Central Bureau
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The Central Bureau was one of two Allied
signals intelligence Signals intelligence (SIGINT) is the act and field of intelligence-gathering by interception of ''signals'', whether communications between people (communications intelligence—abbreviated to COMINT) or from electronic signals not directly u ...
(SIGINT) organisations in the South West Pacific area (SWPA) during
World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
. Central Bureau was attached to the headquarters of the Supreme Commander, Southwest Pacific Area, General
Douglas MacArthur Douglas MacArthur (26 January 18805 April 1964) was an American general who served as a top commander during World War II and the Korean War, achieving the rank of General of the Army (United States), General of the Army. He served with dis ...
. The role of the Bureau was to research and decrypt intercepted
Imperial Japanese Army The Imperial Japanese Army (IJA; , ''Dai-Nippon Teikoku Rikugun'', "Army of the Greater Japanese Empire") was the principal ground force of the Empire of Japan from 1871 to 1945. It played a central role in Japan’s rapid modernization during th ...
(land and air) traffic and work in close co-operation with other SIGINT centers in the
United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
,
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and
India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...
. Air activities included both army and navy air forces, as there was no independent Japanese air force. The other unit was the joint
Royal Australian Navy The Royal Australian Navy (RAN) is the navy, naval branch of the Australian Defence Force (ADF). The professional head of the RAN is Chief of Navy (Australia), Chief of Navy (CN) Vice admiral (Australia), Vice Admiral Mark Hammond (admiral), Ma ...
/
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Fleet Radio Unit,
Melbourne Melbourne ( , ; Boonwurrung language, Boonwurrung/ or ) is the List of Australian capital cities, capital and List of cities in Australia by population, most populous city of the States and territories of Australia, Australian state of Victori ...
( FRUMEL), which reported directly to CINCPAC (Admiral Chester Nimitz) in
Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...
and the Chief of Naval Operations (Admiral Ernest King) in
Washington, D.C. Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and federal district of the United States. The city is on the Potomac River, across from Virginia, and shares land borders with ...
Central Bureau is the precursor to the Defense Signals Bureau, which after a number of name changes is (from 2013) called the Australian Signals Directorate.


Structure

Central Bureau comprised: * administrative personnel * supply personnel * cryptographic personnel * cryptanalytic personnel * interpreters * translators * a field section which included the intercept and communications personnel


History


Origins

Beginning in January 1942, U.S. Navy stations in Hawaii ( Station HYPO), Cavite/Corregidor ( Station CAST) and OP-20-G ( Station NEGAT, at Washington) began issuing formal intelligence decrypts far in advance of the U.S. Army or Central Bureau. General MacArthur had his own signals intelligence unit, Station 6, while he was in command in the
Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...
before the start of the war, and was not fully dependent on the U.S. Navy for that type of information. However, most of the signals intelligence he received was from the U.S. Navy's Station CAST, originally at Cavite in the Manila Navy Yard, and evacuated to Corregidor Island after Japanese successes. Prior to the war, it had to be sent by courier, which caused some delay and annoyance. General MacArthur escaped from Corregidor in the Philippines in a PT boat to Mindanao and flew to Australia from Del Monte on a
Boeing B-17 Flying Fortress The Boeing B-17 Flying Fortress is an American four-engined heavy bomber aircraft developed in the 1930s for the United States Army Air Corps (USAAC). A fast and high-flying bomber, the B-17 dropped more bombs than any other aircraft during ...
. He made his way to Melbourne, arriving there on 22 March
1942 The Uppsala Conflict Data Program project estimates this to be the deadliest year in human history in terms of conflict deaths, placing the death toll at 4.62 million. However, the Correlates of War estimates that the prior year, 1941, was th ...
. The Signals Intelligence units operating in Australia at the time of MacArthur's arrival in Melbourne were as follows: * No. 4 Australian Special Wireless Section at Park Orchards near Ringwood in Melbourne * A small Diplomatic and Press intercept section at Park Orchards * A Diplomatic cryptographic and intelligence section at Victoria Barracks, Melbourne * Some British Army Signals personnel from the Far East Combined Bureau who had escaped from Java * A small
RAAF The Royal Australian Air Force (RAAF) is the principal aerial warfare force of Australia, a part of the Australian Defence Force (ADF) along with the Royal Australian Navy and the Australian Army. Constitutionally the governor-general of Aus ...
Intercept section in Darwin * A small RAN intercept and Direction Finding (D/F) organisation * A small RAN cryptographic and intelligence section at the Navy Office in Melbourne and, eventually, after evacuation from Corredigor by submarine, * the personnel of Station CAST, the US Navy SIGNIT group in the Far East. They were responsible for channeling all SIGINT information to OP-20-G in Washington. It became known as FRUMEL and obtained IBM equipment in 1942 to replace that which had been left behind in Manila Bay on leaving Corregidor and employed it throughout their tenure in Melbourne.


Establishment of Central Bureau

One of Macarthur's first decisions when he arrived in Melbourne was to expand the SIGINT operations already existing in Australia. Brigadier General Spencer B. Akin, MacArthur's Chief Signals Officer held discussions with Major General Colin Simpson. They agreed that a Research and Control Centre to handle Signals Intelligence (SIGINT) was needed. MacArthur subsequently issued orders for the formation of two complementary groups: * An intercept organisation known initially as No. 5 Wireless Section * A research and control centre known as the Central Bureau. Initially Central Bureau was made up of 50% American, 25% Australian Army and 25% RAAF personnel. Central Bureau was a joint US-Australian signal intelligence organisation, established on 15 April 1942 under the command of US Army Major General Spencer B. Akin, with headquarters in
Melbourne Melbourne ( , ; Boonwurrung language, Boonwurrung/ or ) is the List of Australian capital cities, capital and List of cities in Australia by population, most populous city of the States and territories of Australia, Australian state of Victori ...
.Its role was to research and decrypt army and air intercept traffic and work in close co-operation with other SIGINT centres in the USA, United Kingdom and India. A small Naval cryptographic group also became part of the secret new unit. It was led by Commander Eric Nave, who with Professor Dale Trendall had been working on Japanese diplomatic and naval codes at Victoria Barracks. Central Bureau was established in a gabled, ivy-clad mansion called "Cranleigh" in Domain Road, at South Yarra, Melbourne. Major General Akin's Executive Officer, Major (later Colonel) Joe R. Sherr had been evacuated from the Philippines (Station 6). He was responsible for arranging for the first group of US "SIGINT" personnel to come to Australia, and as Akin's control was indirect he was responsible for day-to-day running of the bureau. He was killed when returning from a liaison visit to the wireless Experimental Centre in India, when his aircraft crashed 3 km from Calcutta airfield on 21 September 1943. Sandford had wanted to send "Pappy" Clark to the conference but Akin said that MacArthur would not agree to send Clark (only a major) and so sent Colonel Sherr instead. He was succeeded by Major Abraham "Abe" Sinkov, a mathematician, who was appointed assistant director of Central Bureau. Sinkov had previously been a senior cryptographer in the US Army Signals Intelligence Service under William F. Friedman. Sinkov had previously been in charge of an intercept station in Panama. He had visited Britain in 1941 to facilitate the exchange of cryptographic information. With Sinkov (US Army), the three assistant directors were Australians Alistair "Mic" Sandford (Major then Lt-Col, Second AIF) and Roy Booth (Squadron Leader then Wing Commander, RAAF). They acted as head of their respective service organisations; with Sandford the bureau executive officer under Sherr, then Booth from 1944. The bureau functioned well and harmoniously, with job demarcation as Australian experience was from wireless interception and traffic analysis in the Middle East and the Americans in breaking codes and cyphers, although this "broke down" as the war went on. Signals organisations tend to be "meritocratic" rather than on rank. Experienced intercept
Kana are syllabary, syllabaries used to write Japanese phonology, Japanese phonological units, Mora (linguistics), morae. In current usage, ''kana'' most commonly refers to ''hiragana'' and ''katakana''. It can also refer to their ancestor , wh ...
operators from a
Royal Australian Air Force The Royal Australian Air Force (RAAF) is the principal Air force, aerial warfare force of Australia, a part of the Australian Defence Force (ADF) along with the Royal Australian Navy and the Australian Army. Constitutionally the Governor-Gener ...
unit at
Townsville The City of Townsville is a city on the north-eastern coast of Queensland, Australia. With a population of 201,313 as of 2024, it is the largest settlement in North Queensland and Northern Australia (specifically, the parts of Australia north of ...
were assigned to the new Central Bureau. The RAAF at the time had a number of Kana operators being trained and were about to train a further 13 WAAAF personnel. (
Katakana is a Japanese syllabary, one component of the Japanese writing system along with hiragana, kanji and in some cases the Latin script (known as rōmaji). The word ''katakana'' means "fragmentary kana", as the katakana characters are derived fr ...
is one of the syllabic forms of written Japanese). The cryptanalysts who had operated from the Malinta Tunnel during the
Battle of Corregidor The Battle of Corregidor (; ), fought on 5–6 May 1942, was the culmination of the Empire of Japan, Japanese Philippines campaign (1941–1942), campaign for the conquest of the Commonwealth of the Philippines during World War II. The Bat ...
got out to Australia by submarine in two groups. Their equipment was pushed into
Manila Bay Manila Bay (; ) is a natural harbor that serves the Port of Manila (on Luzon), in the Philippines. Strategically located around the Manila, capital city of the Philippines, Manila Bay facilitated commerce and trade between the Philippines and ...
. They were used to assist the Australian Wireless Group units. A group of cryptographic, cryptanalytic and translator personnel from the Japanese section of the Washington Signal Intelligence Service were also moved to Australia. More Australians were also recruited to Central Bureau after it was established.


Central Bureau-FRUMEL relations

MacArthur was not happy to depend on the Navy's discretion in handling his SIGINT requirements. He felt he had experienced problems with such an arrangement when he was in
Manila Manila, officially the City of Manila, is the Capital of the Philippines, capital and second-most populous city of the Philippines after Quezon City, with a population of 1,846,513 people in 2020. Located on the eastern shore of Manila Bay on ...
. MacArthur's Intelligence Officer (G-2) was Major General Charles A. Willoughby. In Australia the rules laid down by Cmdr Rudy Fabian the head of FRUMEL (through Admiral Leary) for receiving FRUMEL briefings said that Fabian or his representative were to brief MacArthur and his chief of staff Richard K. Sutherland at 1400 each day, but could not copy or distribute the material. The representative was not to be kept waiting. Only MacArthur and Sutherland were to be present; Willoughby, his G2 was excluded. Once Fabian burnt a document in front of Willoughby on his way out and dropped the ashes in his bin to demonstrate that he was not allowed to see it! Commander
Nave The nave () is the central part of a church, stretching from the (normally western) main entrance or rear wall, to the transepts, or in a church without transepts, to the chancel. When a church contains side aisles, as in a basilica-type ...
moved to Central Bureau in mid-1942 from the combined Australian Navy/U.S. Navy operation in Melbourne known as FRUMEL, which came under U.S. Navy control (Lt Rudy Fabian) in mid-1942. Fabian thought Nave had breached security, and got rid of Nave and the civilians (including Professor Thomas Room, who also went to Central Bureau); the Holden Agreement specifically stated that Eric Nave was not to work at FRUMEL, indicating that Fabian had "friends in high places". Although Nave headed up the "Solutions" division there, most records indicate he personally dealt with minor Japanese naval codes and simple substitution ciphers in spite of his Japanese language capability and long history with Japanese codes. However Duffy wrote that ''Nave was actively working on JN-25 until the day he was expelled from Monterrey''. Colonel Sinkov and his American staff worked on the high-level Japanese Army codes. Central Bureau was an unusual cryptographic organisation, coming under the direct command of an area commander (MacArthur) rather than reporting to a central cryptographic organisation; as confirmed by Marshall's reply. This decision led to periodic ructions in the American military establishment about MacArthur's command having its own cryptographic service under his command; a privilege that he jealously guarded.


No.1. Wireless Unit

On 25 April 1942 the small RAAF Intercept Station operating in two back-to-back houses at 21 Sycamore Street and 24 French Street in the suburb of
Pimlico Pimlico () is a district in Central London, in the City of Westminster, built as a southern extension to neighbouring Belgravia. It is known for its garden squares and distinctive Regency architecture. Pimlico is demarcated to the north by Lon ...
in Townsville was given its new name of No. 1 Wireless Unit and became part of Central Bureau. The newly named Unit included 7 RAAF, 1 AMF and 4 United States Army personnel in No. 1 Wireless Unit at Townsville. This RAAF Unit had started earlier in March 1942 as a small intercept station located in the initial two houses at Pimlico under Wing Commander Booth. By 6 July 1942 the intercept operator numbers at Central Bureau had increased from six to twenty nine.


Coral Sea and Kokoda

A message on 9 April 1942 indicated that the "RZP Campaign" against
Port Moresby (; Tok Pisin: ''Pot Mosbi''), also referred to as Pom City or simply Moresby, is the capital and largest city of Papua New Guinea. It is one of the largest cities in the southwestern Pacific (along with Jayapura) outside of Australia and New ...
was to be an invasion not an air raid and which would isolate Australia from America. Fabian at FRUMEL briefed MacArthur who was "incredulous" as he expected the target would be New Caledonia, so Fabian explained the ( JN-25) code-breaking process and showed him the Japanese commander’s intercepted message with the objectives to restrict enemy fleet movements and attack the north coast of Australia. So a transport due to leave the next day for New Caledonia was sent to Port Moresby. On 23 April Fabian showed MacArthur that the IJN was amassing a large force at Truk, and planned to occupy Tulagi also. MacArthur got an Australian reconnaissance plane to "discover" the Port Moresby invasion force on 5 May, leading to the Battle of the Coral Sea. On 19 and 23 May messages indicated that the Japanese were proposing to land at Buna and go overland over the Owen Stanley Range via the Kokoda Track to Port Moresby; though MacArthur, Willoughby and Blamey were unconvinced saying "Nobody in their right senses would land there". Blamey took "minimal precautions" to defend the track, resulting in heavy losses for the 39th Battalion sent there.


Move from Melbourne to Brisbane

On 20 July 1942, General MacArthur moved his headquarters to
Brisbane Brisbane ( ; ) is the List of Australian capital cities, capital and largest city of the States and territories of Australia, state of Queensland and the list of cities in Australia by population, third-most populous city in Australia, with a ...
. A separate American intelligence operation was located nearby in a building called "Palma Rosa" at 9 Queens Road,
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. "Palma Rosa" was commandeered by the Counter Intelligence Corps, G-2 Section, Headquarters U.S. Army Forces in the Far East (U.S.A.F.F.E.). Central Bureau also relocated to Brisbane in September, with the American contingent of six officers and eighteen enlisted men moving first. The bureau moved to the suburb of Ascot, not far from the new American airfield at Eagle Farm Airport. Staff were accommodated as boarders in private homes or in military camps with daily transport by truck or bus. Officers obtained rented accommodation around Ascot and nearby suburbs. Mic Sandford the head of the Australian Army contingent rented a house at 50 Elderney Terrace in nearby
Hamilton Hamilton may refer to: * Alexander Hamilton (1755/1757–1804), first U.S. Secretary of the Treasury and one of the Founding Fathers of the United States * ''Hamilton'' (musical), a 2015 Broadway musical by Lin-Manuel Miranda ** ''Hamilton'' (al ...
; this became a social centre and the scene of frequent dinner and drinking parties. The CB headquarters was in "Nyrambla", a huge house at 21 Henry Street built as a grand mansion in 1886, although the large 6 ha section was subdivided from 1905 and the house was converted into flats in the late 1920s. The house still retained rooms with marble fireplaces, ornate plaster and 4.8m high ceilings, and the building remained the main administrative and training centre for the bureau. When the bureau assumed an augmented role to coordinate land and air forces signals intelligence, additional facilities were located a few minutes walk away at a small public park opposite the Ascot railway station Hence it became known as "Ascot Park" although officially called "Oriel Park". Between the station, Kitchener Road and Lancaster Road, the park had nearly 20 temporary army wooden huts by mid-1943 and 31 by September 1945. Across the road at 77 Kitchener Road a disused brick Fire Station was used for banks of
IBM International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...
punched card A punched card (also punch card or punched-card) is a stiff paper-based medium used to store digital information via the presence or absence of holes in predefined positions. Developed over the 18th to 20th centuries, punched cards were widel ...
equipment used by cryptanalysts to analyze intercepted cyphertext. The machines had been in the garage at the rear of 21 Henry Street but the noise from all-hours operation bought complaints from neighbours. When the IBM machines were removed from 21 Henry Street the garage was occupied by No. 11 Australian Cypher Section and filled with Typex machines which were operated mostly by Australian Women's Army Service (AWAS) personnel.


Australian Special Intelligence Personnel Sections (ASIPS)

In 1942, Sandford raised two intelligence sections to operate at the wireless sites in the field. These personnel, known as ASIPS, would be a liaison between Central Bureau and the Kana operators, greatly increasing the speed in which messages could be decrypted and translated. The first unit was stationed at Coomalie Creek Airfield, NT, under the command of Captain William E Clarke. This ASIP unit, in direct coordination with local air force commanders, decrypted mainly tactical codes which allowed Allied forces to combat the air raids against the north of Australia. In 1943 these ASIP units were sent to New Guinea.


Allied Translator and Interpreter Section

Starting in October 1942, Japanese POWs were interrogated by a joint US-Australian unit called ATIS at two houses called " Tighnabruaich" and " Witton House" at Indooroopilly in Brisbane. ATIS was staffed by Japanese-Americans (Nisei) and Australians who spoke Japanese. After interrogation, the Japanese POWs were often sent to the larger POW camp at Cowra, NSW. Translators at Indooroopilly were also involved in the translation of the captured codebooks from Sio. The heritage-listed site is currently known as the Combined Services Detailed Interrogation Centre, Brisbane


Shootdown of Yamamoto

In April 1943, the US Navy in Melbourne and Hawaii intercepted a Japanese naval message encoded in JN-25, the main and most secure Japanese naval code. The US Navy had not cracked JN-25, so they were only able to recover small portions of the message. The Japanese garrison commander on Ballale did not have JN-25 so the message was retransmitted to him by Japanese signals in Rabaul in a less secure army air to ground code. This message was intercepted by Australian wireless units in Port Moresby and translated by the ASIPs unit in Townsville. This message was forwarded to FRUMEL and Hawaii which allowed the US Navy codebreakers to inform Nimitz that the message was broken. The message contained Admiral
Isoroku Yamamoto was a Marshal Admiral of the Imperial Japanese Navy (IJN) and the commander-in-chief of the Combined Fleet during World War II. He commanded the fleet from 1939 until his death in 1943, overseeing the start of the Pacific War in 1941 and J ...
's itinerary for an upcoming trip to Rabaul. Admiral Yamamoto was the Commander in Chief of the Combined Japanese Fleet, the architect of the attack on
Pearl Harbor Pearl Harbor is an American lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. It was often visited by the naval fleet of the United States, before it was acquired from the Hawaiian Kingdom by the U.S. with the signing of the Reci ...
. However, the message said that the trip might be postponed due to weather, so confirmation was needed. This came when another Army Air/Ground signal was intercepted by 51 Wireless Section in Coomalie Creek near Darwin. This intercept was sent to Central Bureau at 21 Henry Street, Ascot, in Brisbane where it was decrypted and forwarded to FRUMEL where it was reportedly translated by a U.S. Navy linguist.Dufty p. 222 Although Central Bureau may have decrypted the message, the interception of his flight was based on decrypts of Japanese naval messages by FRUPAC/Station HYPO in Hawaii, FRUMEL, OP-20-G in Washington and Station AL on Guadalcanal. Major Lasswell USMC in Hawaii decrypted the Japanese Naval message first and Captain Layton (Pacific Fleet Intelligence in Hawaii) gave it to Admiral Nimitz who authorized a shootdown attempt after determining from ComNavAirSoPac that it could be done with by one of his Army Air Corp units on Guadalcanal. Operation Vengeance was carried out on April 18 and resulted in the shooting down of Yamamoto's "Betty" bomber by P-38s from Henderson Field, Guadalcanal.


The Sio Box

Central Bureau did not break any high level Japanese Army codes until mid-1943 success with the Water Transport Code. In January 1944, one main line Japanese Army code was broken with help from a buried trunk found at Sio,
New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...
, left by retreating Japanese Army troops of the 20th Division. The Bureau spent a day drying the damp pages, and the flood of decoded messages (2000 per day) that ensued meant that the Bureau had to ask the US Navy for assistance with translations. FRUMEL sent translators from Melbourne who had experience with the additional vocabulary and jargon associated with the larger JN-25 code. The Japanese thought that the code books had been destroyed and therefore did not issue a code change. Central Bureau's decryption of the mainline Army code, combined with traffic analysis helped the Allies avoid Japanese strongpoints during the Admiralty Islands campaign, the Allied capture of a group of islands to the north-west of Rabaul. In early April 1944, the Japanese changed their mainline code, suspecting correctly that the old codebooks had been compromised. This meant all mainline Japanese army traffic became unreadable to the Allies overnight. In April and May, Central Bureau, together with analysts from FRUMEL and FRUPAC, was involved in the detection of the Take Ichi convoy, which was intending to reinforce Japanese positions in New Guinea and the Philippines. US submarines attacked the convoy, sinking a number of transports and killing over 4000 soldiers In May 1944, following the Allied invasion of Hollandia in Operation Reckless, Central Bureau moved to Hollandia. In October they moved to Leyte and at the end of the war they were based in San Miguel on Luzon. After the war, they were transferred to Tokyo.


End of the war

On August 14, Emperor Hirohito sent a message through Swiss diplomats that Japan would capitulate under the terms of the
Potsdam Declaration The Potsdam Declaration, or the Proclamation Defining Terms for Japanese Surrender, was a statement that called for the surrender of all Japanese armed forces during World War II. On July 26, 1945, United States President Harry S. Truman, ...
. On the morning of August 15, MacArthur was notified of the emperor's offer of surrender. However, at this point it was still just an offer. MacArthur and General Akin summoned the Central Bureau Australian army officer Major Stan "Pappy" Clark to Manila to make contact with the Japanese. After trying to contact Radio Tokyo and various Japanese army frequencies Clark was finally able to make contact with a Japanese diplomatic station in
Singapore Singapore, officially the Republic of Singapore, is an island country and city-state in Southeast Asia. The country's territory comprises one main island, 63 satellite islands and islets, and one outlying islet. It is about one degree ...
. Following this, a secret Japanese delegation was organised to travel to Manila to meet MacArthur. Akin offered Clark a commission in the US Army to come to Japan, but Clark refused, saying "I've had enough. I want to go home". Central Bureau continued to intercept Japanese communications in the days following the end of the war, providing information on how Japanese forces were reacting to the surrender. Other intercepts regarded information on the condition and treatment of Allied prisoners-of-war. Dufty claims that although these intercepts were "clear evidence" that prisoners had been mistreated, they could never be used in a war crimes trial without jeopardising Ultra's secrets.


See also

* Far East Combined Bureau * National HRO - radio receiver used by the signals units in New Guinea * No 1 Canadian Special Wireless Group - Canadian unit sent to Australia during 1944. Performed duties similar to the RAAF Special Wireless units


Notes


References


Bibliography

* * *


Further reading

* * * * * * *{{cite book , last = Pyle , first = Nell , year = 2006 , title = The ultra experience : service with the Central Bureau Intelligence Corps / told by Doug Pyle and written by Nell Pyle , publisher = Australian Military History Publications , location = Lotus, NSW , isbn = 1-876-43935-1 Military history of Australia during World War II Australian intelligence agencies History of cryptography Signals intelligence agencies of World War II Military communications of Australia