Further operations in the Bismarck Archipelago had been contemplated for nearly two years. The Joint Chiefs’ directive which launched the campaigns against Rabaul in 1942 had authorized operations to follow Arawe and Cape Gloucester, and MacArthur’s early plans called for the capture of Kavieng on northern New Ireland and of Manus in the Admiralty Islands as well as of Rabaul. Further, when the Joint Chiefs were deciding to bypass Rabaul, General Marshall suggested that CARTWHEEL be extended to include seizure of Kavieng, Manus, and Wewak. MacArthur was less than enthusiastic about Wewak, which was a major enemy base. His plan for the drive to the Philippines, RENO III, called for the invasion of Hansa Bay on 1 February 1944, of Kavieng by the South Pacific on 1 March 1944, and of the Admiralties on 1 March 1944.
Responsibility for base construction at Kavieng and at Seeadler Harbour at Manus was to be Admiral Halsey’s, and he began planning these bases in November 1943. Kavieng was supposed to become a minor fleet base, a PT base, and a major air base with six airfields. Manus would serve as an air base (two airfields and a seaplane base) while Seeadler Harbour would be developed into a major fleet base whose complete repair facilities would include drydocks, and a main naval supply base. It would serve Admiral Nimitz’ naval forces as well as the Seventh Fleet.
Halsey, who conferred with MacArthur in Brisbane in late 1943 before departing on a trip to Hawaii and the continental United States, opposed the seizure of Kavieng. He wished to apply the bypass technique and seize Emirau in the Saint Matthias Islands, about ninety miles northwest of Kavieng, for this group had never been taken by the Japanese. Kavieng, on the other hand, was a major air and naval base and was reported to be strongly defended. In December MacArthur told members of Halsey’s staff that an attack against Emirau or Kavieng would serve equally well in the isolation of Rabaul.
Halsey spent four days with Nimitz at Pearl Harbor and then, in early January, flew to San Francisco where he and Nimitz conferred with Admiral King. Here, and later in Washington, the South Pacific commander made known his views on Kavieng and Emirau.
Halsey was not able to carry his point at this time. He did however discuss timing and the question of naval support for Manus and Kavieng. These were important because by now the Central Pacific offensives were well under way. Nimitz’ forces, having invaded the Gilberts in November 1943, were planning their initial move into the Marshalls (Kwajalein and Roi-Namur) in late January. Kavieng, almost four hundred miles from Cape Torokina, lay beyond fighter-plane range of Halsey’s most advanced air base. Thus aircraft carriers would have to provide cover for the invasion forces, and Admiral Nimitz agreed to furnish them. General MacArthur wanted carriers to cover the invasion of Manus as well, in case bad weather kept the Fifth Air Force planes grounded in New Guinea and at Cape Gloucester. Nimitz pointed out, however, that such weather could also affect carrier operations.
Admiral Carney, Halsey’s chief of staff, had visited Pearl Harbor in December and reported that the ships for Kavieng would not be available until 1 May. This would also put off the Admiralties operation. But Admiral Nimitz then suggested that by delaying his second Marshalls invasion (Eniwetok) until 1 May he could provide support for Manus and Kavieng about 1 April. MacArthur was ready and willing to invade Manus and Kavieng in March before moving to Hansa Bay, but the Joint Chiefs ordered Nimitz to deliver a strong carrier strike against Truk during March. No direct naval supporting forces could be available for Manus and Kavieng until April. Nimitz proposed that representatives of all the Pacific areas meet in Pearl Harbor to settle details of co-ordination and timing.
The command question came up again in January when Marshall asked MacArthur’s opinion on a draft directive for the next operations. The draft, Marshall told him, had received the approval of General Kenney, who was also in Washington. Except for Kavieng it did not specify any particular localities to be attacked but authorized advances into the Bismarck Archipelago preparatory to the drive to the Philippines. South Pacific forces attacking Kavieng were to be placed under MacArthur’s “general direction,” and Nimitz was ordered to provide fleet support and more assault shipping for Manus and Kavieng after the approaching conference at Pearl Harbor.
MacArthur objected strenuously. After reviewing the course of CARTWHEEL operations, which took place along two axes and for which, therefore, “loose coordination” sufficed, he argued that in the Bismarck Archipelago the South and Southwest Pacific forces would be converging in a fairly restricted area. South Pacific forces alone could not capture Kavieng, and elements of the forces might have to be mingled. Constant, complete co-ordination of air and surface units would be required. Unity of command, vested in himself, should be applied, urged-MacArthur, with the South Pacific forces under Halsey’s direct command. And, finally, the Joint Chiefs rather than Nimitz should determine the extent of fleet support and additional assault shipping.
In their orders for the extension into the Bismarck Archipelago, dated 23 and 24 January, the Joint Chiefs acceded to MacArthur’s suggestions on fleet support in a left-handed way. They directed Nimitz to provide fleet support and cover for the Manus-Kavieng invasions under his direct command, and to attach more warships and assault shipping to MacArthur’s and Halsey’s forces. The exact amounts were to be determined at the forthcoming Pearl Harbor conference, which would then forward recommendations to Washington for approval.
Control over South Pacific forces remained the same as for CARTWHEEL. Halsey was in direct command under MacArthur’s direction.
The conference at Pearl Harbor convened on 27 January. Halsey, flying out from Washington, had been grounded by bad weather in Fort Worth, Texas, and again in San Francisco, and so was not present. Carney, whom he had authorized to make preliminary arrangements with MacArthur, represented him, as did General Harmon. Representing MacArthur were Sutherland, Kenney, and Kinkaid. Nimitz, Rear Admiral Forrest P. Sherman, and others spoke for the Central Pacific.
Sutherland made it quite clear that MacArthur now definitely wanted the South Pacific to capture Kavieng for use as an air base, not Emirau. Halsey’s proposal was shelved for the time being.
Besides discussing operations in the Bismarck Archipelago, the conference covered a wide range of topics—the value of the Marianas, B-29’s, the possibility of bypassing Truk, and the comparative merits of the Central and Southwest Pacific routes to the Philippines. All agreed that whether Truk was bypassed or not, Seeadler Harbour was essential as a fleet base for the approach to the Philippines.
Nimitz proposed to give long-range support to the Manus-Kavieng invasions with a two-day strike against Truk by the main body of the Pacific Fleet starting about 26 March. In addition he agreed to send two divisions of fast carriers to operate under Halsey’s command during the Manus-Kavieng invasions, while other carrier divisions and fast battleships operated in covering positions.
These were large forces indeed. As originally planned the Bismarck operations would have been extensive. In addition to the naval forces, Halsey planned to use all his land-based aircraft and two divisions in assault, with one in reserve. However, not one of the operations approved by the Joint Chiefs and MacArthur was carried out according to the original plan.
[NOTE: These forces were to include 3 aircraft carriers, 3 light carriers, 7 cruisers, and 18 destroyers. In addition 4 old battleships, 7 cruisers, 4 escort carriers, 48 destroyers, 30 destroyer-escorts, 1 command ship (AGC), 19 transports, 3 LSD’s, 5 minesweepers, 36 LST’s, and 36 LCI’s would be assigned to Halsey’s Third Fleet for Kavieng, while for Manus the Seventh Fleet was to receive 3 light cruisers, 4 escort carriers, 35 destroyers, 8 patrol frigates, 1 AGC, 1 transport, 1 cargo ship, 2 minesweepers, 1 LSD, 13 APD’s, 30 LST’s, 30 LCI’s, 70 LCT’s, and 30 submarines. Halsey and Bryan, Admiral Halsey’s Story, p. 188; Craven and Cate, The Pacific: Guadalcanal to Saipan, pp. 551-52; Kenney, General Kenney Reports, p. 346; Smith, The Approach to the Philippines, pp. 7-8; Halsey, Narrative Account of the South Pacific Campaign, OCMH; Rad, CINCPAC to COMINCH-CNO, 29 Jan 44, in GHQ SWPA G-3 Jnl, 30 Jan 44; Ltr, CINCPOA to COMINCH, 30 Jan 44, sub: Assignment Naval Forces and Assault Shipping to Third and Seventh Fits for Opns Against Bismarck Archipelago, ABC 384 Pac (17 Jan 43) Sec 3-A. ]
Reducing Rabaul and Kavieng
All during the invasions of Arawe, Cape Gloucester, and Saidor, and during the discussions over the Bismarck Archipelago operations, the Solomon’s air command had been putting forth a maximum effort to reduce Rabaul. Completion of the Torokina fighter strip at
Empress Augusta Bay, Bougainville, was a major step forward, for now New Georgia- and Guadalcanal-based bombers could have fighter escort in their attacks. But by the end of 1943 it was clear that high-level bombing would not suffice to neutralize Rabaul. Obviously, success depended on completion of the bomber strips by the Piva River (Piva Uncle and Piva Yoke).
Piva Uncle, eight thousand feet by three hundred feet, was ready as a staging field on 30 December 1943. On 5 January 1944 SBD’s and TBF’s from Munda staged through to attack Rabaul, but by noon, when the bombers arrived over the target, Rabaul was as usual blanketed by heavy clouds. A similar attack two days later met the same difficulties, but on 9 January Piva Yoke was ready and from then on bombers could be permanently based at the Bougainville fields and could reach Rabaul in the morning, before it was covered by clouds.
Thereafter during January TBF’s, SBD’s, B-25’s, and B-24’s struck regularly at Rabaul. The Japanese lost many planes but occasionally received reinforcements from Truk, and continued to resist with fighter interception and antiaircraft fire. “… the skies overhead were the scene of continuous annihilation battles… “
By the end of January heavy bombers had flown 263 sorties over Rabaul; B-25’s, 180 sorties; SBD’s, 368; TBF’s, 227; fighters, 1,850. Losses totaled 8 B-24’s, 14 B-25’s, 8 SBD’s, 5 TBF’s, 19 P-38’s, 37 F4U’s, 5 F6F’s, and 6 New Zealand P-40’s.
Damage to Japanese equipment and weapons on the ground was relatively light, for in late November the enemy had begun the prodigious task of digging every possible item underground in Rabaul’s volcanic rock, a task that was well along by January. But all buildings were knocked flat. Ships and grounded planes were especially vulnerable to low-level bombing and dive-bombing. By February 1944 the Allies had won a signal victory; Japanese surface ships stopped using the harbor.
During the same period Kavieng received increased attention from both Allies and Japanese. Halsey, expecting to assault the base eventually, wanted to reduce Kavieng to help cut the Japanese lines of communication from rear bases to Rabaul. The Japanese, well aware of the threat to Rabaul, decided to strengthen Kavieng and the Admiralties to help protect Rabaul.
In October Imamura had sent the 230th Infantry of the 38th Division from Rabaul to New Ireland. Next month he sent an emissary to Tokyo to ask for one more division. Imperial Headquarters responded by sending the 1st Independent Mixed Regiment to New Ireland. It reached its destination in late 1943 and early 1944. Imamura placed it, together with the 230th Infantry, under Major General Takeo Ito, infantry group commander of the 38th Division. Ito’s soldiers and the 14th Naval Base Force were responsible for defense of New Ireland.
In December Halsey set a trap and ordered Buka bombarded to lure Japanese planes and ships away from Kavieng. Admiral Sherman, lying east of Kavieng with the carriers Bunker Hill and Monterey plus escorts, was then to strike at Kavieng in the hope of catching troopships and warships in the harbor. Before dawn on Christmas morning Sherman launched eighty-six planes, which bombed Kavieng at 0745 and were back aboard their carriers by 1015. But the results were disappointing as there were almost no ships in the harbor.
On New Year’s day Sherman delivered another strike from 220 miles east of Kavieng. Outside the harbor his planes caught some of the ships that had just unloaded part of the 1st Independent Mixed Regiment but the Japanese air cover of forty-two planes prevented the ships from suffering damage. Sherman struck Kavieng again three days later, again without doing much damage; no ships were present and the Japanese planes were out against Cape Gloucester.
In February the Fifth Air Force, using Finschhafen as a fighter base and Cape Gloucester as an emergency field, began to attack Kavieng with the aim of softening it before the projected invasion, cutting the line of communications to Rabaul, and supporting the South Pacific’s invasion of the Green Islands. On the 11th forty-eight B-24’s with P-38 escorts caught Kavieng’s planes on the ground, and the next two days saw similar attacks.
During the first two weeks of February Rabaul’s defenses grew obviously weaker as the Air Command, Solomon’s, maintained the intensity of its attack. There were few attempts to intercept until 19 February. On that date twenty-eight SBD’s, twenty-three TBF’s, and sixty-eight fighters, finding no ships in the harbor, put bombs and rockets on Lakunai airfield. Twenty B-24’s with thirty-five escorting fighters bombed from high altitudes. About fifty Japanese fighters attempted to break up the attack without success. This was the last attempted interception. Thereafter attacking Rabaul became a milk run. Allied pilots encountered antiaircraft fire but no planes. Rabaul no longer could threaten any Allied advance except one directed against itself. [From 1 through 19 February fighters flew 1,579 sorties; B-24’s, 256; B-25’s, 263; TBF’s, 244, and SBD’s 573. ]
Rabaul’s impotence was of course largely brought about by the South and Southwest Pacific air and naval campaigns that had been under way for so long, but it was partly brought about by Admiral Nimitz’ naval forces. The Central Pacific had invaded Kwajalein and Roi-Namur on 31 January and seized them so rapidly that the reserve and garrison forces did not have to be committed.
When the Joint Chiefs told Nimitz that they were willing to delay the Manus-Kavieng invasions in order to proceed directly to Eniwetok, using the uncommitted troops, Nimitz decided to go there as quickly as possible. Accordingly he invaded Eniwetok on 17 February. In support of this move the main body of the Pacific Fleet, commanded by Vice Admiral Raymond A. Spruance, attacked Truk on 16 and 17 February, over one month ahead of schedule. Spruance’s strike was an outstanding success.
The Combined Fleet had already escaped toward home waters, but Spruance’s pilots destroyed or damaged 250-275 planes as well as thousands of tons of shipping. Admiral Koga, thus almost bereft of planes, ordered all naval planes out of the Southeast Area at once. “. . . Rabaul, compelled to face the enemy with ground resources alone and completely isolated, was abandoned.”
The Allies dropped 20,584 tons of bombs on Rabaul throughout the war, and fired 383 tons of naval shells after Rabaul was reduced to the indignity of suffering destroyer and nocturnal PBY bombardment in March. Thirty naval vessels were sunk, 23 damaged. In addition 154 large cargo vessels and 517 barges were sunk; 70 small cargo vessels suffered damage. “. . . The [Japanese] Navy lost the pick of its flight personnel at Rabaul, a fact which told heavily upon subsequent efforts to rebuild our air forces.”
Rabaul was abandoned only in the strategic sense, and it was impotent only for offensive action. It could have defended itself with bloody efficiency had the Allies attacked. The garrison of New Britain numbered almost 98,000 men (76,300 in the 8th Area Army and 21,570 in the naval forces). The rugged country of Gazelle Peninsula was well suited for defense. By the war’s end some 350 miles of tunnels and caves had been excavated. At peak strength Rabaul had 367 antiaircraft guns (of which 73 were destroyed by air bombing), ranging in type and caliber from 13.2-mm. to 120.7-mm. dual purpose. There were 43 coast defense guns (1 destroyed) of calibers up to and including 150-mm. Of the 475 artillery guns and howitzers (37-mm. to 150-mm.), none was destroyed by bombing, nor were any of the 1,762 machine guns. Imamura’s men also had tanks, mines, ditches, caves, bunkers, and concrete pillboxes, as well as rifles, grenades, bayonets, and ample ammunition.
Rabaul would not have been as valuable to the Allies as it was to the Japanese in their southward advance. It would have been useful to the Allies only in a northward move against Truk and the Marianas. Because the Joint Chiefs had decided to advance westward, and because Seeadler Harbour in the Admiralties was better than Rabaul’s, the Japanese fortress was not worth the price the Japanese surely would have exacted.
Seizure of the Green Islands: Plans and Preparations
In December 1943 Admiral Halsey’s planes were bombing Rabaul, his ships were patrolling the Solomon Sea, and his ground troops in Bougainville were either fighting the enemy or consolidating positions in anticipation of a fight.
But this was not enough to satisfy him. When he learned that Nimitz’ plans, as they stood in December, would not permit the invasion of Manus and Kavieng for several months, he decided to seize an air base site within fighter range of Kavieng in the meantime.21 At a conference in Port Moresby on 20 December attended by MacArthur, Kinkaid, Carney, Chamberlin, and others, the South Pacific representatives proposed that the Southwest Pacific attack Manus directly while South Pacific forces captured the Green Islands, some 37 miles northwest of Buka, and established there an airfield and PT boat base. Situated 117 miles east of Rabaul and 220 miles southeast of Kavieng, this circular coral atoll was not strongly held. The Japanese used it only as a barge staging base between Rabaul and Buka. Allied seizure of the atoll would put South Pacific fighter planes within range of Kavieng, extend the range of PT boat patrols as far as New Ireland, and cut the Japanese seaborne supply route to Buka.
MacArthur, deciding for the time being against a move to Manus in advance of the projected invasion of Hansa Bay, approved simultaneous attacks against Manus and Kavieng and told the South Pacific to go ahead with the plan to attack the Green Islands about 1 February.
The island group consists of four flat, thickly wooded coral atolls which encircle a lagoon. The group is about nine miles long from north to south, five miles from east to west. Horseshoe-shaped Nissan, the main island, provided good landing beaches on its west shore inside the lagoon, but it was not known whether the passage between Barahun and Nissan would accommodate landing craft. Therefore Halsey sent four PT boats from Cape Torokina to examine the passage on the night of 10-11 January. They found seventeen feet of water there, or enough to float an LST.
Admiral Halsey, who returned to Noumea on 3 February, placed control of the operation and responsibility for the co-ordination of amphibious planning in Admiral Wilkinson’s hands on 5 February. This action confirmed warning orders which had been issued in early January.
Only destroyer-transports and landing craft were assigned to the attack force. Command of the landing force was given to General Barrowclough of the 3rd New Zealand Division. Barrowclough’s division (less the 8th Brigade Group), the 976th Antiaircraft Artillery Gun Battalion of the U.S. Army, a PT base unit, communications units, a boat pool, and a large naval base unit including an entire construction regiment, constituted the landing force. Halsey ordered the Solomon’s air command and Ainsworth’s and Merrill’s cruiser task forces to support and cover the invasion, and arranged with MacArthur for Kenney’s air forces to deliver the attacks on Kavieng during the first fifteen days of February.
As South Pacific headquarters estimated that Rabaul and Kavieng would be virtually neutralized by mid-February, D Day was set for the 15th. General Barrowclough, who had been island commander at Vella Lavella, moved his headquarters to Guadalcanal in January to be near Wilkinson during the planning. They decided to send a large reconnaissance party to Green in order to determine the strength of the enemy garrison and to examine possible airfield sites, beaches, and naval base sites, and the lagoon tides. The party was to spend twenty-four hours ashore.
Three hundred and twenty-two soldiers of the 30th New Zealand Battalion and twenty-seven American and eleven New Zealand hydrographic, air, small boat, communications, and intelligence specialists boarded three APD’s on 29 January. The destroyer-transports hove to west of Barahun about midnight and launched landing craft. Two of the torpedo boats that had checked the passage led the landing craft through to the beach. Once ashore the reconnaissance party waited for daylight while the APD’s hauled clear. Guarded by the New Zealand soldiers, the specialists set to work and gathered their data. They found a good airfield site, and estimated that the enemy garrison numbered about a hundred. The twelve hundred native inhabitants proved so friendly and cooperative that preliminary naval bombardment to support the main landing was omitted. The specialists were not molested, but the enemy fired on one landing craft that went to the south part of the island where there was an abandoned Roman Catholic mission and killed three New Zealanders and one American. When Rabaul heard of the landing Kusaka sent six bomb-carrying fighters to Green. They attacked the landing boats but did no damage.
The APD’s reclaimed the New Zealanders and Americans on 31 January and returned safely to Guadalcanal. On the way back two of the escorting destroyers sank a Japanese submarine near Buka Passage.
The Japanese Green Islands garrison reported it had suffered heavy losses, asked for reinforcements, and fled northwest in three landing craft to the Feni Islands. Kusaka put 123 men aboard a submarine on 1 February and sent them to Nissan. The submarine hove to off the northeast coast about midnight in a sea so rough that after 77 men had gone ashore, the submarine commander called off the operation and returned to Rabaul with 46 men still on board. The return of the original garrison to Nissan on 5 February brought total enemy strength to 102.
In the meantime the South Pacific’s APD’s returned from service in the Cape Gloucester operation. Shortly before 12 February the APD’s, LST’s, LCI’s LCT’s, LCM’s, and patrol boats and coastal transports of the amphibious force took aboard the 5,806-man New Zealand-American landing force at Tulagi, Guadalcanal, the Russells, New Georgia, and Vella Lavella. The ships, timing their departures so as to meet off Bougainville on 14 February, sailed from their various ports on the 12th and 13th.
[Note 15-26 Eleven destroyers escorted; two aircraft rescue boats and two tugs were also in the amphibious force. There were 4,242 New Zealanders and 1,564 Americans in the landing force. ]
A Japanese reconnaissance plane spotted them west of Bougainville on 14 February, reported their presence to Rabaul, and kept contact. Admiral Kusaka sent thirty-two planes against the ships throughout the moonlit night of 14-15 February. They did no damage to Wilkinson’s ships but managed to hit the cruiser Saint Louis in Admiral Ainsworth’s task force, which was operating south of Saint George’s Channel. Twelve Japanese planes were lost.
The APD’s arrived in the transport area west of Barahun shortly after 0600 on 15 February and promptly dispatched LCVP’s toward the passage. Thirty-two fighters of the Solomon’s air command were on station overhead. But Kusaka did not yield easily. He sent out seventeen bombers and about fifteen of these attacked the landing craft. They scored no hits. At the same time Kenney’s airmen, with four A-20 and seven B-25 squadrons, delivered a strong blow against Kavieng which kept that base from attacking the invaders at Green.
Within two hours all men of the New Zealand combat units went ashore on Nissan. During the day all ships and boats were completely unloaded and with the exception of the LCT’s, all left for the south once they were emptied. The LCT’s remained as part of the naval advanced base.
Between 15 and 20 February the New Zealand infantrymen hunted down and killed the Japanese garrison. Ten New Zealanders and 3 Americans were killed; 21 New Zealanders and 3 Americans were wounded.
By 17 March 16,448 men and 43,088 tons of supplies had been sent to the Green Islands. The 22nd Naval Construction Regiment had begun work at once. Within two days of the landings a PT boat base opened. This extended the range of torpedo boat patrols to New Ireland and along the entire northeast coast of Bougainville. By 4 March a 5,000-foot fighter field was ready; in late March a 6,000-foot bomber field was opened. Kavieng now lay within range of fighters and light bombers as well as heavy bombers from Bougainville. But, stripped of its naval planes when Admiral Koga ordered their withdrawal in February, it had already ceased to menace the Allies.
SOURCE: Cartwheel: Reduction of Rabaul; By John Miller Jr. (United States Army Center of Military History)