Fortress Rabaul: The Battle for the Southwest Pacific, January 1942-April 1943

by Bruce Gamble

  The first week of raids did achieve some damage, as confirmed in a postwar report by the Imperial Navy: “Enemy aircraft frequently invaded the skies over the Rabaul anchorage, bombing and strafing, but our ships put up fierce resistance and repulsed them. Three enemy planes were shot down. Damage suffered—one dead, fifteen injured, and minor damages to two transports.” A separate report submitted by the Imperial Army listed four dead and fifteen wounded among units of the South Seas Force.

  But the claim by the Japanese that three Australian planes were shot down in late January was pure invention. No Catalinas were lost over Rabaul during the early raids, partly due to the ineffectiveness of the few shore-based antiaircraft guns, and also because there were no Japanese fighters to oppose the flying boats. Vice Admiral Nagumo had ordered Akagi and Kaga back to Truk as soon as Rabaul was secured, leaving only a few floatplanes for aviation support.

  WITHIN HOURS of the invasion, the Imperial Navy’s 4th Construction Detachment, assisted by an army construction battalion, commenced repairs to the runway at Lakunai airdrome. That same afternoon, Cmdr. Ryutaro Yamanaka of the land-based Chitose Air Group arrived at Rabaul from the Marshall Islands to inspect Lakunai and “encourage the army engineer troops on the scene.” Such coordination between the two services was uncommon, but it got results. By the end of the month, the airdrome was completely repaired.

  Rabaul’s first land-based fighters, formerly assigned to the Tainan Air Group, were delivered by the aircraft transporter Kasuga Maru a few days after Yamanaka’s visit. Less than a week later, on January 31, a contingent of fifteen fighters of the Chitose Air Group was transferred from the Marshalls.

  The first fighters sent to Rabaul were not the highly regarded Zeros but obsolescent Mitsubishi A5M4s, known to the Japanese as Type 96 carrier fighters. With their fixed landing gear, open cockpit, and teardrop wheel covers, the planes resembled something from a Disney cartoon. They were also significantly slower than the Zero, and with only two 7.7mm machine guns in the nose, did not pack much firepower. However, the Type 96’s gnatlike maneuverability was superb.

  Although not designed or equipped for night combat, the new arrivals teamed up with the searchlight crews to challenge the Catalinas’ nocturnal raids. The first combat occurred on the night of February 3, when two of the five Catalinas that attacked shipping in Simpson Harbor were caught in the beams of the powerful searchlights. One got out of trouble by diving through the volcanic steam billowing from Tavurvur, but the other, piloted by Flt. Lt. Godfrey E. Hemsworth, was held firmly by the searchlights.

  Within moments, twenty-two-year-old FPO 1st Class Hiroyoshi Nishizawa darted in behind the Catalina and fired more than one hundred rounds into the main wing, fuselage, and empennage of the big plane. In turn, Nishizawa may have been startled when a stream of bullets and tracer rounds snaked toward him from the Catalina’s midsection. Firing a pair of Lewis machine guns from the waist gun blister on the seaplane’s port side, nineteen-year-old Sgt. Douglas F. Dick saw the Japanese fighter go into a spin. He claimed a kill and, when other crewmen later confirmed his report, was credited with a “probable” victory.

  But Nishizawa had merely been dodging the return fire, for his Type 96 fighter was not damaged. Ironically, he believed he had fatally damaged the Catalina, which plunged toward the water. He was credited with a victory, the first of many attributed to the rail-thin, often sickly pilot who would eventually become one of the Imperial Navy’s greatest aces.

  Hemsworth and his crew were far from finished. Nishizawa’s gunfire had hit the port propeller, disabling the engine, but Hemsworth used a few tricks of his own to escape. A former commercial pilot with many years of experience, he rolled the heavy seaplane into a steep dive while simultaneously feathering the damaged propeller. Leveling off at minimal altitude, he exited Simpson Harbor in the darkness on one engine.

  Throughout the night, Hemsworth held the damaged Catalina aloft, the miles and the hours crawling by while raw fuel leaked into the bilges from bullet holes in the wing tanks. When he reached the Huon Gulf, Hemsworth made a flawless nighttime water landing off Salamaua so that the crew could make temporary repairs to the damaged propeller. At dawn Hemsworth took off using both engines, after which he feathered the bad prop for the remainder of the journey. He could not cross the Owen Stanley Mountains on one engine, so once again he flew the long way around the Papuan Peninsula, this time at an altitude of only fifty feet. Finally, more than twenty-five hours after starting the mission, Hemsworth landed the bullet-riddled Catalina in the harbor at Port Moresby.

  LAND-BASED NAVY FIGHTERS also caused trouble for one of the first RAAF reconnaissance missions over Rabaul. On February 6, Flt. Lt. David W. I. Campbell and his crew from 32 Squadron crossed Simpson Harbor at ten thousand feet and noted a fighter taking off from Lakunai. Only four minutes later the enemy aircraft reached the Hudson’s altitude and commenced a gunnery attack. The agile fighter, undoubtedly a Zero, raked the Hudson with machine gun bullets and cannon fire. One shell exploded among a stack of sea markers, polluting the cabin with a silvery cloud of metallic powder; another detonated in the cockpit, severing the little finger from Campbell’s left hand and smashing his wrist. Shrapnel from the same shell also badly injured the copilot, fracturing bones in his left leg and arm and wounding his right hand. In the dorsal turret, Sgt. Geoffrey A. O’Hea returned fire but was himself wounded in the left leg. The only crewmember not injured was Sgt. Gordon Thomson, a twenty-one-year-old native of Manchester, England. Moving from position to position inside the fuselage, he administered first aid to the wounded men and helped Campbell fly the damaged plane. The latter, despite terrible pain and heavy loss of blood, remained at the controls for another three hours before landing safely at Port Moresby. Campbell was later awarded a Distinguished Flying Cross, and Thomson earned a Distinguished Flying Medal.

  THE BUILDUP OF air power at Rabaul gained momentum with the arrival of the 24th Air Flotilla, commanded by Rear Adm. Eiji Goto, at the end of January. The transfer of his headquarters from Truk was timed to coincide with the deployment of the Yokohama Air Group, whose fourteen Kawanishi flying boats occupied the former RAAF seaplane facility near Sulphur Creek.

  Goto went on the offensive almost immediately. On the night of February 2-3, six flying boats conducted the first attack on Port Moresby. The huge seaplanes dropped twenty-one bombs on Seven Mile airdrome, killing an Australian sergeant but otherwise causing little material damage. Two nights later, nine flying boats bombed the town itself, demolishing a house and two commercial buildings. The Australians, with no fighters and only a few antiaircraft guns, quickly realized that Port Moresby was virtually defenseless.

  Meanwhile, less than a week after Goto commenced his bombing campaign, a small flotilla of vessels departed Simpson Harbor and sailed two hundred miles down the island’s southern coast to Gasmata, known to the Japanese as Surumi. The village boasted a grass airstrip, used previously as a refueling stop by the RAAF, and on February 9 a unit of Special Naval Landing Forces went ashore and secured the site. Engineers of the 7th Establishment Squad immediately began making improvements to the field. Working quickly, they developed a forward base with a runway some 3,600 feet long and 100 feet wide.

  The purpose for building the advance base was later explained by a naval correspondent: “Although the Surumi airfield … was capable of accommodating only a small number of fighters or serving as an emergency landing strip for land attack planes, it was highly important as a relay air base to the Port Moresby, Lae, and Salamaua areas.” Unmentioned by the Japanese was the defensive element provided by the forward base, which enabled Imperial Navy fighters to patrol the skies over central New Britain and intercept Allied attackers well south of Rabaul.

  FLYING OFFICER GEOFF LEMPRIERE, 24 Squadron’s intelligence officer, was one of those individuals whose luck vacillated between fortune and misfortune. Remaining in Rabaul on January 22 in order to destroy classified documents, he missed the squa
dron’s evacuation. Then, after joining up with a band of Lark Force soldiers attempting to escape south along the coast, he was slowed by a random injury to his leg that developed into a badly infected ulcer. The party he was traveling with “borrowed” a small boat from a Catholic mission in the hopes of sailing to New Guinea, but they blundered into the harbor at Gasmata on the night of February 9 and were captured. This, however, turned out to be advantageous for Lempriere, whose infected leg would likely have become gangrenous if left untreated. Instead, a Japanese doctor at Gasmata provided expert medical attention—and probably saved his life.

  More ironies followed. While Lempriere underwent treatment on the afternoon of February 11, three RAAF Hudsons attacked the transports being unloaded in the harbor. The mission was led by John Lerew, who of course had no inkling that his former squadron mate was literally right under his nose.

  As luck would have it, the first A5M4 fighters assigned to the newly acquired base arrived from Rabaul at that very moment. An hour and twenty minutes earlier, FPO 1st Class Satoshi Yoshino had led four of the open-cockpit fighters from Lakunai airdrome. As they approached Gasmata, Yoshino was alerted by radio that enemy bombers were attacking. His fighters were in a perfect position to strike.

  For Lerew, descending to mast height to attack one of the transports, the timing could not have been worse. In a flash, Yoshino hit the Hudson in both engines. The right engine and wing caught fire, but Lerew continued his attack, releasing his bombs at an altitude of only twenty feet. He pulled up sharply, maintaining control of the burning plane long enough for the other three crewmembers to move toward the rear escape hatch. Just as the Hudson’s right wing separated and the doomed plane nosed over, Lerew squirmed out of the cockpit side window and parachuted to the jungle below.

  Yoshino, having fatally damaged Lerew’s aircraft, next went after the Hudson piloted by Flg. Off. Graham I. Gibson. This plane also crashed, diving at a steep angle directly into a hillside. The Japanese claimed to have shot down the third Hudson as well, but Flt. Lt. William A. Pedrina and his crew managed to escape. The Aussie airmen fought hard and were officially credited with shooting down one fighter and probably destroying another, though only one Mitsubishi was actually hit, with total damage amounting to six bullet holes. After ensuring that the sky was clear of Australian bombers, Yoshino and the rest of his flight landed safely at Gasmata.

  Lerew, meanwhile, survived his adventurous parachute descent into the dense jungles of New Britain and began searching for his crewmen. No trace of them was found, and it is believed that all three perished in the Hudson’s fiery fuselage before they could jump. Moving deeper into the bush, Lerew lived off the land for several days while evading the Japanese. He finally encountered friendly natives and was led to a coastwatcher, who arranged for a sailing schooner to take him to Port Moresby. Ten days after being shot down, Lerew rejoined his squadron.

  The daring attack had cost the RAAF two Hudsons and the lives of seven men, but for once the lightweight bombers gave as good as they got. Japanese records revealed that two transports, the 4,390-ton Kinryu Maru and 7,072-ton Kizui Maru, were damaged by direct hits at Gasmata on February 11. Although both vessels eventually returned to service, dozens of Japanese had been killed or wounded.

  CHAPTER 7

  Stronghold

  CONSIDERING THE RAAF’S almost-embarrassing lack of resources, the long-range attacks against New Britain were nothing less than heroic. To the Japanese, however, the raids were nothing more than a minor harassment—too insignificant to affect the development of Rabaul. Indeed, as ship after ship offloaded troops and supplies onto the busy wharves and jetties, the town experienced a population explosion.

  During the first hours of occupation, the Japanese grabbed everything they could lay their hands on, ransacking stores and gorging themselves on foodstuffs and liquor, but once the pickings were gone the South Seas Force was left to deal with severe overcrowding. Conditions grew worse as more personnel came ashore, and the combat troops were eventually outnumbered by support units. Temporary encampments helped relieve the housing shortage, but the Japanese also erected hundreds of hastily built wooden buildings.

  Prior to the invasion, Rabaul consisted of about 330 structures of all types, including warehouses and commercial buildings. Over the next few months the Japanese tripled that figure, constructing more than 600 wooden structures for an aggregate of 2.8 million square feet of floor space. The army and navy revamped or constructed twenty-nine sawmills, mostly using native labor, which together generated an output of more than seven hundred thousand board feet of lumber per month.

  Everywhere around Rabaul, engineers began enlarging and improving the military complex. Simpson Harbor could already handle three hundred thousand tons of shipping, but the Imperial Navy made it even better, adding anchorages in Keravia Bay and Matupit Harbor. Vice Admiral Inoue, the commander of the Fourth Fleet, officially dispersed the invasion fleet on January 29 and established the Rabaul Area Force. Subordinate commands included the 8th Special Base Force, the 6th Torpedo Squadron, the 14th Minesweeper Flotilla, floatplane units, a naval construction detachment, and the Special Naval Landing Force antiaircraft batteries.

  Air power received similar attention. Lakunai airdrome, which the Japanese called Rabingikku, was established as the main base for Imperial Navy fighters, primarily because a low area near the midpoint of the runway was deemed unsuitable for constant use by heavy aircraft. Engineers added approximately one hundred revetments and planned to resurface the runway, but periodic flooding prevented that from becoming a reality. The field conditions remained substandard throughout much of 1942 thanks to the steady fall of ash from Tavurvur, only a mile from the end of the runway on the opposite side of Matupit Harbor.

  Vunakanau airdrome was greatly expanded as the main base for Imperial Navy land attack aircraft as well as fighters. The runway, extended to a length of 5,200 feet and widened to 135 feet, was paved with a four-inch-thick layer of concrete. Protective revetments for sixty bombers and ninety fighters were added, along with numerous wooden buildings for storage, administration, and housing. New barracks space alone totaled some 70,000 square feet, providing accommodations for 2,500 personnel.

  Many of the roads that crisscrossed the Gazelle Peninsula were likewise improved. Prior to Japanese occupation there were just over 100 miles of paved roads, most of which were built by German engineers before World War I. The Japanese expanded that mileage four-fold, bringing in the 31st Field Road Construction Unit and “special details” (a euphemism for POW labor) to build 395 miles of new roads. The completed network provided numerous options for moving large quantities of troops and supplies.

  Defensive emplacements and weapons were also imposing, with batteries installed and manned independently by army and navy units. The first heavy batteries were placed by the Maizaru 2nd Special Naval Landing Force, which set up four 80mm Type 99 antiaircraft guns, followed soon thereafter by the 47th Field Antiaircraft Artillery Battalion, equipped with at least a dozen 75mm Type 88 guns. The latter, which somewhat resembled the fearsome German 88mm Flak, was not nearly as lethal, but the Japanese more than made up for the difference by installing almost a hundred Type 88 and Type 99 guns at Rabaul. In addition, two dozen 120mm and larger dual-purpose guns, which could be used against ships as well as aircraft, were placed in strategic locations around the harbor. And that was only the heavy stuff. Smaller-caliber antiaircraft weapons included approximately 100 Navy Type 96 25mm automatic cannons (in both twin- and triple-barrel versions), plus approximately 120 heavy machine guns and rapid-fire cannon manned by army units.

  Each weapon had its own bubble of lethal coverage, and the Japanese placed the guns, to the extent possible, so that the kill zones overlapped. The Type 88s, for example, had a theoretical effective range of 9,000 meters (29,000 feet), while the lighter Type 96 cannon were deadly up to 5,500 meters (18,000 feet). In all, the caldera was surrounded by nearly four hundred antiaircraft g
uns, most of them concentrated in a C-shaped ring that started at the tip of Crater Peninsula and extended all the way around the basin to Kokopo. Any Allied aircraft attempting to attack Rabaul would first have to fly through this ring of fire and then run the gauntlet again in order to egress from the target.

  Coastal defense systems at Rabaul were equally impressive. To streamline command and control, the Gazelle Peninsula was divided into areas of military responsibility. Simpson Harbor and Rabaul township were the navy’s domain, while the army controlled most of the remaining area. Naval defense batteries included thirty-eight heavy rifles—all but one having a bore of 120mm or larger—protected by at least fifty concrete pillboxes housing heavy machine guns. The army added dozens of 150mm howitzers, 75mm infantry guns, mortars, and antitank guns to this formidable group of weapons. In the southern part of the peninsula, army zones were further subdivided into sectors, each defended by eight hundred to four thousand troops. Fortifications included numerous pillboxes, bunkers, and reinforced caves. Choke points were created with roadblocks and antitank ditches, and foot trails were sowed with land mines. Any beaches that might be used for an Allied amphibious landing—particularly Talili Bay, the Keravat River area, and Kokopo—were heavily mined.

  The array of weaponry dedicated to ground defense was astounding. Potential invaders would first have to navigate through a maze of underwater obstacles designed to rip the bottoms out of landing craft, then fight inland past a hornet’s nest of fixed defenses: almost 240 heavy cannon and howitzers, roughly the same number of antitank guns and field guns, 23 heavy mortars, and approximately 6,000 machine guns and grenade launchers.