Capture of Outlying Islands
Overwater assaults on the lesser islands of the Admiralties, along with mopping-up actions on Manus, comprised the last phase of combat operations. In light of the losses on Hauwei and with the expectation that landings would be opposed, attacks on the outlying islands would be made in considerable force. Pityilu Island, 3 miles north of Lugos Mission, was the first scheduled for attack on 30 March by the 1st Squadron, 7th Cavalry, reinforced (Map No. 3, pages 8-9). The other islands were objectives of the 12th Cavalry; the 1st Squadron, reinforced, would seize and mop up Koruniat
and Ndrilo Islands on 1 April and two days later the 2d Squadron, reinforced, would attack Rambutyo.
Pityilu Island, thought to be defended by 60 Japanese, is nearly 3 miles long and varies in width from 250 to 650 yards. The beach chosen for the assault is the only one suitable for landing; it is of white, hard sand and is located about the center of the southern shore. Six waves transported in LVT's, LCM's, and LCV's would make up the assaulting force, which would move inland through the coconut plantation covering the western two-thirds of the island.
Naval gunfire, artillery, and air strikes had been used against this island at various times before the attack date. Destroyers had first bombarded it to keep down hostile fire when the approaches to Lorengau and Lugos Mission were being cleared of mines. A Japanese naval gun captured on Hauwei Island had been put back into commission and used to augment the fires on Pityilu. Preparation for the attack began at 0630 on 30 March by 2 destroyers which fired 30 rounds each until 0730. A spectacular air strike followed the naval fire.
For the first 10 minutes P-40's dive-bombed the landing beach; the next 10 minutes P-40's and Spitfires strafed the entire island. Immediately afterwards the 61st Field Artillery Battalion, which had registered the previous day from positions on the south side of the Lorengau air strip, pounded the island with a heavy concentration of 105's. When the artillery barrage was lifted, two LCS's (Landing Craft, Support) on either flank of the beach opened up with their rockets. By this time the assault waves were approaching the shore, and the rockets searched the island in front of the first wave.
The successive waves landed unopposed and the troops established a beachhead with Troop C as the left wing, Troop A in the center, and Troop B on the right. At 1000 some patrols sent out immediately after landing reported no contact with the enemy. The Reconnaissance Platoon moved by buffalo to the west, while Troop C in reserve on the beach sent patrols west into the interior. Troops A and B, with one medium tank leading the way, began an advance east toward the rain forest which covered that end of the island.
As the troops advanced they ran into light machine-gun and sniper fire which was easily silenced. Enemy guns in a hut, encountered by Troop B after moving 1,000 yards along the south coast, were neutralized by the tank, which blew up the entire position.
At 1212, after progressing 1,500 yards, Troop A ran into heavy resistance from dug-in positions midway between the north and south shores. Troop A started to withdraw to permit an artillery concentration to be placed on the position, but the Japanese followed the withdrawal so closely that it was impossible to evacuate our wounded until a light tank was brought up to cover this operation. Then a 45-minute artillery concentration was placed on the enemy bunker, after which Troop A, aided by the light tank, attacked the position and killed 14 Japanese.
Troop B came upon a hastily constructed trench containing 21 Japanese, who gave their position away by loud chatter. When 2d Lt. John R. Boehme and two privates went out to investigate the position, they were wounded by fire from the group. In spite of his wound, Pvt. Paul A. Lahman advanced on the position, firing clip after clip from his BAR. He was credited by Lieutenant Boehme with the destruction of practically the entire force. At 1720 the squadron withdrew on regimental orders to a position on the western edge of the rain forest and established a perimeter for the night. The Reconnaissance Platoon patrolled the western end of the island and returned to report no contact. Although the attacking force then did not know it, all the Japanese garrison had been killed or wounded. After a bombardment the next morning, the squadron advanced and discovered more dead Japanese, which made a total of 59 killed against 8 cavalrymen killed and 6 wounded in the mopping up of Pityilu.
Seizing Pityilu was an expensive operation compared with the other small islands, which turned out to be either unoccupied or
harboring only a handful of Japanese who hid out in the interior. Until 4 April our command did not have knowledge of the enemy document of 2 March that had ordered the calling in of the garrison units from Rambutyo, Peli, Pak, and Pityilu. In preparation for the 1st Squadron, 12th Cavalry's attack on Ndrilo and Koruniat, which had earlier been suspected of harboring naval guns, PT boats and a rocket boat as well as the customary artillery took the islands under fire. Bombing and strafing by the RAAF and heavy mortar fire from Mokerang Point also preceded the assault, which moved out on I April, transported in native canoes. No Japanese were found on Koruniat or on Ndrilo, and the next day the 1st Squadron returned to Lombrum Point.
Rambutyo, an island 11 miles long and 5 miles wide, was also invaded by a strong force. On 3 April the 2d Squadron, 12th Cavalry, with two platoons of engineers and two platoons of the shore battalion, were loaded on destroyers at 0600. After a bombardment the troops landed at noon and met no resistance. Some Japanese were thought to be hiding in the rugged interior, so the 2d Squadron's task was a mopping-up operation through unusually steep country and heavy jungle, where water was hard to find. By 23 April, with the aid of an Angau warrant officer and native guides and patrols, 30 Japanese had been killed and 5 more captured. Further mopping up was left to the native police recruited by Angau.
Meanwhile on 9 April the 1st Squadron of the 12th had occupied Pak Island. Three prisoners, captured on 10 April, had escaped from Rambutyo by native canoe. On 12 April more Japanese were found on the east end of Pak and destroyed, eight of them in a large coral cave from which they fought until the cave was blown in on them by a demolition section from the 8th Engineers.
Mopping-up actions on the small islands completed the combat operations of the 1st Brigade Combat Team, which had initiated the invasion of the Admiralties and whose units had fought almost continually for over a month. On 4 April the 5th Cavalry began moving to a semipermanent bivouac area on Koruniat Island, and after its operations were completed the 12th Cavalry moved to Salami Plantation. The troops of the 1st Brigade would settle down to housekeeping, rehabilitation, and training, with existence in the tropics made more bearable by the arrival of refrigeration, bakery, and laundry companies. The 2d Brigade continued to rout out the remnants of Japanese defenders on Manus.
Final Mopping Up on Manus
After the hard struggle to break the last enemy holding positions on Manus, the 2d Brigade Combat Team pushed inland after the scattering enemy, and penetrated much of the thick jungle, swamps, and high mountains covering the interior. The Angau and native guides helped the 7th and 8th Cavalry patrols make their way through this rugged terrain, while the 302d Cavalry Reconnaissance Troop, trained for overwater patrolling, probed coastal areas around the entire island.
Eastern Manus was the area assigned the 8th Cavalry to clear of Japanese, many of whom were thought to have fled to this area from Los Negros. Less Troop A which had suffered high casualties, the 1st Squadron established a perimeter on the high ground at Rossum. From Number Two Road and from the 2d Squadron positions along Loniu Passage, aggressive patrols then covered the entire network of native trails. The Japanese encountered were always in small groups of stragglers, for the most part wandering aimlessly across country trying to exist on the raw flesh of dogs and on what they could steal from the native gardens. Constant pressure was maintained on the remaining enemy, although the pursuing troops were frequently rotated for rest and rehabilitation. Up to 2 May when the regiment was withdrawn to bivouac at Hauwei Island, the 8th Cavalry had accounted for 285 enemy dead after suffering a total loss of 4 troopers killed and 7 wounded.
Although the attack on Pityilu limited the 7th Cavalry's patrolling efforts, by 30 March its patrols operating from Lorengau had covered all the ground west of Number Two Road to the Tingo-Hiwal trail, making a wide area around Lorengau secure for the building of the naval base. After the 1st Squadron completed the occupation of Pityilu, it carried on patrolling activities from Lugos Mission. The 2d Squadron was assigned the difficult task of moving inland along Number One Road as far as Kawaliap. A base reconnaissance camp would be established at Yiringo by a reinforced troop while the other troops established themselves at designated points along the road to facilitate shuttling of supplies, secure the route, send out local patrols, and set ambushes.
Supplying an entire squadron, ordered to move as far as 15 miles inland, presented a serious problem. Continuous rains had made the red clay Number One Road impassable for all vehicular transportation but a D-7 dozer with trailer, and beyond Tingo nothing could get through. On 2 April Troop E moved 500 yards west of the Lihei River and established a supply base for the planned patrols. A dozer moved supplies to the east bank of the river, but troops had to take over from there, ford the river waist-deep, and then climb up a series of steep hills that were almost impossible for men carrying loads. Because this supply base was so difficult to reach, a new one had to be set up and by 8 April another suitable route was devised. Buffaloes carried supplies up the Tingau River to a point
north of Sabon, and from there native carriers were ready to relay them to the inland patrols when troops of the 2d Squadron reached their assigned positions. Since natives could carry a 41-pound load from Sabon to Yiringo in about 3V2 hours, while the same task took the average soldier 2 or 3 days, the new supply arrangement eased the burden on the troopers considerably.
By 10 April the troops of the 2d Squadron had stationed themselves at Yiringo, Drano, Lundret, and Sabon. On the previous day a large group of enemy stragglers, attempting to gather in the Drabito-Metawarri area south of the 2d Squadron's farthest point of penetration, had been bombed by P-40's from the 73d Wing RAAF. The southern coastline as far as Patusi Bay had been combed by the 8th Cavalry, so the 2d Squadron's efforts were directed to a thorough clearing of the area north and west of the Number One Road. Living under terrible conditions of rain and heat, the squadron patrolled the interior until 17 April when it began to move to Hauwei island, its mission completed. The squadron had accounted for 82 enemy (lead and had lost 1 man killed and 4 wounded. However, the heavy rains contributed to a high disease rate and 74 men had to be evacuated. The 1st Squadron kept its perimeter at Lugos Mission until 5 May, and the Japanese accounted for by its patrols, aided by the natives, raised the 7th Cavalry's total of Japanese killed during the mopping-up period to 102. Seven prisoners were taken.
After 5 May the entire 7th Cavalry established a semipermanent camp at Hauwei Island. The 1st Squadron was relieved at Lugos Mission by the 1st Squadron, 8th Cavalry, which continued mopping-up operations until the close of the official campaign on 18 May. The 2d Squadron was also assigned to further patrolling on 17 May. While the 8th Cavalry concentrated on the northeastern area, the 302d Cavalry Reconnaissance Troop continued its extensive patrolling along the coast. Natives furnished by Angau served the 8th Cavalry not only as bearers, scouts, and canoe paddlers, but also as police boys and "hired assassins" who tracked down and killed Japanese. The troopers also became adept at hunting Japanese, often acting as if it were a mere sporting proposition. On one occasion a native reported to an 8th Cavalry patrol that three unarmed Japanese were in a hut to their front. Three members of the patrol dropped their arms, moved into the hut and, after a scuffle, killed the three with knives. The total number of Japanese killed by the 8th Cavalry
in this last period of mopping up was 133, with 15 captured and 18 additional bodies discovered. Many of the dead discovered during the period had perished from starvation.
In the final destruction of the Japanese, the 302d Cavalry Reconnaissance Troop demonstrated its skill in hunting and ambushing an enemy in unknown and difficult country. The unit, consisting of 8 officers and 177 men, had been intensively trained before the operation, and the experience gained saved many lives. Aside from losses suffered in the ambush at Hauwei, the troops sustained only two casualties from 10 March to 12 May, during which time at least a part of the troop was in daily contact with the enemy. A considerable part of the success of the troop lay in its mastery of the art of concealment. It was essentially a "sneak and peek" organization which made stealthy landings in small boats by daylight and darkness; then concealed the craft and obliterated all traces of the landing. All the troopers were adept at mapping and map correction and the establishment of trail-watching posts. When the enemy ceased using the trails and moved through virgin jungle in the later phases of the campaign, the troopers learned how to find them. By tactful handling of the natives and by mastering their language quickly, the troopers won indispensable assistance. When Japanese came to the villages hunting for food the troopers were immediately informed.
Messages from patrols were sent chiefly by native runners, by pigeons, and by code on radio sets. Although the native runners and the pigeons were reliable, the pigeons would not fly when soaked in a tropical downpour and waterproof covers had to be provided for their cages. Sometimes the weight of the radio hampered small moving patrols. Simple codes were improvised and six Sioux Indians who could speak their tribal language fluently improved on these codes, sending messages in the clear with impunity. Although the missions of the troop were chiefly of reconnaissance, they killed 48 Japanese and captured 15 prisoners in their extensive patrolling of the island during May.
Enemy dead accounted for by all the units involved in the last phase of operations on Manus reached a total of 586. Prisoners, captured mostly in the last days when the starving Japanese were more disposed to surrendering, totaled 47. During the mopping up, our forces suffered the relatively small losses of 6 killed, and 12 wounded. At the close of the official campaign it was estimated that 150
additional Japanese were still hiding out in the jungle. Patrols and armed natives continued to find these, but as most of them were dying of starvation, they were no longer a threat.
Service troops and construction equipment had come ashore along with combat troops immediately after the reconnaissance in force had seized its beachhead, when every man was needed to defend the initial hold against counteroffensives. The Brewer Operation was conceived with the prime objective of developing an advance naval and air base to neutralize Japanese power in the Bismarck area. Therefore the planned immediate establishment of two airdromes and light naval facilities called for a high priority on service troops who were to be employed at these tasks as soon as practicable. In addition to their use for strategic objectives, service troops also had aided tactical operations in the Admiralties immeasurably. After accounting well for themselves in their emergency combat role, helping to defend the early perimeter, the first service units ashore took up the varied tasks of building air and naval facilities as well as performing the indispensable services for the combat troops. The quick repair of the Momote air strip brought fighter planes almost to the front lines. Engineers directly helped in the destruction of the enemy; without the bulldozer, combat operations inland on muddy roads, especially with armor, would have been impossible. As the fighting reached the mopping-up stage and more service units came ashore, the activities of building a more habitable base involved more men than did services for troops engaged in combat.
After the initial stages of operations, signal communications between Army, Air Corps, and Naval forces were greatly improved by the arrival of the 99th Signal Battalion at Salami on 16 March. This unit took over the switchboards and was responsible for all wire communications on Los Negros until 20 April. On 9 April a radio station and message center was set up at Salami Plantation by a scction from the 832d Signal Service Company.
In transforming the devastated island into a naval and air base, health precautions were as essential as construction. Early in the operations the 52d Malaria Control Unit began searching for mosquito breeding places and carried on an extensive oiling program. This work was also kept up by the 28th Malaria Survey Unit which on 22 March made the first blood survey of natives in Mokerang village.
Natives were of great use in both tactical operations and construction work. The Angau Detachment recruited them for pack trains, for scouting, for police work, and for actually hunting and killing the enemy. By 11 May the. entire population of 17,000 was under the control of Angau and 5,000 were being rationed and cared for. In 5 camps, 1,231 native laborers (a few of whom were women and children) were employed on various projects. Many were assigned to cavalry units and to the air forces. The 58th Evacuation Hospital used a large number in malaria control, and the greatest part were engaged in various overhead duties, including improvement of the villages.
The 40th Naval Construction Battalion, which had defended the air strip with the cavalrymen on 3-4 March, was joined by other Seabees of the 17th, 46th, 78th, and 104th Naval Construction Battalions. The Seabees were to work on the Momote air strip as well as on dock and road construction. Other sections working on roads and maintenance were taken from the 8th Engineer Squadron and the 592d Engineer Shore Battalion. On 16 March the Momote air strip was in use and the airdrome well on its way to completion; however, the captured Lorengau airdrome was discovered not to meet the requirements for the second airdrome planned for the Admiralties. Therefore, at Mokerang Plantation, a coral-surfaced modern airdrome 100 by 8,000 feet was put under construction. By 18 May the Momote airdrome was extended to 7,000 feet and surfaced with coral, completely equipped with taxiways, hardstandings, and storage areas.
Many naval facilities, begun soon after the landings, were finished by the end of the official campaign. A floating Liberty dock, a fixed Liberty dock, and a pile dock at Mokerang were ready for use. An LST pile dock was almost complete and a pipeline jetty had been built at Porlaka. Facilities for a full-fledged base were begun: storage for 7,000 barrels of bulk petroleum was ready at Momote
and space was being built for 30,000 barrels at Mokerang. Channels into the harbor were also improved and buoyed and a crib dock constructed.
Areas around the air strips were becoming more habitable. Camps had been built for the RAAF and AAF, and more living quarters could be constructed from the lumber turned out by a sawmill operated by the engineers. Drainage was the biggest obstacle to providing healthful living conditions. Tropical rains kept troops busy and often made them repeat their agonizing efforts. just as the engineers had nearly filled a swamp about 100 yards wide on Hauwei Island, the rains came and the swamp spread to three times its original size. Nevertheless, by 18 May, eastern Los Negros and the Lorengau area of Manus as well as some of the outlying islands looked very little like the lush and dangerous territory invaded by the 1st Cavalry Division a month and a half before.
page created 28 June 2001
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