navy’s own narrative of the attack published on the Navy’s official website, fails to include any role of Lolita, or her commander and crew, except that she was ‘ordered to investigate’. (95)

On the night of Sunday 31 May 1942, Sydney Harbour was protected by three sets of induction loops (97) laying on the sea bed. The Outer Loop – No’s. 1 to 6 was well outside the Sydney Harbour heads. A second, No. 11 lay across the sea bed between North and South Heads, at depths from 22 to 36 fathoms (40 to 65m). (98) A third shorter Inner Loop – No.12, lay across the harbour floor between Middle Head and Lady Bay on South Head. The Inner Loop was at a depth of approximately seven fathoms (12.8m). While the loops could pick up electric pulses generated in the loop wires caused by the magnetic fields from large vessels including large submarines, there is no evidence the loops had been tested to determine they were able to detect a midget submarine – despite such submarines having been used by the Japanese at Pearl Harbor, less than six months earlier.

In addition, the main branch of the harbour leading to the naval fleet and the city was partially protected by an incomplete anti-submarine ‘boom net’ between Georges Head at the western end, and Laings Point (99) at the east. The net was to have been completed in March 1942. The main fixed central section of the net had been completed, however, the ‘boom gates’ across the east and west shipping channels had not been completed. Each of those openings were being patrolled by HMAS Lolita at the eastern channel, and HMAS Yarroma at the west. (100) Both vessels were anchored rather than conducting ‘active’ patrolling. (101)

Chuma, in midget submarine M14 arrived first. He crossed the Inner Loop at 8.01 pm, approximately two minutes after a ferry (102) and whilst the crossing was detected on the Loop equipment, the personnel in the Loop Station believed the detection was caused by the ferry. Chuma then proceeded along the western channel and slipped through the opening, undetected by Yarroma.

There are accounts from two eyewitnesses of the events that followed. Melding those, we can reconstruct the most probable course of events that arose within the ‘fog of war’ that night.

At about 8.15 pm, a maritime worker – James Cargill, with his colleague William Nangle, aboard a construction barge adjacent to the incomplete net noticed ‘something unusual’ between the net and the West Channel Marker located inside the net. (103) He recounted in his statement he thought it was a fishing launch without lights. He rowed his work boat across the ‘50 yards’ (45m) to investigate, went alongside and found the object to be of steel construction with two large cylinders with iron guards. He then paddled to Yarroma to report his investigation and informed the commander, Sub-Lieutenant Eyres, the object was a submarine or a mine. He suggested Eyres should ‘come and investigate’. Eyres did not, but weighed anchor and moved closer. With the assistance of a searchlight, Eyres determined the object was just naval wreckage and at 9.52 pm, Eyres reported a ‘suspicious object’ in the net to the Operations Room at Garden Island. He was asked for further information.

Extract from certified survey dated 24 June 1942 showing the location of the three sets of induction loops – No. 1 to 6 (Outer Loop) outside the harbour, No.11 between North and South Heads, and No. 12 (Inner Loop) between South Head and Middle Head. Loops 7 to 10 had not been installed. (104)

At 10.10 pm, Eyres signaled the object was ‘metal with a serrated edge on top’ moving in the swell. This time he was ordered to investigate further. Eyres did not. Not wanting to approach the object fearing it may be a mine, at 10.20 pm Yarroma signaled Lolita to ‘come over’ from her position at the eastern end of the net. The eastern gate was then left unprotected, as no backup vessel was on duty at the net.

With a sailor from Yarroma, Cargill again rowed to the object. This time the object was higher out of the water, and the sailor recognised it as a submarine. He asked to be returned to Yarroma as quickly as possible. Cargill took him back. Eyres took Cargill’s name and told him to return to his barge. Cargill said the time by then was 10.30 pm, but it was probably earlier as Lolita was still coming across to the western channel. Having received that information, Eyres should have sent a third signal reporting the object was a submarine. However, there is no record of any such signal, possibly because subsequent events negated the need.

Later, Cargill was of the view, (105) the submarine had come around the western end of the completed part of the net, hit the West Channel Marker, and then went astern. However, in doing so, it inadvertently reversed into the net, catching one of the protection rings around its propellers in the net.

The commander of Lolita, Herbert Spencer Anderson, fondly referred to as ‘Tubby’ by his crew, bought Lolita across to the western end of the net and approached the object. By using their Aldis signaling lamp, Nelson and Able-Seaman James Crowe, also onboard Lolita, immediately recognized the object as a ‘baby submarine’. To them, it appeared the submarine had become entangled in the net and was thrashing about in an attempt to break free.

Anderson consulted Nelson and together they immediately realised the implications and risk to the fleet, if the submarine was to break free and escape into the harbour. Anderson ordered a message to be sent to the Port War Signal Station – ‘Have sighted enemy submarine and proceeding to attack’. Nelson said, the message was acknowledged by the Signal Station. (108)

Given the submarine was between the net and the West Channel Marker, (109) it was not possible for Lolita to make a passing run to attack the submarine. Anderson maneuvered Lolita astern towards the sub where the first depth charge was pushed over the stern under the submarine’s bow. Expecting a massive explosion, Lolita sped away, but there was silence. Nothing! No explosion! The charge failed to explode. They reasoned, the charge was set to explode at the required depth of 100 feet (30.5m) – the depth at which they had been instructed to set their depth-charges. (110) According to Nelson, they attached floats to a second depth charge in the hope it would slow its rate of descent so the pressure trigger would fire. They again reversed close to the submarine, pushed the second depth-charge over the stern and sped away. Again, nothing – there was no explosion!

As Anderson, with Lolita, approached a third time, Nelson saw the periscope rotating on them. Nelson knew they had been spotted by the crew of the submarine. Nelson recounted:

We then made a third run and as we came up alongside the submarine to drop it, the explosion occurred. We listed very heavily as we were caught in the force of the explosion.

We were just getting away from them when it [the explosion] lifted our stern, keeled us over and covered us with debris and thick orange flames and black smoke. We got out of it.

The explosion was not from the third depth charge, but was the explosion of the forward self-destruct charge in the submarine. Lolita signaled the submarine had exploded, and resumed her patrol.

Meanwhile, Muirhead-Gould, was dining at his Navy residence – Tresco, located above Elizabeth Bay. He was with Captain Bode, Commander of the USS Chicago. In his later report, Muirhead-Gould held that Bode left the dinner at 10.20 pm and as he left, he suggested to Bode that he should take Chicago to sea. At 10.27 pm, Muirhead-Gould ordered all ships to ‘Take anti-submarine precautions’ and at 10.36 pm issued a further signal ‘Presence of enemy submarine at boom gate is suspected. Ships are to take action against attack’.

Just nineteen minutes later at 10.54 pm, the Naval Auxiliary Patrol vessel Lauriana and the anti-submarine ship HMAS Yandra, then near the entrance to the harbour, sighted the conning tower of another midget submarine. At 11.07 pm Yandra fired a full pattern of six depth charges. The effect of the explosions temporarily damaged Yandra’s steering gear and sent the noise and shock waves of further explosions across the harbour and into surrounding suburbs. (114)

There is nothing in Muirhead-Gould’s subsequent reports of what he discussed or discovered. Whilst there will always be some doubt about the exchange between Muirhead-Gould and Anderson, there is little doubt in Nelson’s recollection. Nelson referred to Muirhead-Gould as being ‘a little bit icky ticky’, ‘a little bit under the weather’ when he came aboard. As recounted by Nelson, Muirhead-Gould said, ‘What are you? What are you yachties playing at, running around dropping depth charges in the harbour’. The response from Anderson was unambiguous, ‘We saw a submarine Sir, and we reported it’. Muirhead-Gould responded, ‘Did the captain have a black beard? I’ve been told all the Japanese submariners have got black beards.’

Just as Anderson responded, ‘No Sir’, there was the sound of a massive explosion from further up the harbour.

As recounted by Nelson, Anderson said to Muirhead-Gould, ‘But Sir, if you hurry back up town, you might be able to find that captain yourself, he’s evidently working up town’.

Muirhead-Gould told Anderson that was an insolent way to talk to a senior officer and ordered him to place himself on report to his office in the morning. The further response from Anderson was, ‘Okay Sir, yes Sir’. The Rear-Admiral re-boarded his barge and disappeared up the harbour and nothing more was heard of the incident.

Whilst it is conjecture, it may have been that exchange between Anderson and Muirhead-Gould that was to write HMAS Lolita, Anderson and his crew out of the history of the Battle of Sydney Harbour.

The explosion heard from further up the harbour was the detonation of a torpedo from the second midget submarine. It had slipped into the harbour past Yarroma while Cargill was trying to persuade Eyres to act. The torpedo had exploded under HMAS Kuttabul killing twenty-one naval personnel – nineteen Australians and two from the Royal Navy. By this time, the harbour was swarming with vessels and the sound of guns firing. Chicago and other ships, further up the harbour and around Garden Island, had opened fire on sighting submarines. Ferries continued to run across the harbour through the mayhem - because Muirhead-Gould had ordered them to, in the belief that more vessels would keep any submarines submerged and unable to attack.

At 2.14 am Chicago slipped her moorings and steamed down the harbour heading to sea. Whilst heading down the western channel outside the boom net, Chicago sighted a submarine coming into the harbour. It would be the third submarine Yarroma failed to detect that night at the western end of the boom net. Chicago was unable to lower her guns sufficiently to take any action. She alerted the authorities.

Throughout the turmoil, the off duty vessels of the Hollywood Fleet remained at anchor in Farm Cove. Out of sight of the action, and out of sight of the signal station on Garden Island, and with no radio telephone sets installed on most vessels, they were unable to receive any orders. Those vessels that were fitted with radio telephone sets had turned them off – because they were not on duty. Notwithstanding, and according to Caruthers, Marlean and Toomeree got underway to investigate the commotion and patrol at the boom net. (116) Of the remainder, Esmeralda was unable to move due to engine repairs, and Leilani was unmanned – her crew were on shore leave. At 3.10 am, a message was finally hand delivered to the Commanders of Seamist and Steady Hour to get underway. Townley, the commanding officer on Steady Hour ordered Reg Andrew with Seamist to patrol between Bradleys Head and the western boom gate and set his depth charges at 50 feet.

After several runs in the designated search area, at 4.30 am Seamist was called by the auxiliary minesweeper HMAS Goonambee to investigate an object in Taylors Bay. (117) Only a buoy was sighted and Seamist resumed her patrols. At approximately 5.00 am when passing Taylors Bay, Andrew on Seamist sighted an object in the Bay. Andrew with Seamist moved into the Bay and recognising it to be the conning tower of a submarine, he moved Seamist into attack. Coming to the area where the submarine had just submerged, commander Reg Andrew ordered the first depth-charge, to be dropped, and fired a red flare. There was a tremendous explosion followed by a massive column of water. Seamist rode the resulting wave like a surf boat.

Andrew swung Seamist around and again saw the submarine. He called for another flare and a second depth charge. As he steered Seamist back towards the submarine, both Andrew and the coxswain thought there were two other submarines behind them in the Bay. Andrew fired another flare and dropped the second depth charge. Again, there was a massive explosion as Seamist tried to escape. But this time the concussion from the explosion disabled one of Seamist’s twin engines.

Realizing he would be unable to launch another attack, Andrew signaled Steady Hour for assistance. Following a fruitless search by Steady Hour for the additional submarines, Yarroma with her submarine detection ASDIC equipment was called to assist. At 6.40 am, Yarroma obtained a contact. She was ordered out of the way and Steady Hour ran in and dropped two depth charges. Eighteen minutes later, Yarroma picked up a contact and dropped a depth charge. The explosion caused her engines to be lifted off their mounts and she too had to retire. (118) Steady Hour continued the action for another two hours. In total, it was said nine depth charges were dropped in Taylors Bay that morning, but with Seamist and Yarroma out of the action, it was likely to have been just seven.

Nelson recounted, that having seen the flares and hearing further explosions, Lolita moved to the area. Eyres on Yarroma ordered Anderson to stand-by. Whilst doing so, a ferry heading to Manly approached the battle area. Anderson ordered the ferry back to the Quay. But having received a belligerent ‘I’m not going back to the Circular Quay’, from the ferry captain, Anderson sought advice from Nelson. Nelson suggested ‘machine gun shots across the bow’. Anderson agreed and according to Nelson, that’s what was done – Lolita fired across the bow of the Manly ferry. The ferry immediately turned and headed back to the Quay, averting a potential disaster as the battle continued.

With the last detonation of the Hollywood Fleet’s depth charges at 8.27 am on the morning of Monday 1 June 1942, the Battle of Sydney Harbour came to an end. Two enemy submarines had been destroyed and the third, M24, had snuck out of the harbour. She was detected leaving the harbour across the inner loop in an outward direction, but again, the loop operators ignored her as they thought it was ‘just another ferry’.

The wreckage of M21 was retrieved from the bottom of Taylors Bay, and Chuma’s M14, attacked by Anderson in Lolita was cut free from the boom net and lifted. (119) Both were placed on Clarke Island to be examined. It was another 64 years before the third midget submarine, M24 was found on the seabed off Bungan Head, north of Sydney. The wreck of M24 is now a protected site. (120)

At 1.05 am on the Monday 1 June whilst the Battle raged, a trawler San Michele, reported the sighting of a large submarine off Cronulla steaming south at 2 to 3 knots. The report advised the submarine was clearly observed in moonlight and appeared to be about 200 feet (60m) in length. (122) There was no immediate air search.

Air patrols were launched the following morning in search of the mother ships or mother submarines. Nothing was found. (123) The following day, the Minister for the Navy, Mr Maikin, provided a brief narrative of the Battle to the House of Representatives of the Federal Parliament. The Minister informed the Members he had visited Sydney to ‘acquaint’ himself with the circumstances of the attack and had interviewed the ‘officer in charge’ of the defences. Maikin said he was completely satisfied with the efforts of all those associated with such defences for the protection of Sydney Harbour during the Battle. (124) The following day, Prime Minister John Curtin addressed the House regarding the war situation facing Australia. Of the Battle of Sydney Harbour, he said: (125)

The recent attack on Sydney Harbour has brought the battle closer to our daily lives than did any previous incident in the war. The vigilance and prompt action of the naval forces guarding our shores prevented any material success from being achieved by this desperate venture. The Government extends its sympathy to those who have been bereaved. Whilst the outcome must strengthen our confidence in the men who protect us from the enemy, the attack itself emphasizes the need for ceaseless vigilance, and dispels any lingering doubt that any one may have had that Australia is not in the front line.

Whilst the search for the mother submarines or ships continued, the British Admiralty issued a warning that the attacks in Sydney showed the ‘Japanese can transport these weapons very far afield’ and ordered that ‘Every possible precaution is to be taken’. (126) The advice was extraordinary, because less than 24 hours before the attack on Sydney, the British had already suffered a similar attack in the western Indian Ocean. The Japanese Western Attack Group dispatched two midget submarines into the allied harbour at Deigo Suarez at the northern tip of Madagascar. The British battleship HMS Ramillies had been struck by a torpedo which blew a 9 metre square hole in her. (127) But it is disturbing, the Admiralty failed to inform the commanders at other allied ports. Had the Admiralty properly informed Muirhead-Gould, the Battle of Sydney Harbour may have been curtailed by allied anti-submarine actions off the coast of Sydney.

Over the following days, divers found a submarine in Taylors Bay – M21. She was hauled into shallow waters and lifted and taken to Clarke Island. Charts salvaged from the remains revealed the attack had been carefully planned and was preceded by a number of over-flights. The charts included photographs from those flights showing the location of vessels in the harbour. The collection included details of Port Kembla and Newcastle harbours and other targets.

To add to the tension, two ‘small submarines’ were reported in Vaucluse Bay at 4.10 am during the night after the Battle. Depth charges were dropped by one of the Hollywood Fleet vessels – Nereus. (128) For a city on edge, the further explosions after those on Sunday night and early Monday morning, would have caused further anxiety for all surrounding residents and the commanders of the moored vessels of the Allied naval fleet. The submarines were not sighted and the report was dismissed. (129)

Whilst casualties were minimal, the attack was a disaster for the Navy – the enemy had breached the allies major naval base. Had M24’s torpedoes found their target, the loss of USS Chicago, or any one of the other major ships, would have been a major blow to relations between Australia and the US.

Commander Ford of the USS Perkins said in his 2 June report ‘It was good fortune rather than good harbour defence which prevented great damage’. (131) McInerney, Commander of the Destroyer Division Nine in Pearl Harbour said on 4 June, ‘From personal observation, entering Sydney during daylight and darkness, the control over entering ships leaves a great deal to be desired’ and ‘I believe that an enemy surface ship, flying false colors and making false signals, could enter the harbour during daylight or darkness, under present conditions’. (132) These were hardly ringing endorsements of Muirhead-Gould’s protection of Sydney Harbour! On 12 June 1942, Vice-Admiral Leary USN, Commander of the allied naval forces in the South-West Pacific Area, directed ‘that necessary action be taken to provide maximum protection to vessels in Sydney Harbour from enemy submarines’. (133) (134)

In the weeks following the attack, the submarine attack group dispersed along the east coast of Australia attacking merchant shipping. There were over 20 submarine incidents that resulted in the sinking of three vessels and damage to another two.

The Battle of Sydney Harbour and subsequent shelling, remains the first and only time in history that Australia’s largest and most populous city – Sydney, has been attacked! And, the Battle included more ships of the Royal Australian Navy, than any other battle in which the Navy has participated. (135)

82 In researching this publication, I have examined many post war accounts of the Battle including the official account by Hermon Gill, Royal Australian Navy 1942-1945, Vol. 2. The two most accurate accounts in my view are – Japanese Submarine Raiders 1942 by Steven Carruthers and A Very Rude Awakening by Peter Grose. Both are based on extensive research and provide in-depth analyses of the Battle and the roles played by the vessels of the Hollywood Fleet. If any criticism can be laid with Carruthers and Grose, it is their failure to cite the sources for the specific evidence on which they rely. If, however, it is accepted that the material on which they rely is contained within the numerous documents and archives included in their bibliographies, then we can have confidence that their accounts provide an accurate portrayal of the Battle of Sydney Harbour.

83 AWM78, 418/1 - Sydney Log, plus Carruthers, S., Japanese Submarine Raiders 1942, 2006, p.39 and Gross, P., A Very Rude Awakening, p.98, 99

84 The RAN Daily Narratives for 1st Feb 1942 to 31 May 1942 records HNMS Tromp arrived at 0600k/31 from Townsville and did not depart until June. However the Sydney Log records Tromp departed on 31 May with HMAS Warrego and USS Selfridge escorting a convoy en-route to Townsville.

86 Podcast S1E1 – Midget Submarines – The Attack on Sydney Harbour, UNSW Canberra hosted by Prof. Tom Frame, 3 October 2017, Rear Admiral Peter Briggs agreed ‘Yes audacious – it certainly is’.

87 http://www.navy.gov.au/hmas-westralia-i. No source is cited for this. There is no evidence in the Sydney Log of HMAS Westralia or USS Chicago being at sea on 31 May 1942.

88 NAA: B6121, 162I - Midget Submarines - Attack on Shipping in Sydney Harbour. Official Reports. Newspaper Cuttings.

89 NAA: MP1049/5, 2026/21/79 - Midget Submarine Attack on Sydney Harbour., p.70-73., B6121,162K: Midget Submarine Attack on Sydney Harbour, p.42., and Grose, P., A Very Rude Awakening, p.54

90 Carruthers uses the name Chuma being the name used by Koichi Ban in the Letter of Appeal to the Australian Government on 13 April 1978, p.18. The Australian War Memorial (AWM) uses Chuma. But both Grose and Jenkins use Chuman without explanation. I will use Chuma respecting the name used by Koichi Ban and as adopted by the AWM.

92 Official reports use a consistent numbering of M14, M21 and M24 (First referred to as Midget A) adopting the numbers painted on the submarines (eg See NAA: B6121, 162K, p.13 for Midget 21). Authors of various accounts have used a combination of numbers and commander names. Grose includes an explanation at p.88 and uses the commander’s names rather than any number. To enable readers to better understand the Battle of Sydney Harbour, I have adopted the system used in the official reports. This approach is also consistent with the Defence Honours and Awards Appeals Tribunal, Report of Review dealt with in the chapter ‘Anderson’s Appeal’. Also see Appendix C – Midget Submarine Nomenclature.

94 NAA: MP1049/5, 2026/21/79, - Midget Submarine Attack on Sydney Harbour., p. 23

96 Carruthers, S., Japanese Submarine Raiders – A Maritime Mystery., Grose, P., A Very Rude Awakening

97 Induction Loops consist of electrical cables that are laid on the seabed. As a submarine or ship passes over them, the magnetic field of the vessel causes an electrical current to flow in the cable. The detection of the current indicates the presence of the submarine or ship. See https://en.wikipedia.org/wiki/Anti-submarine_indicator_loop.

98 NAA: B6121, 162K – Midget Submarine Attack on Sydney Harbour – Signals., p.224

99 Referred to in some documents as Green Point and sometimes Laings Point, the NSW Geographic Names Board in 1977 resolved the confusion, formally adopting the name, Laings Point.

100 It was later discovered that Yarroma had anchored, rather than conducting active patrolling. Carruthers, S., Japanese Submarine Raiders 1942, p.37

101 NAA: SP338/1, 201/37 – (Japanese) Midget Submarine Attack on Sydney Harbour, May 31st June 1st 1942., p.43, Minute Paper signed but signature cannot be determined.

102 It is said that M14 followed a ferry across the loop, but there is no evidence to support this. As the loop equipment did not give a position along the loop, M14 could have crossed the loop at the western end whilst the ferry passed into or out of the harbour via the eastern channel. Given Chuma was caught just inside the western end of the boom net, it is most probable he proceeded down the western channel of the harbour.

103 James Cargill, Statement made 3 June 1942. NAA: SP338/1, 201/37 - (Japanese) Midget Submarine Attack on Sydney Harbour, May 31st June 1st 1942., p.58

104 AWM 246, 9/26 – Sydney: Approaches to Port Jackson show A/S [Anti-Submarine] defences, 24 June 1942

105 Testimonial and map, Carruther’s Collection, held by RAN Sea Power Centre - Australia. See also Carruthers, S., Japanese Submarine Raiders 1942, p.119

106 Interview with James Nelson, handwritten transcript in Carruthers Collection held by RAN Sea Power Centre - Australia. See also Carruthers, S., Japanese Submarine Raiders 1942, p.121, 253

108 Interview with James Nelson, Handwritten transcript in Carruthers Collection held by RAN Sea Power Centre - Australia See also Grose, P., A Very Rude Awakening, p.115

109 Also referred to by other authors as the ‘west channel pile light’ and the ‘pile light’. The West Channel Marker identifies the south-east end of the western channel leading from the harbour.

110 NAA: SP338/1, 201/37: (Japanese) Midget Submarine Attack on Sydney Harbour, May 31st June 1st 1942., p.4. This was an order from the Naval Officer in Command (NOIC) of Sydney Harbour Rear-Admiral Muirhead-Gould.

112 Australian’s at War – Transcript of Interview with James Nelson, Archive number: 1639, 30 June 2004. UNSW Canberra, Time: 03:23:30:00. This interview suggests, the third depth charge was dropped. At Time: 03:16:00:00, Nelson said ‘… all told we dropped three but none of the charges went off.’

113 The official report records 10.35 pm - MP1049/5, 2026/21/79 - Attack File, p.29

114 NAA: SP338/1, 201/37: (Japanese) Midget Submarine Attack on Sydney Harbour, May 31st June 1st 1942., p.17

116 Carruthers, 2006, p.157. Carruthers relies on the account given by Lieutenant Wilson, the duty officer at Garden Island during the Battle. The account was given to the AWM historian H Gill. See also NAA: Sp338/1, 201/37: (Japanese) Midget Submarine Attack on Sydney Harbour, May 31st June 1st 1942., p.181

117 NAA: SP338/1, 201/37: (Japanese) Midget Submarine Attack on Sydney Harbour, May 31st June 1st 1942., p.47

118 AWM PRO3229: Papers of Horace Frank Doyle. Doyle was an Able Seaman aboard Yarroma.

119 NAA: SP338/1, 201/37: (Japanese) Midget Submarine Attack on Sydney Harbour, May 31st June 1st 1942., p.92

122 NAA: B6121, 162K: Midget Submarine Attack on Sydney Harbour - Signals, P.197

123 NAA: B6121, 162K: Midget Submarine Attack on Sydney Harbour - Signals, p.180 onwards

126 NAA: B6121, 162K: Midget Submarine Attack on Sydney Harbour - Signals, P.185

128 NAA: SP338/1, 201/37: Midget Submarine Attack on Sydney Harbour, May 31st June 1st 1942, p.145

129 NAA: B6121, 162K: Midget Submarine Attack on Sydney Harbour - Signals, p.167

133 Leary had been appointed as overall commander of naval resources in the South-West Pacific Area (SWPA) in April 1942. However, by delegation, the Australian Commonwealth Naval Board retained responsibility for the protection of coastal shipping and convoys around Australia. David Stevens, The Royal Australian Navy in World War II, p.152

135 Podcast ‘S1E1 – Midget Submarines – The Attack on Sydney Harbour’, UNSW Canberra, Hosted by Prof. Tom Frame, 3 October 2017

4 - THE BATTLE OF SYDNEY HARBOUR