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Rabaul


Relief map of
              Simpson Harbor

Photograph of Rabaul under
                attack

U.S. Marine Corps. Via ibiblio.org


Rabaul (152.167E 4.2S) is a port on the magnificent natural anchorage of Simpson Harbor, located on Gazelle Peninsula on the northeastern tip of New Britain. The anchorage was mapped by the English explorer Philip Carteret in 1767, who named the mountains surrounding the anchorage, and rediscovered by Cortland Simpson of the Royal Navy in 1872, who gave the name of his ship to Blanche Bay and his own name to Simpson Harbor at the north end of Blanche Bay.

Geologically, Rabaul is a sunken caldera about eight miles (13 km) long and  six miles (10 km) wide. The caldera is ringed by mountains, of which The Mother (Mount Komvur) at 2247' (684 meters) on Crater Peninsula east of Rabaul was the tallest. The Mother was flanked by the North and South Daughters. Small earthquakes are common, sometimes coming in swarms of thousands of quakes in a single month. The caldera has erupted catastrophically over thirty times in the last half million years, the most recent taking place about 1400 years ago. This eruption, which was comparable with the famous Krakatoa eruption in 1883, ejected about 2.4 cubic miles (10 km3) of volcanic ash and likely destroyed all life within thirty miles of the caldera. Much smaller eruptions occurred in 1791 near South Daughter and in 1851 at Sulfur Creek east of Simpson Harbor. So many vents were located on the peninsula marking the northeast side of the caldera that it became known as Crater Peninsula.

The area was claimed as a protectorate in 1884 by the Germans, who had perfected the processing of copra. The original administrative center was at Kokopo (152.267E 4.35S), on the coast some distance southeast of the caldera. However, the administrative capital was moved to Rabaul Town in 1910 at the instigation of "Queen Emma" Forsyth, a half-Samoan, half-American woman of considerable local influence in the Bismarcks. The originally swampy ground was drained (Rabaul means "place of mangroves" in the native Kuanua tongue), a wharf and warehouses set up complete with tram lines, and an extensive road net was constructed that included almost a hundred miles (160 km) of roadway. This included a tunnel through the caldera rim to the northwest coast.

Australian troops drove the Germans out in September 1914, during the First World War, and Australia received a Class C mandate over the area from the League of Nations on 9 May 1921. Rabaul became the capital of the Mandated Territory of New Guinea. By 1939 Rabaul was the largest and most Westernized town in the Mandated Territory of New Guinea, with department stores, a movie theater, and a golf course.There was a civilian airfield at Lanukai (152.185E 4.224S), with regular service by Quantas, and a military airfield on more stable ground at Vunakanau (152.134E 4.328S) nine miles (14 km) south of the town. The town was the only sizable settlement anywhere in the Bismarcks, with about 350 buildings and a thousand Europeans, three thousand Chinese, and six thousand indigenous inhabitants.

Volcanic eruptions in the spring of 1937 on the west side of the anchorage climaxed in a pyroclastic eruption that destroyed two Tolai villages and killed 500 villagers. Rabaul was heavily blanketed in volcanic ash and a volcanic cone of 700' (210 meters), Vulcan, was created almost overnight.  This was followed almost immediately by a short eruption at Tavurvur at the west side of the southeast tip of Crater Peninsula. These eruptions convinced the Australian government to move the capital to Lae, though the move was only partially complete when war broke out.  Tavurvur remained active throughout the Pacific War, and the Japanese found that excavation of fortifications was hindered by the strong sulfurous fumes underground.

The port was protected by a battalion of Australian infantry (2/22 Battalion, "Lark Force", numbering about 1390 men), two 6" (152mm) coastal guns at the tip of Crater Peninsula, two obsolete antiaircraft guns (one with a cracked breach) and a few obsolescent aircraft of 24 Squadron – all the Australians could spare.  The decision was made on 12 December 1941 not to reinforce or withdraw the garrison, and in a diplomatic cable, the Australian naval chief of staff acknowledged that the garrison were "hostages to fortune" (Gamble 2010). 

Japanese Invasion. The Japanese recognized the value of the port in their planning for the Centrifugal Offensive, and final plans for its seizure were formulated on 3 January 1942 in a meeting between General Horii and Admiral Inoue at Truk. The first air raids on Rabaul were launched from Truk the next day. Although coast watcher Cornelius L. Page on Tabar (152.03E 2.93S) gave warning of the first raid, by 16 G3M "Nells" of Chitose Air Group, the Australian antiaircraft guns could not reach their altitude and the Wirraways of 24 Squadron were late launching and lacked the speed to catch the bombers in any case. The Japanese in turn were very inaccurate with their bombing. A second raid by 11 H6K "Mavis" flying boats of the Yokohama Air Group at dusk was also wide of the mark. Repeat raids on 6 and 7 January were more accurate, destroying or damaging most of the Australian aircraft on the ground. A daring reconnaissance flight over Truk on 9 January showed a large gathering of shipping in the anchorage. However, Japanese raids did not resume until 16 January, when another pair of raids by Nells and flying boats suggested the invasion would take place soon. In fact, the invasion group had sailed from Guam two days earlier and a powerful covering force sailed from Truk the next day. For reasons that have never been explained, orders were issued from Canberra that Norwegian freighter Herstein at Rabaul was to continue to load copra and no evacuation of civilians was to take place.

The arrival of four of Nagumo's carriers on 20 January 1942 was marked by a massive raid by 18 A6M Zeroes, 45 B5N "Kates", and 28 D3N "Vals". Six of the defending Wirraways were promptly shot down, and the Japanese then roamed at will over the port, although the ancient Australian antiaircraft guns managed to account for  two Kates and a Val.  Herstein was wrecked and collier Westralia sunk.  The remaining Hudson flew out with wounded men. A second raid on 22 January destroyed the coastal battery, and the remnants of 24 Squadron were evacuated to the south coast in whatever vehicles were available. They were eventually evacuated by flying boat.

The commander of Lark Force, Colonel John J. Scanlan, who had received word that the Japanese fleet had been sighted to the north, then made the controversial decision to inform his men they were going on a field exercise for the next two days. Perhaps he thought this would put the men on alert without destroying their morale, but it also meant that the men took only a light load of rations and other supplies with them. This would prove disastrous in the subsequent retreat into the interior. Preparations were further disrupted by the "rather botched demolition" of the airfield bomb depot, which leveled everything within a quarter mile, killed several civilians, and shattered the vacuum tubes in the force's radios. With communications thus cut off, it would be days before the Australian high command had any clear idea what had happened at Rabaul.

Elements of the South Seas Detachment began their landings in the early hours of 23 January, rapidly driving back Lark Force and taking the town and airfields. Scanlan had commented that it would soon be "every man for himself" and this was interpreted as an order, turning the retreat into a rout. Scanlan himself fled the battlefield with his staff while fighting was still taking place. The surviving Australians were hunted down, and on 4 March about 150 Australian prisoners of war were massacred at Tol and Waitavalo Plantations on the south coast of New Britain, likely on the orders of Horii. The pretext offered was that the Australians had been ordered by leaflet to surrender at once or be killed to the last man, but they had not surrendered at once. Another 400 Australian troops managed to escape on civilian boats, including Brigadier Walter McNicoll, the territorial administrator. The Japanese themselves suffered far more casualties from an outbreak of malaria than in combat.

The Japanese subsequently developed Rabaul into their most important base in the South Pacific. Lakunai was ready to receive fighters by 25 January and medium bombers by mid-February. The Japanese eventually made Vunakanau their main airfield and completed new airfields at Rapopo (152.308E 4.351S), on the coast 14 miles (23 km) southeast of the town, in December 1942; Tobera (152.224E 4.398S), inland of Rapopo, in August 1943; and Keravat (152.015E 4.313S), on the north coast 13 miles (21 km) southwest of the town. Keravat suffered from such poor drainage that it was all but abandoned by the Japanese, but the other four fields were modern facilities with all-weather concrete runways and revetments for 80 to 120 aircraft each (totaling 265 fighter and 166 bomber revetments for the Rabaul area.) Vunakanau eventually had a 5200' by 135' (1585m by 40m) runway paved with four inches (10cm) of concrete. Rapopo had a 4350' (1325m) concrete runway, on ground cleared using Army tanks and prisoners of war, since no bulldozers were available.

Rabaul town tripled in size during the occupation, with the Japanese engineers building more than 600 structures with an aggregate floor space of 2.8 million square feet (260,000 m2) using the output of 29 sawmills and native labor. The road net was expanded by 395 miles (635 km) of new roadway, 23 diesel power stations with a capacity of about a megawatt were installed and thirteen new wells were drilled with a capacity of 290,000 gallons per day.

The garrison eventually numbered 100,000 troops with tanks and artillery.  Antiaircraft defenses totaled 367 antiaircraft guns, including almost 100 75mm and 80mm antiaircraft guns, 24 120mm dual-purpose guns, about 100 25mm antiaircraft guns, and about 120 heavy machine guns and cannon. Coastal defenses included 43 coastal defense guns, of which 37 were of 120mm caliber or larger. Other fixed defenses included about 240 heavy cannon and howitzers, about 240 antitank guns and field guns, 23 heavy mortars, and 6000 machine guns and grenade launchers.  Early warning was provided by two Type 1 Model 1 radar sets at Tomavatur Mission and nine Type 1 Model 2 radar sets at other locations on New Britain and the surrounding islands. The warning network typically provided an hour's warning of air raids.

Rabaul became the focus of the first Allied counteroffensive of the war, CARTWHEEL. This began with small probing raids staged through Port Moresby from northern Australia, and over the next two years the air counteroffensive grew in intensity until the fortress was isolated and smashed from the air. However, the base remained in Japanese hands throughout the war.

Carrier Strike of 20 February 1942. In an effort to disrupt Japanese preparations for a move against Australia and create a diversion from the Japanese advance into the Netherlands East Indies, Brown led Task Force 11 (Lexington) on an attempted raid against Rabaul. Departing from Fiji on 16 February 1942, Brown took his force north of the Solomons, planning to strike Rabaul from the northeast on the morning of 21 February. The plan depended heavily on surprise and was to be coordinated with a B-17 strike from Townsville.

However, Mavis flying boats and G4M "Betty" medium bombers were already operating out of Rabaul, and Japanese traffic analysis tipped off Goto that something was in the works. Goto ordered searches to the east, and at 1030 on 20 February, one of the three flying boats sent on patrol sighted Brown's force at a distance of 460 miles from Rabaul. The Mavis was promptly shot down by the American combat air patrol, along with a second Mavis spotted on radar north of the fleet, but the element of surprise had been lost. Brown continued towards Rabaul for several hours before calling off the raid, risking a counterstrike in order to create a greater diversion

At 1310 the Japanese had launched a strike of seventeen Betty bombers, armed with two 550 pound bombs apiece because their torpedoes had not yet arrived at Rabaul. No fighter escort was possible at this range, but the Japanese pilots were contemptuous of their opponents and confident in their own abilities. The strike came in two waves, of which the first was spotted on American radar at 1621. Most of the combat air patrol was vectored against this wave, shooting down five of the Bettys before they reached their release point. The remaining four Bettys missed Lexington and were either shot down or damaged so severely they were later forced to ditch. Only two of the crews were recovered. One of the crippled Bettys attempted a suicide dive on Lexington but crashed far short of the carrier.

The second wave caught most of the American Wildcats out of position, leaving just two fighters in a position to intercept. One of the pilots found that his guns had jammed; the other pilot, "Butch" O'Hare, was all that stood between the Japanese and Lexington. O'Hare attacked so aggressively and with such skill that he succeeded in knocking five Bettys out of formation. The three remaining bombers failed to hit Lexington, although one bomb exploded close enough to Lexington to inflict some splinter damage. A second crippled bomber attempting a suicide crash also missed Lexington. The remaining American fighters caught up with the retreating Japanese survivors and inflicted further losses. Only two of the seventeen Betty bombers that set out on the strike ever returned to base. The Americans lost two Wildcats, one of whose pilots was recovered. "Butch" O'Hare was credited as the first naval ace of the war and an ace in a day with five kills, and was awarded the Medal of Honor; however, postwar analysis credits him with only two solo kills and several assists in this action.

Brown might plausibly have raided Rabaul while its air arm was crippled, but he had no way of knowing what other air assets the Japanese had at Rabaul, and he was concerned about his fuel status. The Japanese quickly reinforced their base, but the raid did force a brief postponement of the seizure of Lae.

B-17 and Catalina raids continued against Rabaul, joined by medium bomber (B-25 and B-26) raids from 6 April 1942 on.

The Rabaul Disaster. Ironically, no raid on Rabaul prior to November 1943 came close to inflicting as much damage on the base as Japanese carelessness. On the afternoon of 14 September 1942, a fuel dump in the eastern part of Rabaul town caught fire. Spilled burning fuel touched off a munitions dump near the waterfront, and the resulting explosions continued for twelve hours. Allied prisoners of war who were put to work as stevedores later claimed that they regularly loosened caps on fuel drums, but this sabotage was likely a minor contributing factor to the disaster. Ugaki, who was visiting the port at the time, noted that the ammunition was "piled up without any order" (Gamble 2010), a serious violation of safe handling procedure for explosives.

Rabaul Raids of November 1943. On 1 November 1943, the Allies made a daring leapfrog landing at Cape Torokina on Bougainville. Koga immediately ordered a powerful cruiser force under Kurita to join 8 Fleet at Rabaul. The six heavy cruisers, one light cruiser, and five destroyers of this force joined two heavy and one light cruisers and five destroyers already present in the harbor on 4 November. However, two oilers accompanying the force were crippled by Allied aircraft and forced back to Truk, while two of three transports carrying reinforcements were badly damaged and barely made harbor.

The Japanese reinforcements were a serious threat to the Bougainville landings, since Halsey had no surface combatants heavier than a light cruiser with which to meet them. Halsey did have Saratoga and Princeton of Task Force 38, but because the distance from Rabaul to Bougainville was so short, the Japanese could race in during the night when carrier aircraft could not operate. Halsey's only options were to raid the cruisers in Rabaul Harbor itself, or leave the Bougainville landings unprotected from a bombardment and possible counterlanding. Halsey chose to risk his carrier force.

The carriers, which were refueling near Rennell Island, received the order to raid Rabaul on the evening of 4 November 1943. Sherman raced north at 27 knots, and arrived at the designated launch point 57 miles southwest of Cape Torokina at 0900 on 5 November. The weather was favorable, with enough wind for easy launching and enough cloud cover to confuse the Japanese aircraft that spotted the force into believing only cruisers were present. A strike consisting of 52 F6F Hellcats, 23 TBF Avengers, and 22 SBD Dauntlesses was launched at once. Air cover for the carriers was provided by land-based fighters.

The strike achieved almost complete surprise, which was fortunate, as there were over 150 aircraft stationed at Rabaul. A heavy combat air patrol of 70 fighters met the American strike. However, the Japanese fighters expected the Americans to split up before attacking, and by the time the Japanese realized the Americans were holding formation right through the heavy antiaircraft fire, it was too late to intercept effectively. The ships in the harbor were unprepared and vulnerable.

In spite of the heavy antiaircraft fire and waiting Japanese fighters, the Americans lost just five fighters and five bombers. No Japanese ships were sunk, but Maya suffered a bomb hit directly down her stack that put her out of action for five months; Takao was hit twice on the waterline; and four other cruisers and two destroyers were damaged.

The strike returned to its carriers by 1445 and Sherman raced out of the area. A Japanese strike by 18 B5N "Kates" missed the American carriers but attacked two LCTs and a PT boat in the twilight, reporting that they had sunk two carriers, three cruisers, and a destroyer.

By 8 November 1943 Halsey had been reinforced with a second carrier group built around two heavy and one light carrier (Task Group 50.3, Montgomery). This group joined Sherman for a second strike on 11 November. There were now perhaps 270 planes at Rabaul, of which 100 had been borrowed from carrier air groups. Sherman's group was again concealed by heavy weather, but its strike found poor weather over Rabaul as well and accomplished little. Montgomery launched about 185 aircraft, including over 100 bombers as well as fighters for the combat air patrol. The strike ran into 68 A6M "Zeros" that did their best to work past the Hellcats to attack the bombers, resulting in a confused air battle. The Japanese suffered a destroyer sunk, another destroyer and a light cruiser badly damaged, and three other ships slightly damaged.

Montgomery had been spotted and the Japanese launched a strike of 67 Zeros, 27 D3A "Vals", 14 Kates, and a few G4M "Bettys." This strike was detected 119 miles out by SK radar and intercepted by the combat air patrol, reinforced by 12 Hellcats and 24 F4U Corsairs from New Georgia.  The Vals evaded the fighters but found the American antiaircraft accurate and deadly. No ships were hit, but Montgomery was compelled to cancel a second strike against Rabaul.

Montgomery lost just 11 aircraft, but the Japanese lost eight fighters and at least 31 bombers. Koga withdrew his cruisers, removing the surface threat to the Bougainville landings, and also withdrew the carrier air groups that had been sent to Rabaul to beef up its air striking power. In two weeks of heavy combat, these groups had lost 50% of their fighters, 85% of their dive bombers, and 90% of their torpedo bombers.

It has been argued that the Rabaul raids illustrated the dangers of the divided American offensive. Halsey had no heavy units, and few carriers, because most of these ships were preparing for the Gilberts campaign. On the other hand, the rough handling given the Japanese carrier air groups at Rabaul meant that the Japanese were unable to mount a serious naval defense of the Gilberts.

Airsols Campaign of 1944. By December 1943 Rapopo had been severely damaged, with few buildings remaining. The Japanese went underground, excavating facilities in the soft volcanic soil and rock with the use of almost 98,000 Japanese Army and Navy troops, 1457 Chinese slave laborers, and about 6000 Indian prisoners of war captured at Singapore. The ground defenses remained formidable, and Morison famously commented that "Tarawa, Iwo Jima and Okinawa would have faded to pale pink in comparison with the blood which would have flowed if the Allies had attempted an assault on Fortress Rabaul."

Instead, the Allies concluded that Rabaul should be isolated and bypassed. This required constant air strikes against the fortress to negate it as an airbase. By late January 1944, R.J. Mitchell, Commander AIRSOLS, had moved his headquarters to Cape Torokina on Bougainville and was ready to launch his air offensive. Mitchell had his pilots briefed by carrier pilots who had participated in earlier strikes, who, perhaps predictably, regaled their audiences with the terrors and wonders of the Japanese fortress.

On 17 December 1943, Mitchell launched his first big strike, a fighter sweep. At that time, the Japanese had approximately 140 fighters, 60 heavy and 50 light bombers, and 42 float planes in the Bismarcks, versus 268 fighters (69 P-39, 71 F4U, 58 F6F, 39 P-40, and 31 P-38), 252 light and medium bombers, and 631 heavy bombers available to AIRSOLS. Each side lost two planes in the strike, suggesting neither side was coming to grips with the enemy. A second strike on 19 December included B-24 Liberators, sixteen of which broke through the weather to attack shipping in Simpson Harbor. This prompted the Japanese fighter pilots to engage more vigorously, and losses were two Allied and five Japanese aircraft. Allied pilots reported that the enemy skill level seemed to have jumped considerably, but the Japanese could not possibly accept such a loss ratio for long. By 28 December the aggregate score was 40 Japanese aircraft destroyed for losses of 24 Allied aircraft, though only 192 tons of bombs were dropped.

The new year shifted the emphasis from heavy bomber raids to light bomber raids. A raid on 7 January 1944 claimed two enemy planes in the air and five on the ground at the cost of five Allied aircraft. A second raid on 14 January cost the Allies four aircraft versus three for the enemy. AIRSOLS claimed its first ship kills in the campaign on 17 January, when four merchant ships and a salvage vessel were sunk.

Raid intensity and frequency continued to increase, and by late January the Allies were taking regular tolls of the enemy while minimizing their own losses. The final air battle over Rabaul occurred on 19 February 1944. The Allied aircraft found little shipping in the harbor and expended their munitions against the airfields instead. Losses were one Allied fighter versus around a dozen Japanese. Two days earlier, Spruance had staged a highly successful raid on Truk, and the decision was made to withdraw most of the Japanese aircraft at Rabaul.

The Allies had won the air campaign over Rabaul. Total Japanese losses were something in the  neighborhood of 359 aircraft from November 1943 to March 1944. AIRSOLS combat losses were 136 aircraft. Thereafter AIRSOLS continued to stage raids over the fortress, gradually destroying the antiaircraft gun positions and keeping the runways cratered. In spite of AIRSOLS' best efforts, the Japanese preserved over half their antiaircraft guns by moving them frequently among prepared positions dug into the ground, and at least one concrete runway was kept usable at all times. In March the emphasis shifted to incendiary attacks on supply dumps by New Zealand pilots, which forced the Japanese to move their remaining stores underground. 

War Crimes. In addition to the Tol Plantation massacre, the Japanese at Rabaul systematically murdered almost all the Allied airmen who fell into their hands over Rabaul. One Japanese witness testified of human vivisection during one series of executions (Gamble 2010):

I asked him what he was going to do. He did not reply, but laughed and produced some medical instruments. I then realized he was going to carry out a dissection and had possibly obtained permission from Lieutenant Nakayama or 8 Naval Base Force, so I ordered the sightseers who had crowded around to disperse and those who had work to do to go back to their unit. This doctor then cut the jugular vein of the suffering prisoner of war before opening his abdomen. He then took some dark-looking object out, which ... he handed to the NCO. He then quickly stepped over to the next prisoner of war who was still alive and writhing on the ground, so the doctor cut his jugular vein, opened him up and took a dark-looking object out. The whole process took about 5 or 6 minutes. The doctor was wearing surgical gloves. I saw the doctor, NCO and driver get on their autobike afterward; the NCO was carrying a shallow white tray containing whatever objects they had removed from the two prisoners of war.

As soon as all the prisoners of war were placed in the hole I gave the coup-de-grace by stabbing each one in the throat.

Imamura was convicted of permitting the mistreatment of prisoners of war and was imprisoned until 1954.

Japanese forces at Rabaul, 15 August 1945

8 Area Army (Imamura)

 
17 Division (Sakai)


38 Division (Kagesa)


39 Independent Mixed Brigade (Sakamoto)


65 Brigade (Matsuda


1 Independent Amphibious Battalion


8 Tank Regiment


9 Artillery Command


 
7 Medium Artillery Regiment



5 Independent Medium Artillery Battalion     



3 Independent Heavy Artillery Battalion



2 Independent Artillery Mortar Battalion


12 Construction Unit


17 Construction Unit


22 Construction Unit

8 Fleet (Samejima)


2 Maizuru SNLF


8 Special Base Force


Torpedo Squadron 6


Minesweeper Flotilla 14


Photo Gallery


Simpson Harbor and surroundings

U.S. Marine Corps

Attack on Simpson Harbor

U.S. Navy

Parafrag attack on Vunakanau airfield

U.S. Army

Aircraft revetments at Vunakanau

U.S. Air Force

Parafrag attack on the docks at Rabaul town

U.S. Air Force

Rabaul town during high-altitude raid

U.S. Marine Corps

Reconnaissance photo of Vunakanau

U.S. Air Force

Strike on Simpson Harbor with Rabaul town in
                background

U.S. Marine Corps


References

Collie and Marutani (2009)

Gamble (2010)

Larrabee (1987)

Lundstrom (2006)

Morison (1950)

Rottman (2002)

Sakaidi_(1996)

Shaw and Kane (1963; accessed 2011-7-6)

Tillman (1979)

Willmott (1983)



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