Journal of the Australian War Memorial - Issue 30

The Japanese Navy's operations against Australia in the Second World War, with a commentary on Japanese sources

Author: Tanaka Hiromi

{1} It appears that before the Pacific War broke out the Japanese navy did not have sufficient military intelligence on Australia. For the navy, the most important intelligence information was nautical charts, and few charts of Australian waters are to be found in the collections of the Hydrographic Department, the agency responsible for producing them. This fact is testimony to the lack of plans for naval operations directed against Australia.

{2} Once the war began, however, the unexpected speed and success of Japan's offensives led to an expansion of the scope of operations to the Lesser Sunda and Solomon Islands. As a result, navy planners began to take Australia into serious consideration, seeing it as a imminent threat because of its membership in the British Commonwealth and the possibility that it could become a huge base for Anglo-American operations against Japanese-held territories. On 10 January 1942 the Imperial General Headquarters-Government Liaison conference decided upon the following two points of policy:

  1. To cut the lines of communication between India and Australia on the one hand and between Australia and Britain and the USA on the other.
  2. To seal off Australia from the Anglo-American powers.

{3} These points, both aimed at Australia, show the growing importance of that country in the thinking of the Japanese government and the Japanese military at the time. Australia was being taken very seriously, and every means of sundering Australia's firm relationship with Britain and the United States was being considered. In accordance with these policies, the Japanese navy proposed three operations directed against Australia. Because this was a time at which the navy had ample forces at its disposal, all three plans were activated. They were:

(a) air attacks on Darwin;

(b) air and ground attacks on Port Moresby (the navy's part was dubbed operation MO, and although it was strictly speaking not against Australia itself but against New Guinea, Port Moresby fell within the area defended by air forces based in Australia);

(c) midget submarine attacks on Sydney.

{4} Of course (a) and (c) involved the direct clash of Japanese and Australian forces, and (b) did not. Operation MO led to the Battle of the Coral Sea, the world’s first contest of aircraft carriers, between Japanese and US naval forces.

{4} This paper will comment first on preliminary Japanese studies of Australia. Then it will undertake an examination of (a) the Darwin operations, briefly note a few features of (b) the Battle of the Coral Sea, and then move on to (c) the Sydney attacks. In the cases of (a) and (c), particulars of the various military actions will be discussed, followed by a survey of documentary materials and postwar studies relating to them. Finally, an overview will be given of relevant materials in the collections of the Australian War Memorial.

1. Japanese intelligence reports and other background material on Australia

{5} The extent to which Japan studied and collected intelligence on Australia before the war is unclear. Today there are more such Japanese materials in the US Library of Congress than in Japan itself.

{6} Among Japanese army materials are to be found a 206-page publication in Japanese, Roster of prominent Australians, volume 3 of a 1942 road atlas covering the area between Sydney and Melbourne (certainly volumes 1 and 2 also existed), and a collection of reports on Australian airfields.

{7} Most numerous in the navy materials are commentaries on the natural features of the country and nautical charts of Australian waters, particularly of the coasts, produced by the Hydrographic office. They are to be found in the library of the Maritime Safety Agency in Tokyo and the US Library of Congress. There are also some research materials concerning airfields in the North-west of Australia and air routes. One notices that many nautical charts lack figures for water depth, a remarkable situation in light of the more serious interest the navy had in Australia as compared to the army.

{8} The overall amount of material on Australia is small in comparison to that on China, Britain, the USA, the Soviet Union, and fellow members of the Tripartite Pact, Germany and Italy. The relative amounts do not necessarily provide an accurate barometer of the strategic importance of these countries to Japan, but it is still true that countries in which Japan’s stake was small tended to be represented by very small collections of information. The volume of material on Australia is about the same as that on India. The Japanese service most hindered by the lack of good intelligence was the most cautious when combat in the Australian area became imminent. That is to say, the Army, which had carried out very few studies of Australia, held back the aggressive impulses of the comparatively well-informed Navy.

2. Darwin: historical background

{9} The attacks of 1942 on Darwin were the first against Australia itself. The first actions were not air attacks but mine-laying operations carried out by submarine. On 12 January, I-121 laid mines off Darwin, and on 27 January, I-123 did the same. Both boats had the mission of observing merchant vessels and warships and severing trade routes. This mission, strategically suited to submarines, was also in line with the policies adopted by the Imperial General Headquarters-Government Liaison Conference of 10 January.

{10} The air attacks on Darwin that began on 19 February, however, had a somewhat different basis. After victory on Java, Japanese military leaders were concerned that Allied forces would escape to the Indian Ocean and Australia. Therefore, they decided to sweep all Allied air power and naval units from the Indian Ocean and Australian areas.

{11} One link in the ensuing operations was designed to secure Japanese command of the sea and air at the Arafura Sea. Darwin threatened not only control of the Arafura Sea but the taking of Koepang and Timor Island; thus, plans were drawn up that aimed at destruction of all air forces at Darwin. The Japanese navy committed powerful forces to the operation, a carrier group and land-based air forces. That is, in order to achieve local superiority, the navy intended to mount an intense air attack against Darwin.

{12} The attack was carried out by a carrier force (under the command of Vice-Admiral Nagumo Chuichi) and land-based air units on Bali Island. The carrier force consisted of the Akagi, Kaga, Soryu and Hiryu, the main elements of the Pearl Harbor attack - and that were to be destroyed in the Battle of Midway four months after the attacks on Darwin. Their striking forces consisted of thirty-six A6Ms (Zero fighters), eighty-one B5Ns (‘Kate’ torpedo bombers) and seventy-two D3As (‘Val’ dive bombers) led by the hero of Pearl Harbor, Commander Fuchida Mitsuo. Its targets were the warships and merchant vessels in Darwin’s harbor and harbor facilities.

{13} The land-based force consisted of fifty-four medium bombers under the command of Vice Admiral Tsukahara Nishizo. Its purpose was to destroy the airfield facilities and runways at Darwin. In total, 243 aircraft were to attack Darwin. Though the forces involved were not quite as large as those at Pearl Harbor they belonged to the same general scale of operations.

{14} On 10 February, aerial reconnaissance of Darwin was carried out and photographs obtained that allowed an accurate estimate of the air forces deployed there and the warships and merchant vessels anchored in the harbor. Japanese commanders understood that Allied combat potential at Darwin was rather limited; nevertheless, attacks were carried out as planned.

{15} On 19 February, the carrier air attacks were launched, The land-based air forces followed up. Because resistance was light and Japanese fliers were by this time at the peak of their skill, the expected results were achieved. It was clear to Japanese commanders at the time that the damage inflicted on the enemy could not equal that of the attack on Pearl Harbor, where the entire US Pacific Fleet had been anchored. A question remains as to what purpose was served by an attack of such magnitude.

{16} Further, the success of the operation in covering the rear of the offensive operations against Timor proved to be only temporary. It simply could not be claimed, as did Japanese navy releases, that the Darwin attacks were a great success, because from this time forward Allied forces contested control of skies in the area. In some respects, subsequent Allied concentrations of air units at Darwin marked a turning point in the struggles of that theatre.

{17} Soon after the Darwin operation, Japanese units on Timor came under persistent attack by Allied aircraft from the Darwin area. The 23rd Air Group stationed at the Koepang air base was chosen to hit back at the Allies, and on 25 and 27 April, it carried out its attacks. But because of concerns over Allied interceptors, the Air Group carried out its attacks at very high altitude, and the damage inflicted on the target was accordingly minor. Further, the Air Group suffered unexpectedly heavy damage from Allied P-39 Airacobras and P-40 Kittyhawks. Because of concern over the Allied air threat from Darwin, Japanese commanders withdrew the main forces at Koepang and stationed these at Rendari on Celebes Island. Even after this, Koepang suffered continual Allied air attacks.

{18} Japanese forces carried out daylight bombing raids against Darwin on 23 August. Losses to allied interceptors were heavy, however, and daylight raids were halted Night attacks took place on 23 and 26 November, but the results were unclear; and following photo reconnaissance of Darwin, Japanese commanders were greatly concerned over Allied concentrations there, though this concern seems in retrospect to have been exaggerated.

{19} In January 1943 the 23rd Air Group received a new commander, Rear Admiral Ishikawa Shingo. He was a man of aggressive temperament who in the past had campaigned against the London naval arms limitation treaty (1930) and actively promoted the construction of the Yamato-class super-battleships. He aimed not only to rebuild the Group but to resume offensive operations, specifically daylight air raids. These raids were soon begun and are summarised below.

1943 No of planes Target
2 March 30 Darwin, Batchelor Airfield
15 March 49 Darwin
2 May 44 Darwin
10 May 9 Milingimbi
28 May 16 Milingimbi
28 June 36 Darwin
30 June 50 Brock's Creek
6 July 48 Brock's Creek

Note: Japanese army air forces attacked Darwin on 20 June with 51 aircraft and on 22 June with an unknown number of aircraft.

{20} Rear Admiral Ishikawa left his command in August of 1943 to return to Japan. Rear Admiral Ito Yoshiaki replaced him, and because of supply difficulties and the importance of combat operations in New Guinea the air attacks on the Darwin area gradually subsided.

3. Sources for the study of the Darwin operations

{21} Scholars in Japan have completely neglected the year and a half of action at Darwin. Its part in the larger scheme of the Pacific War has not been discussed. One reason is that this part of the war cannot be directly tied to the process of Japan's defeat. Another is certainly that Japanese military historians have been preoccupied by Japan’s struggle with its principal adversary, the United States. But Darwin and its associated actions deserve scrutiny.

{22} Because the offensive actions against Darwin took place during the height of Japanese military power, a relatively large body of materials concerning them has survived, principally daily action narratives, battle reports, and studies of various operations. Because they are official documents, these materials are difficult for any but specialists to use.

{23} After the war, the Second Demobilization Ministry conducted interviews of repatriated officers and men under the auspices of US Occupation authorities. These interviews which concerned various actions of the war, were duly recorded. Today they are available in the US Library of Congress. In Japan these materials have been viewed with caution because they were used as tools of the prosecution at the Tokyo Trials. But they are of value because the interviews took place soon after the actions described, when memories were still fresh. Moreover, there was a new atmosphere in Japan at that time that allowed the interviewees to speak freely. Finally, the interview records are fairly raw and undoctored. They exist on microfilm and are available to anyone. But because the film is bad, they are very hard to decipher.

{24} Some Japanese veterans of the Darwin actions wrote down their experiences, but none of their writings significantly revise the accounts in official sources. It is to be hoped that in the future Japanese and Australian sources will be compared and collated so as to allow scholars in both countries to carry out comprehensive research on the fighting at Darwin.

4. A short note on sources for the Battle of the Coral Sea

{25} Concerning the Battle of the Coral Sea, I presented a paper titled ‘A Japanese view: Coral Sea to Midway’ at the conference on that battle sponsored by the Australian National Maritime Museum in May of l992. I would direct your attention to that paper, and today I will have only a few brief remarks on the subject.

{26} In Japan there is a steadily growing interest in the Battle of Midway, but there are no studies focusing on the Coral Sea, nor are there any serious scholars undertaking work on it at present. There is no scarcity of sources, as there are ample daily action narratives, battle reports and other official documents concerning the Battle of the Coral Sea, Further, several works have recently been published about the main Japanese carriers at the Coral Sea, the Zuikaku and Shokaku. In general, circumstances are favourable for further study of this historic battle. There is still much to be done in exploiting the sources available in Japan, the USA and Australia. The first step would seem to be a careful collation of materials from all three countries.

{27} A chronology of Japanese operations against Australia for the year 1942 is given below:

10 January
Imperial General Headquarters-Government Liaison Conference decides to cut Australian communications with Britain, India and the USA and to use the Navy to seal off Australia from Britain and the USA

12 January
Submarine I-121 lays mines off Darwin

2 February
The Second Air Division attacks Port Moresby

6 February
At a joint meeting of Army and Navy staffs, the Army opposes Navy’s plan to attack Australia

12 February
In the Diet the Prime Minister proclaims that ‘is time to realise an India for the Indians and to keep an eye on Australia’.

19 February
Japanese carrier planes and land-based aircraft attack Darwin

28 February
Imperial General Headquarters-Government Liaison Conference decides upon a region in which a new order will be built under Japanese leadership; debate is held on the mutual dependence of the USA, Britain and Australia and of Britain, India and Australia; further debate occurs on the effect that isolating Australia would have on these relationships

25 April
Navy air groups attack Darwin

29 April
At a conference on the Port Moresby Operation (MO), the Combined Fleet chief of staff orders that air operations carried out by MO-connected units of the Eleventh Air Fleet against targets on Australian soil be conducted with caution

29 April
The commander-in-chief of the MO halts attacks on Townsville

7-8 May
Battle of the Coral Sea; MO cancelled

31 May
Midget submarine attacks shipping in Sydney Harbour

7 June
Submarine I-24 shells Sydney

13-16 June
23rd Air Group mounts new series of attacks against northern Australia, attacks Darwin

18 July
Seventeenth Army ordered to take Port Moresby by overland route

30 July
Navy medium bombers and Zeroes attack Darwin in daylight

23 August
Navy air forces attack Darwin

15 September
Imperial General Headquarters establishes a defence zone in the Pacific bordering on Australia

5. Midget submarine attacks on Sydney

{28} On 10 April, 1942, the commander-in-chief of the Combined Fleet issued the following orders to all submarine units:

  1. To reconnoitre the enemy's fleet bases in the Indian Ocean and the South Pacific
  2. To destroy the enemy’s maritime commerce
  3. To lend support to the Port Moresby (MO) Operation.

{29} In accordance with this order, the Eastern Advanced Detachment received midget submarines from the tender Chiyoda and proceeded in the direction of Australia and New Zealand. The Detachment was to carry out reconnaissance of enemy bases there, and if they sighted major enemy warships the midgets were to be launched to attack them. The Eastern Advanced Detachment was made up of six submarines. I-29 probed off Sydney and Newcastle, and on 23 May it carried out aerial reconnaissance by a submarine-launched plane. Powerful warships were discovered at anchor in the harbor and, as a result, the Eastern Detachment Commander ordered the submarines to prepare for action. I-121 carried out a second aerial observation of the area on 29 May, and the order was issued to attack.

{30} Three midget submarines were sent into Sydney harbor. Lieutenant Matsuo Takahiro commanded the one released by the submarine I-22, Lieutenant Junior Grade Ban Katsuhisa the one released by I-24, and Lieutenant Chuma Kaneyo the one released by I-27. The damage inflicted by the midgets was below expectation, and after an accommodation vessel in the harbor was damaged, the attack was called off. All three midgets were lost.

{31} The I-22 and other submarines, which lingered outside Sydney until 3 June to recover the midgets, finally gave up their vain searches and switched to an attack mode. They began their warfare on maritime commerce. The results were as follows:

8 June: fired on an ironworks, a shipyard and gun emplacements at an airfield; 34 shells expended.

3 June: sank two merchantmen off Sydney;
7 June: fired on Sydney; 10 shells expended.

4 June: sank one merchantman in Bass Strait.

4 June: reconnoitred Brisbane.

{32} In all, the Eastern Advanced Detachment sank six merchantmen during this operation, but the yield of these actions was disappointing. Too much effort was expended at the outset launching the unorthodox midget attacks. Also, many torpedoes misfired in the attack on merchant shipping. The force failed in its most important mission of cutting supply lines between Australia and its British and American allies. Several Japanese sources shed light on the midget attacks on Sydney and related operations. Many of the daily action narratives of the submarines still exist. Normally such materials were delivered ashore upon return to home base; from there they went to the command of the Combined Fleet and thence to the Navy Ministry. In 1942 this procedure was still working perfectly, and documents relating to the Sydney attacks made it safely to Tokyo. There are six files full of these documents still extant today. They are preserved in the library of the National Institute of Defence Studies in Tokyo.

{33} Those like Lieutenant Matsuo who commanded the midgets were celebrated as ‘war gods’ during the war and a number of biographies of them exist. Unfortunately, they belong to the category of hagiography rather than legitimate scholarship and are of little value to serious researchers. Beside these there are some accounts of the Sydney actions that read like novels but incorporate actual interviews; they yield some useful facts to supplement the official record.

{34} In all, these materials cannot be said to be abundant . But because the subject has been so little investigated, the possibility exists for fruitful work, particularly if it is based on the official documents.

6. Japanese materials in the collection of the Australian War Memorial

{35} The Australian War Memorial holds materials on the Japanese military from the Allied Translator and Interpreter Section (ATIS) of the South-West Pacific Area of GHQ. These are of course Japanese military documents captured by the Allies that served as the basis for the many English translations produced by ATIS. The series AWM 82 has military manuals, savings books, diaries, and a highly varied assortment of other materials including official papers, rosters, and military orders. Let me note my personal gratitude for the care with which these original materials have been preserved: they are generally in fine condition.

{36} In this box is to be found captured documents relating to the New Guinea front and the Rabaul area. For a time, ATIS was located at Sydney, and consequently all captured Japanese materials were sent there. But ATIS was eventually moved to the United States, and when this happened, the American and Australian authorities must have discussed how they would divide the captured materials among themselves. Probably because the Australians had played a major role on New Guinea and Rabaul, they retained the documents related to these areas. I would be curious to know if this were the case; I would welcome it if someone in Australia could find out why these ATIS documents wound up at the AWM.

{37} Captured Japanese documents that remained in the hands of the Australian authorities first went to the Department of Defence and then to the AWM. They were organized and filed through the efforts of Doris Heath in 1987. In 1990 Mr Suwada Etsu made an inventory of the materials in Box 10; in 1995 I was able to draw up a detailed catalogue of Boxes 1-9 and Box 11. I hope to publish a comprehensive catalogue of these materials within two or three years.

{38} Thus we have a good fix on the original ATIS materials in Australia, but what happened to the ATIS materials that were taken to the United States? There is evidence that they were transferred from the US Department of Defense to the Japanese Section of the Asian Division, US Library of Congress, in about 1955. Professor Umetani Noboru of Osaka University reported in an article that he visited the Japanese Section in 1962 and was amazed to see a vast quantity of ATIS documents. But when he visited again, in 1965, the documents had disappeared.

{39} I have been able to find no record of when or where the ATIS documents were transferred. According to Mr. Kuroda, on the staff of the Japanese Section at the time, there was a strong sentiment among librarians that the Library of Congress was a repository of books, not official records, and therefore the ATIS materials should not be retained. Mr. Kuroda heard reports that the materials were returned to the US Army, assembled in Hawaii, and ultimately burned.

{40} There are good reasons to doubt the story of the destruction of these materials. For one thing, it is hard to believe that the Japanese Section would have surrendered these documents solely on the ground that the Library of Congress houses only books and not documents. Further, the Chinese and Korean Sections insisted that Japanese responsibility for the war should be pursued and would have strongly resisted any move to discard these materials. That they existed in considerable quantity is beyond doubt, and until there is confirmation of their destruction, historians should continue to pursue their whereabouts.

NOTE: In accordance with Japanese practice, Japanese names appear with the surname first.

©Tanaka Hiromi

Tanaka Hiromi is with the Defense Academy, Japan.