Chapter 6: Eastward to Iboki
In many respects, Arawe was a sideshow to the main campaign for control of western New Britain. Occasionally, the fighting there was violent, marked by bloody clashes in the enveloping jungle; at other times, days went by with only minor patrol action. General Cunningham had accomplished his major objective when the 112th Cavalry assault troops seized control of Arawe Peninsula. Further operations to clear the Japanese from the area were undertaken primarily to remove a lurking threat to the DIRECTOR Force’s position. On the enemy side of the front, Major Komori was determined to hold the Americans back from an objective that they actually did not want—Lupin airfield. (See Map 24.)
Allied press claims of the capture of the grass-choked airstrip, which were broadcast right after Z-Day, considered ground patrolled to be ground controlled. When Komori’s 1st Battalion, 81st Infantry forced the withdrawal of the 112th Cavalry’s outposts on 25 December, the Japanese were convinced that they had regained possession of a desirable prize. Komori’s primary mission became the denial of the airfield site to the Americans.
The defenses closing off the neck of Arawe Peninsula were the target of repeated small-scale Japanese attacks during the last week of December. The 112th’s lines held firm, and the enemy troops reeled back, shaken and hurt, after each unsuccessful effort. The American artillery and mortar fire was particularly galling to the Japanese who were given no rest from punishment even though they broke contact. On the 29th, after eight days of wandering in the jungle, the 1st Battalion, 141st Infantry reached Komori’s positions, and the enemy commander directed the new arrivals to take over the front lines. The depleted companies of 1/81 and the original Merkus garrison were assigned to hold the rear areas of the wide sector from Omoi to the Pulie River which was Komori’s defensive responsibility.
With the arrival of 1/141, the Japanese ceased their attacks on the American positions. Instead, in the jungle about 400-500 yards forward of the 112th’s lines, the enemy soldiers constructed a defense in depth, a complex of foxholes, trenches, and weapons emplacements that gave them alternate positions from which to cover approach routes. Patrols of cavalrymen discovered the Japanese were digging in
on the 1st, but were unable to drive them back. Repeatedly, in following days, the Americans attacked the Japanese, but without success. Shifting frequently from hole to hole, using the concealment offered by a thick mat of undergrowth and the shallow connecting trenches they had dug, the men of the 1/141, were quite successful in holding their ground. On 6 January, General Cunningham told General Krueger that “officers and men participating in these operations report they have not seen a single Japanese—and that they are unable to locate machine guns firing on them from a distance of 10 to 20 yards.”2
Cunningham asked that he be sent reinforcements, noting that artillery and mortar fire seemed to have little effect on the hidden Japanese positions. He stated his belief that to continue attacks “along present lines is to play with the enemy’s hand.”3 The ALAMO Force commander was asked for tanks to help root out and destroy the defenses that the American soldiers faced. Krueger took immediate steps to answer the request from Arawe, and a Marine tank platoon was underway from Finschhafen on 9 February, together with a company of the 2nd Battalion, 158th Infantry.
The only tank unit available for reinforcement of Cunningham’s force was Company B, 1st Tank Battalion, which had been left behind because of the limited operating area for armor at Cape Gloucester when the BACKHANDER Force sailed. When the 1st Marine Division commander was informed of the contemplated commitment of some of his armor reserve—and promised that the tanks would be returned to his control when they were required—he suggested that all of Company B be employed. Rupertus noted that the tank company was the smallest self-sustained unit for combat operations.4 Accordingly, the remainder of Company B boarded an LCT on the 11th and made a stormy overnight passage through rough seas to Arawe.
From 13 to 15 January, while the 112th Cavalry continued pressuring the Japanese with combat patrols, the Marine tankers worked with the two companies of 2/158 which were to make the principal effort against the enemy position. The infantrymen provided a squad to cover each light tank and rehearsed tactics for the assault, while tank and infantry officers made a thorough reconnaissance of the zone of attack. The plan called for two five-tank platoons, each with an infantry company in support, to advance on a 500-yard-wide front on 16 January. The day’s objective was 1,000 yards from the line of departure, and within the intervening distance lay all the maze of defenses that the 1st Battalion, 141st Infantry had held so doggedly for two weeks.
On the morning of the 16th, a squadron of B-24s dropped 136 1,000-pound bombs on the Japanese defenses, and 20 B-25s followed with a heavy strafing and bombing attack.5 This aerial preparation, coupled with an intensive artillery and 81-mm mortar bombardment, paved the way for the assault. The tanks led off and kept moving forward despite soft ground and
bomb craters which caused several machines to bog down until recovery vehicles could pull them free. Working well together, despite incredibly thick vegetation which practically blinded the tank drivers and commanders, the tank-infantry teams churned and shot their way through the enemy position. When a pocket of resistance developed on the right of the line, a section of the reserve tank platoon and a troop of the 112th quickly finished off the holdouts while the advance continued. By 1600, the predetermined objective had been reached, and Cunningham ordered a withdrawal to the peninsula’s main line of resistance. Two tanks, one which had thrown a track on a steep slope and another which was hopelessly bogged down in swampy ground, were destroyed by demolitions to prevent their use as enemy strongpoints when the Americans pulled back.
The attack of 16 January accomplished its objective. Komori ordered the remnants of 1/141 to withdraw to the Lupin vicinity where they could “fight to the glorious end to defend the airfield.”6 The few Japanese who did not get the word to retreat were wiped out on the 17th by flame-throwing tanks and a supporting force of cavalrymen. When the battered enemy troops paused to regroup in positions near the airfield, the Komori Force’s commander made a head count and found that his two understrength battalions and their supporting units had lost 116 killed in action and 117 wounded in three weeks fighting. In addition, 14 men had died of various illnesses and 80 more were sick enough to be unfit for duty. The sick roll promised to grow, for the Japanese were on short rations and the amount of food to be doled out shrank daily. One ineffective airdrop of supplies was received on New Year’s Eve,7 an event that did more to whet appetites than appease them. Primary reliance was placed on supply by barge from Gasmata and by carrying parties using the trail to Iboki. Neither method was satisfactory; the last barge to get through the gantlet of preying torpedo boats and planes reached the Pulie River mouth on 5 February, and the carriers were unequal to the task of keeping up with consumption. The Komori Force slowly starved while it held an objective that the Americans showed little sign of wanting.
Mounting doubts about the utility of the airfield he defended plagued Major Komori. American light planes were flying over his positions, and the Lupin garrison reported that they could hear the takeoffs from Arawe Peninsula. The DIRECTOR Force engineers had built an emergency strip for artillery observation planes on 13 January and, with grading and coral surfacing, it soon came into regular use. By 8 February, the disillusioned Japanese commander was reporting to his superiors that the value of Lupin “is so insignificant that it seems the enemy has no intention of using it.” He outlined the increasing difficulty of holding his position with dwindling supplies and concluded that his force would soon be cut off and left “with no alternative but self-destruction.”8
At first, Komori’s broad hints that he be allowed to abandon his untenable defenses were answered by orders that he
continue to “smash the enemy’s project for construction of an airfield.”9 The Komori Force’s supposed exploits in holding Lupin, recognized. by two Imperial citations, formed a bright spot in an otherwise dismal picture of withdrawal and defeat of the Japanese forces in western New Britain. Eventually, the 17th Division had to face the fact that if it did not give Komori permission to pull out and join the general exodus, he and his men would be isolated and destroyed. On 24 February, Komori’s radio crackled out the eagerly awaited retirement order and he lost no time quitting Arawe. Passing on the word to his scattered elements to abandon their positions and head north up the track through Didmop, Komori was soon on his way toward a mid-island trail junction at Upmadung and a rendezvous with the 51st Reconnaissance Regiment which was to cover the Matsuda Force’s withdrawal. (See Map 29.)
A month of patrol clashes and ambushes had convinced General Cunningham that it was worthwhile to clear the whole Arawe area of Japanese troops. As 1/141 was abandoning its defensive sector near Lupin, an attack force composed of 2/112 and the tanks of Company B was making final preparations to drive them out. On the 27th, when the American force advanced to the airfield and beyond, they found that their quarry had eluded them.
The bloodless attack saw the birth of a new technique of communication between tank crews and the men they supported. Dissatisfied with the radio links they had with the infantry, particularly the close-in supporting squads, the Marine tankers installed field telephones at the rear of their machines through which the riflemen could contact the tank commanders. The improvement in tank-infantry cooperation was immediate, and the innovation proved to be sound enough to have a permanent part in armored support tactics.
In the several weeks before the Japanese withdrew beyond the Pulie River and gave up the airfield, General Cunningham’s force suffered a few scattered casualties in patrol actions. The sum of these added little to the official total for the DIRECTOR Force in the campaign, 118 killed, 352 wounded, and 4 missing in action, which was compiled as of 10 February. That date was declared the end of DEXTERITY Operations by General Krueger. It marked the link-up of Australian troops advancing overland from Sio on the Huon Peninsula with the American task force that had seized Saidor; it also was the day when Marine and Army patrols from the BACKHANDER and DIRECTOR Forces were supposed to have met at Gilnit on the Itni River. This event, which actually took place a few days later than ALAMO Force reported it, signified the completion of the “assigned mission of establishing control over the western tip of New Britain.”10
The Gilnit meeting between patrols from the two Allied task forces on New
Britain was less significant an event than it had appeared it would be during the planning stages of DEXTERITY. Intelligence available before the operation had indicated that only two main routes of withdrawal from Cape Gloucester were available to the Japanese garrison. One of these lay south toward Gilnit and Cape Bushing and the other followed the northern coast. A maze of native trails, most of them narrow and difficult to travel, was known to exist in the jungle waste in the island’s interior, but the exact, or even approximate, location of these trails was not known.
Gradually, as the fighting at Cape Gloucester wore on, the weight of evidence accumulating in the hands of the Allies indicated that the northern trail-net was the only practical withdrawal route for the Japanese. The efficiency of the antibarge campaign, the rugged nature of the terrain along the southern coast, and the presence of DIRECTOR Force at Arawe combined to give the enemy little chance to use the Cape Bushing area as a jump-off point for further movement east by sea or land. Even though the 1st Division became increasingly sure that the Japanese would retreat, by northern routes, it could not neglect the possibility that the trails south to the Itni would be used. Native reports that sizeable bodies of enemy troops were in the Gilnit area continued to come in after the 141st Infantry was identified in the fighting around the BACKHANDER beachhead. (See Map 23.)
The only certain answer to the question of what the Japanese were doing lay in aggressive patrolling. An Army observer attached to the 1st Division during early January noted that the Marines were “patrol conscious” and that “all units are encouraged to exert the maximum effort in patrolling as it is felt this activity is the best means possible for keeping up morale and alertness.”12 This description fitted the actions of the 1st and 5th Marines closely in the period following the capture of the airdrome. While the ADC group drove forward against the enemy troops holding the Borgen Bay defenses, the Marines guarding the newly won airfields sought the elements of the 53rd Infantry that had scattered after the fall of Razorback Hill.
Combat and reconnaissance patrols made a thorough search of the jungle lowland and foothills bordering the airfield perimeter, driving Japanese stragglers before them and securing the ground. The debris left by the enemy in retreat eventually revealed the main track over Mt. Talawe, but progress along its trace was slow and painstaking. Each branching trail, and there were many, had to be checked before the area of patrol effort could be extended. The primary mission of the BACKHANDER troops was the security of the airfields, and there was no inclination to overlook any Japanese group whose attacks might delay construction progress.
Behind the Marine-manned perimeter and the active screen of patrols, Army aviation engineers labored around the clock to build a runway and hardstands on the site of Airfield No. 2. Work on Airfield No. 1 was abandoned almost as soon as it began, when it became apparent that the field that could be built would not be worth the effort necessary to ready it for use. The Japanese had made no attempt to drain their airstrips or to obtain
practical gradients, and, as a result, when the 1913th Aviation Engineer Battalion began work on 3 January it was plagued by drainage problems caused by the heavy rains.13 Often the engineers’ bulldozers and graders appeared to be working in an enormous mud trough, as they sought to find firm ground on which to construct the field. A second aviation engineer battalion began work on the runway on 13 January, and a third came in on the 17th to build the necessary hardstands and roads. The only letup in construction activity occurred when a Japanese bomber made a nuisance raid, and the soldiers, like the Marines on the hills above them, headed for a safe place that would still afford them a view of the awesome antiaircraft barrage put up by the 12th Defense Battalion and the Army’s 469th Antiaircraft Artillery (Automatic Weapons) Battalion.
The Japanese had realistically concluded that air raids, and these only in irritant strength, were the only means left to them of hindering work on Cape Gloucester airfield. All during the period that the Marines who had seized the airdrome were conducting local patrols to consolidate the perimeter defenses, elements of the 53rd Infantry were holding blocking positions across the trails that led to Borgen Bay from Mt. Talawe and Sag Sag. General Matsuda had charged the 53rd with the task of defending the inland flank of the Japanese troops battling the Marines for Aogiri Ridge and Hill 660. Since American patrols from the airfield did not venture as far as the enemy trail blocks, and the Japanese showed an unusual lack of offensive spirit, there were no significant contacts between the two forces in the vast area south of Mt. Talawe. When the Marines did come over the mountain, the troops they ran into were not men from the badly mauled 53rd Infantry but elements, of the fresh 51st Reconnaissance Regiment.
Colonel Jiro Sato, the reconnaissance unit’s commander, had received orders to evacuate Rooke Island soon after D-Day, but it was not until the night of 7 January that he was able to make his move to New Britain. Then, using landing craft that had been carefully hidden from the eager hunting of Allied planes and torpedo boats, most of Sato’s 380-man force sailed undetected across Dampier Strait and up the Itni to Nigol. The regiment’s rear echelon made the night crossing on the 15th. After he traveled north and reported to Matsuda’s headquarters, Sato was given the mission of holding the western trail approaches to Nakarop and reinforcing the 53rd Infantry’s position.
On 12 January, the enemy reconnaissance unit set up in the jungle near Aipati village, not far from the junction of the main government track from Sag Sag to Natamo with the trail leading to the airfield. Thus, on 19 January, when a strong patrol from 3/1 reached this spot, it was an outpost of the 3rd Company of the 51st which it encountered. The Marines took the Japanese by surprise, killing six and driving off the rest, then scouted around long enough to make sure that they had found the main cross-island track before returning to base. The American discovery of this important trail occasioned the dispatch of strong combat patrols from the airfield, but these started too late to run
into anything but rear-guard action by the Japanese.
By 21 January, the Matsuda Force was under orders to withdraw from western New Britain. The 17th Division commander, General Sakai, had recommended the move about mid-January, arguing that the combination of steadily mounting combat losses and the effective throttling of the sea supply route meant the eventual annihilation of all the troops under Matsuda.14
The authorities at Rabaul shared Sakai’s pessimistic view of the situation, and General Imamura authorized a withdrawal to the Talasea area.15 The movement was actually underway before the formal order was issued.
When the 51st Reconnaissance Regiment took up positions guarding the trail complex south of Mt. Talawe, it was replacing part of the 53rd Infantry, mainly detachments of sick and wounded, who were headed east away from the scene of the fighting. On the 16th, General Sakai added to this movement of “forces not having combat strength” by directing General Matsuda to send all such men to the Iboki-Karai-ai sector and to dispatch elements of his command to “occupy key points along the north coast and protect rear supply lines, making these points bases for counterattacks.”16 The units selected the 65th Brigade Engineers, the 31st Road Construction Unit, and two field hospitals, had the mission of improving the coastal track and preparing casualty convalescent stations at Kokopo, Karai-ai, Iboki, Upmadung, Kandoka, and Numundo. (See Map 29.)
On the 21st, the formal withdrawal order was sent to Matsuda., directing him to disengage his units in contact with the Americans and concentrate in the Iboki area prepared for further movement to Talasea. General Sakai’s chief of staff understated the case when he commented that “this withdrawal, under present formations and over existing terrain, will be an extremely difficult one.” Ominously, he predicted that if the arrangements to send the sick and wounded to the rear proved “too obvious an obstruction to the efficient execution of the withdrawal, unavoidable instances when wounded and sick must be disposed of are to be expected.”17
General Matsuda set up a schedule of withdrawal that put the 53rd Infantry and 23rd Field Artillery on the trail first, but only as far as the east bank of the Natamo River, where strong defenses were constructed to cover the retreat of the main body. According to plan, all of the Matsuda Force would be across the Natamo by 1 February, using trails that converged on a main track which skirted the immediate coastal region until it reached the vicinity of Kokopo. The existence of this track was known to the Allies, but they had no way of pinpointing its
location until patrols actually walked along its path.
In recognition of the comparative good shape of the 51st Reconnaissance Regiment, Matsuda designated Sato’s unit as rear guard to cover both stages of the enemy withdrawal, the disengagement from contact in western New Britain and defense of the Japanese rear after most of the men had made the exhausting march to Iboki. The 51st was to take up positions on the Aria River southeast of Iboki, holding open both the track from the coast which swung inland there and the trail overland to Komori’s force at Arawe. On 24 January, Sato moved to Nakarop where he got his withdrawal orders, and, four days later, he was marching east at the tail of the Matsuda column.
The reconnaissance troops, like most Japanese combat units, made a deliberate withdrawal. Covering forces, strong enough to hold off sizeable American patrols, set up in ambush at various stages in the retreat. Usually, when action was joined, the Marines attacked to develop the strength and dispositions of the enemy unit opposing them, then pulled back to gather reinforcements, and came on again to wipe out the blocking force. Quite often when the attack was renewed the Japanese had moved on, and the only sensible course for the following troops was a wary, methodical pursuit.
Most of the Marine patrols reported that the Japanese appeared to be retreating south, an observation explained by the fact that many of the feeder trails in the web that cut the cross-island track led south at first, then east, and finally either north toward Kokopo or south again toward Gilnit. The route that much of the Matsuda Force was using in retreat actually led off from the trail to Gilnit at a point below the trail junction at Agulupella. Small wonder then that there was a strong disposition on the part of BACKHANDER Force headquarters to scour the southern region for Japanese troops that might be there. Unquestionably, the victorious Marines had the strength to pursue any reasonable course in clearing western New Britain of the enemy. As it happened, the Japanese withdrawal from the southern part of Itni valley was complete. A patrol of platoon strength could probably have scouted the trail to Gilnit and Cape Bushing with safety, once it was past the area of rear guard action straddling the enemy withdrawal route. Not having the benefit of hindsight, the 1st Marine Division gave the task of checking Gilnit to a composite battalion. (See Map 23.)
The assembly of this battalion came at the end of a week of vigorous patrolling, marked by occasional sharp clashes with the enemy rear guard. Units from all three of the 1st Division’s infantry regiments converged on Agulupella, the focal point of patrols coming from Sag Sag, the airfield, and the beachhead. As a result of an exchange of positions immediately following the capture of Hill 660, the 5th Marines with 2/1 attached held the beachhead, and the 7th and 1st Marines occupied the airfield perimeter. Units of the 5th made the initial contact with elements of the enemy’s rear guard at Natamo Point on 20 January. Thereafter, the reinforced regiment, operating under the ADC’s command, stuck close to the northern shore, driving ahead to close off the coastal track. Its sweep along Borgen Bay became the first leg of an advance that was eventually to find it landing in assault on Willaumez Peninsula.
In the center of the island, the first significant contact with the Japanese guarding Matsuda’s rear, elements of the 51st Reconnaissance Regiment, came on 23 January. A composite company of 1/1 following the trail from the airfield ran into an enemy machine gun and a few protecting riflemen, whose fire held up the patrol temporarily until the advance guard drove them off. Then about 1,500 yards of cautious advance later, the same or a similar small group opened up on the Marines again. In the flurry of return fire two of the Japanese were killed and the rest fled. Holding up for the night in his own ambush position close to Mt. Langila, the patrol commander resumed his advance the next day until his lead elements were pinned down by the fire of at least one enemy rifle platoon reinforced with machine guns. The Japanese positions blended so artfully into the shrouding jungle that the Marines had little at which to aim. Though the patrol’s return fire was heavy in volume, it had no apparent effect. Action was broken off, almost miraculously with no Marine casualties, and night defensive positions astride the trail were again occupied. On the 25th, the Marine patrol pulled back to await relief; its ammunition pouches were almost empty and the men were short of food. Half of the rations carried for the patrol by an ANGAU-led group of 40 native porters proved to be spoiled.
Company K of 3/1 made the relief on 26 January and moved out immediately toward the cross-island trail. After an uneventful day’s march and a night in perimeter defense, Company K moved unchecked through the area where the Japanese had held off the Marines on the 24th. At the trail junction, the men from K ran into elements of a composite company of the 7th Marines which had landed from LCMs at Sag Sag on the 22nd.
Travelling east on the government track and searching the surrounding area thoroughly, the 7th Marines’ patrol had reached Aipati on the 24th. The next day, the trail junction was occupied, and the company followed the airfield trail for several hundred yards without finding any sign of the Japanese. On the 26th, this patrol pattern was repeated and in addition a platoon was sent half a mile to the south towards Agulupella; neither unit encountered any enemy. A small reconnaissance patrol, four Marines and three natives, moving cautiously along the main track, was ambushed near Niapaua, where trails forked to Nakarop and Agulupella. One of the scouts was killed before the men were able to slip away.
A 7th Marines patrol from Aipati travelled a mile toward Niapaua on the morning of the 27th without seeing any sign of live Japanese. When Company K of 3/1 reached the cross-island track, it borrowed a machine gun platoon from the 7th’s composite company and started east to check the ambush site. Late in the afternoon, the scouts preceding the march formation sighted about 50 of the enemy set up on the far side of a stream that cut across the track. Prudently, the company commander held up for the night, ready to drive ahead in the morning. At 0700, 28 January, the Marines attacked and soon broke through the position spotted the day before. A short distance farther on, Company K ran into a storm of rifle, machine gun, and mortar fire that betrayed the presence of a reinforced company dug in across the track. The Japanese, holding high ground that commanded the Marine
position, were able to fend off all attempts to reach them, and the battle lapsed into a stalemated fire fight. After three hours of fruitless exchange, the Marines pulled back out of mortar range, taking 15 casualties with them.
Company K held its ground on the 28th while reinforcements, the rest of the 7th Marines company from Aipati and weapons elements of the 7th sent from the airfield, joined. Major William J. Piper, Jr., executive officer of 3/7, now took command of the combined group. Piper’s force found the Japanese position abandoned when it advanced on the 30th and proceeded without hindrance to Niapaua. From there, Piper moved south to Agulupella where he had orders to await the formation of a larger force, designated the Gilnit Group.
Elements of the 5th Marines were also directed to join the enlarged patrol headed for Gilnit. Scouts and combat patrols from 2/1 and 2/5, pressing southwest along the trail behind Aogiri Ridge, encountered Japanese rear guard detachments and drove them off. On the 28th, Company E, 2/5, moved through Magairapua, once Colonel Katayama’s headquarters, and then on to Nakarop, where General Matsuda was known to have been located. In both tiny villages and all along the trail between, there were deserted bivouac areas, littered with enemy gear but empty of troops. Matsuda’s own quarters was so well camouflaged that its location near the trail was not discovered until several days later.
At Nakarop, Company E was joined by Major Barba’s 1/5. Barba had broken off operations along the coast on 28 January and driven through Japanese delaying forces in an effort to reach Niapaua and aid Company K of 3/1 in reducing the trail block it had encountered. On the 29th, a heavily reinforced Company G, 2/5, and a large party of native carriers reached Nakarop from the beachhead. This force, dispatched by the ADC to join the Gilnit Group, plus Barba’s battalion with Company E attached, filed into Agulupella on 30 January to unite with Major Piper’s command. Lieutenant Colonel Puller was designated by General Rupertus to lead the combined units.
Puller’s command, six reinforced rifle companies and headquarters elements, numbered 1,398 Marines, 3 Australian officers, and 150 native carriers. The supply problem posed by its size was staggering and not easily surmounted. So long as the group stayed in the vicinity of Agulupella, native carriers could just barely maintain it by a constant shuttle from the beachhead dumps. The condition of the trails deteriorated steadily as heavy traffic and flooding rains turned the paths into slithery channels of mud. As supply by hand-carry slowed, air drop, both by the division’s Piper Cubs and Fifth Air Force B-17s, was instituted to keep Puller’s men fed and provided with essential items of equipment.
During the buildup at Agulupella, evidence mounted that the Japanese had not fled south, evidence that soon included the actual withdrawal order dug up in a cache of staff papers found at Matsuda’s headquarters, and the 1st Division decided to reduce the size of the Gilnit Group. Accordingly, the 1st Battalion, 5th Marines was detached, and the patrol strength dropped to 384 Marines plus the native carrier group. Puller had units of his command patrolling vigorously throughout the central part of the island while he
waited to build up sufficient reserve supplies to make the march to the south. A further complication arose when scouts discovered that a rain-swollen branch of the Itni near Arigilupua, about three miles from Agulupella, was too wide and deep for fording. Puller sent Company K, 3/1, to outpost Arigilupua while a detachment from the 17th Marines bridged the stream.
Captain George P. Hunt, the Company K commander, was given permission by Puller to reconnoiter the trail to the south, while the Gilnit Group was held up by the bridging operation. Hunt selected a small patrol of 11 men from his unit and set out down the well-defined track. With no enemy to stop him and no heavy equipment to slow him down, Hunt reached Nigol on the Itni in one day’s march. Bivouacking for the night, the Marines moved about a mile farther to the river bank opposite Gilnit on the next day and then returned to Nigol. The only Japanese sighted in two days was a sick straggler who was sent back to Agulupella.
Puller received Hunt’s report of his findings shortly before the main patrol started out for Gilnit. The bridge at Arigilupua was completed on 6 February, and Puller left with about half of his command immediately, meeting Hunt on the trail. Major Piper, who was serving as patrol executive officer, kept a portion of the unit with him and followed Puller, searching all the side trails and bivouac areas encountered. According to plan, the two elements of the patrol leap-frogged each other, exchanging personnel as necessary, with one group always moving ahead on the principal track while the other checked the jungle to either flank. Weapons crewmen, burdened with heavy loads of mortar and machine gun ammunition and parts, found the going particularly rugged. To all patrol members the trip was unforgettable, if only for the monotony of their steady diet of rain and K rations.
The food situation was dictated by the means of resupply. It had been decided to try to keep the patrol subsisted and equipped entirely by air drop, and the division’s light planes were handed the task. The little Cubs, whose peak carrying capacity was two cases of K rations, one held on the observer’s lap and the other placed on a desk behind him, flew all day long. Often the pilots logged 10-12 hours in the air, landing, refueling, and taking off again, in a regular pattern from dawn to dusk.18 All drops were made at villages along the route, Arigilupua, Relmen, and Turitei, according to schedule, with special requests filled as they were received.
One of the items asked for by Puller in an urgent dispatch, several hundred bottles of mosquito lotion, raised a few eyebrows at division headquarters, but the request was filled promptly. The Gilnit Group commander’s well-known disdain for the luxuries of campaigning caused the wonder, but the explanation was simple and a lesson in jungle existence. As a patrol member later remarked:–
Hell, the colonel knew what he was about. We were always soaked and everything we owned was likewise, and that lotion made the best damn stuff to start a fire with that you ever saw.19
The advance party of the patrol reached the river opposite Gilnit on the 9th, and the main body arrived the following day. Puller sent a small scouting party across the Itni to the patrol objective; again there was no sign of recent enemy occupation. A platoon sent to Cape Bushing encountered no Japanese, but did find ample signs of the area’s one-time garrison, the 141st Infantry. Considerable quantities of weapons, ammunition, and equipment were found in the various enemy camps; surprisingly, there were even some food supplies left behind. Anything that was of use to division intelligence officers, or to ANGAU for distribution to the natives, was set aside; everything else was destroyed.
Puller was ordered to wait in the Gilnit area until he was contacted by the Army patrol dispatched from Arawe. According to the reports the Marines received, the soldiers were held up east of Gilnit by enemy opposition at Attulu Hill, once the 141st Infantry’s command post. Both native and Marine scouts explored the hill and found no Japanese, and Puller radioed division that in his opinion there were no enemy forces in the area to be discovered.
On the 14th, the division made its own contact with Puller when two LCMs with a platoon of 1/7 on board arrived from the airfield. The boats carried some extra supplies for the patrol which was about to set out on its return trip up the track to Agulupella. About midday on 16 February, elements of the Arawe patrol reached Gilnit via the river and met the platoon that Puller had left behind a few hours earlier for that purpose. Its mission fulfilled by the contact with the soldiers, the last Marine unit moved out briskly in the trace of Puller’s column, bringing to an effective conclusion 1st Division combat operations in the southern Itni valley.
On the maps issued to BACKHANDER troops prior to D-Day, the coastal track that paralleled the shore of Borgen Bay appeared to be the most logical and, in fact, the only practical northern route of withdrawal for the Japanese. By the time enemy resistance collapsed at Hill 660, Marine intelligence officers were reasonably sure that their maps were wrong. Somewhere in the miles of jungle and swamp south and east of the bay were other trails, their existence confirmed by captured papers and the reports of natives and prisoners of war. The names of the villages of Aisalmipua and Kakumo began to crop up as way stations on a frequently used supply route, but the natives could not agree on their location, except to confirm that they lay along a trail from Agulupella to Kokopo. (See Map 29.)
The government track from Sag Sag that ended at the coast a few hundred yards west of Natamo Point was about the only trail that the Allies were sure existed in the Borgen Bay area. They were unaware of the presence of another trail which led to Nakarop from the east side of the point, this one broader, in better shape,
and partially corduroyed in its wettest stretches. Still a third important track not recorded on preinvasion maps ran from the village of Old Natamo east of the Natamo River to Kakumo.
In order to effect their retreat without hindrance, the Japanese had to block the trails that led through Agulupella long enough for the main body of the Matsuda Force to get clear and started for Kokopo. In the center of the island, the 51st Reconnaissance Regiment executed this task with seeming ease, and along the coast the same job was performed well by a rear guard made up of elements of the 53rd Infantry, the 39th Field Antiaircraft Battalion, and the 11th Company of 3/141. The vigorous resistance put up by these latter troops had the effect of clouding the issue of what route the Matsuda Force had taken. When they had delayed the Marines as long as was necessary to let the main body of the Japanese escape, the defenders just faded away. Helping the rear guard’s withdrawal was the natural caution which characterized the patrol operations of veteran troops in the jungle.
At every natural obstacle along the trails that had to be used for any sizable troop movement, there was the threat of ambush. A sudden burst of fire from a single machine gun or a fusillade of shots from a few well-placed riflemen could be the cause of hours of delay. Much of the time the enemy could not be seen and the terrain stalled attempts to outflank his positions, leaving just the few men at the point of a patrol to reply to the fire that swept the trail clear. Under the circumstances, it took steady nerves, quick reactions, and a considerable amount of quiet courage to be a scout and take the lead on a patrol into enemy-held territory. The situation was ideal for a few determined Japanese, probably no more than 300 by the last few days in January, to hold up the advance of thousands.
The coastal track rimming Borgen Bay looped across the base of Natamo Point, making the narrow, jungle-covered spit of land an excellent site for rear guard action. Inland, the several rivers and numerous streams discharging into the bay helped turn the rain-sodden ground into one of the worst stretches of swampland in western New Britain. The Japanese knew that the Americans would have to advance up the coastal corridor and waited for them in prepared positions.
An enemy map of the point, captured on 3 January, showed machine gun emplacements and rifle pits sufficient to hold a reinforced platoon located there. When a patrol started out to check the point on 20 January, there was a strong possibility that the Japanese might be holding it. Still, the shore of Borgen Bay east of Hill 660, was sprinkled with abandoned positions and these might also be vacant. When the patrol, most of Company A, 1/5, led by regimental scouts, reached the estuary that cut into the base of the point, all doubts were dispelled. Automatic weapons fire lashed across the water and forced the Marines to take cover. For two hours, the patrol’s supporting mortars and machine guns sought to silence the enemy guns, but to no avail. Finally, because ammunition was getting low, artillery fire was called down to cover the Marines’ withdrawal.
On the 21st, the 75-mm howitzers of 1/11 fired on the suspected locations of the enemy weapons, and, on the following morning, a reinforced company tried to attack but could make no headway. A platoon that worked its way through the swamp to come up on the east side of the point
spotted positions that appeared to hold a company and then pulled back. Ten enemy soldiers were killed and several wounded in the day’s exchange of fire, most of these when the patrol, on its first approach, caught the crew of a strongpoint unawares. All through the night, artillery harassed the Japanese on the point, and, at 0910 in the morning, a squadron of A-20s appeared from Finschhafen to bomb and strafe ahead of a two-company attack supported by tanks.
The tanks, mediums of Company A, were transported across the bay by LCM to a beach about a thousand yards from the point and then lumbered up to lend supporting fire to the infantry assault. From offshore, a rocket DUKW laid down a barrage on the Japanese positions, and 1/11 fired in advance of the Marine skirmish line. In a series of short, violent fights, the Japanese were killed or driven from their defenses. In late afternoon, when Natamo Point was securely in American hands, the bodies of 30 enemy soldiers were counted in and around the wrecked and smoking gun pits. Some 15-20 machine guns and two 20-mm cannons were destroyed in the day’s action. A Japanese 75-mm gun located somewhere in the jungle to the southeast of the point started firing late in the afternoon, but 48 rounds in reply from a 155-mm seacoast artillery battery located in the beachhead silenced the piece.21
About half of the hundred-man garrison of Natamo Point fled the Marines’ final attack and escaped down the trail to Agulupella or across the Natamo River to the 53rd Infantry’s positions on the eastern bank. In a follow-up advance on the 24th, the 1st Battalion, 5th Marines accounted for 10 more of the enemy while clearing the track as far as the river. The explosion of small-arms, mortar, and artillery fire that greeted any attempt to cross brought an effective halt to the day’s advance. For five days, the Natamo River marked the limit of the 5th Marines’ advance to the east, as the Japanese held on tenaciously.
On 25 January, an attempt to land a rifle platoon, reinforced with a half track and machine guns, in a coconut grove about 300 yards east of the river was repulsed by heavy Japanese fire. Similarly, a lodgement on the east bank of the river could not be held in the face of overwhelming enemy resistance. Before attempting another frontal assault, patrols from 1/5 followed the river south to find a suitable crossing, but the swamps defeated their efforts. On the 27th, Company B followed the corduroyed trail that led to Nakarop from Natamo Point until a strong Japanese rear guard was encountered about 4,000 yards inland. In the resulting fire fight, the Marines had one man killed and three wounded; the enemy lost 15 soldiers but accomplished his mission of holding up the advance. On the 28th, the 1st Battalion, 5th, less Company B which remained to hold the lines along the Natamo, moved out along this trail with the mission of reaching Nakarop. This battalion, spurred on by reports of the action at Niapaua, made quick work of two rather feeble attempts to delay its progress and bivouacked three and a half miles inland, not far from its objective. But the next day’s advance disclosed that the Japanese were gone.
Not only had the enemy disappeared from in front of the Marines working along the trails inland, but he had abandoned his positions guarding the Natamo’s
west bank, too. Scouts who moved 2,000 yards upstream on the 30th, then forded the river, and came down on the opposite bank found the defenses deserted. On the 31st, a patrol crossed the river mouth and proceeded to Old Natamo; three Japanese who were found in a pillbox near the beach were killed, but no one else was sighted. One of Lieutenant Colonel Puller’s patrols reached Kakumo on the same day. The natives told the Marines that the last Japanese had left the village heading east the previous day.
In its advance to the Natamo and movement down the trail to Nakarop, the 1st Battalion, 5th Marines had had 6 men killed and 33 wounded. Estimated enemy dead among the rear-guard detachments was close to 75, and the wounded probably reached a similar figure. In military terms, the cost to the Japanese was negligible for the prize gained, time for the main body of the Matsuda Force to get well underway for Iboki, Talasea, and, eventually, Rabaul.
The next obvious step for the 1st Marine Division was aggressive pursuit of the retreating Japanese. Patrols of 2/1, attached to the 5th Marines, followed the coastal track as far as Namuramunga, reaching the village, which was seven miles from Old Natamo, on 2 February. Two other patrols of the 1st Marines’ battalion cut directly through the jungle from the coast to find the Agulupella-Kakumo-Kokopo trail and establish conclusively the enemy withdrawal route. Only stragglers, sick and wounded men, were encountered by any of the patrols; the Japanese left behind were too weak from hunger to offer any resistance.22
On 3 February, General Rupertus conferred with General Krueger at Finschhafen to discuss further actions by the 1st Marine Division. Both field commanders reacted unfavorably to a directive from GHQ that had just arrived ordering a new Final Beachhead Line in western New Britain, one that would include all of Borgen Bay in the defended perimeter. The feeling among the staff at GHQ was that the new line would prevent the Japanese from returning and shelling the landing beaches supporting the growing airfield. Rupertus and Krueger, knowing that their current problem was not the return of the Japanese but the destruction of the troops that had fled, ignored the message, feeling that it was based on premises no longer valid. Instead, Rupertus was given the go-ahead signal for an immediate pursuit of the Matsuda Force as far as Iboki and alerted to Krueger’s plan of continuing the advance to the Willaumez Peninsula and beyond.23
The 5th Marines got the mission of keeping the pressure on the retreating enemy
and, if possible, cutting off and destroying some part of the Japanese force. A simultaneous overland and overwater advance was planned with the help of landing craft of the Army amphibian engineers. The division’s Cub planes were to scout ahead of the advancing Marines, spotting suitable landing beaches and keeping tabs on the Japanese. The 5th Marines knew where the enemy was heading and the route he was taking, but the jungle shielded the troops from aerial observers. Under the circumstances, when the Japanese might easily be waiting in ambush for their pursuers, the Marine advance had to be both swift and cautious.
Bad weather was a frequent factor in holding up the LCM-borne phases of the 5th Marines’ pursuit. Crashing surf denied the forward beaches to landing craft and placed the burden of catching up on the patrols operating along the coastal track. When the seas and the limited number of LCMs available permitted, large elements of Colonel Selden’s unit were able to leap-frog the foot patrols and bite off 10- and 15-mile chunks of the coast at a time. Alternately in the lead, as the 5th moved east, were elements of the attached scout platoon from division tanks, men of the regiment’s own intelligence section, and, often, a brace of Army scout dogs and their handlers, loaned for the operation. Kokopo, Gorissi, and Karai-ai were occupied in their turn, and in each village the natives told the same story—the Japanese were still ahead. Prisoners seized along the trail in the mop-up of stragglers confirmed the continued head start.
On the 24th, patrols from sea and land reached Iboki, fully expecting to encounter Japanese resistance at this primary supply base. But there were no enemy defending troops to be found, only sick and starving individuals who had fallen behind. The last cohesive unit of the Matsuda Force, the 51st Reconnaissance rear guard, had passed through the village on the 16th.
Despite his disappointment at missing contact and visiting further destruction on the Japanese, Colonel Selden was able to view his regiment’s accomplishment with some pride. On short notice, actually less than a day’s warning, the 5th had started its 20-day trek and worked out a successful method of operation that made the best use of the men and transportation available. As Selden later summarized the effort, he had:
... 5,000 men on this jaunt of sixty-odd miles over some of the worst jungle terrain in the world. We kept the Nips on the move by having fresh men out every morning. With few exceptions, men were not called upon to make marches on two successive days. After a one-day hike, they either remained at that camp for three or four days or made the next jump by LCMs.
... To have accomplished my march four days prior to the deadline without loss or even having a man wounded was, in our estimation, quite a feat.24
Allied Progress Report25
As the 5th Marines moved into a staging area at Iboki Plantation, the final arrangements for continuing the 1st Division’s advance along New Britain’s north coast were being made. General Krueger intended to make a landing on Willaumez
Peninsula, secure it, and drive on for Cape Hoskins and the Japanese airfield there. The landing craft needed for the pending operation would be a mixed and scant force of Navy LCTs and Army LCMs. Most of the amphibious shipping available to Seventh Fleet was tied up in support of landings in the Admiralties.
The success of DEXTERITY was an influential factor in hastening the schedule of operations designed to isolate Rabaul. On 13 February, General MacArthur issued a directive calling for the seizure of Manus in the Admiralties and Kavieng on New Ireland with a probable target date of 1 April. There was strong sentiment at General Kenney’s headquarters to slice the delay time and secure the enemy airfields in the Admiralties ahead of the projected D-Day, if the Japanese garrison appeared to be weak. Intensive aerial scouting convinced the Allied Air Forces leader that a reconnaissance in force into the Admiralties could be risked, and he was able to persuade General MacArthur to order the move. A reinforced squadron of the 1st Cavalry Division made the first exploratory landing on Los Negros Island on 29 February and, in a sense, caught a tiger by the tail. The Japanese garrison, much stronger than aerial reconnaissance had indicated, battled fiercely to throw the cavalrymen off the island. General MacArthur made the decision to reinforce the troops ashore rather than withdraw them, and throughout March, American soldiers in overwhelming strength poured into the Admiralties. The capture of two airfields and an excellent deep-water harbor in the islands had the effect of hastening the tempo of operations in the Southwest Pacific and forging an important link in the chain of Allied bases that ringed Rabaul.
So swift was the pace of advance in early 1944, that the strategic importance of Cape Gloucester’s airfield shrank steadily while the engineers were still working to get it ready for use. The airfield site at Saidor, its seizure termed by MacArthur a vital “exploitation of the New Britain landings,”26 turned out to be usable by transports and other heavy aircraft several weeks before the runway at Cape Gloucester was ready for regular traffic. Captain Petras landed General Rupertus’ plane on Airfield No. 2 on 28 January, and the first Army transport came down on the field on the 31st. Pierced steel planking was laid the whole length of the runway to overcome the effects of heavy rains, but the site was simply a poor one, and a staggering amount of work and materials would have to be devoted in an effort to make Cape Gloucester into a first-class airfield. The changing strategic situation made this task unnecessary. The 35th Fighter Squadron moved into the field on 13 February, while the aviation engineers were still fighting the cape’s unsuitable terrain, and the 80th Squadron followed on the 23rd. Within a month, recall orders had been issued for both units so that they might be committed in support of MacArthur’s advance west along New Guinea’s coast toward the Philippines.
Marine operations following the seizure of Cape Gloucester had strong overtones of an aggressive police of the area. The 1st Division’s patrols pressing the retreating enemy toward the east made a clean sweep of stragglers at the same time they were trying to find and destroy elements of the main body of the Matsuda Force.
The bothersome problem presented by the hulking presence of Rooke Island close inshore to the airfield was taken care of by Company B of the 1st Marines. Landing from LCMs on 12 February, the company patrolled vigorously for a week and confirmed the finding by ALAMO scouts that the Japanese had pulled out. The garrison once considered for Rooke no longer seemed necessary, and the Marines returned to Cape Gloucester on the 20th. By the end of February, New Britain was clear of any effective Japanese force as far east as a line joining Iboki and Arawe.