Operation Dayton

'Dayton' was the Australian recapture of the area of North-East New Guinea, including Madang, on the coast of North-East New Guinea by elements of Major General Allan J. Boase’s 11th Division as the culmination of the Huon peninsula and Finisterre range campaigns which had followed the 'Postern' seizure of Salamaua and Lae (22 September 1943/26 April 1944).

By the end of March 1944, the US 'Flintlock' and 'Catchpole' seizures of the Marshall islands and the encirclement of the Japanese bastion at Rabaul on New Britain with operations such as 'Appease', 'Backhander' and 'Brewer' had spurred the Japanese to fresh endeavours as they sought to strengthen their contracted defensive zone.

In February, Lieutenant General Takeshi Takashina’s 29th Division and some six infantry battalions were despatched from Manchukuo to the Mariana islands group, and Lieutenant General Tsunenorio Kayanomiya’s (from 6 April Lieutenant General Yoshitsugu Saito’s) 43rd Division in Japan was readied to follow them as soon as possible. Garrison units were sent to the Bonin islands group, where they eventually came under the control of Lieutenant General Tadamichi Kuribayashi’s 109th Division being formed there for the defence of this island group. In anticipation of an early attack on the Palau islands group, one regiment of Lieutenant General Genzo Yanagida’s 33rd Division was sent there pending the arrival of Lieutenant General Masao Baba’s 4th Division.

At a time early in March the headquarters of Lieutenant General Hideyoshi Obata’s 31st Army was created on Saipan in the Mariana islands group to exercise control, under the overall direction of Admiral Mineichi Koga’s (from 3 May Admiral Soemu Toyoda’s) Combined Fleet, of all army units in the islands of the central Pacific. Its main line of defence was that part of the new perimeter running from the Bonin islands group in the north-east through the Mariana islands group, Ponape and Truk in the Caroline islands group, to the Palau islands in the south-west, where it abutted the zone of responsibility of General Korechika Anami’s 2nd Area Army in western New Guinea.

The backbone of the defence of the islands was to be land-based aircraft: Vice Admiral Chuichi Nagumo’s new 14th Air Fleet, formed from the remnants of Vice Admiral Jinichi Kusaka’s 11th Air Fleet, was being created as quickly as it could be provided with new aircraft and freshly trained aircrew.

At the insistence of the Japanese army, supreme command in the Central Pacific area was allocated to the Japanese navy, and on 4 April the Central Pacific Area Fleet was formed under Nagumo’s command with its headquarters on Saipan, but this new command was a fleet only in name. It comprised Vice Admiral Chuichi Hara’s 4th Fleet, now reduced to a collection of miscellaneous small craft, the 14th Air Fleet and the 31st Army. Operational and tactical command of the army formations in the field remained the responsibility of the army.

Equally radical changes were made farther to the south. Recognising that practical communications between General Hitoshi Imamura’s 8th Area Army on New Britain with the Japanese forces on New Guinea had been terminally severed by the Allied capture of the Admiralty islands in 'Brewer', Imperial General Headquarters in mid-March transferred Lieutenant General Hatazo Adachi’s 18th Army and its supporting air formation, Lieutenant General Kumaichi Teramoto’s 4th Air Army, to the control of Anami’s new 2nd Area Army on New Guinea, leaving the 8th Area Army with Lieutenant General Harukichi Hyakutake’s 17th Army to hold Bougainville, New Britain and New Ireland as best it could.

In order to bring into its zone the 18th Army, which was currently reorganising at Madang and Wewak after its costly retreat to the west along the northern coast of New Guinea from Lae and Salamaua, the 2nd Area Army's boundary was shifted east to 147° E. At about the same time Lieutenant General Yoshio Ishii’s 32nd Division and Lieutenant General Shunkichi Ikeda’s 35th Division were ordered south from China to strengthen the 2nd Area Army. The two divisions were due to arrive in Halmahera and western New Guinea respectively at the end of April, but it was now realised that reinforcement of the island garrisons would achieve nothing more than a delay in the US advance. As long as the Allies had air superiority and control of sea communications they could always bring overpowering strength to bear when and where they chose.

Koga remained convinced that, sooner or later, the forces of his Combined Fleet would have to meet the Pacific Fleet in what the Japanese wilfully believed would be the 'decisive battle' restoring naval superiority to the Japanese empire, and in August 1943 he had prepared plans for concentrating the Japanese fleet in readiness to engage the US Navy if it attempted to penetrate the defensive zone.

On 8 March he issued an order to the fleet detailing the 'Kon' general plan which was to be implemented in the event of an attempted invasion of the Caroline islands group or Mariana islands group. In February Koga transferred the main body of the Combined Fleet from Truk to Palau as a result of the threat posed to the former by US air attack, but at the end of March the activities of the US carriers forced him once again to abandon his fleet base.

On the last day of the month Koga and his staff left in two Kawanishi H8K 'Emily' four-engined flying boats for Davao in the Philippine islands group, where he intended to establish is new headquarters. Koga’s flying boat disappeared without trace, however, after the flying boat carrying his staff flew into a storm and crashed into the sea.

While the Japanese were trying to re-establish their defences, the US forces were preparing to destroy them. The strategy for the Pacific during 1944 had been clearly outlined by the US Joint Chiefs-of-Staff in a directive of 12 March. So far as New Guinea was concerned, MacArthur’s South-West Pacific Area forces were to advance from eastern New Guinea to Hollandia in a single bound bypassing the Japanese bases at Wewak and Hansa Bay. From Hollandia MacArthur was to move to the north-west along the coast seizing such bases as he believed necessary, and then, using the Halmahera islands group as a stepping stone, cross to the Philippines. Nimitz’s Central Pacific Area forces were to furnish support for the Hollandia landings and then thrust forward in two directions: to the north-west in the direction of Japan through the Mariana islands group, and to the west toward the Philippine islands group through the Palau islands group.

The Huon peninsula campaign (22 September 1943/1 March 1944) was a series of battles fought along the coast of North-East New Guinea in parallel with the battles of the Finisterre range campaign (19 September 1943/24 April 1944) fought farther inland, although on an approximately parallel axis to the north-west, along the line of the valleys of the south-eastern Markham river and north-western Ramu river. The two axes met at Bogadjim on 17 April 1944 and then pushed farther to the north-west to take Madang on 24 April and end at Alexishafen on 26 April. The two campaigns were therefore fought along axes to the north-east and south-west of the Huon peninsula, and were divided geographically by the south-eastern Saruwaged and north-western Finisterre mountain ranges.

The campaign formed the initial part of the great offensive which the Allies, most especially the USA and Australia, with New Zealand and Dutch support, launched in the Pacific late in 1943 and resulted in the Japanese being pushed north from Lae at the mouth of the Markham river to Sio on the north-east coast of North-East New Guinea over the course of a four-month period. The coastwise advance was characterised by a number of US and Australian amphibious landings, while the inland advance was undertaken largely by the Australians. Throughout the Huon peninsula campaign, the Allied forces had a major advantage through the industrial and technical edges which Allied industry had achieved over that of the Japanese by this stage of World War II, while the Japanese were severely hampered by a lack of supplies and reinforcements resulting from the very effective Allied interdiction efforts at sea and in the air.

The campaign proper was preceded by the 'Postern' amphibious landing of 4 September by troops of Major General George F. Wootten’s Australian 9th Division to the east of Lae on the south coast of the Huon peninsula’s eastern extremity in the area between Hopoi and the mouth of the Busu river, thereby cutting off the garrison of Lae. This was followed by an advance to the west along the coast toward Lae, where the force landed from the sea was to link with Major General George A. Vasey’s Australian 7th Division. This latter formation had been flown from Port Moresby into Tsili Tsili on the Watut river, down which it advanced to Nadzab on the Markham river, which had been taken on 5 September in the first successful US combat parachute assault, and the Australian formation then advanced 50 miles (80 km) down the Markham river toward Lae. Meanwhile, Australian and US forces mounted diversionary attacks around Salamaua on the south-east coast of the Huon Gulf.

Heavy rain and flooding slowed the progress of the 9th Division, which had to cross several rivers. The Japanese also organised strong defensive rearguards, so Lae was not taken until 16 September as the culmination of 'Postern', when men of the 7th Division entered the town via the river route from the north-west before men of the 9th Division advancing from the east, but the main body of the Japanese garrison escaped to the north.

With Lae is their hands at a time earlier than had been anticipated, the Allies acted swiftly to exploit their advantage. The first phase of the new campaign consisted of an amphibious landing by Allied troops north of Siki Cove near the confluence of the Siki river and south of the Song river on Scarlet beach. Located farther to the east on the peninsula from Lae, in strategic terms Finschhafen (occupied by the Japanese on 11 March 1942) was more significant than Lae in the minds of the Allied planners for its potential to support operations across the Vitiaz and Dampier Straits into New Britain and the main Japanese base around Rabaul. As a result of faulty intelligence, which underestimated the Japanese strength in the area, the assault force chosen by the Allied commanders consisted of only Brigadier W. J. V. Windeyer’s 20th Brigade of Wootten’s 9th Division. Meanwhile Vasey’s 7th Division was to advance to the north-west from Lae and Nadzab in a separate campaign, advancing through the Markham and Ramu river valleys toward the Finisterre range.

After the Japanese resistance at Lae had collapsed on 15 September 1943, MacArthur ordered that Finschhafen be seized as quickly as possible, and on 17 September he set the invasion date for just five days later. Rear Admiral Daniel E. Barbey’s VII Amphibious Force loaded supplies at Buna and assembled the invasion force off Lae on 21 September, where the Australian 20th Brigade was embarked. The force was sighted by a force of six Mitsubishi Ki-21 'Sally' twin-engined medium bombers escorted by Mitsubishi A6M Reisen 'Zero' single-engined fighters, but the Japanese bombs fell wide and several of the aircraft were downed by Allied fighters.

Barbey wished to deliver the landing in the dark to avoid the possibility of intervention by Japanese aircraft, and the Australians agreed to a landing just before dawn on 22 September. Confusion reigned, showing that Barbey’s force still had much to learn about night landings, and this was the first opposed amphibious landing that Australian forces had made since the landings on the Gallipoli peninsula in World War I. The Australian force was carried and landed by Task Force 76, with the fast transport Brooks, tank landing ships and infantry landing ships, and these landed the 20th Brigade on both sides of Finschhafen. Support was provided by the US destroyers Lamson, Mugford, Drayton and Flusser, and escort by the US destroyers Conyngham, Perkins, Smith, Reid, Mahan and Henley.

Major General Kurihanao Yamagata had redeployed 3,000 men of his 21st Independent Mixed Brigade to the south at Hanisch Harbour, facing Lae, leaving only 1,000 men in Finschhafen itself and a few hundred in the vicinity of the landing beaches to the north of the village. Yamagata was caught by surprise, and an attack by six Mitsubishi G4M 'Betty' twin-engined medium bombers escorted by 35 A6M fighters beaten off by Allied fighters and anti-aircraft fire after damaging one ship.

Navigational errors resulted in the troops being landed on the wrong beaches, with some of them coming ashore at Siki Cove and taking heavy fire from the Japanese defences in pillboxes and behind log obstacles. After reorganising on the beach, the Australians pushed inland. The Japanese put up stiff resistance around the high ground at Katika, but were eventually forced back, and by the end of the day, for 94 casualties, the Australians had secured a significant beach-head. Late in the day some 30 Japanese bombers, escorted by as many as 40 fighters, of the Wewak-based 4th Air Army were despatched to attack the Allied shipping around Finschhafen. Forewarned by the destroyer Reid, serving as an air picket and fighter controller in the Vitiaz Strait, the Allies were able to concentrate five squadrons of US fighter aircraft over the convoy and in the aerial battle that followed 39 Japanese aircraft were shot down and the raid turned back.

On 25 September the Japanese submarines I-177 and I-176 tried for the last time to supply Lae and Finschhafen. Three other submarines, Ro-100, Ro-104 and Ro-108, were deployed against the naval operation, the last sinking Henley on 3 October.

On the following day the Australians began their advance toward Finschhafen, about 5.6 miles (9 km) to the south of the landing, with the 2/15th Battalion leading the way to the Bumi river. The Japanese had established strong defences along the river’s southern bank, which the Australians attempted to outflank by sending a force to the west, though this involved a climb over steep terrain. Once they had located a suitable place to cross the river, the Australians began wading across but were engaged by a group of Japanese naval infantry on a high feature overlooking the river. Despite taking 94 casualties, the Australians were able to establish themselves to the south of the Bumi, and at that point the 2/13th Battalion began to advance on Finschhafen from the west. Meanwhile, the 2/15th Battalion attacked the left flank of the Japanese who had opposed their crossing. After advancing up the steep slope under fire, sometimes on their hands and knees, the 2/15th Battalion took the position at the bayonet point, killing 52 Japanese in close combat.

The continued advance to the south spread the Australians, and concerns that their western flank was exposed persuaded them to send the 2/17th Battalion along the Sattelberg track to deflect any Japanese thrusts from that area. At Jivevaneng, the battalion was stopped as the 80th Regiment launched a series of determined attacks as it tried to break through to the coast.

At this point, Australian fears of a Japanese counterattack grew, and they requested reinforcements from MacArthur, but the request was denied as MacArthur’s intelligence staff believed that there were only 350 Japanese in the vicinity. There were, in fact, already 5,000 Japanese around Sattelberg and Finschhafen, and throughout the early part of October this number grew to 12,000 as the Japanese began to prepare a major counterattack. The Australians did receive some reinforcement, in the shape of the 2/43rd Battalion, whose arrival meant that the 2/17th Battalion, deadlocked around Jivevaneng, could be freed for the advance on Finschhafen, thus enabling the entire 20th Brigade to concentrate on that objective.

After an attack across the Ilebbe Creek by the 2/13th Battalion, which cost the Australians 80 casualties on 1 October, the Japanese naval troops holding Finschhafen began to withdraw, and on 2 October Finschhafen fell to the Australians and the Japanese abandoned the Kakakog Ridge under heavy Australian artillery and air attacks. Once the 20th Brigade was established in Finschhafen, it linked with the militiamen of the 22nd Battalion, which had cleared the coastal area in the south of the peninsula, advancing from Lae over the mountains.

The Japanese from the Finschhafen area had meanwhile pulled back into the mountains around Sattelberg, a mountain which dominates the Huon peninsula and the straits to the east, and here Yamagata planned a counterattack. Allied air operations from the airfield at Finschhafen began on 4 October and, on the following day, the 2/17th Battalion was sent to Kumawa to maintain pressure on the retreating Japanese, and for the next couple of days minor clashes were fought before the Australian battalion established itself at Jivevaneng again on 7 October.

The Japanese had begun to plan a counterattack as the Australian advanced on Finschhafen. The main part of Lieutenant General Shigeru Katagiri’s 20th Division moved from Madang as the Japanese began to concentrate their forces around Sattelberg, where their main force arrived on 11 October. The Australians learned of the Japanese intentions by means of captured documents, and by mid-October 1943 Brigadier Bernard Evans’s 24th Brigade had been brought up to reinforce the 20th Brigade. The first wave of the Japanese counterattack fell on the 24th Brigade around Jivevaneng on 16 October, but was poorly co-ordinated and pushed back.

On the following day Japanese aircraft attacked Allied forces around Scarlet beach, and soon after this an attempted Japanese amphibious landing was all but destroyed at sea by the fire of Australian and US anti-aircraft guns and machine guns. Only a small number of Japanese managed to make it ashore amidst the devastating fire but, by the following day, all of them had been killed or wounded by Australian mopping-up operations.

The main part of the Japanese counterattack had penetrated the forward and thinly stretched Australian lines throughout the previous night. The Japanese exploited the gaps in the line between the 2/28th Battalion and 2/3rd Pioneer Battalion to launch an attack toward the coast with the objective of capturing the high ground 1.7 miles (2.7 km) to the west of Scarlet beach, and splitting the Australian forces at Katika.

The 24th Brigade responded to the Japanese penetration by withdrawing from Katika and the high ground to the north of Scarlet beach to strengthen the defences around the beach-head, and the 20th Brigade moved into position along the Siki Creek to block the Japanese advance toward Finschhafen. Despite the fact that it had yielded the high ground, the Australian resistance was strong, with field and anti-aircraft artillery engaging at ranges as short as 220 yards (200 m) and therefore over open sights. As result, the Japanese attack was diverted from Scarlet beach and channelled down Siki Creek. Even so, the Japanese did manage to break through to Siki Cove by 18 October, thereby driving a wedge between the 24th Brigade in the north and the 20th Brigade in the south. The Japanese also captured a considerable quantity of Allied supplies, including ammunition, weapons and rations, helping to replenish their own dwindling supplies.

During the night of 18/19 October, the Japanese cut the route that the Australians were using to supply the 2/17th Battalion at Jivevaneng and established a roadblock on the road linking Jivevaneng and Sattelberg. The 2/17th Battalion and a number of other Australian units, including most of the 2/3rd Pioneer Battalion and part of the 2/28th Battalion, were thus isolated behind the Japanese line. In order to keep them supplied, emergency air drops of ammunition were flown in by aircraft of No. 4 Squadron.

At this point the impetus of the Japanese attack began to wane. The strength of the Australian resistance had inflicted heavy losses and as a result the Japanese were unable to take advantage of the gains they had made. This allowed the Australians to begin their own counterthrust on 19 October. Following a heavy artillery preparation, the 2/28th Battalion retook Katika. The Australians received reinforcements on the next day, a squadron of Matilda infantry tanks of the 1st Tank Battalion arriving by landing craft at Langemak Bay amidst tight security aimed at keeping the arrival hidden from the Japanese. Accompanying the tanks was Brigadier David A. Whitehead’s 26th Brigade, whose arrival meant that the whole of the 9th Division was now committed. On 21 October the Japanese withdrew from Siki Cove, but the fighting around Katika lasted four more days as the Japanese attempted to retake it against fierce resistance from the 2/28th Battalion. Katagiri ordered his units to pull back to Sattelberg by 25 October after it had become clear that the counterattack had been defeated. The Japanese had suffered 1,500 casualties, including 679 men killed, while the Australians had lost 49 men killed and 179 wounded.

A mission established in the later part of the 19th century, Sattelberg is about 5 miles (8 km) inland and, as a result of its size and its height of 3,150 ft (960 m), its possession by a large Japanese force was a significant threat in the minds of the Australian commanders as it offered good observation of the coastal area and could serve as a base for the Japanese to disrupt the Australian lines of communication. Wootten therefore decided that its capture was imperative. The main approach to the mission lay along the road through Jivevaneng. Although the main thrust of the Japanese counterattack had been turned back by 25 October, possession of Jivevaneng was still in doubt and the 2/17th Battalion was currently fending off Japanese attacks. The 2/13th Battalion was therefore brought up, and the two battalions then began clearing operations, which had been completed by the night of 2/3 November, when the Japanese ceased their assault and withdrew from the area round the village. Follow-up actions on 6 November resulted in the destruction of the roadblock which the Japanese had established on the Sattelberg road to the east of Jivevaneng.

With the situation at Jivevaneng decided, the Australians started to press their advance to the west in the direction of Sattelberg. The force allocated the task was the recently arrived 26th Brigade with the support of nine of the 1st Tank Battalion’s Matilda infantry tanks. At the same time, Brigadier Cedric R. V. Edwards’s 4th Brigade, a militia unit detached from Major General Edward J. Milford’s 5th Division, was brought up to relieve the 26th Brigade of garrison duties around Finschhafen.

The tanks moved up to Jivevaneng under the cover of an artillery barrage designed to drown out their noise in an effort to keep their presence secret until the start of the advance. On 16 November the 2/48th Battalion, supported by the guns of the 2/12th Field Regiment and the machine guns of the 2/2nd Machine Gun Battalion, captured Green Ridge overlooking the track designated as the forming-up point for the advance on Sattelberg, which began on the following day.

The advance got off to a bad start as it was hampered in the inland area by the ruggedness of the terrain, comprising largely of thick jungle and steep razorback ridges. This severely constrained the ability of forces to manoeuvre, and Whitehead, the brigade commander, decided to switch to infiltration tactics. He sent columns of infantry, of no greater than company size, to advance along narrow fronts ahead of one or two tanks, with engineers in support to improve the track or deal with booby traps or mines. This allowed the 2/48th Battalion to advance up the main track as the 2/23rd and 2/24th Battalions protected its southern and northern flanks respectively. The Australians took none of their first-day objectives: the 2/48th Battalion was checked in front of Coconut Ridge by stubborn resistance after one of the tanks had been disabled and two others damaged. On the flanks, the 2/23rd and 2/24th Battalions came up against pillboxes and machine gun nests, suffering many casualties, and Coconut Ridge was not taken until the following day.

The advance then continued, and by 20 November the 2/48th Battalion had secured Steeple Tree Hill, the 2/23rd Battalion was advancing toward its southern portion from Kumawa and the 2/24th Battalion continued to strike to the north in the direction of the '2200' feature. Initially, this had just been conceived as a holding action to protect the 2/48th Battalion’s flank, but as a result of the slow progress on the main track, at this point Whitehead decided to change the effort of his brigade from a single central thrust to a double-pronged attack, with the 2/24th Battalion also attempting to break through to Sattelberg from the north.

To the north-east, closer to the coast, the establishment of Australian observation posts on key terrain overlooking the Japanese force’s main supply routes had by now started to affect the supply situation of the Japanese forces around Sattelberg as supply parties were ambushed while they attempted to bring up food and ammunition. The Australians were also short of supplies and, as a result, paused on 21 November as further supplies arrived, and then resumed their advance on the following day. The main thrust was aimed at the point at which the track jinked to the north. Here the 2/48th Battalion turned to the north-east, while the 2/23rd Battalion left the track and began advancing to the north-west in the direction of the '3200' feature to the west of Sattelberg. Coming up against increasingly steep terrain and very strong Japanese defences around the '2200' feature, the 2/24th Battalion tried unsuccessfully to bypass the position and strike toward Sattelberg.

To the north, the Japanese made another counterattack on 22 November, aiming to relieve the supply situation around Sattelberg and to recapture Finschhafen. The counterattack was blunted by the Australian position in depth round Pabu and, lacking the weight of the counterattack of October, was beaten back, with little effect on Australian operations around Sattelberg.

The Japanese fortress around Sattelberg was methodically reduced by a five-day Allied programme of intensive bombing to 23 November. On this day the Japanese also undertook a major close support effort as 44 of their aircraft attacked Australian positions round Jivevaneng. This did not change the situation around Sattelberg, however, as the Australians had now reached its southern slopes and on the following day began probing toward its summit. Throughout the day the Australians launched a number of attacks, but these were handled very severely by heavy defensive fire until a platoon fought its way almost to the top. With the Australians in possession of a decisive toehold just below the summit, the Japanese withdrew under the cover of darkness and during the morning of the following day the advance to the mission was completed.

Although the main Australian effort after the landing at Scarlet beach late in September had been the drive on Finschhafen, a secondary effort was made by men of the Papuan Infantry Battalion as their undertook reconnaissance in the area to the north of the main engagement area in the direction of Bonga and Gusika, and throughout the early part of October the 2/43rd Battalion also undertook patrols in the area. Intelligence gathered by these patrols and confirmed by air reconnaissance revealed that the Japanese were using the area’s tracks to supply the forces in the west at Sattelberg. The Australians established observation posts and, in concert with further reconnaissance, these indicated to the Australians that one hill, which they named 'Pabu' and was part of a larger feature dubbed 'Horace the Horse', was the key to the area. Its location placed it directly astride the main Japanese supply route, and its proximity to the Australian forward positions at North Hill meant that it was in range of Australian artillery and could therefore be occupied by a small force supported by indirect fire. In mid-October Evans, commander of the 24th Brigade, had ordered the withdrawal of Australian forces on 'Pabu', however, as he had sought to shorten Australian line to improve the defence of beach-head’s perimeter.

After the counterattack of October had been driven back, the Australians sought to regain the initiative. Evans was replaced by Brigadier S. H. W. C. Porter, and Wootten decided to establish a position in depth behind the Japanese forward line with a force established once again at 'Pabu'. On 19/20 November, three companies from the 2/32nd Battalion under the command of Major Bill Mollard occupied the position and started to attack the Japanese resupply parties moving through the area, inflicting heavy losses on these latter.

Meanwhile Adachi, commander of the 18th Army, ordered Katagiri to launch another counterattack. Despite the fact that the Japanese supply situation was now acute, with ammunition running low and men limited to one-third of their daily rations, the counterattack was scheduled for 23/24 November. However, the Australian occupation of 'Pabu' and the threat it posed to the Japanese supply route, forced the Japanese commander to bring his schedule forward and to divert some of the effort away from the recapture of Finschhafen and onto the Australians advancing toward Sattelberg in the south.

In an effort to retake 'Pabu' and the ground to the north of the Song river, a force comprising single battalions of the 79th Regiment and 238th Regiment advanced to the south along the coastal track from Bonga. From 22 November, the Japanese attacked the Australians round North Hill, which was held by the 2/43rd Battalion. This cut off the Australian forces on 'Pabu', which now comprised only two companies of the 2/32nd Battalion, and during the next three days these companies were attacked almost without break. On 25 November the Japanese assaults had been blunted and the Australians began to push reinforcements forward. The two remaining companies of the 2/32nd Battalion were sent forward on 26 November, supported by four Matilda tanks and artillery, to advance toward 'Pabu' and reinforce its garrison, which was under its heaviest attack since it had been occupied. The reinforcement reached 'Pabu' and in the process secured 'Pino Hill' to its south.

On the following day the Japanese ended their attack on the Australian right, and men of the 2/28th Battalion were then sent to the east to secure the position’s flanks. On 29 November, the 2/32nd Battalion was relieved by the 2/43rd Battalion, but during the exchange it was struck by a Japanese artillery bombardment which killed or wounded 25 men. During the 10 days for which the 2/32nd Battalion had held 'Pabu', Mollard’s force had endured repeated artillery and mortar fire as well as a host of infantry assaults, but with the assistance of effective artillery support had held its ground, and thereby helped blunt the force of the Japanese counterattack at a time when Australian forces were making only slow progress toward the Japanese fortress at Sattelberg. The casualties during the fighting around 'Pabu' were 195 Japanese and 25 Australians killed, and 51 Australians wounded.

With a the defeat of his second counterthrust and the loss of Sattelberg, Katagiri decided to fall back to the north. Here he intended to establish a defensive line in the Wareo area and wait for the Australians to follow up their victories with a further advance. By this time, Katagiri’s force was suffering from a shortage of men as a result of a lack of reinforcements, and his supply situation had still not been rectified.

Wootten wished strongly to regain the initiative and decided to resume the advance in the north with a view to securing the remainder of the Huon peninsula. The first stage of Wootten’s plan involved an advance to the north and securing a line along a ridge that extended between Gusika on the coast and Wareo 4.35 miles (7 km) inland. The plan was to involve two main drives: having secured Sattelberg, the 26th Brigade was to advance to Wareo on the left, and the 24th Brigade was to advance on the right up the coast to secure Gusika and two large water features about 2 miles (3.2 km) inland near the head of the Kalueng river, known collectively to the Australians as 'the Lakes'. A third, minor advance was entrusted to the 20th Brigade, which was to advance in the centre toward Nongora and the Christmas hills.

In the advance on the right, the 2/28th Battalion advanced on Bonga and, with armoured support, captured Gusika on 29 November. The battalion later crossed the Kalueng river and moved toward the lagoon farther to the north along the coast. The 2/43rd Battalion then advanced from 'Pabu' toward 'Horace’s Ears', where a Japanese stand checked the Australians, though only briefly. The 24th Brigade then continued to the east in the direction of 'the Lakes', where it was to assume responsibility for the central drive from the battalions of the 20th Brigade, which were to be rested for the next stage of the campaign.

In the centre, the 2/15th Battalion left Katika to take Nongora on 30 November. The unit advanced over broken country and, after crossing the Song river, the leading company was engaged by machine gun fire from a strong defensive position. This halted the company for a short time until the battalion’s other companies came up. Skirting the Japanese position, the battalion continued toward Nongora, where it halted short of the high ground and established a defensive position for the night. On the following morning, the Australians launched a costly and unsuccessful company-sized attack against the ridge, but after darkness the Japanese abandoned the position, allowing the 2/15th Battalion to occupy it and then clear Nongora on 2 December. After this, the battalion started to send out fighting patrols toward the Christmas Hills area in the west, and to the east toward the Lakes to make contact with the 24th Brigade.

The two brigades linked on 3 December, and the following day a composite force of the 2/32nd and 2/43rd Battalion took over the advance to the Christmas Hills, which were secured on 7 December after the Japanese had abandoned the position in the wake of a series of flanking moves by the Australians, an intense artillery and mortar bombardment, and a frontal assault.

On the left, meanwhile, the advance began on 28 November. Wareo is about 3.4 miles (5.5 km) distant from Sattelberg on the map, but as a result of the nature of the terrain, the actual distance to be travelled was estimated as being at least four times that figure. For the advancing Australian infantrymen, the burden was made even greater by the fact that heavy rain had turned the tracks into a muddy morass that could not be traversed by motor transport. Combined with the unavailability of New Guineans to serve as bearers, this meant that the Australians had to carry almost all of their own supplies on their backs. In an effort to keep the advance moving, the entire 2/24th Battalion was tasked with carrying supplies for the 2/23rd Battalion leading the advance from Sattelberg.

On 30 November, the 2/23rd Battalion reached the Song river and fought its way across this watercourse. On the following day, after sharp fighting in the course of a renewed counterattack by the Japanese, The Australian unit took Kuanko. To the north of the abandoned village, the Japanese had deployed in strength and launched a strong counterattack, which retook the vital high ground but was then checked by a heavy Australian artillery bombardment. At this stage, the 2/24th Battalion was released from its portage task and sent to the west for a flanking movement around the Japanese position, cutting the track between Kuanko and Wareo, and capturing Kwatingkoo and Peak Hill early on 7 December after the Japanese had pulled back. From here, it was only a short march to Wareo, which the Australians secured early on the next day.

The main Japanese strength then began to withdraw to the north in the direction of Sio, but sporadic fighting continued around Wareo over the following week as isolated Japanese pockets fought rearguard operations. The most significant action during this time took place on 11 December when the 2/24th Battalion attacked the '2200' feature to the north-east of Wareo, near the Christmas Hills, and killed 27 Japanese.

In the next phase of the campaign the Australian forces advanced along the coast toward Sio, about 50 miles (80 km) from Finschhafen. After the capture of Gusika, the responsibility for the first part of this advance was assumed by the infantry of Edgar’s 4th Brigade. The brigade arrived from Finschhafen, where it had been the garrison, and on 5 December its 22nd Battalion began the advance, crossing the Kalueng river. Lacking the experience of the units of the 2nd Australian Imperial Force, the brigade’s militia battalions advanced more cautiously than they might otherwise have done, and were supported by US rocket-equipped landing craft, which bombarded Japanese positions along the coast. At the same time the expansion of the airfield around Finschhafen and the establishment of a naval facility there enabled the Allies to use Consolidated PBY Catalina twin-engined flying boats and PT-boats to add further weight to the Allied attacks on Japanese resupply efforts.

The Australians encountered stiff resistance as the Japanese forces in this area fought to buy the time needed for the forces falling back from Wareo. Initially, the 22nd Battalion’s attack was turned back, but fire support from artillery and armour then helped overcome this opposition, and the advance continued with the 22nd and 29th/46th Battalions advancing in turns up the coast with the 37th/52nd Battalion moving on their left farther inland. The Australians reached Lakona on 14 December and, after finding the Japanese to be positioned in strength, the 22nd Battalion worked its way around the town, enveloping the Japanese defenders and pushing them back to the cliffs, where on 16 December tanks were used to launch the final attack. After this the 29th/46th Battalion took over the coastal advance to Fortification Point, which it reached alongside the 37th/52nd Battalion on 20 December, when it crossed the Masaweng river and moved onto the high ground to its north.

The 4th Brigade suffered 65 killed and 136 wounded on top of rising casualties from disease, and at this time was replaced by the 20th Brigade, with the 26th Brigade taking over the flank protection role inland. The advance then accelerated as Japanese morale began to crumble and organised resistance diminished. Large gains were made against only limited resistance, which often amounted to minor skirmishes against small groups of Japanese. Hubika fell on 22 December with no opposition, and Wandokai two days later. Blucher Point was reached on 28 December, where the 2/13th Battalion regained contact with the retreating Japanese and fought a sharp contact. Elsewhere, that same day, US forces landed farther to the west at Saidor in 'Michaelmas'.

This threat to their rear sealed the Japanese decision to drawn back from the area of Sio, and over the course of two weeks the Australians advanced swiftly along the coast, overcoming only occasion resistance as the Japanese continued to withdraw to the west in the direction of Madang as they attempted to avoid being cut off by the US force at Saidor. The 2/15th Battalion took over the advance on 31 December, reaching Nunzen on 1 January 1944. The Sanga river was crossed on 2 January, and on the following day the 2/17th Battalion reached Cape King William. More river crossings followed at the Sazomu and Mangu rivers as Kelanoa fell on 6 January. The Australians next crossed the Dallman and Buri rivers were forded as they rounded Scharnhorst Point on 9 January. After a final action at Nambariwa, the 2/17th Battalion reached Sio on 15 January.

The operations of the 9th Division during the Huon peninsula campaign were the largest by the Australian army to that point of the war, destroyed the Japanese offensive capabilities in the region, and enabled the Australians to gain control of maritime lines of communication and airfields which now furthered their ability to conduct offensive operations in North-East New Guinea and New Britain.

After the capture of Sio, on 21 January the 9th Division handed over to the 5th Division, which was a militia formation, and this was part of the wider Australian plan to make the veteran divisions of the 2nd AIF available for more intense operations elsewhere, most especially the Philippine islands group, while using the less experienced militia formations to undertake the lower-intensity operations required to mop up isolated pockets of Japanese resistance. In the event, inter-Allied political considerations precluded the 9th Division’s involvement in the Philippines campaign which started in October 1944, and it was subsequently employed for the 'Oboe' operations in Borneo during 1945.

Meanwhile, one of the 5th Division’s constituent units, Brigadier C. E. Cameron’s 8th Brigade, undertook clearing operations around Sio from January to March 1944, and also also advanced along the coast to link with the US forces around Saidor.

Located to the north of the Huon peninsula, Madang was a district capital of its part of the Mandated Territory of New Guinea, and in 1944 possessed a usable but largely undeveloped anchorage. The town had been bombed by the Japanese on 21 January 1942 as part of the preparations for their 'R' move against Rabaul two days later, but Madang was not itself occupied until 1 January 1943. The Japanese completed an airfield in February 1943, and began work on a road to Lae in April of the same year. This was intended to supply the forward Japanese forces in North-East New Guinea, which could not longer receive supplies by barge as a result of Allied air superiority.

Following the US 'Dexterity' seizure of Saidor and the collapse of the Japanese position in the Huon peninsula, Australian forces drove the Japanese rearguard out of the town on 24 April 1944.

During the Huon peninsula campaign, the 9th Division had suffered 1,082 battle casualties including 283 men killed in action and one missing. These casualties were relatively light in the wider context of the division’s involvement in the war as this formation had suffered more than twice that casualty rate during the fighting around El Alamein earlier in the war. Even so, there were a number of factors which combined to make the fighting on the Huon peninsula somewhat harder and certainly more morally exhausting than any in which the division had been involved before this time. These factors included the harsh terrain, the closeness of the combat, and the lack of hot food, water and motor transport. Disease was also another significant factor, and during the campaign as much as 85% of the division’s personnel were incapacitated by illness at some stage.

Nevertheless, the single most significant factor was the fighting quality of the Japanese soldier. In Australian minds, the Japanese soldier had a reputation for being a tough opponent who took no prisoners. Despite this perception, the Australians were bolstered by the confidence resulting from their superiority. Among the Japanese, on the other hand, the matériel edge which the Australians possessed and their relative abundance of ammunition, artillery and air support were the main psychological factor that governed their perceptions of the Australians. To counter this, Japanese commanders exhorted their troops to draw upon their spiritual superiority to achieve victory. In the end, although many of the significant actions of the campaign were infantry engagements which occurred far from the Australian base areas, a fact which limited their technical superiority, the Australians had a decisive edge with their combined arms tactics. Although preliminary air bombardment, particularly that which was employed around Sattelberg, proved largely ineffective in terms of its physical effects, it did serve to reduce Japanese morale and, used in combination with artillery bombardments which caused significant casualties, it severely disrupted the Japanese lines of communication, which were already stretched to their limits. Suffering from ammunition shortages that limited their fire support, the Japanese defenders were overwhelmed by Australian infantry that had a level of artillery support that was unprecedented for an Australian division in the Pacific, and who advanced in concert with tanks that they employed in a manner that exploited the element of surprise.

The Japanese losses were significantly higher, although exact numbers have not been established. About 12,500 Japanese soldiers were involved, and it is believed that about 5,500 of these were killed, though some sources suggest a higher toll, and as only 4,300 Japanese reached Sio at the end of the campaign, it is possible that the number of dead was closer to 8,000. The Japanese also lost large quantities of matériel: of the 26 pieces of field artillery which the Japanese deployed to the region, 18 were captured by the Australians, and the Japanese also lost 28 out of their 36 heavy machine guns.

At the start of the campaign, the Australian army had been the only ground formation engaged against the Japanese in the region. By the end, though, the involvement of US forces in the region had increased as the US Army took over responsibility for the main Allied effort from the Australians.

Elsewhere, the 7th Division’s advance in the Finisterre range campaign, fought in parallel with the Huon peninsula campaign, saw the capture of Shaggy Ridge and a subsequent advance toward Bogadjim and then Madang. During March Brigadier Heathcote H. Hammer’s 15th Brigade of the 7th Division began to advance north on a broad front from the crest of the Finisterre mountain range, and on 21 March a patrol made contact on the coast with US forces which had moved to the west from Saidor after their 'Michaelmas' operation. The 15th Brigade entered Bogadjim on 13 April, and Madang was occupied during 24 April in 'Dayton' by Brigadier Claude E. Cameron’s 8th Brigade and the 15th Brigade, the former coming up the coast in small craft from Sio and the latter from Koropa on the lower reaches of the Ramu river. On 25 April a battalion of the 8th Brigade was sent slightly farther north along the coast to occupy Alexishafen, thereby bring the Huon peninsula, Finisterre range and 'Dayton' operations to an end.

During April the headquarters of Boase’s 11th Division relieved that of the 7th Division, and Boase thus assumed command of all units in the area. During May and June, Australian activity was confined to maintaining pressure on the Japanese by active patrolling. Hansa Bay was occupied on 16 June and patrols pushed forward as far west as the Sepik river.

In July and August, US forces clashed with Japanese forces, including some of those who had escaped from the Huon peninsula, around the Driniumor river. Meanwhile, the Australian army efforts in the Pacific were scaled back, and it was not until a time late in 1944 and early in 1945, when several campaigns were launched in Bougainville, New Britain, Aitape and Wewak, and Borneo, that once more it undertook major campaigns against the Japanese.