This was the US seizure of the Cape Merkus area on the Arawe peninsula of New Britain island by Brigadier General Julian W. Cunningham’s ‘Director’ Task Force (15 December 1943/24 February 1944).
The undertaking was planned and executed to divert the attention of General Hitoshi Imamura’s 8th Area Army from Cape Gloucester, farther west on New Britain, where the ‘Backhander’ main landing was to be made 11 days later.
‘Director’ (i) was the first step in what became the Battle of Arawe, was fought between US and Japanese forces within the New Britain campaign. As such, the battle was an element of the left-hand movement of the Allied forces within the larger ‘Cartwheel’ plan to isolate the Japanese base area round Rabaul on the north coast of New Britain within the ‘Elkton III’ scheme created by General Douglas MacArthur’s South-West Pacific Area command. The primary object of ‘Director’ (i) against the Merkus peninsula and Arawe, toward the western end of the south coast of New Britain, was to create a diversion for the larger ‘Backhander’ landing at Cape Gloucester later in December 1943. The Japanese were expecting an Allied offensive into the western end of New Britain, and was reinforcing the region at the time of the Allied landing in the Arawe area on 15 December 1943. The Allies secured Arawe after about a month of intermittent fighting with the outnumbered Japanese force.
The initial Allied objectives for the landing included the seizure of an area in which a PT-boat base could be established, and the diversion of Japanese forces away from Cape Gloucester. The PT-boat base was subsequently deemed superfluous to requirement, however, and therefore was not built. At the time of ‘Director’ (i) there was only a small Japanese force at Arawe, although reinforcements were on their way to this remote position.
The main US landing on 15 December was successful despite a failed subsidiary landing and problems with the co-ordination of the landing craft. The US forces quickly secured a beach-head and established a defensive perimeter. Japanese aircraft made large-scale raids against the US lodgement in the days following the landing, and late in December the Japanese unsuccessfully counterattacked the US force. In mid-January 1944 the US assault force, by this time reinforced with additional infantry and tanks, launched a brief offensive which drove back the Japanese. The Japanese withdrew from the Arawe area toward the end of February as part of a general retreat from the western end of New Britain to develop a larger and more effective defence for their base area round Rabaul.
After assessing the military situation in the contiguous South Pacific Area and South-West Pacific Area during July 1942, shortly before the launch of ‘Watchtower’ to take Guadalcanal island in the Solomon islands group as the first step of the Allied strategic counter-offensive in this theatre, the US Joint Chiefs-of-Staff directed that the main objective of the Allied forces in the South Pacific and South-West Pacific Areas was to be the seizure of the major Japanese base at Rabaul on the north coast of New Britain’s north-eastern tip. From August 1942, US and Australian forces fought a series of offensives in New Guinea and the Solomon islands group with the object of eliminating Japanese positions in the region and allowing the establishment of major air bases from which Rabaul could be bombed. The Japanese forces fought a determined defensive campaign but were never able to achieve anything more than a delay in the Allied progress.
In June 1943 the Allies began the ‘Cartwheel’ major offensive to bring about the capture of Rabaul. During the next five months, MacArthur’s Australian and US forces advanced along the north coast of North-East New Guinea, capturing the town of Lae and the Huon peninsula in ‘Postern’. The US forces of Admiral William H. Halsey’s South Pacific Area simultaneously advanced through the Solomon islands group from Guadalcanal in operations such as ‘Toenails’ and ‘Cherryblossom’ against New Georgia and Bougainville respectively, and established an air base at Bougainville in November. In June, as as ‘Cartwheel’ was getting under way, the Joint Chiefs-of-Staff decided that the capture of Rabaul was not longer necessary as the Japanese base there could be neutralised by maritime blockade and aerial bombardment. MacArthur initially opposed this change of plan, but it was endorsed by the British and US Combined Chiefs-of-Staff during the ‘Quadrant’ conference at Quebec during August 1943.
In assessing the strategic situation in the South-West Pacific late in September 1943, the Imperial General Headquarters came to the conclusion that the Allies would attempt to break through the northern part of the Solomon islands group and the islands of the Bismarck archipelago during the coming months as they advanced toward Japan’s inner perimeter in the western and central Pacific. The Imperial General Headquarters accordingly despatched reinforcements to perceived strategic locations in the area in an attempt to slow the Allied advance. The Japanese kept strong forces in the area of Rabaul, however, as they believed that the Allies would attempt to capture this key Japanese base area. At this time the Japanese positions in the western part of New Britain were limited to airfields at Cape Gloucester on the island’s western tip and several small way stations to provide small craft and barges travelling between Rabaul and New Guinea with shelter from Allied aerial attacks.
On 22 September 1943, MacArthur’s headquarters at Brisbane in the Australian territory of Queensland ordered Lieutenant General Walter C. Krueger’s ‘Alamo’ Force (as the US 6th Army was named so that it did not come under Australian control) to secure the western end of New Britain and the surrounding islands. The two objects of this task were establish air and PT-boat bases from which to attack the Japanese forces in an round Rabaul, and to secure the Vitiaz and Dampier Straits between New Guinea and New Britain so that convoys could safely pass through them as they steamed to the north-west to undertake amphibious landings farther to the west along New Guinea’s north coast and beyond. To this end, MacArthur directed that Saidor on the coast of North-East New Guinea and both Cape Gloucester and Gasmata, the latter on New Britain’s south coast, were to be captured in ‘Dexterity’. For the two elements of ‘Dexterity’ to be undertaken on New Britain, Major General William H. Rupertus’s 1st Marine Division was selected for ‘Backhander’ against Cape Gloucester, and the strongly reinforced 126th Regimental Combat Team of Major General William H. Gill’s 32nd Division was to take Gasmata.
There was, however, disagreement between senior Allied commanders about whether or not it was necessary to land forces in western New Britain. Major General George C. Kenney, commander of the Allied Air Forces, South-West Pacific Area, opposed the landings on the grounds that his formations did not need airfields at Cape Gloucester as the existing bases in New Guinea and surrounding islands were adequate to support the planned landings in the region. Vice Admiral Arthur S. Carpender, commanding both the US 7th Fleet and the Allied Naval Forces, South-West Pacific Area, and Rear Admiral Daniel E. Barbey, commanding Task Force 76, supported the occupation of Cape Gloucester to ensure Allied movements through the Vitiaz and Dampier Straits, but were against the proposed landing at Gasmata as it lay uncomfortably close to the Japanese air bases at Rabaul. The Gasmata operation was therefore cancelled early in November in response to the concerns raised by the air and naval commanders as well as intelligence reports that the Japanese had reinforced their garrison at Gasmata.
On 21 November, a conference between MacArthur’s headquarters staff, Kenney, Carpender and Barbey was held in Brisbane, and at this the decision was made to land a small force in the Arawe area for three purposes: to divert Japanese attention from Cape Gloucester, to provide a PT-boat base, and to establish a defensive perimeter and make contact with the marines once they had landed on Cape Gloucester. The PT-boat at Arawe would be ideally placed, it was believed, for the disruption of the Japanese barge traffic along the southern shore of New Britain and for the shielding of the Allied naval forces allocated to ‘Backhander’ from naval attack.
The Arawe area is on the south coast of New Britain about 100 miles (160 km) from the island’s western tip, and its main geographical feature is Cape Merkus, which ends in the L-shaped Arawe peninsula. The several small islands of the Arawe islands group lie to the south-west of the cape. Late in 1943, the Arawe peninsula was covered by coconut trees which formed part of the Amalut Plantation, while the terrain inland from the peninsula and on its offshore islands was swampy. Most of the area’s shore comprises limestone cliffs. There was a small unused airfield some 4 miles (6.4 km) to the east of the Arawe peninsula’s neck, and a coastal trail led to the east from Cape Merkus to the Pulie river where it split into tracks running inland and along the coast. The terrain to the west of the peninsula was a trackless region of swamp and jungle, which presented severe difficulties toward any type of military movement. Several of the Arawe area’s beaches were suitable for landing craft, the best of these beaches being those at House Fireman on the peninsula’s west coast and near the village of Umtingalu to the east of the peninsula’s base.
‘Alamo’ Force was responsible for co-ordinating plans for the two invasions of western New Britain. The ‘Director’ (i) landing at Arawe was scheduled for 15 December as this was the earliest date by which the air bases around Nadzab in New Guinea, which were needed to support the landing, could be made operational, and also provided the landing force with the time it needed to undertake essential training and rehearsals. As it was believed that Arawe was only lightly defended, Krueger decided to use a force smaller than that which had been intended for the landing at Gasmata. This ‘Director’ Task Force was concentrated on Goodenough island, to the north of Milne Bay on the south-eastern tip of New Guinea, and here the force was stripped of all equipment deemed unnecessary for combat operations. Logistical plans called for the assault echelon to carry general supplies for 30 days ammunition sufficient for three days of intense combat. After the landing, the holdings would be enlarged to general supplies for 60 days and ammunition for six days except for anti-aircraft ammunition, of which a 10-day supply was thought necessary. The assault force and its supplies were to be carried in fast ships which could unload their cargo rapidly.
The commander of the PT-boat force in the South-West Pacific Area, Commander Morton C. Mumma, opposed the construction of large PT-boat facilities at Arawe as he had sufficient bases and the Japanese barge traffic usually operated along the north coast of New Britain. Mumma took his concerns to Carpender and Barbey, who eventually agreed that he would not be required to establish a base there if he thought it unnecessary. Mumma instead allocated six of his PT-boats to be stationed at Dreger Harbour just to the south of Finschhafen on New Guinea and at Kiriwina island of the Trobriand islands group to operate along the south coast of New Britain to the east of Arawe on a nightly basis, and asked only for emergency refuelling facilities at Arawe.
As commander of the ‘Director’ Task Force, Cunningham issued orders for the landing on 4 December. He directed that the task force would initially capture the Arawe peninsula and its surrounding islands and establish an outpost on the trail leading to the Pulie river. The main assault force was to land at the House Fireman beach on the Arawe peninsula at about dawn. Two troop-sized forces would conduct separate operations about an hour before the main landing: one was to take Pitoe island to the peninsula’s south, as it was believed that the Japanese had established a radio station and a defensive position there which commanded the entrance to Arawe harbour, and the other was to land at Umtingalu and establish a blocking position on the coastal trail to the east of the peninsula. Once the Arawe beach-head had been secured, amphibious patrols would be conducted to the west of the peninsula in an attempt to make contact with the marines at Cape Gloucester. US Navy personnel on the planning staff were concerned about these subsidiary landings, as a night-time landing at Lae in September had proved difficult.
The ‘Director’ Task Force was based on the US Army’s 112th Cavalry Regimental Combat Team, which had arrived in the Pacific theatre during August 1942 but had not yet seen combat. This unit had been converted to an infantry role in May 1943, and had undertaken the unopposed ‘Chronicle’ landing on Woodlark island on 23 June. The 112th Cavalry was smaller and more lightly armed than US infantry regiments as it had only two battalion-sized squadrons rather than the three battalions of each designated infantry regiment. Moreover, the squadrons were smaller and more lightly equipped than their infantry equivalents.
The 112th CRCT’s combat support units were the 148th Field Artillery Battalion equipped with the 105-mm (4.13-in) M2A1 howitzer, and the 59th Engineer Company. The other combat units of the ‘Director’ Task Force were two batteries of the 470th Anti-Aircraft Artillery Battalion (Automatic Weapons), most of the 236th Anti-aircraft Artillery Battalion (Searchlight), Company A of the United States Marine Corps’ 1st Amphibious Tractor Battalion, and a detachment of the 26th Quartermaster War Dog Platoon.
The 2/158th Infantry was held in reserve to reinforce the ‘Director’ Task Force if required, and several engineer, medical, ordnance and other support units were scheduled to arrive at Arawe after the landing had been completed. Cunningham requested a battery equipped with 90-mm (3.54-in) anti-aircraft guns, but none was available. The US Navy’s Beach Party No. 1 was also to be landed with the ‘Director’ Task Force and remain at Arawe until the beach-head had been secured.
The ‘Director’ Task Force was supported by Allied naval and air units. The naval force was Barbey’s Task Force 76 (7th Amphibious Force) 1, and USAAF and RAAF warplanes operating under the command of the 5th AAF were to support the landing, but only limited air support was to be available after 15 December as the available aircraft would then be required for strategic missions against Japanese bases.
Australian coastwatchers stationed on New Britain were reinforced during September and October 1943 to provide warning of air attacks from Rabaul bound for the Allied landing sites and to report on Japanese barge and troop movements. In addition to a coastwatcher team already in place at Cape Orford near Wide Bay, five other parties were sent to Cape Hoskins, Gasmata, Open Bay (on the north coast at the base of the Gazelle peninsula), the area to the south of Wide Bay, and the neck between Wide Bay and Open Bay. The Gasmata party was discovered by the Japanese while en route to its destination and destroyed, but the other teams were in place by the end of October.
At the time of the Allied landing, the Arawe area was defended by only a small force, though reinforcements were on their way to the area. The Japanese force at Arawe comprised 120 soldiers and sailors organised in two temporary companies drawn from Lieutenant General Hidemitsu Nakano’s 51st Division. The reinforcements were elements of Lieutenant General Yasushi Sakai’s 17th Division, which had been shipped from China to Rabaul during October 1943 to reinforce western New Britain ahead of the expected Allied invasion. The convoys carrying the division were attacked by US submarines and bombers, and suffered 1,173 casualties. The 1/81st Regiment was assigned to the defence of Cape Merkus, but did not depart Rabaul until December as it needed reorganisation after the losses it had suffered when the ship transporting it from China was sunk. In addition, two of its rifle companies, most of its heavy machine guns and all its 70-mm (2.76-in) Type 92 Battalion Gun equipments were retained by Imamura’s 8th Area Army at Rabaul, leaving the battalion with just its headquarters, two infantry companies and one machine gun platoon. Commanded by Major Masamitsu Komori, this battalion was a four-day march from Arawe when ‘Director’ (i) was launched. One company of the 54th Regiment, some engineers and detachments from other units were also assigned to the Arawe area. All the ground forces at Arawe came under the overall command of Major General Iwao Matsuda, commander of the 65th Independent Mixed Brigade, from his headquarters near Cape Gloucester.
The Japanese air units at Rabaul had been greatly weakened in the months before ‘Director’ (i) by prolonged Allied attacks and the transfer of Lieutenant General Einosuke Sudo’s 7th Air Division to western New Guinea. Even so, Vice Admiral Jinichi Kusaka’s 11th Air Fleet had 100 fighters and 50 bombers based at Rabaul at the time of the ‘Director’ (i) landing.
The Allies possessed little accurate intelligence on the terrain of western New Britain and on the exact location of Japanese forces, and therefore flew a large number of air photography sorties over the region, and small ground patrols were landed from PT-boats. A team from Special Service Unit No. 1 reconnoitred Arawe on the night of 9/10 December and concluded that there were few Japanese troops in the area, but the Japanese detected this party near the village of Umtingalu and strengthened their defences there.
‘Dexterity’ was preceded by a major Allied air offensive intended to neutralise if not destroy Japanese air strength on the airfields of the Rabaul area. From 12 October until a time early in November, the 5th AAF frequently attacked the airfields around the town, as well as ships in its harbour. US carrierborne aircraft also attacked Rabaul on 5 and 11 November in support of the marines’ ‘Cherryblossom’ landing on Bougainville.
The Allied air forces began pre-invasion raids on the western part of New Britain on 13 November. Few attacks were made on the Arawe area, however, as the Allies hoped to achieve tactical surprise for the landing and did not want to alert the Japanese to their intentions. Instead, heavy attacks were made against Gasmata, Ring Ring Plantation and Lindenhafen Plantation on New Britain’s south coast. The Arawe area was attacked for the first and second times on 6 and 8 December, meeting little opposition on either occasion. It was not until 14 December, the day before the landing, that heavy air attacks on Arawe were made: Allied aircraft flew 273 sorties against targets on the south coast of New Britain on that day. In addition to these air raids, TF74.2 (two US and two Australian destroyers) shelled the Gasmata area during the night of 29/30 November.
The ‘Director’ Task Force had been concentrated at Goodenough island by 2 December. The 112th CRCT had been informed of its selection for the Arawe operation on 24 November, and departed Woodlark island for the short voyage to Goodenough island in two convoys of 30 and 31 November. A full-scale rehearsal of the landing was held at the island on 8 December. This revealed problems with co-ordinating the waves of landing craft, and demonstrated that some of the force’s officers were inadequately trained in amphibious warfare. There was no time for further training to rectify these problems, however. On Goodenough island the troopers of the 112th CRCT were issued with several types of infantry weapons with which they had not previously been equipped. Each of the regiment’s rifle squads received a Browning Automatic Rifle and a Thompson sub-machine gun, and 2.36-inch (60-mm) bazookas, rifle grenades and flame-throwers were also issued. The cavalrymen received little training on the use of these weapons, so did not know how to make the best use of them in combat.
The men of the task force boarded their transport ships during the afternoon of 13 December, and the convoy sailed at 24.00 to Buna in New Guinea to rendezvous with most of the escorting destroyers. The force feinted to the north in the direction of Finschhafen before turning toward Arawe after dusk on 14 December. The convoy was detected by a Japanese aeroplane shortly before it anchored off Arawe at 03.30 on 15 December, and the 11th Air Fleet at Rabaul started to prepare an attack on it.
Shortly after the convoy arrived off Arawe, Carter Hall launched LVT amphibious tractors and Westralia lowered landing craft, both operated by specialised army and marine units, before departing for New Guinea at 05.00. The high-speed transports carrying A and B Troops of the 112th CRCT’s 1st Squadron closed to within 1,000 yards (915 m) of Umtingalu and Pilelo island respectively, and unloaded the soldiers into rubber boats.
The attempt of A Troop to land at Umtingalu, to the east of the main assault, failed. At about 05.25 the troop came under fire from machine guns, rifles and a 25-mm cannon as it was nearing the shore, and all but three of its 15 rubber boats were sunk. Assigned to support the landing, the destroyer Shaw could not open fire on the Japanese positions until 05.42 as its crew initially could not determine if the soldiers in the water were in the warship’s line of fire. Once a clear shot was possible, Shaw silenced the Japanese force with two salvoes from its 5-in (127-mm) guns. The surviving cavalrymen were rescued by small boats and later landed at House Fireman beach. The US losses in this part of ‘Director’ (i) were 12 men killed, four missing and 17 wounded.
The landing of B Troop on Pilelo island was successful. The object of this part of the operation was to destroy a Japanese radio station believed to be at the village of Paligmete on the island’s east coast. It had originally been intended that the troop woulds land near Paligmete, but the site for the landing was changed to the island’s west coast after A Troop came under attack. After disembarking from their boats, the cavalrymen advanced to the east and came under fire from a small Japanese force stationed in two caves near the village of Winguru on the island’s north coast. Ten cavalrymen were detached to contain the Japanese while the remainder of the troop continued to Paligmete, which was unoccupied and did not contain the suspected radio station. Most of B Troop’s men then attacked Winguru, using bazookas and flamethrowers to destroy the Japanese positions. One US and seven Japanese soldiers were killed in the fighting. Personnel of the RAAF’s No. 335 Radar Station also landed on Pilelo island on 15 December, and established a radar station there in 48 hours.
The 2nd Squadron, 112th CRCT made the main landing at House Fireman beach. The landing was delayed by a strong current and difficulties in forming the LVTs into an assault formation, and the first wave went ashore at 07.28 rather than 06.30 as had been planned. The supporting destroyers had bombarded the beach with 1,800 5-in (127-mm) rounds between 06.10 and 06.25, and North American B-25 Mitchells attack bombers strafed the area once the bombardment had ended, but the landing area was not under fire as the troops approached the beach. This allowed Japanese machine gunners to fire on the LVTs, but the Japanese weapons were rapidly silenced by rockets fired from the submarine chaser SC-742 and two DUKW amphibious trucks. The first wave of cavalrymen was fortunate to meet little opposition as there were further delays in landing the follow-up waves as a result of the different speed of the two types of LVTs used: the four follow-up waves were scheduled to land at five-minute intervals after the first wave, but the second in fact landed 25 minutes after the initial force and the succeeding three waves landed simultaneously 15 minutes later. Within two hours of the landing, all of the larger Allied warships but Barbey’s flagship had departed Arawe. Conyngham remained in the area to rescue the survivors of the landing at Umtingalu, and withdrew later in the same day.
The landed cavalrymen rapidly secured the Arawe peninsula. A patrol sent to the peninsula’s toe met only scattered resistance from Japanese rearguards. More than 20 Japanese located in a cave on the eastern side of the peninsula were killed by members of E Troop and personnel of the squadron headquarters. The remaining Japanese in the area retreated to the east. The 2nd Squadron reached the peninsula’s base at 14.30 and began to prepare its main defensive line. By the end of 15 December, more than 1,600 Allied troops were ashore. The two Japanese companies which had been stationed at Arawe had withdrawn to the north-east to take up positions at Didmop on the Pulie river about 8 miles (13 km) from the neck of the Arawe peninsula, and the naval unit defending Umtingalu had retreated inland in disorder.
The Allied naval force off Arawe had come under heavy air attack shortly after the landing. At 09.00 eight Aichi D3A ‘Val’ dive-bombers escorted by 56 Mitsubishi A6M5 Reisen ‘Zero’ fighters had evaded the USAAF combat air patrol of 16 Lockheed P-38 Lightning fighters and attacked the recently arrived first supply echelon, which comprised five tank landing craft and 13 medium landing craft, but these had evaded the bombs aimed at them. The first wave of attackers had suffered no losses, but at 11.15 four P-38 fighters had shot down a Zero, and at 18.00 a force of 30 Zero fighters and 12 Mitsubishi G4M3 ‘Betty’ and Mitsubishi Ki-21-II ‘Sally’ bombers had been driven off by four P-38 fighters. The Japanese lost two Zero fighters in the day’s air actions, but both pilots survived.
Although the US ground troops faced no opposition in the days immediately after the landing, naval convoys carrying reinforcements to the Arawe area were repeatedly attacked. The second supply echelon came under continuous air attack on 16 December, resulting in the loss of the coastal transport APc-21 as well as damage to the submarine chaser SC-743, yard minesweeper YMS-50 and four tank landing craft: some 42 men were killed or seriously wounded on these vessels. Another reinforcement convoy was attacked three times by dive-bombers on 21 December as it unloaded at Arawe. In overall terms, at least 150 Japanese aircraft attacked Arawe in that day. More air attacks were made on 26, 27 and 31 December. The Allied air forces were able to mount a successful defence of the Arawe area as the coastwatcher parties in New Britain provided warnings of between 30 and 60 minutes of most incoming raids. Between 15 and 31 December, at least 24 Japanese bombers and 32 fighters were shot down near Arawe, and during this same period Allied aircraft also raided the Japanese airfield complexes at Rabaul and Madang in New Guinea which were believed to be the bases from which the attacks were being launched. In air combats over Rabaul on 17, 19, and 23 December, 14 Zero fighters were shot down by Allied aircraft.
The process of unloading ships at Arawe was hampered by air attacks and congestion on House Fireman beach, one of the factors which contributed to this problem being the beach party, which was inexperienced and also too small. The problems with unloading meant that some tank landing craft left the area before discharging all their cargo.
The pace and weight of the Japanese air attacks on Arawe declined after 1 January. As a result of the heavy losses they suffered during attacks on Arawe and Cape Gloucester, and the damage caused by Allied raids on Rabaul, Japanese air units conducted only small-scale raids at night after this date. The Japanese naval fighter units at Rabaul and Kavieng, to the north-west on New Ireland, were also kept busy throughout January and February 1944 in efforts to defend their bases from continuous Allied air attacks. Few raids were made against the Arawe area after 90-mm (3.54-mm) anti-aircraft guns arrived there on 1 February. These weak attacks did not disrupt the Allied convoys: in the three weeks after the landing, 5,613 tons of supplies as well as 541 pieces of artillery and vehicles were transported to Arawe. On 20 February, the Japanese air units at Rabaul and Kavieng were permanently withdrawn to Truk in the Caroline islands group, ending any significant aerial threat to Allied forces on New Britain.
After the ‘Director’ (i) landing, the 59th Engineer Company constructed logistics facilities in the Arawe area. Because of the weight of the Japanese air raids, priority was initially given to the construction of a partially underground evacuation hospital, which was completed in January 1944. The underground hospital was replaced with a 120-bed above-ground facility in April 1944. Pilelo island was selected for the site of the PT-boat facilities, and a refuelling pier and dispersed fuel storage bays were built there. A 172-ft (52-m) pier was built at House Fireman beach between 26 February and 22 April to accommodate small ships, and three tank landing craft jetties were also built to the north of the beach.
An airstrip 920 ft (280 m) long and 100 ft (30 m) wide was quickly constructed for artillery observation aircraft on 13 January, and this was later upgraded and surfaced with coral. The engineer company also constructed 5 miles (8 km) of all-weather roads in the Arawe region and provided the men of the ‘Director’ Task Force with water by means of a salt-water distillation facility on Pilelo island and wells dug on the mainland. These projects were continuously hampered by shortages of construction materials, but the engineers were able to complete them by improvising and making use of salvaged material.
The 112th CRCT strengthened its defensive positions in the week after its landing. As A Troop had lost all its weapons and other equipment during the landing attempt at Umtingalu, supplies were air-dropped into the beach-head during the afternoon of 16 December to re-equip the troop, which was also assigned 50 replacement personnel. Most of B Troop was also transferred from Pilelo island to the mainland in the days after the landing. The regiment improved its defensive line on the neck of the peninsula by removing vegetation in order to create clear fields of fire, establishing minefields and wire entanglements, and laying down a field telephone network. A reserve defensive line was also established closer to Cape Merkus, and patrols were conducted each day along the shores of the peninsula in search of Japanese personnel attempting to infiltrate the US rear area. These patrols located and killed between 10 and 20 Japanese near Cape Merkus. In addition, the regiment established a network of observation posts throughout the Arawe area, these including positions in villages, key positions on the peninsula, and on several offshore islands. G Troop was assigned to secure Umtingalu, and after doing established a patrol base at the village as well as two observation posts along the track which connected it to the main defensive line.
Sakai, the commander of the 17th Division, gave instructions that the Arawe area be urgently reinforced after he had learned of the US landing. He did not believe that this would be the main Allied effort in western New Britain, however, and Komori’s force was ordered to make haste. The 1/141st Regiment, stationed at Cape Bushing on the south coast of New Britain some 40 miles (64 km) to the east of Arawe, was also directed to move by sea to counter the Allied invasion. One of this battalion’s infantry companies remained at Cape Bushing, however. Komori was appointed the commander of all Japanese forces in the Arawe area, which were subsequently designated as ’Komori’ Force. The 1/141st Regiment landed at the village of Omoi on the night of 18 December, and started to move on the next day to link with Komori’s men at Didmop, but took eight days to cover the 7 miles (11.25 km) between Omoi and Didmop as it became lost on several occasions while travelling through trackless jungle and paused whenever contact with US forces seemed likely. Komori reached Didmop on 19 December, and gathered under his command the units which had retreated from Umtingalu. On the basis of discussions with personnel who had witnessed the landing at Arawe, Komori mistakenly concluded that they had greatly overestimated the size of the Allied force. As a result, on 20 December he decided to launch a counterattack against the US position.
After establishing its beach-head, the ‘Director’ Task Force undertook a series of reconnaissance patrols as Cunningham had been ordered to gather intelligence on Japanese forces in western New Britain. On 17 December he dispatched a patrol of cavalrymen in two LCVPs to the west of Arawe to investigate the Itni river area. These landing craft encountered seven Japanese barges carrying part of the 1/141st Regiment near Cape Peiho, some 20 miles (32 km) to the west of Arawe, on 18 December. After an exchange of gunfire the US soldiers abandoned their landing craft and returned to Arawe along the coast. Another patrol travelling in LCVPs was engaged by Japanese barges near Umtingalu on 18 December but was able to return to Cape Merkus. Japanese barges were also sighted near Arawe on 23 December. Cunningham came to believe that a large Japanese force was being concentrated for an attack on the beachhead, and contacted Krueger on 24 December to request that he be reinforced by the 2/158th Infantry. Krueger concurred and ordered that three of the battalion’s four infantry companies be sent to Arawe. Company G of the 2/158th Infantry arrived on 27 December, and the other two companies early in January.
After organising his force while awaiting the 1/141st Regiment, Komori began his advance on Arawe on 24 December. He arrived at the airstrip to the north of Arawe during the early hours of the next day and during the morning elements of the ‘Komori’ Force ambushed two platoon-sized US in trucks to the north-east of Umtingalu. The US units withdrew to the village and reinforced G Troop’s defensive position there. The US force defeated several Japanese attempts to move around Umtingalu during the day, and killed at least three Japanese soldiers. Cunningham believed that the force encountered around Umtingalu was the advance guard of a much larger Japanese force advancing from Gasmata, and withdrew the troopers stationed around the village to positions behind the main defensive line which, at 22.30 that night, was hit by a poorly co-ordinated attack by 50 Japanese. The Japanese nonetheless overran some US positions before being driven back by the fire from the 112th CRCT’s 60-mm (2.36-in) mortars. The Americans lost one man killed and eight wounded, and estimated that the Japanese had suffered 12 casualties.
The Japanese offensive continued after the attack on 25 December. Two small attacks, each involving 15 soldiers, were made against the eastern edge of the main defensive line on the nights of 26 and 27 December, and were also repulsed by the 112th CRCT’s light mortars, and inflicted only a small number of casualties on the US force. On 28 December part of the 112th CRCT’s B Troop left the defensive line in an attempt to reach Umtingalu, but withdrew after encountering snipers and some light mortar fire. A platoon of C Troop also made an unsuccessful patrol from the western end of the defensive line in the course of which it suffered six casualties from Japanese machine gun and rifle fire. On the same day, Komori dispatched a force of between 20 and 30 soldiers to destroy the US mortar positions. The Japanese soldiers infiltrated the US positions by wading through swamps at the western end of the defensive line, but were detected before they could reach dry land. The Americans launched a strong response, which included a counterattack by elements of three cavalry troops and a platoon from the 158th Infantry supported by mortars, and the Japanese force suffered 17 casualties.
The 1/141st Regiment arrived in the Arawe area on the afternoon of 29 December, and conducted several small and unsuccessful attacks in early January 1944 before taking up positions about 400 to 500 yards (365 to 460 m) to the north of the US defence line. These positions comprised shallow trenches and foxholes which were difficult to see. While there were only about 100 Japanese soldiers in the area, they moved their six machine guns frequently, making them difficult targets for the US mortars and artillery.
A US patrol located the Japanese defensive position on 1 January 1944, and B Troop of the 112th CRCT launched an attack later in the morning of the same day, but was beaten off by heavy fire and suffered the loss of three men killed and 15 wounded. On 4 January, G Troop lost three men killed and 21 wounded in an unsuccessful attack on well-built Japanese positions. This attack had been undertaken without artillery support in an attempt to surprise the Japanese, and also included a feint against Umtingalu involving several landing craft. Further US attacks on 6, 7 and 11 January failed to make progress, but provided the cavalrymen with experience in manoeuvring through the Japanese defensive positions. These US operations were conducted on only a limited scale as Cunningham and the 112th CRCT’s other senior officers believed that the unit had already achieved the goals of the landing at Arawe and did not want to incur unnecessary casualties.
On 6 January Cunningham requested further reinforcement, including tanks, to tackle the Japanese defences. Krueger approved this request and ordered CompanyF of the 158th Infantry and Company B of the 1st Marine Tank Battalion to Arawe, these two units arriving on 10 and 12 January respectively. The marine tanks and two companies of the 158th Infantry then practised tank/infantry co-operation from 13 to 15 January, and during this period the 112th CRCT continued its patrols into Japanese-held areas. By this time, the ‘Komori’ Force had sustained casualties of at least 65 men killed, 75 wounded and 14 missing, and was also suffering from severe supply shortages and an outbreak of dysentery.
The ‘Director’ Task Force launched its attack on 16 January. During the morning, a squadron of Consolidated B-24 Liberator heavy bombers dropped 136 1,000-lb (454-kg) bombs on the Japanese defences, and 20 B-25 attack bombers strafed the area. After an intensive artillery and mortar bombardment, the marine tank company, two companies of the 158th Infantry and C Troop of the 112th CRCT attacked. The tanks led the advance, each tank being followed by a group of infantrymen. The cavalry troop and three tanks were initially held in reserve, but were sent into action at 12.00 to mop up a Japanese position. The attack was successful, and had reached its objectives by 16.00. Cunningham then directed the force to withdraw to the main defence line. During this part of the operation two marine tanks, which had become immobile, were destroyed to prevent the Japanese from using them as pillboxes. US engineers destroyed the Japanese defensive position during the following day. The ‘Director’ Task Force suffered 22 killed and 64 wounded in this operation, and estimated that it had killed 139 Japanese.
After the US attack, Komori pulled his remaining force back to defend the airstrip. As this was not an Allied objective, the Japanese were not subjected to further attacks by ground troops other than occasional patrol clashes and ambushes. As a result of the supply shortages, many of the Japanese soldiers were no ill and malnourished. Attempts to deliver supplies in by sea from Gasmata were disrupted by PT-boats and the force lacked enough porters to supply itself through overland trails. Komori concluded that his force was serving no purpose, and on 8 February informed his superiors that it faced destruction as a result of supply shortages. Komori was ordered to hold his position.
The 1st Marine Division’s ‘Backhander’ landing on Cape Gloucester during 26 December 1943 had meanwhile been successful. The marines secured the airfields which were the primary objective of the operation on 29 December against only light Japanese opposition. Heavy fighting took place during the first two weeks of 1944 when the marines advanced south to the east of their initial beach-head to secure Borgen Bay. Little fighting took place once this area had been captured, and the marines patrolled extensively in an attempt to locate the Japanese.
On 16 February, a marine patrol from Cape Gloucester made contact with an army patrol from Arawe at the village of Gilnit. On 23 February, the remnants of the Japanese force at Cape Gloucester were ordered to withdraw in the direction of Rabaul. One day later the ‘Komori’ Force was also directed to withdraw as part of the general Japanese retreat from western New Britain. The Japanese immediately began to leave their positions, and headed to the north along inland trails to join other units. The Americans did not detect this withdrawal until 27 February, when an attack conducted by the 2nd Squadron of 112th CRCT and a marine tank company to clear the Arawe area of Japanese encountered no opposition. The ‘Director’ Task Force later established a number of observation posts along the south coast of New Britain and extended its reconnaissance patrols. Komori fell behind his unit, and was killed on 9 April near San Remo on New Britain’s north coast when he, his executive officer and two enlisted men were ambushed by a patrol of the 2/5th Marines.
The Japanese force at Arawe had suffered much heavier casualties than the Allies. The ‘Director’ Task Force’s total of casualties between 15 December 1943 and the end of major fighting in the area were 118 dead, 352 wounded and four missing. Most of these were men of the 112th CRCT, which lost 72 men killed, 142 wounded and four missing. Japanese casualties over this period were 304 men killed and three captured.
In the period immediately following the Japanese withdrawal, the ‘Director’ Task Force remained at Arawe and, as was standard at the time, the 112th CRCT continued to improve the defensive positions in the area, and sent out combat patrols to search out Japanese stragglers. Elements of Major General Rapp Brush’s 40th Division began to arrive at Arawe in April 1944 to assume responsibility for garrisoning the area. The 112th CRCT was informed that it was to be deployed in New Guinea early in June, and the ‘Director’ Task Force was dissolved at this time. The 112th CRCT sailed for the Aitape area of New Guinea on 8 June and next saw combat there during the Battle of Driniumor River. The 40th Division maintained a garrison at Arawe until Major General Alan H. Ramsay’s Australian 5th Division assumed responsibility for operations on New Britain late in November 1944.