Operation Michaelmas

This was the US amphibious seizure of Saidor on the north coast of North-East New Guinea by Brigadier General Clarence A. Martin’s ‘Michaelmas’ Task Force (reinforced 126th Regimental Combat Team) of Major General William H. Gill’s 32nd Division within Lieutenant General Walter C. Krueger’s 6th Army, otherwise known as ‘Alamo’ Force and under MacArthur’s direct control (2 January/10 February 1944).

By a time late in 1943, the Japanese had constructed a small airstrip at Saidor, but provided only a weak garrison for this operationally important area. The possession of this airstrip would allow Lieutenant General George C. Kenney’s 5th AAF to project Allied air power farther into the approaches to the Vitiaz and Dampier Straits and also trap some 12,000 Japanese troops of Lieutenant General Masachika Hirata’s 20th Division at Sio, some 75 miles (120 km) to the east.

The campaign in the South-West Pacific Area late in 943 and early in 1944 was dominated by General Douglas MacArthur’s ‘Cartwheel’ undertaking, which comprised a series of operations directed at isolating and neutralising Rabaul, located in the north of New Britain island and the main base of the Imperial Japanese forces in the South-West Pacific area. MacArthur’s original ‘Elkton III’ plan had called for Australian troops to capture first Lae, then Finschhafen and finally Madang in a combination of airborne and amphibious assaults. The distance from Finschhafen to Madang is 178 miles (286 km), however, and thinking in terms of a shore-to-shore operation, which would be limited in radius of action to the distance which landing craft could sail in one night, the commander of Allied land forces in New Guinea, General Sir Thomas Blamey, recommended in August 1943 that an intermediate objective should first be taken. Saidor was selected as this intermediate target as it had beaches suitable for the operation of landing vessels and craft, a harbour and a pre-war airstrip.

It was recognised that the capture of Saidor might make that of Madang unnecessary, as each covered the Dampier and Vitiaz Straits, and both would provide air bases close to the major Japanese base area at Wewak. For the time being, though, both were considered objectives.

The Battle of Finschhafen prevented the early occupation of Saidor, for here the Japanese took back the initiative and threatened to derail MacArthur’s strategy, but ultimately failed to dislodge the Australian 9th Division or prevent the occupation of the Finschhafen area. With the Battle of Finschhafen won, the 9th Division initiated a pursuit of Lieutenant General Hatazo Adachi’s retreating Japanese 18th Army on 5 December 1943. Adachi was in a difficult situation as he sought to conduct a fighting withdrawal with his inland right flank vulnerable to attack from the Australian 7th Division in the Ramu river valley and his seaborne left flank open to amphibious assault. MacArthur knew that he now had an opportunity to destroy the 18th Army, and on 10 December decided that Saidor should be seized on or about 7 January, provided that 'Backhander' was proceeding satisfactorily.

Undertaken just after the ‘Director’ and ‘Backhander’ operations against Arawe and Cape Gloucester on New Britain island, ‘Michaelmas’ effectively closed the Dampier and Vitiaz Straits between New Guinea and New Britain, the latter the primary base area of General Hitoshi Imamura’s 8th Area Army, and also provided the Allies with an ideal stepping stone toward Madang, the ultimate objective of the Huon peninsula campaign of the South-West Pacific Area. The capture of the airstrip at Saidor also allowed construction of an air base to assist Allied air forces to conduct operations against Japanese bases at Wewak and Hollandia farther to the west along the north coast of New Guinea. In the short term, however, MacArthur’s objective was to cut off the 6,000 or more Japanese troops retreating from Sio in the face of the Australian advance from Finschhafen.

Following the US landing at Saidor, the Japanese opted to retreat rather than to fight, and pulled back across the foothills of the rugged Finisterre mountain range. The retreat was a nightmare for the Japanese troops involved as they struggled through thick, humid and disease-ridden jungle, across the rain-swollen rivers, and over cliffs and mountains. Large numbers of the men fell victim to starvation, fatigue, disease, drowning and even exposure as the nights in the Finisterre mountain range were bitterly cold. On the other hand of the tenuous ‘front’, the US troops were also hampered by the ruggedness of the terrain, the inclemency of the weather, communication problems, misunderstandings of various types, too high a degree of caution and, above any or all of these factors the resolution and resilience of the Japanese troops. Inevitably, therefore, the US troops were unable to prevent large numbers of Japanese soldiers from slipping past them.

After considerable construction adversely affected by the extreme wetness of the local weather, the air base was completed and proved useful. While the base at Nadzab, to the south-east across the mountains in the Markham river valley, was surrounded by mountains and was therefore unsuited for missions which required take-off or landing at night, Saidor presented no such problem, and during March 1944 Consolidated B-24 Liberator heavy bombers staged through Saidor for night attacks on Hollandia.

‘Michaelmas’ had been planned by MacArthur’s South-West Pacific Area command to cut the line of retreat for the 20th Division and Lieutenant General Hidemitsu Nakano’s 51st Division. Thus instead of falling back relatively easily from the pressure of the Australian forces of Lieutenant General Sir Edmund Herring’s Australian I Corps (Major General George F. Wootten’s 9th Division) and up the Markham river valley (Major General George A. Vasey’s 7th Division and Major General Allan J. Boase’s 11th Division) advancing to the north-west along the coast of the Huon peninsula, the 18th Army had to retreat to the west through the trackless hinterland to its fall-back positions between Wewak and Mackay.

On 24 December 1943, MacArthur ordered Rear Admiral Daniel E. Barbey’s 7th Amphibious Force to seize Saidor, and Barbey was given just nine days to plan and carry out the assault, scheduled for 2 January 1944. The ‘Michaelmas’ operation was therefore created and implemented quickly in an attempt to capitalise on the success of the South-West Pacific Area’s forces in their ‘Postern’ offensive against Lae and Salamaua as the left flank of the ‘Elkton III’ offensive. After South-West Pacific Area engineers had secretly built an airstrip at Tsili Tsili in the Watut river valley inland of Lae, fighters could escort the bombers of Kenney’s US 5th AAF raiding the major Japanese base at Wewak and destroying more than 100 aircraft, thereby giving the Allies air superiority over eastern New Guinea.

On 4 September 1943, Barbey’s 7th Amphibious Force and Brigadier General William F. Heavy’s 2nd Engineer Special Brigade landed the 9th Division on the south coast of the Huon peninsula some 20 miles (32 km) to the east of Lae, so preventing Japanese movement round the coast. On the following day the 503rd Parachute Infantry landed at Nazdab in the Markham river valley inland of Lae, thereby cutting this line of Japanese movement, while the 7th Division was flown into Tsili Tsili and began to move down the Watut river, toward its confluence with the Markham river, before turning up the Markham river valley inland of the Saruwaged and Finisterre ranges to reach the Ramu river, the Kankiryo Saddle and the line of descent to the sea at Bogadjim. By a time early in September it was clear to the Japanese that Lae could not be held, and the town fell on 16 September.

Four days earlier, Salamaua had been taken by a brigade of Major General Stanley G. Savige’s Australian 3rd Division advancing from its base at Wau, and a force of the 32nd Division which had landed at Nassau Bay on 29/30 June.

MacArthur acted swiftly to capitalise on this success. It was known that Japanese reinforcements were on their way to Finschhafen, MacArthur’s next objective, so on 22 September Brigadier W. J. V. Windeyer’s 20th Brigade of Wootten’s 9th Division was moved by sea to Katika, farther round the coast from Finschhafen. The brigade undertook a small but very hard battle before capturing Finschhafen on 2 October, whereupon the Japanese survivors fell back onto the Satelberg, an area of high ground inland of Katika, where they were reinforced by the leading elements of the 20th Division.

Unfortunately for the Allies, the length of the Battle of Finschhafen, which started on 21 September 1943 and ended only with the capture of Satelberg mountain on 8 December, prevented the early occupation of Saidor. The Japanese thus managed to regain the operational initiative and threatened to derail MacArthur’s strategy, but ultimately failed to dislodge Wootten’s 9th Division or prevent the occupation of the Finschhafen area. With the Battle of Finschhafen essentially won by the end of November 1943, the 9th Division began a pursuit of Adachi’s retreating 18th Army on 5 December. Adachi was in a difficult and precarious position as he sought to conduct a fighting withdrawal with his inland right flank vulnerable to attack by Vasey’s 7th Division in the Ramu river valley and his left flank on the coast and therefore open to amphibious assault. The fact that he had an opportunity to destroy the 18th Army was clear to MacArthur, who decided on 10 December that Saidor should be seized on or about 7 January, provided that ‘Backhander’ to take Cape Gloucester on the south-western tip of New Britain was progressing well. On 17 December Krueger, commanding the all-US ‘Alamo’ Force which did not fall within Blamey’s purview, received orders setting a target date of 2 January for the seizure of Saidor.

Krueger allocated the 32nd Division to the Saidor operation as it was at Goodenough island, to the north of Papua’s south-eastern tip, but no longer required for the New Britain campaign. Martin, the assistant division commander, was appointed to the command of the ‘Michaelmas’ Task Force, which was built around the 126th Regimental Combat Team. This latter had been rebuilt after its torrid time in the Battle of Buna-Gona, and had received nine weeks of amphibious training, the first six in Australia and the last three at Milne Bay, just to the south of Goodenough island. The units assigned to the task force were currently located at Goodenough island, Milne Bay, Oro Bay, Lae, Finschhafen, Port Moresby, Kiriwina, Arawe, Cape Cretin and the Australian mainland.

Barbey rapidly assembled 7,200 men, 1,800 tons of supplies and 300 vehicles at Goodenough island, with sealift provided by nine of the high-speed destroyer conversions which had just been employed at Cape Gloucester as well as several infantry landing craft and tank landing ships. Escort was provided by nine US destroyers and the British Rear Admiral V. A. C. Crutchley’s Australian and US cruiser force. The Japanese navy was preoccupied with an attack on Kavieng by the carrierborne warplanes of Rear Admiral Frederick C. Sherman’s Carrier Division 1 and did not attempt to contest the landings.

The ‘Michaelmas’ Task Force had five responsibilities, which were to seize the Saidor area, establish facilities for the operation of one fighter group, support the establishment of air forces in the area, assist the establishment of light naval forces in the area, and construct austere port and base facilities. Notably, the task force received no explicit instruction to fight the Japanese. Lieutenant General Frank H. Berryman’s Australian II Corps was to co-operate by exploitation along the coast, while the 7th Division was to contain the Japanese forces in the Bogadjim area, between Saidor and Madang, by the large-scale use of fighting patrols.

There was neither time nor opportunity for any form of ground reconnaissance on the Saidor area, so aerial photographs were used to select three beaches (Red, White and Blue), on the western side of Dekays Bay. Events were to show that these were ‘narrow, rocky and exposed to heavy seas. The South-West Pacific Area’s intelligence staff in Brisbane believed that there were no more than 4,500 Japanese in the area between Sio and Saidor, and only 1,500 between Saidor and Madang, and estimated that if the Japanese decided to counterattack at Saidor, it would take them seven days to bring up 3,000 men. Martin therefore chose to dispense with a preliminary aerial bombardment, and this paved the way for a landing at dawn.

The 2,400 assault troops (to be followed by another 9,600 men) and their supplies and vehicles had to be loaded on board the ships at Goodenough island on 31 December, just five days after the ‘Backhander’ assault on Cape Gloucester. Barbey’s 7th Amphibious Force allotted six tank landing ships, 10 destroyer-based high-speed transports and 17 infantry landing craft. On 30 December it was discovered that only nine of the high-speed transports would be available, so new embarkation tables had to be drawn up, shifting personnel not required in the assault waves to the infantry landing craft, and the landing schedule was revised in the light of the reduced number of landing craft available.

The difficulty of simultaneously supplying the ‘Michaelmas’, ‘Director’ and ‘Backhander’ operations at Saidor, Arawe and Cape Gloucester, as well as the smaller undertaking on Long Island to the north-east of Saidor where a radar station was being created to support ‘Backhander’, persuaded Krueger to request a postponement of ‘Michaelmas’, but after Vice Admiral Thomas C. Kinkaid, the commander of the Allied Naval Forces and the US 7th Fleet, had assured MacArthur that enough supplies would be delivered, MacArthur refused Krueger’s request with the words ‘I am most anxious that if humanly possible this operation take place as scheduled…[Saidor’s] capture will have a vital strategic effect which will be lost if materially postponed.’

The various assault ships and other craft were escorted by the US destroyers Beale, Mahan, Flusser, Lamson, Drayton, Hutchins, Smith and Conyngham under the command of Captain Carter, and the undertaking was covered by Crutchley’s task force comprising the Australian heavy cruisers Australia and Shropshire, US light cruisers Nashville and Phoenix, Australian destroyers Arunta and Warramunga, and US destroyers Helm, Ralph Talbot, Bush, Ammen, Bache and Mullany.

(On 25 August 1942 a Japanese convoy of seven motorised landing craft carrying 353 marines of the 5th Sasebo Special Naval Landing Force, commanded by Commander Tsukioka, had stopped to rest at the southern end of Goodenough island. This force was bound for Taupota and participation in the Battle of Milne Bay, and was stranded when their craft were destroyed by Curtiss Kittyhawk fighter-bombers of the RAAF’s No. 75 Squadron. On 22 October 1942 the Australian destroyers Stuart and Arunta landed 640 men of the Australian 2/12th Battalion, part of Brigadier F. O. Chilton’s 18th Brigade of Vasey’s 7th Division, from Milne Bay. The Australians landed on each side of the island’s southern tip during the night, and on the following day there was fierce fighting until, during the night, a rescue mission evacuated about 250 Japanese soldiers by submarine to nearby Fergusson island, where they were collected by a cruiser and transported to Rabaul. The remaining Japanese defenders on Goodenough island were mopped up and the island was declared secure on 27 October.)

After a halt at Oro Bay, the US attack force moved through the Vitiaz Strait and arrived in Dekays Bay before dawn on 2 January with the shore obscured by low cloud and drizzle. Barbey therefore postponed H-hour from 06.50 to 07.05 to provide more light for the naval bombardment, and then to 07.25 to provide the landing craft with more time in which to form their run-in dispositions. Destroyers fired 1,725 5-in (127-mm) rounds, while rocket-equipped infantry landing craft loosed off 624 4.5-in (114-mm) rockets. There was no air bombardment, but B-24 Liberator heavy bombers, North American B-25 Mitchell medium bombers and Douglas A-20 Havoc attack bombers of Kenney’s US 5th AAF attacked Saidor airstrip later in the morning.

The initial wave of landing craft reached the shore at about 07.30, and the first four waves of ramped personnel landing craft from the high-speed transports arrived within the space of 15 minutes. Each of the six tank landing ships in the assault towed one mechanised landing craft of Heavy’s 2nd Engineer Special Brigade, and of the six tank landing ships two carried bulldozers, two rocket-equipped DUKW amphibious trucks, and two carried spare fuel. The mechanised landing craft beached shortly before 08.30 and the tank landing ships soon after that. The Shore Battalion/542nd Engineer Boat and Shore Regiment laid Australian-made mesh to provide a roadway across the beach for vehicles. All six of the LSTs had unloaded by 11.45. There was little opposition: only 11 Japanese soldiers were killed by the naval bombardment or assault troops. There were perhaps 150 transient Japanese troops in the area of Saidor, and all of these fled into the interior. US casualties were one soldier killed and five wounded, and two sailors drowned. Nine Nakajima Ki-49 ‘Helen’ medium bombers, escorted by as many as 20 Mitsubishi A6M Reisen ‘Zero’ and Kawasaki Ki-61 ‘Tony’ fighters, bombed the beach area at 16.30, and there were three more air raids during the night. During the rest of the month there were 49 air raids, but most of these were small.

Since October 1943 it had been the Japanese strategy on New Guinea to conduct fighting withdrawals in the face of Allied advances in order to trade space for the infliction of losses on the Allies. At the Rabaul headquarters of Imamura’s 8th Area Army, the staff debated whether Aoki’s 20th Division and Nakano’s 51st Division, currently operating in the area to the to the east of Saidor, should attack Saidor or try to bypass it as they moved to the west to link with the rest of the 18th Army at Wewak. In view of the poor condition of these two divisions, Imamura relieved the 18th Army of responsibility for the Sio area and ordered Adachi to withdraw to Madang.

Adachi had flown from Madang to the headquarters of the 51st Division at Kiari at a time late in December, and learned of the landing at Saidor shortly before heading overland to the headquarters of the 20th Division at Sio, where he received Imamura’s orders. Adachi placed Nakano in overall command of the forces to the east of Saidor and ordered Lieutenant General Heiduke Abe’s 41st Division to move from Wewak to undertake the defence of the Madang area. Adachi then departed for Madang in the submarine I-177. To harass the US forces in and around Saidor, he withdrew eight companies from Major General Masutaro Nakai’s ‘Nakai’ Detachment, which was in essence the infantry group of the 20th Division facing Vasey’s Australian 7th Division in the Finisterre mountain range, and these deployed along the Mot river in the Gambumi area, where they succeeded in repelling US attempts to cross the river until 21 February, when they withdrew with their task completed. However, weakening the Japanese front in the Finisterre mountain range front provoked an Australian attack, resulting in the loss of the entire Kankirei position.

In organising the withdrawal of his force, Nakano selected two routes, one following the coast and the other running along the ridge lines of the foothills of the Finisterre mountain range. Initially, the 20th Division was to take the coastal route while the 51st Division and some naval units took the inland route, but this was changed at the last minute and both divisions took the inland route. Additional rations and supplies were to be delivered by submarine, but the 51st Division decided to move out rather than await the arrival of the submarines and thereby run the risk exhausting its rations as it waited. The 51st Division already had experience in crossing the mountains, and Nakano was confident of its ability to negotiate them. In the event, one submarine was discovered by Allied aircraft and failed to reach its objective, while on 16 January the submarine I-181 was sunk in the St George Strait by the US submarine chasers PCS-1422 and PCS-1459. A third submarine got through, but this was a small boat able to carry only five tons of supplies, which were distributed among units of the 20th Division.

The 10,000 surviving men of the 20th Division and 51st Division, as well as the headquarters of the 18th Army, were thus bypassing Saidor and moving to the north-west toward Madang, covered by the 78th Regiment on their southern flank in the Finisterre mountain range, thereby evading the attentions of Vasey’s 7th Division in the Ramu river valley. The Australians, with fresh brigades in the line, cleared the Finisterre mountain range during January under difficult circumstances and forced the 78th Regiment to join in the general retreat of the 18th Army from the Huon peninsula.

The difficulty of the march the Japanese were attempting had been considerably underestimated, and sick and wounded men had to make their way through trackless regions. The first troops reached Madang on 8 February, and the whole movement had been completed by 23 February. the 18th Army had anticipated that units reaching Madang would probably have lost much of their equipment, as was indeed the case, so stores were gathered together from distant Wewak and Hansa, and stockpiled near Madang. In addition emergency articles such as some food, shoes and clothing were collected near the mouth of Minderi river, supplied by the ‘Nakai’ Detachment.

The Japanese troops attempted to reach Madang via Gali, but suffered heavy casualties from coastal shelling near Gali by US destroyers and, on 26 January, by Rear Admiral Russell S. Berkey’s light cruisers Nashville and Phoenix and destroyers Bush, Ammen and Mullany off Madang.

A US observation post in the mountains at Mambit counted 965 Japanese troops passing through Yagoyoga between 6 and 10 February, and 2,613 between 11 and 23 February. Something in the order of another 1,000 passed through before 6 February. From prisoners of war, the ‘Michaelmas’ Task Force was able to construct a fairly complete and accurate picture of the identity and strength of the opposing Japanese forces. On 12 January, Martin received intelligence from the ‘Alamo’ Force to the effect that the Japanese were concentrating around Sio, and would attempt to force their way through to Madang. In response to Martin’s request for reinforcements, the 1st and 3rd Battalion Combat Teams of the 128th Infantry were sent to reinforce Saidor, and arrived on 16 January. Martin came to believe that an advance to the east and an attack on the withdrawing Japanese would ‘provide an opportunity to destroy the Japanese before they could organise an attack on the Saidor position’, but Krueger did not immediately grant permission for such an operation. There was still the possibility of Japanese attack, and the 32nd Division was required for the forthcoming operation to take Hansa Bay. On 20 January, a staff officer visiting the ‘Michaelmas’ Task Force was asked to raise the possibility with Krueger, but on 21 January Martin received a letter stating that the mission of his task force remained unchanged. There followed a series of inconsistent and contradictory messages until 9 February, when Martin was authorised to take offensive action.

Major General Alan H. Ramsey’s 5th Division relieved Wootten’s 9th Division on 20 January, after Sio had been secured, and continued the push up the coast. The Australian and US forces met some 14 miles (22.5 km) to the south-east of Saidor on 10 February, the day on which the ‘Alamo’ Force declared ‘Michaelmas’ complete. Thus though plans were quickly made for offensive operations from Saidor, the link of US and Australian forces removed the need for any such effort as this had sealed the previous gap on the Allies’ eastern flank.

The threat of Japanese counterattacks, which had been further magnified by the reports of the local population, had already delayed the transition from defensive to offensive operations, and the torrential rains, which rendered all tracks and rivers impassable, caused great difficulty with the movement of troops and supplies to outlying sectors. Japanese units, brought from Madang, blocked access to the main escape routes, and although the task force pushed its attacks and patrolled vigorously, efforts to prevent the escape of the Japanese retiring before the Australians were not completely successful.

On 18 February the headquarters of the 32nd Division reached Saidor and this division then assumed the primary role in the pursuit of the 18th Army to the north-west. The 7th Division had pushed to the north out of the Ramu river valley and met the 32nd Division at Kul on the eastern shoulder of Astrolabe Bay on 21 March. The Australians pushed on to Bogadjim, which they secured on 13 April. The Japanese were in full retreat and abandoned Madang, which the Australians entered on 24 April.

With a large construction programme envisaged for the Saidor area, engineers constituted almost 30% of the ‘Michaelmas’ Task Force. An engineer headquarters (five officers and five other ranks) had been organised on 24 December, a mere nine days before the operation’s start date, and later a Jeep and its driver were borrowed from the 114th Engineer Battalion to provide transportation. The officers did not know each other and therefore were unaware of each other’s capabilities, and it later emerged that none of them had experience with amphibious operations, and only one had experience in air base construction, although this was to be the engineers’ most important task.

Saidor had possessed a grass civilian airstrip before the start of the war, and before they abandoned Saidor in 1942, Australian troops had sabotaged this airstrip by digging trenches across the runway. The US engineers quickly filled these after their arrival, and the overgrown kunai grass was flattened by 2½-ton trucks driven over it. By the afternoon of 4 January, 1,800 ft (550 m) of runway was ready for use, and a Piper L-4 light liaison aeroplane took off from it on the following day. The 863rd Engineer Aviation Battalion arrived on 9 January and improved the airstrip, making it possible for 12 Douglas C-47 Skytrain transport aircraft, loaded with ammunition, to land on 11 January. The ‘Alamo’ Force wanted an all-weather runway, 6,000 ft (1830 m) in length and 100 ft (30 m) in width, preferably in a location where a second, parallel runway could be constructed if required, and the construction of this second runway was requested by the 5th AAF on 24 January. The 8th Engineer Squadron survey detachment laid out a new runway oriented about 10° from the existing airstrip, and the whole site was then stripped, leaving the subgrade exposed. This was a major error as, in the period between 10 to 31 January, there were only three days on which it did not rain, and 25 in (635 mm) of rain fell, as was quite normal for that time of year. As a result, construction was seriously delayed. Gravel was taken from the nearby Nankina river and laid to a thickness of 8 in (200 mm) and topped with crushed aggregate. The rain and frequent rolling gave a good water-bound surface. Part of the surface was sealed with bitumen, but delays caused by the weather prevented it all being sealed before being overlaid with Marston mats. The runway was declared ready for emergency landings on 4 February but the surface deteriorated under use, and was finally completed on 6 March. Construction of the taxiways and dispersal areas continued through April, and the air base was complete and in operation by 7 May.

On 5 March, the engineers began construction of the bulk petroleum installation. Storage was provided for 20,000 barrels of aviation fuel in one 10,000- and five 2,000-barrel tanks. A fuel jetty was constructed, allowing tankers to discharge into a pipeline which ran over a catwalk to the storage tanks. Work was completed on 8 April.

Considerable effort had also to be expended on road construction. The 808th Engineer Aviation Battalion had to be assigned to road work, the task being beyond the resources of the Shore Battalion. Gravel was laid to a thickness of 2 ft (0.61 m). By a time late in January, the weather and damage to the roads by heavy military traffic forced the engineers to impose a ban on morning road use: by the middle of the day the sun had dried the roads and traffic could resume. Initially, the Nankina river could be forded, but the heavy seasonal rains turned it into a fast-flowing torrent. A portable bridge was flown in from Milne Bay and erected in a day, but it took two weeks to construct the approaches. In the meantime the troops on the other side had to be supplied by water.

To open the area best suited for camp sites, another bridge had to be erected over the Nankina river, and this took the form of a permanent structure with concrete abutments. An 8-ft (2.4-m) rise in the river’s water level complicated the work, but the 112-ft (34.1-m) bridge was opened to traffic on 17 February.

Local labour was supplied by an Australian New Guinea Administrative Unit (ANGAU) detachment, initially comprising eight Australian army officers and 11 member of the native police, but one week after the landing 199 native labourers were brought in from Lae. The ANGAU detachment at first found it difficult to lure the frightened local people in from the bush, but as the word spread that there was food and safety to be had within the US lodgement, large numbers of people began to arrive on foot, and the ANGAU established a native settlement in the Biding river area. By 13 February there were 680 native labourers at work, and they constructed camps for the Americans, carried supplies to units in the mountains and brought back the wounded, and worked in the hospital. The ANGAU also carried out patrols, providing intelligence on the Japanese positions.

The amphibian engineers had brought six mechanised landing craft on the first day, and these were then joined by another six towed by the six tank landing ships on the second day. Unfortunately, within days the rocky beaches and reefs caused nine to be damaged so badly that they had to be sent back to Cape Cretin for repair. Later in January, the rest of Company B, 542nd Engineer Boat and Shore Regiment, was sent to Saidor. A 100-ft (30-m) lighter wharf was begun on 19 January and completed on 5 March. The unseasoned local timber used in its construction soon took a battering from heavily loaded barges bumping into them in high seas and had to be replaced with steel piles. A 330-ft (100-m) wharf, able to accommodate a Liberty ship, was completed on 6 May, and other construction activities included jetties for servicing PT-boats, landings for LSTs, a 250-bed hospital which was opened on 11 May, a quartermaster dump, and a staging area for 9,000 men.

Saidor was soon in full use by the 5th AAF. During March, B-24 bombers staged through Saidor for night attacks on Hollandia, and a raid on Hollandia on 16 April encountered a weather front which closed Nadzab and the other airfields in the Markham river valley, and more than 30 aircraft made their way to Saidor. A Lockheed F-5 Lightning reconnaissance aeroplane and a North American B-25 Mitchell medium bomber collided on the runway, and two aircraft crash-landed, but the other aircraft which diverted to Saidor eventually returned to their bases.

Krueger reported that the ‘MICHAELMAS Task Force tried hard to block these escape routes. But the torrential rain, the ruggedness of the country with its impenetrable rain forests and jungles and impassable rivers, and the resistance of enemy troops pushed forward from Madang to guard the trails leading eastward, made this effort fall short of success.’ Australian commanders were critical. In a letter to Blamey, Berryman, who had visited Krueger in an attempt to ensure that the Japanese would not escape, wrote that ‘about 8,000 semi-starved, ill-equipped and dispirited Japanese bypassed Saidor. It was disappointing that the fruits of victory were not fully reaped, and that once again the remnants of the 51st Division escaped our clutches.’ Lieutenant General Sir Leslie Morshead of the New Guinea Force reported to Blamey that the ‘Michaelmas’ Task Force appeared not to have made ‘any appreciable effort’ to sever the Japanese troops’ line of retreat. Sadly for the men of the 32nd Division, many of these Japanese would later have to be fought again under less advantageous circumstances at the Battle of the Driniumor River in ‘Persecution’.

Krueger officially terminated ‘Dexterity’, of which ‘Michaelmas’ was a component, on 10 February 1944, and all which now remained was the final act of the Huon peninsula campaign: the capture of Madang as the culmination of ‘Dayton’.

On 24 April command of the 18th Army in eastern New Guinea was switched from Imamura’s 8th Area Army at Rabaul to General Korechika Anami’s 2nd Area Army at Davao on the island of Mindanao in the Philippine islands group. The 2nd Area Army was also made responsible for the eastern part of New Guinea as far to the east as the Huon peninsula. The remnants of the 18th Army were withdrawing to the north-west through Wewak and Aitape to Hollandia just on the Netherlands New Guinea side of the border.

In the Australian 5th Division’s advance from Sio to Saidor between 20 January and the end of February, 734 Japanese were killed, 1,793 found dead, and 48 taken prisoner. The Australian and Papuan casualties amounted to three men killed and five wounded. The 32nd Division at Saidor killed 119 Japanese and captured 18, while itself losing 40 men killed, 11 wounded and 16 missing.