‘Lay in wait and then go around the flank. Lure them. Harass them and exhaust them by ceaseless activity. Finally…open the offensive…the enemy must never be allowed to escape’
—Major-General Horii Tomitaro to his troops on the eve of the Japanese invasion of Papua
Allied commanders were still dismissing the possibility of an overland invasion when the Japanese launched one. On 10 August the land invasion of Papua—Operation Order A-10 from 17th Army HQ in Davao, the Philippines—began. Major-General Horii received his instructions that day in Rabaul, and issued the Nankai Shitai order for the invasion of Papua and the capture of Port Moresby. His 10,000 troops—Shimada and Yamasaki among them—prepared to board the transports, but the US attack on the Solomons delayed their departure until 17 August.
Horii personally had grave doubts about the enterprise. He had done his own arithmetic, and calculated that securing his daily three-ton supply of food and ammunition would require 230 carriers a day to the front line. The twenty-day round trip from Buna to the end of the Kokoda Track at Owers’ Corner would demand 4600 carriers; if the front line were extended to Port Moresby, an impossible 32,000 carriers would be needed.1 The hope, by that stage, of course, was that Port Moresby would yield up their needs; and there was the expectation of ‘Churchill supplies’ scavenged off the local tribes and abandoned enemy camps. Each man received a two-week supply of rice.
The Japanese commander even warned Army HQ in Tokyo about the logistical problem; it made the attack on Port Moresby extremely difficult, if not impossible, Horii is reported as having said. ‘He was a very gracious and strong back-boned man,’ remarked Nishimura Kokichi. ‘And I admired him for complaining to Tokyo.’
In fact, in July Horii told Tokyo that 20,000 Allied troops were stationed in Port Moresby. According to Lieutenant-Colonel Tanaka Kengoro:‘He was not confident of victory despite the atmosphere of success after previous victories in the war.’2 Horii perhaps confided in his most trusted officers, but said nothing to his troops, of course, who were itching to depart and brimming with self-confidence.
Horii’s orders offer a fascinating insight into the Imperial Army’s preparation for battle. The coming battle would be fought ‘in an extensive jungle’, he said, ‘in sparsely settled, uncivilised country, the roads of which are very poor’. The Australians numbered at least 4000 (the figure, attributed to Australian prisoners captured at Kokoda, refers to supply troops at Port Moresby). In fact there were 350 Australians at Isurava, and 1200 marching over the mountains.
Of the Australians’ fighting quality, Horii wrote: ‘In comparison with the American infantry, the fighting spirit of the Australian infantry is strong. In the Kokoda and Rabaul battles, winding roads…and natural objects were ably utilised. Their use of automatic small arms at close range, their sniping and grenade throwing were good.’ The Shitai must ‘advance unexpectedly quickly’ to avoid enemy impediments such as destroyed bridges and defiles. ‘It is of vital importance not to allow the enemy any time…Where there are no bridges, swim across rivers…’
Before contact with the enemy, his battalions would ‘take advantage of the natural features of the land’. It was the smartest advice Horii gave. He elaborated: ‘One unit will attack from the front, while the main force will venture a bold, resolute and prompt flanking envelopment and charge the enemy’s rear flank…a frontal, headlong and reckless advance…will cause our forces great losses.’3
Most of Horii’s troops had not had jungle combat experience, contrary to the widely held belief in Australia that they were the greatest jungle fighters in the world. They were certainly highly experienced in warfare, but none of the 144th Regiment—his core infantry—had fought in mountainous jungle like this. ‘We had never experienced combat in jungle,’ said Shimada.4 On the other hand, they had invaded Guam and Rabaul, albeit with relatively little resistance, and had spent months in New Britain, training extensively in similar country. Morale building and jungle exercises were a daily regimen.*
The terrain would not dissuade them from deploying the night charge, as Horii explained. He gave his troops last-minute, step-by-step instructions in night attacks:
- After flanking approach by crawling.
- Attract the enemy with smoke, firing or shouting from the front, then charge from a different direction.
- If nightfall is 20 or 30 min off, utilise the night for the charge.
- Utilising rain and fog charge when the enemy is off-guard.
- Charge when the enemy’s attention is diverted by bombing…
- Charge suddenly from positions which the enemy believes to be unapproachable, such as cliffs, rivers, streams…and jungles.
The Imperial Army were warned, ‘not to allow overzealousness to cause grouping together at vital points’ during night charges. ‘Supply,’ Horii added briefly, ‘will be difficult.’5
The tactical imperative of surprise and encirclement was drummed into every man: ‘Never engage the enemy in combat without having concealment,’ instructed one soldier’s notebooks (later found on a Japanese corpse). Horii urged his troops: ‘Lay in wait and then go around the flank. Lure them. Harass them and exhaust them by ceaseless activity. Finally, when they are completely exhausted, open the offensive…You must fire with accuracy from cover and the enemy must never be allowed to escape.’6
At 9.20 a.m. on 17 August the Nankai Shitai paraded at Rabaul Harbour, bowed twice in the direction of the Imperial Palace in Tokyo, and marched aboard the 5960-ton Ryoyo Maru transport and other smaller vessels. The convoy left Rabaul at 6.00 p.m. bound for the Papuan beachhead.
‘The military operation for the occupation of Port Moresby’ had begun, wrote the exhilarated Warrant Officer Sadahiro. ‘After seven months’ preparation and training, at last the time has come to rise and strike dauntlessly with the iron maul.’7 The troops, however, experienced a very rough crossing. Throughout the night the weather worsened; the ships heaved on a gathering swell. A horse was washed overboard. Lieutenant Horibe stood on the deck as dawn approached, and the wind and rain howled around him: ‘The waves started to roar,’ he wrote, but the weather saved them from air attacks.
The grumbling Lieutenant Noda complained that it was ‘unspeakably hot and humid. If this goes on for another day I shall be ill.’ Later he whinged, ‘The rain came down and the wind rose, and having spent my time on deck I know I shall catch a cold.’8
Allied aircraft and warships offered no resistance—they were occupied in Guadalcanal—and the Nankai Shitai were allowed another unchallenged passage across the Solomon Sea.9 Indeed, the beachhead was well supplied throughout August, with the Japanese completing five safe trips between Rabaul and New Guinea that month. They delivered tons of rice, arms, medical stores and ammunition to the beachhead and for transfer to Kokoda. The invading force was, at this stage, properly fed, fit, and, with two weeks’ rations per man, confident of a swift descent on Port Moresby.
The first barges of the Kusunose Butai landed at Buna at dawn, 18 August, in motor-propelled mobile landing craft, each holding 50 men. The trip from ship to shore took twenty minutes. All day, and the next, the barges ran ashore at Buna. The scene resembled the arrival of a colonising power: two battalions of the 144th Regiment—about 1600 troops; the full complement of the 55 Mountain Artillery and cavalry regiments; several companies of the Sasebo 5SNLP and support units; 700 Rabaul natives; and 170 horses.
Within days several more battalions, of the Yazawa 41st Infantry Regiment and other units, as well as another 175 Rabaul natives and 230 horses, came ashore.10 By 22 August about 6000 Japanese combat troops, of a total force of 10,000—including six infantry battalions and one mountain gun unit at part-strength—had landed, or were advancing to Kokoda. That did not include Yokoyama’s 2000 troops then at Kokoda–Deniki.With reinforcements the total would later exceed 13,000.
The combat troops set off immediately to join Yokoyama’s men. Each soldier received a fifteen-day ration, consisting of about thirty pounds of rice, miso (bean paste), shoyu sauce in powdered form and salt, according to Yamada Kuzuo, a first class private. His basic kit consisted of a rifle, 60 rounds, a spare uniform, a water bottle, two hand-grenades, a steel helmet and a camouflage net. Extra food rations and supplies made the total load as heavy as 50 pounds, and sometimes at lot more.
The diary of Watanabe Fukuichi, 26, offers a snapshot of a typical Japanese junior officer. He was Second Lieutenant Watanabe, a primary school teacher in civilian life, and now a machine-gunner in the Koiwai Battalion, Yazawa Butai, (41st Infantry Regiment). He was five feet, two inches tall. His company had 110 men, twenty per platoon. All officers wore their swords; Watanabe’s sword, at two feet, six inches long, was almost half his height. He also carried a six-chamber revolver, a map case, a compass, a bottle of creosote and ten days’ supply of ‘anti-malaria medicine’.An orderly carried his rations.
Each company had two heavy machine-guns (Jukis) with a crew of eight men each.There were four boxes of ammunition, each with 600 rounds (twenty brass strips of 30 rounds). During the march these were packed into canvas bags, and each man carried a number of bags, in addition to normal kit, depending on his weight.
Watanabe complained that his Juki often jammed and required a complete overhaul. Being a heavy machine-gun, it was particularly awkward to use. The firing rate, he noted, was twenty rounds every four or five seconds.
The riflemen had old Meiji 38s. Only half the troops had hand grenades, due to a shortage. These were fragmentation grenades, with a four to five second fuse. To ignite it, ‘the safety pin was removed with the teeth, then the grenade tapped sharply on something hard, and thrown on the count of three’. One knew they were live by a hissing sound.
Soldiers usually wore jungle-green uniforms (though some wore khaki), and all held their trousers up with the 1000-stitch belt (the Senninbari Haramaki) presented by family or friends before their departure. On his feet Watanabe wore hobnailed boots, and rubber-soled shoes during landing (others had webbed-toed boots, which were light and offered better grip).A string loin cloth (the Fundoshi) completed Watanabe’s attire.*
Watanabe and other officers would probably have seen the latest secret intelligence assessment of the enemy that came in just before he set off. It warned:‘The Australian soldier has a greater fighting spirit than the English, American or Filipino.’11