The alarm in Western Australia

On 6 March 1944 the American submarine Haddo, patrolling the Lombok Strait between Bali and Lombok, picked up radar echoes from at least two large ships. She could not get a sight of them. Her commanding officer, Lieutenant Commander Chester Nimitz Jr – son of Admiral Chester Nimitz, commander of the Pacific Fleet – hesitated for a long time over whether to report so uncertain a contact. In the end he decided that it was better to raise a false alarm than to allow the base he sailed from to be taken by surprise. Years later he wrote that a single slogan kept ringing in his head: “Remember Pearl Harbor”.

That report set off an alarm in Western Australia that lasted several days. For several days the Allied commands and the Australian government reckoned with the possibility that the Japanese fleet was crossing the Indian Ocean to bombard Perth and its port, Fremantle, or to strike them with carrier aircraft. Six RAAF squadrons flew to Western Australia, the port was closed, submarines put to sea, and on 10 March the sirens wailed over Perth. There was no Japanese fleet. On 20 March the threat was judged to have passed, and the reinforcements returned to their bases.

War chronologies combine both ends of this story in a single entry under 6 March – rightly, since that was the day of the report that started it all. The alert itself, however, was declared only on 8 March, after a meeting of the Australian chiefs of staff, and the ships Haddo had detected were not heading for Australia at all.

A port at the end of the world

Throughout the war Fremantle was one of Australia’s most important ports. From 1939 convoys bound across the Indian Ocean for the Middle East and Europe assembled there. In the spring of 1942, after the fall of the Dutch East Indies, American submarines that had lost their bases in the Philippines and Java moved to Fremantle. The port became the US submarine force’s second base after Pearl Harbor; Dutch boats also operated from it, and British ones from mid-1944. According to Australian studies, 154 submarines sailed from Fremantle on 341 war patrols during the war. From here boats set out for the South China Sea and the waters of Indonesia to wage the American submarine war of early 1944.

Perth and Fremantle, however, lay thousands of kilometres from the rest of populated Australia, and their inhabitants felt defenceless. The fear was greatest in March 1942, when the Japanese were occupying Java and their aircraft were bombing Darwin and towns in the north of the state such as Broome and Wyndham. No attack on the south-west ever came, but the anxiety remained. In March 1943 Prime Minister John Curtin wrote to Churchill and Roosevelt that the port was exposed to naval bombardment and carrier air raids.

At the beginning of 1944 the defences of the Perth–Fremantle area were weaker than two years earlier. The anti-aircraft guns and coastal batteries were manned largely by the Volunteer Defence Corps – men who held civilian jobs and took their places at the guns only when called out. In the event of an attack, command would pass to the Australian III Corps of Lieutenant General Henry Gordon Bennett – the same man who had escaped from Singapore as it surrendered in February 1942. Air power consisted of three RAAF squadrons: a fighter squadron flying Boomerangs, a patrol squadron with Beauforts and a squadron of Vultee Vengeance dive bombers. American Catalina flying boats of the US Navy’s Patrol Wing 10 also patrolled over the Indian Ocean.

The Japanese fleet at Singapore

Anxiety had been growing since February. After the American strikes on the Marshall Islands, the commander of the Combined Fleet, Admiral Mineichi Koga, withdrew his main forces from Truk – at the last moment, before the American carrier raid of 17–18 February. Some of the ships went to the Palau Islands and some further west, to Singapore and to the anchorage off the Lingga Islands south of it. The Japanese had simple reasons: Singapore lay close to the oilfields of Sumatra and Borneo, so the ships did not have to wait for tankers, which were increasingly falling victim to American submarines, while local dockyards and calm waters allowed repairs and training before the decisive clash in the Pacific.

The Allies saw it differently. A strong naval force at Singapore stood at the gates of the Indian Ocean, and the memory of Nagumo’s raid of April 1942, when Japanese carriers bombed Colombo and Trincomalee and sank the British carrier Hermes, was still fresh. The British reinforced Admiral James Somerville’s Eastern Fleet with cruisers from the Atlantic and the Mediterranean; the Americans sent several warships to the Indian Ocean and more submarines to Fremantle to hunt the Japanese fleet in South-East Asian waters. Most of these, however, arrived only after mid-March; 16 boats were on hand.

The headquarters of General Douglas MacArthur, commander of the South-West Pacific Area, judged in February that the Combined Fleet might strike at Fremantle – if only to draw Allied forces away from the offensives being prepared in New Guinea and the Bismarck Archipelago. MacArthur nonetheless sent no additional forces west, believing that ships could be stopped by land-based air power. On 28 February he instructed the commander of the Allied air forces, General George Kenney, to be ready to move 60 heavy bombers to Western Australia within twenty-four hours, and three fighter squadrons for the defence of Perth.

On 4 March Curtin cabled Churchill to ask how the British assessed the risk of Japanese raids in the Indian Ocean. His cable crossed with a message Winston Churchill had sent the day before: the Japanese might raid Allied shipping, but “it is not thought that any serious danger could arise to India or Western Australia”, since the Japanese fleet would rather husband its ships for later stages of the war. Even so, the commands in Perth raised their state of readiness. From 4 March the volunteers manning the anti-aircraft and coastal guns had to report to their posts within six hours rather than, as before, within twenty-four. At Cunderdin airfield, north-east of Perth, bombs were stockpiled for the heavy bombers that might fly in as reinforcements.

Cruisers on the Aden–Fremantle route

The Japanese had no intention of sending their main forces into the Indian Ocean. They did, however, decide to send a small force there – the first raid by Japanese surface warships in those waters since the spring of 1942. At the end of February the commander of the Southwest Area Fleet, Vice Admiral Shirō Takasu, ordered three heavy cruisers – Aoba, Chikuma and Tone – to attack shipping on the route from Aden to Fremantle. They were commanded by Rear Admiral Naomasa Sakonju. The ships left the Lingga anchorage on 27 February, and on 1 March the light cruisers Kinu and Ōi, with destroyers, escorted them through the Sunda Strait. According to the findings of a post-war trial, Takasu ordered that captured seamen be killed, except for radio operators and others who might have valuable information.

The Allies knew nothing of this force. Their cryptanalysts did, however, read that on 4 March another force – two battleships, a carrier and destroyers – had left Singapore heading east towards Surabaya. Rear Admiral Ralph W. Christie, commander of Allied submarines at Fremantle, concluded that it might turn into the Indian Ocean and strike at Perth. He therefore sent Haddo to keep watch in the Lombok Strait. The echoes Nimitz Jr saw on his screen on 6 March most probably came from Kinu and Ōi, which were waiting near the straits to escort the heavy cruisers back.

The alert

On 8 March the Australian Chiefs of Staff Committee warned the government that a Japanese force might have entered the Indian Ocean and might strike at Perth and Fremantle during the full-moon period, around 9 March. From Haddo’s report, the phase of the moon and the assumed speed of the Japanese ships, the staff officers calculated that the most likely time was the early hours of 11 March, and the whole period of danger from the night of 9–10 March to the morning of 14 March. The same day Somerville ordered all Allied ships in the central Indian Ocean, between 80 and 100 degrees east, to divert south or west.

All defensive positions were manned. Five serviceable American submarines put to sea from Fremantle to lie in wait on the expected force’s route, and two Dutch boats took up positions off Rottnest Island opposite the port. Sailors on leave were recalled by radio. The port was closed, ships were dispersed to nearby anchorages, and two American submarine tenders sailed for Albany on the south coast. III Corps units were placed at six hours’ notice, exercises were cancelled, and the coastal batteries on Rottnest were manned. On 10 March the Australian light cruiser Adelaide and the British heavy cruiser Sussex anchored in the Fremantle roads among the dispersed ships to protect them with their anti-aircraft fire.

Six squadrons to the west

The air forces required the greatest effort. At a meeting in Brisbane on 8 March Kenney instructed Air Vice-Marshal William Bostock, head of RAAF Command, to take personal charge of the air defence of Western Australia. That same day Bostock ordered six RAAF squadrons to move west. Two Spitfire fighter squadrons, Nos. 452 and 457, were to fly from the Darwin area to Perth. No. 31 Squadron, flying Beaufighters, and the Dutch No. 18 Squadron with B-25 Mitchell bombers went to the “Potshot” field airstrip on Exmouth Gulf in the north-west of the state, to be covered by the Dutch No. 120 Squadron, flying Kittyhawk fighters, which came all the way from Canberra. Other units were brought into Darwin to replace the Spitfires, and Kenney recalled the American 380th Bombardment Group, equipped with heavy bombers, from New Guinea to the Darwin area, from where it could if necessary fly on to Geraldton or Cunderdin. Men, fuel and bombs were carried by American transport aircraft.

The move did not go smoothly. The Spitfires flew down the west coast in bad weather, staging through airfields without proper equipment or ground crews; one crashed at Carnarvon and another force-landed near Perth. The two squadrons reached Guildford near Perth only on 12 March, two days late. One pilot was killed when the Kittyhawks flew from Queensland to Darwin. On 10 March a severe cyclone struck Exmouth Gulf and flooded the airstrip, while stormy weather hampered patrols by the Catalinas and Beauforts and raised fears that the Japanese force was approaching under cover of cloud. The air commander in Western Australia, Air Commodore Raymond Brownell, considered in any case that the three squadrons at Exmouth Gulf were too far from Perth to help him; Bostock wanted them there because he also reckoned with an attack on Darwin.

On the afternoon of 10 March the radar station at Geraldton several times detected something its operators took to be an unidentified aircraft. On Brownell’s advice General Bennett declared an air-raid alert for Perth and Fremantle. The sirens wailed, the anti-aircraft defences manned their positions, fighters were brought to readiness, and the evacuation of patients from hospitals began. No raid came, and the alert was soon called off. The authorities explained nothing until the following day, when the state minister responsible for civil defence, Alexander Panton, said only that the sirens had been sounded for good reasons and that it had not been a joke. The city was alive with rumours of a raid, even of an invasion.

On 11 March one of the submarines reported signals from a Japanese ship’s radar – and this too turned out to be a false alarm. Air patrols in improving weather found nothing. On 12 March most units were stood down, on 13 March the garrison returned to normal duties, and the submarine tenders came back to Fremantle. On 20 March Kenney informed Bostock that the danger had passed and ordered the squadrons sent to Western Australia to return to their bases – this is the return of forces on 20 March recorded in war chronologies.

The crime aboard Tone

The only ship the Japanese raiders came across was the British steamer Behar (about 6,100 tons), sailing from Fremantle to Colombo on her way to Britain. On the morning of 9 March, roughly halfway between Australia and Ceylon, she was sighted by Tone. Her master, Captain Maurice Symons, ordered a raider-attack signal to be sent; the cruiser opened fire, killing three of the crew, and Behar soon sank. Tone picked up 104 or 108 survivors, according to different sources – seamen and passengers, among them two women. Sakonju, fearing that the signal had given his force away, broke off the raid that same day. The cruisers returned through the Sunda Strait in mid-March. The Allies learned of Behar’s loss only on 17 March, when a ship that had picked up her signal put into Fremantle.

Sakonju reprimanded Tone’s captain, Captain Haruo Mayuzumi, for taking prisoners and ordered them killed. Mayuzumi, a Christian, asked for them to be put ashore, and his executive officer, Commander Junsuke Mii, also opposed the killing; Sakonju refused. When the cruisers put into Tanjung Priok, the port of Batavia, on 15 March, a group of between a dozen and a few dozen people – the master, the senior officers and both women – was transferred to Aoba and put ashore; they survived the war in prison camps. On the night of 18 March, after leaving port for Singapore, Tone‘s officers murdered the remaining prisoners by beheading them. The number of victims given in studies ranges from 65 to more than 100; the figures most often cited are 72 or 89. After the war the British tried those responsible in Hong Kong. Sakonju was sentenced to death and executed on 21 January 1948; Mayuzumi received seven years’ imprisonment. Takasu did not live to stand trial, dying of illness in September 1944.

A false alarm and its place in the war

By the spring of 1944 the threat to Australia was essentially a thing of the past: the initiative in the Pacific lay with the Allies, and Japan was saving its ships for the great battle it expected in the central Pacific. The March alarm nonetheless showed how much the Australian commands and government feared a repeat of 1942 – and how little it took to set them off: a single unconfirmed radar echo near the Lombok Strait. During March the Allies established that the ships at Singapore were undergoing repairs and training and that the Japanese were planning no major operations in the Indian Ocean.

The commanders concluded that the exercise had its good side. Christie believed that the military and civilians in Western Australia had grown complacent before the alarm. The Australian and American air forces had tested how quickly they could move squadrons across the whole continent, and the Volunteer Defence Corps had shown that it could be mobilised within a few hours. On 13 March The West Australian wrote that the alarm had reminded the population of the threat of “hit-and-run” raids, but sharply criticised the authorities’ silence. The government explained why the west had been reinforced and the sirens sounded in March 1944 only on 17 August 1945, two days after Japan’s surrender.

Sakonju’s raid was the last operation by Axis surface warships against shipping, and Behar was the last Allied merchant ship sunk by a surface raider. Militarily it achieved almost nothing: Somerville cancelled the rerouting orders as early as mid-March. Admiral Koga was killed on 31 March 1944, when his aircraft disappeared in a storm on the way from Palau to the Philippines, and the ships assembled near Singapore sailed out in June for the great Battle of the Philippine Sea. Until the end of the war Fremantle remained one of the main bases of the Allied submarine fleet, from which boats set out against the Japanese shipping lanes. No attack on Perth ever came.