Australia–Japan Research Project at the Australian War Memorial

Research essay

Japanese submarine operations against Australia 1942-1944, by Dr David M. Stevens

Background
Between January 1942 and May 1944, the submarines of the Imperial Japanese Navy (IJN) took part in more than forty separate operations in the waters surrounding Australia. More than twenty Australian and Allied ships were sunk, and probably twice as many were attacked. In addition to the torpedo and gun attacks that ranged from the Arafura Sea to the Great Australian Bight, Japanese submarines conducted surface bombardments against Sydney, Newcastle and Port Gregory, and mined the approaches to Brisbane, Darwin and the Torres Strait. Other activities included the midget submarine raid against Port Jackson on 31 May–1 June 1942, while submarine-launched aircraft carried out reconnaissance flights over Sydney (three times), Melbourne and Hobart. Clearly it was not on the scale of the Battle of the Atlantic. However, for what was undoubtedly the most comprehensive and widespread series of offensive operations ever conducted by an enemy against Australia, the Japanese submarine campaign has received remarkably little recognition or analysis.

In fact, once the great sea battles of the Coral Sea and Midway had largely removed the threat of enemy surface forces, Japanese submarines constituted the major threat to Allied maritime interests in the South West Pacific Area. Being self sufficient in food and essentials, Australia was never in danger of being starved into submission. Nevertheless, Australian heavy industry relied fundamentally upon imports and the domestic shipping industry, and the Commonwealth’s economy was extremely vulnerable to dispersed pressure against key points. Equally at risk was the effective prosecution of the Allied war effort in New Guinea. With virtually no internal land routes available and only a few small airfields, the campaign to Australia’s north was solely dependent upon sea lines of communication and their control by friendly forces. Reduced by requisitions, enemy action and collisions, Australia’s merchant fleet had little or no spare capacity. Hence, even minor shipping losses had the potential to suspend manufacturing and military plans, while a concerted enemy campaign might hope to overextend defences, disrupt the bulk of communications and reduce the nation to strategic irrelevance.

As early as 10 January 1942 a conference at the Japanese Imperial General Headquarters agreed to cut the sea lines of communication leading east and west from Australia, sealing off the Commonwealth from the Anglo-American powers. This was certainly an achievable goal early in the Pacific war, when the Japanese held the initiative. But, although subsequent orders to their submarine fleet reiterated the intention to isolate Australia, the IJN never allocated sufficient forces to sustain an interdiction campaign. By mid-1943, they had lost their chance. The increasing diversion of fleet submarines to transport tasks and the massive influx of American aid to Australia meant that a decisive anti-shipping campaign was far beyond Japan’s capabilities.

Part of the IJN’s problem related to an inadequate doctrine, which saw submarines as an adjunct to the battle fleet rather than an independent strategic weapon. But it would be wrong to think that the operations by Japanese submarines were insignificant. In addition to the direct effect of sinkings and damage, their activities were an important factor in a series of industrial disputes within Australia’s maritime workforce that hampered cargo flow and exacerbated the shipping shortage. Moreover, any doctrinal shortcomings should not obscure the success of individual Japanese submarine commanders. Lieutenant K. MATSUMURA of I-21, for example, was one of the most successful commanders of the war in terms of merchant tonnage sunk. More than half his total of almost 60,000 tons was achieved in Australian waters.

The Australian response to the threat varied according to the levels of enemy submarine activity. The first sinking by an enemy submarine off the east coast took place on 3 June 1942 and, to its credit, the Royal Australian Navy (RAN) was swift to introduce coastal convoys. On 8 June, nine merchant ships began their passage from Sydney to Brisbane, escorted by a destroyer and a corvette. Thereafter, convoy escort became the primary focus of naval operations in Australian waters and an ongoing and critical task for local naval authorities. During 1943–1944, the anti-submarine campaign involved more than a third of the RAN’s resources in men and tonnage. The maritime squadrons of the Royal Australian Air Force (RAAF) were likewise heavily engaged and, during the peak of the Japanese campaign, the RAAF employed three additional reserve squadrons. Even training aircraft were ordered to carry weapons and keep a sharp lookout for submarines.

The scale of Allied shipping movements on the east coast and in support of the New Guinea campaign has rarely been appreciated by Australian military historians. In May 1943 alone, 172 coastal and oceanic convoys travelled to and from Australian ports. The RAAF provided day air cover to every one of these convoys when within range, while the Allied navies provided an average of two escorts per convoy. Australian warships provided the largest proportion of the escort force, while the remainder was a constantly changing mixture of American, Dutch, British, Indian and Free French vessels. Between 1942 and 1944, more than 6,500 Allied steamers travelled safely to and from Australia. More importantly, over the same period almost 190,000 Australian military personnel were transported to New Guinea without loss from enemy action.

Historiography

The most important recent publication on the IJN is Kaigun: Strategy, tactics and technology in the Imperial Japanese Navy, 1887–1941 (Annapolis: US Naval Institute Press, 1997), by D.C. Evans and M.R. Peattie. Reference to this book would be a good starting point for any researcher wishing to understand the IJN’s force structure decisions and general capabilities in the lead up to the Second World War. There have also been several good general reference works dealing specifically with the IJN’s submarine force. The two most deserving of close examination are Submarines of the Imperial Japanese Navy 1904–1945 (London: Conway, 1986), by Norman Polmar and Dorr B. Carpenter; and The Japanese submarine force and World War II (Annapolis: US Naval Institute Press, 1995), by Carl Boyd and Akhiko Yoshida. Both provide some coverage of Australian operations within the context of the overall submarine campaign, the latter work offering a better analysis of Japanese campaign planning and the constraints under which the IJN laboured. Boyd and Yoshida have also included an extensive bibliography covering both Japanese and English language sources. Now somewhat dated, but still offering a useful comparison between the Japanese and American approach to submarine warfare, is Undersea victory: The influence of submarine operations on the war in the Pacific, by W.J. Holmes (New York: Doubleday, 1966). Presenting a valuable personal perspective on submarine operations are two works written by former IJN officers: Sunk: The story of the Japanese submarine fleet (New York: Henry Holt, 1954), by HASHIMOTO Mochitsura (translated by E.H.M. Colegrave.); and I-Boat captain (Canoga Park: Major Books, 1976), by ORITA Zenji and Joseph D. Harrington. Although both exhibit numerous small errors, they do contain some details on the Australian campaign not readily available elsewhere.

The best starting point for the Australian perspective on the campaign is undoubtedly the 22-volume official history series Australia in the War of 1939–1945. Despite the extremely broad scope of Australia’s war at sea, the two volumes covering the RAN by G.H. Gill, Royal Australian Navy 1939–1942 (Canberra: Australian War Memorial, 1957), and Royal Australian Navy 1942–1945 (Canberra: Australian War Memorial, 1968), provide a reasonably comprehensive survey of naval activities in local waters. The two glaring weaknesses are the scarcity of information from Japanese sources and, because they were written before the general revelation of Allied code-breaking success, the lack of coverage given to the signals intelligence side of the anti-submarine campaign. Similar strengths and problems are apparent in the two relevant RAAF volumes: D. Gillison, Royal Australian Air Force 1939–1942 (Canberra: Australian War Memorial, 1962); and George Odgers, Air war against Japan 1943–1945 (Canberra: Australian War Memorial, 1957, reprinted 1968). Unfortunately, there is little coverage of sea transport and logistic problems in the four army volumes devoted to the Pacific war, but the volume in the civil series by S.J. Butlin and C.B. Schedvin, War economy 1942–1945 (Canberra: Australian War Memorial, 1977), does examine the shipping crisis in some detail. Another civil volume, The role of science and industry (Canberra: Australian War Memorial, 1958), by D.P. Mellor, gives brief consideration to the local production of the “Asdic” underwater echo-ranging device.

Some of the limitations apparent in the official histories can be alleviated by reference to the numerous books written since the 1970s, when Australian researchers gained increasing access to official records. The two best works on the overall submarine campaign are those by Stephen Carruthers, Australia under siege: Japanese submarine raiders 1942 (Sydney: Solus Books, 1982), and David Jenkins, Battle surface: Japan’s submarine war against Australia 1942–44 (Sydney: Random House, 1992). Australia under siege was the first to seriously reassess the campaign and look deeper into the intelligence aspects. Battle surface provides more and better analysis and, to date, offers the most comprehensive survey of information from primary and secondary Japanese sources. Jenkins also includes an extensive bibliography. Central to both books is the midget submarine attack on Sydney Harbour. The interest in this incident has inspired several other works of which the first was J.F. Moyes, Mighty midgets (Sydney: NSW Bookstall Co., 1946). More important are Hugh Clarke and T. Yamashita’s, Fire one (Sydney: Angus & Robertson, 1978, first published by Horwitz in 1966 as To Sydney by stealth), and The coffin boats: Japanese midget submarine operations in the Second World War (London: Leo Cooper, 1986), by Peggy Warner and SENO Sadao. Less trustworthy in fact and more fanciful in assessment are two works by Lew Lind: The midget submarine attack on Sydney (Sydney: Bellrope Press, 1990); and Toku tai: Japanese submarine operations in Australian waters (Maryborough: Kangaroo Press, 1992). Notwithstanding their shortcomings, Lind’s books benefit from the author’s close working association with members of the Japanese Midget Submarine Association.

Standing out, by virtue of their unique subject matter and detailed coverage, are two further books on particular aspects of the underwater campaign. The first, Sensuikan I-124 (Darwin: Tall Stories, 1997), by Tom Lewis, deals primarily with the exploits of a Japanese minelaying submarine, sunk by the RAN off Darwin in January 1942. The second, Australian Hospital Ship Centaur: The myth of immunity (Hendra: Nairana Publications, 1993), by Chris Milligan and John Foley, includes a thorough assessment of Japanese activities off Australia at the time of Centaur’s sinking in May 1943. Although concerned more with German operations, U-boat far from home: The epic voyage of U-862 to Australia and New Zealand (Sydney: Allen & Unwin, 1997), by D.M. Stevens, does include some comparisons with Japanese submarine operations in the Pacific. Stevens has dealt directly with facets of the submarine and anti-submarine campaign in three articles published in the Journal of the Australian War Memorial: “I-174 the last Japanese submarine off Australia” (April 1993); “The role of radio intelligence in the anti-submarine war around Australia 1942–45” (October 1994); and “The sinking of HMAS Kuttabul: a reassessment” (April 1995). Two related articles, “The war cruise of I-6, March 1943” and “The role of maritime power in the New Guinea campaign 1942–43” were published in the Australian Defence Force Journal in September/October 1993 and July/August 1995 respectively.

Although the targets of the Japanese attacks, the vessels and men of the Merchant Navy receive the smallest share of the coverage in popular histories. Still an important resource, despite its age, is Ships in battledress (Sydney: Currawong Publishing, 1945), by J.H. Adams. Books dealing with specific shipping lines obviously focus on the vessels of particular fleets, but are no less important for that. Publications of this type include: War service of the Merchant Navy: A record of the participation of the merchant ships of Huddart Parker Ltd. (Melbourne: Huddart Parker Ltd., 1951); S.W. Roskill, A merchant fleet at war: Alfred Holt & Co. 1939–1945 (London: Collins, 1962); and B.A. Wilkinson & R.K. Willson, The main line fleet of Burns Philp (Canberra: The Nautical Association of Australia, Inc., 1981). American ships attacked in Australian waters are dealt with by A careless word … a needless sinking (New York: American Merchant Marine Museum, 1984), by A.R. Moore. Although dealing specifically with the service of RAN personnel manning the guns of Defensively Equipped Merchant Ships (DEMS), DEMS? What’s DEMS? (Brisbane: Boolarong Publications, 1986), by Alex Marcus, provides a more general narrative covering most of the merchant ships lost or damaged off the Australian coast.

Finally, mention must be made of the increasing number of books written about individual RAN units. Many of these “ship histories” are written and published by former crew members and, not surprisingly, vary markedly in content and quality. Some consist primarily of reproductions of official reports and a brief narrative, while others rely solely on reminiscences. Despite their failings, these works can be of great value in providing a personal perspective, and are often the only record of wartime experience at the junior sailor level. Importantly, several of these books deal with the operations of the Australian-built corvettes, which bore the brunt of the escort task, but which have tended to be overlooked in many more general histories. Also worthy of review are what might be termed "illustrated histories", such as The secret battle 1942–44: The convoy battle off the east coast of Australia during World War II (Ringwood: Lamont Publishing, 1995), by R. Wallace, a former seaman in HMAS Warrnambool. In a somewhat similar vein are the four volumes in the HMAS series, published by the Australian War Memorial during the Second World War. In addition to official artwork and photographs, each of these volumes includes a number of personal anecdotes and short stories. Notwithstanding the restrictions imposed by wartime censorship, several of these essays provide vivid pictures of convoy duties and anti-submarine activity off Australia’s coast.

Archival sources

Because of the covert nature of much of the Japanese submarine campaign, its broad scope and the variety of nationalities and services taking part, official records tend to be somewhat dispersed. Search aids for the National Archives of Australia and the Australian War Memorial are easily accessed through their web sites and are also covered by Professor David Horner in his research essay “Official Australian records of the Pacific War”. What follows here are some of the more important series held by the major institutions, together with a small sample of key files that illustrate the type of material that may be accessed. However, in addition to the records held in Australian archives, a researcher looking to explore new viewpoints may find it necessary to consult archival repositories in the United States. The latter are a particularly important source for translations of original Japanese records, especially since the IJN destroyed much of its own material at the end of the war.

Australian War Memorial (AWM)

The records held by the AWM cover the full range of material from technical and intelligence reports through to captured documents and private diaries. They are particularly valuable for technical and sociological studies. Important references to the Japanese submarine campaign can often be found in unexpected areas. For example, an intelligence report by HQ 1 Aust Corps (AWM 54, 423/11/132), dated 5 August 1942, contains a realistic assessment of the failings of Australian anti-submarine measures, one not readily apparent from RAN and RAAF records.

Private Records
	PR84/47	Technical report on Japanese midget submarines
	PR85/161	Aircraft over Sydney
	PR86/241	Salvage of midget submarine
AWM 54, Written records, 1939–1945 War
	81/4/51	RAAF maritime trade protection narrative
	423/11/2	COIC weekly summaries
	504/9/2	Submarine shelling of Sydney Harbour
	505/4/16	K. NAKAMURA’s report on Japanese submarines off E. Coast of Australia, 1942
	622/5/1	Strikes by Navy on enemy submarines
	622/5/4	Appreciations – Japanese submarine movements in Australian waters, May 1943
	917/7/2	Characteristics of Japanese submarines
AWM 55/56, Advanced ATIS publications
	Enemy publication No. 288, Characteristics of submarines and anti-submarine operations.
	Interrogation report No. 56, officer from I-1
AWM 58, Translations of Japanese documents
	058	Extracts from translated diary of member of I-1
	0323	Translated notebook from submarine I-1
	0648	I-1 operations log
AWM 69, Official History 1939–45 War, Series 2 (Navy): Records of G.H. Gill
	23/3	Enemy submarines on the Australian coast
	23/16	Merchant ship losses, war bonuses and extra risk pay
	23/32	Organisation of convoys around Australian coast
	23/86	DEMS personnel
	23/90	Merchant shipping sunk by enemy action.
	82	Australian coastal convoys
	185	Japanese midget submarines attack on Sydney Harbour
AWM 78, Reports of proceedings, HMA Ships and establishments
	These contain a monthly summary of each ship’s activities
AWM 124, Naval Historical Records collection
	4/473	Report of investigation into Japanese torpedo
	4/474	Condensed report of Japanese torpedo
	U/K	Death of a sub (documentary broadcast of the killing of the first enemy submarine to be sunk in Australian waters)
AWM 188, Naval Historical Section research files
	6	Japanese submarine activity in South West Pacific
	28	Convoys
	40	Enemy submarines on the Australian coast
	43	Merchant ship losses and damage

National Archives of Australia (NAA)
Notwithstanding the AWM collection, the NAA is probably the more important source for the official Australian campaign record in the form of reports, correspondence and messages from service and government authorities. These records are essential for an understanding of higher direction and policy, but also cover the specifics of individual anti-submarine actions, and are thus equally vital for studies of command and tactics. NAA repositories exist in each state capital and records tend to reside in the repository closest to the originating agency. As a result, wartime Navy Office records, including signals intelligence aspects, are generally held in Melbourne (Victoria), while many of the records produced by the Naval Officer-in-Charge (NOIC) Sydney remain in Sydney (New South Wales). Most RAAF and Commonwealth Government records reside in Canberra (Australian Capital Territory).

NAA Australian Capital Territory

AA 1969/100	Royal Australian Air Force Unit Records, 1937–1961
A 816	Defence Correspondence Files, 1928–1958
	43/302/18 Special Intelligence Organisation
A1196	Air Force Office Correspondence Files, 1935–1960
A2031	Defence Committee Minutes, 1926–
A2585	Naval Board Minutes, 1905–1976
A2682	Advisory War Council Minutes, 1940–1945

NAA Victoria

B5553	Fleet Radio Unit Melbourne, periodic summaries, 1944–1945
MP 456/4	Salvage Board, general correspondence, 1942–1946
MP 1049/5	Navy Office, correspondence files, 1923–1950
	2021/8/362	Documents captured from I-1
	2026/12/432	Reports from O.C. convoys, 1942
2026/12/543	Report of torpedo attack on O.C. 93
MP1587/1	Historical Records Files 1912–1964 (some items in this series are retained by the Naval Historical Directorate, Canberra)
	155E	Submarine attack SS Portmar and LST 469
	155U	Submarines, Japanese
	174AB	Captured documents from I-1
	283C	Enemy and Allied minefields
	316A	CINCPAC bulletins

Naval Historical Directorate (NHD)

A less widely known organisation, but one that should be considered by any researcher into Australian naval history, is the RAN’s Naval Historical Directorate (Naval Headquarters, CP4-1-003, Campbell, ACT, 2601, Tel: 02 6265 9111). The NHD may be visited during normal office hours, but an appointment should be made before arriving. Although not an archival repository, the NHD holds a substantial amount of information on RAN ships and personnel, including narratives of their wartime activities. The NHD also retains the wartime card index system used by the RAN to track the movements of individual merchant ships. An extremely important resource for the anti-submarine campaign is the “RAN Daily Narrative”, which covers almost the entire period of the war, and provides daily assessments of enemy activity together with convoy and escort details. Other relevant material held by the NHD includes translated portions of the war diaries of the Japanese submarines I-6 and I-174, and a copy of the PhD thesis, The impact of the submarine threat on Australia’s maritime defence 1915–54 (UNSW, 2000), by D.M. Stevens.

Unites States

Naval Historical Center, Washington DC

In October 1945, General Headquarters (GHQ), Far East Command, directed the Japanese Government to prepare a complete history of the war in the Pacific. This history developed as a series of monographs written by former officers of the Imperial Japanese Army and Navy. These monographs now provide the primary translated source materials held by the Naval Historical Center. They are held in microfilm format. Those monographs covering submarine operations in Australian waters include:

# 102 Submarine operations (December 1941–April 1942)
# 108 Submarine operations in first phase operations (December 1941–April 1942)
# 110 Submarine operations in second phase operations, Part I (April–August 1942)
# 111 Submarine operations in second phase operations, Part II (August 1942–March 1943)
# 163 Submarine operations in third phase operations, Part I (March–November 1943)

Another product of GHQ Far East Command was the 1952 publication The Imperial Japanese Navy in World War II. This offers an organisational breakdown of the Japanese submarine command through to December 1943.

The Naval Historical Centre also holds relevant documents in Box 86 “Records of Japanese Navy”, together with 230 reels of microfilm containing original Japanese source material in the JD (Japanese Document) series. JD-37 to JD-39 include various unit and individual submarine records. These documents are in Japanese, but portions of JD-38 covering the March 1943 war diary of I-6 have been translated into English and are now held by the NHD in Canberra.

Also available on microfilm are the “Reports of the US Naval Technical Mission to Japan 1945–46”, which includes a large number of reports prepared by USN and Royal Navy officers interrogating Japanese officers and examining Japanese equipment. The library of the Australian Defence Force Academy in Canberra holds a copy of this series. Of most interest are:

· No. S-01-1 Ship and related targets, Characteristics of Japanese naval vessels, Submarines, January 1946.
· No. S-01-6 Ship and related targets, Characteristics of Japanese naval vessels, Submarines, Supplement I, January 1946.
· No. S-01-7 Ship and related targets, Characteristics of Japanese naval vessels, Submarines, Supplement II, January 1946.
· No. S-17 Ship and related targets, Japanese submarine operations, February 1946.

US National Archives

Any serious research into the specifics of Japanese submarine operations off Australia will eventually require an examination of RG 457, Records of the National Security Agency, which may be viewed at the US National Archives at College Park, Maryland. The sheer enormity of the holdings is daunting, and range from memorandums, messages, studies and reports, through to decrypted copies of individual Japanese naval messages. The following listings provide some idea of the content, but are in no way exhaustive.

Entry 9002 Studies on cryptology

· SRH-64 Japanese Submarine Operations, 23–25 Jan 1942
· SRH-144 Radio intelligence in World War II, Tactical Operations Pacific, Feb 1943.
· SRH-287 Radio intelligence in World War II, Tactical Operations Pacific, Mar 1943.
· SRH-288 Radio intelligence in World War II, Tactical Operations Pacific, Apr 1943.

Entry 9014 Translation reports of intercepted Japanese naval messages, 1942–1946

· SRN1–290908 Individual translations: Japanese Navy messages

Entry 9015 Japanese naval radio intelligence summaries, 1942–1946

· SRNS – 1517 “Fleet Radio Unit Melbourne, 7th Fleet daily digests 20 Mar 1942–31 Oct 1944”
· SRNS – 1518 “Fleet Radio Unit Melbourne, 7th Fleet out/in messages Mar 1942–Mar 1944”
· SRNS – 11459/1516 “Declassified traffic intelligence summaries of Japanese naval forces 1942–46”

Entry 9020 United States Navy records relating to cryptology, 1941–1945

· SRMN – 004 “OP-20G file of CINCPAC intelligence bulletins 16 Mar–1 June 1942”
· SRMN – 006 “Summaries/translations of JAPANESE messages Feb–Dec 42”
· SRMN – 008 “CINCPAC and COMFOURTEEN CI bulletins/radio digests 1 Mar–31 Dec 42”
· SRMN – 009 “CINCPAC fleet intelligence summaries 22 Jun-8 May 1943”
· SRMN – 013 “Commander in Chief, Pacific intell bulletins 1 June 42–23 Sep 45”

Another valuable resource in the US National Archives is RG 331, “Supreme Commander for the Allied Powers (SCAP), monographs 1945–51: History of the non-military activities of the occupation of Japan”. SCAP-783 covers the investigations into the sinking of the Australian Hospital Ship Centaur and includes interrogation reports of Japanese submarine officers involved in operations off Australia.

Conclusions

Between 1942 and 1944 Japanese submarines regularly operated off the Australian coast. Far more than the activities of enemy surface raiders or aircraft, submarine attacks were widespread and took place over a significant period of time. Despite the campaign’s potential to seriously disrupt Australia’s economy and war effort it has so far received very little academic attention. No operational studies were conducted by the Australian armed services, and the literature published since the war has been restricted primarily to narrative accounts and personal reminiscences. Many facets of the submarine campaign in Australian waters were unique and this lessens to some extent the specific value of the huge body of research already conducted into anti-submarine warfare in the Atlantic. The limitations of this broader context mean that many of the issues surrounding the Australian campaign, including those of emerging technology, policy, strategy, tactics and training, still deserve a more complete and thorough analysis.

Printed on 03/13/2025 11:10:51 AM