Victory in the Bismarck Sea

Aug. 1, 1996

The March 4, 1943, entry in the diary of Lowell Thomas, the famous radio newscaster, was typically succinct: “From the coast of New Britain to the coast of New Guinea, the waters are strewn with the wreckage of Japanese ships and airplanes. the battle of the Bismarck Sea was spectacular victory.”

The Bismarck Sea

Few Americans had ever heard of it or knew where it was. However, it was to be the scene of a major victory for landbased aircraft over warships–one that would have made Billy Mitchell, the old champion of airpower, very proud.

The three-day battle had its origins in the US plan to take the initiative from Japan and push the network of Allied air bases away from Australia toward Japanese-dominated areas–Gen. Douglas MacArthur’s “island-hopping” strategy. First, however, the Allies had to deal with Japanese forces on New Guinea.

From March 1942 to January 1943, the Japanese had been able to send convoys from Rabaul, on New Britain, across the Bismarck Sea to New Guinea with few losses. No Allied naval presence existed, and Allied airpower was to weak to halt Japan’s warships. Allied forces operated from Port Moresby on the south side of the giant island to prevent Japanese forces from moving closer to Australia.

In late February 1943, when Japanese ships attempted to reinforce and resupply their New Guinea garrisons, they had to be attacked and stopped if the Allies were to have a chance to carry out MacArthur’s bypass strategy. Buna, across the Owen Stanley Range, about 100 miles northeast of Port Moresby, was a worrisome enemy base and had to be neutralized first. In the June 1944 issue of Air Force, Lt. Gen. George C. Kenney, commanding general of Allied Air Forces in the southwest Pacific, explained what happened there.

“Too Expensive”

“Our fighters began to patrol over Buna. If [a Japanese pilot] came up, we shot him down. If he did not come up, we strafed him on the ground. In between times, heavies, mediums, and light bombers dug holes in his runways, battered down his revetments, burned up his stores, and strafed his personnel. The [Japanese] kept filling up the bomb craters, and we kept making new ones. He replaced his airplanes, and we promptly shot them out of the air or burned them on the ground. Before long, he tired of the game and didn’t bother to fill in the holes on the runway. It had cost him around seventy-five planes, and he decided that it was too expensive.”

However, the Japanese wanted the base back in operation and staged their main forces from Rabaul on the Bismarck Sea coast off New Britain, 500 air miles from Port Moresby. Enemy convoys from there had tried to relieve Buna, but it finally fell to Allied ground forces in January 1943. It cost the enemy about 300,000 tons of shipping sunk or damaged and scores of planes destroyed by Fifth Air Force bombers and fighters.

While ground forces continued to clean up enemy stragglers, General Kenney’s air units began to carry out almost daily attacks on enemy concentrations farther up the New Guinea coast. There were three chief targets:

  • Lae, a major Japanese base and the most active airfield on the northern side of New Guinea.
  • Salamaua, with an important harbor and airfield.
  • Finschhafen, a shipping center and anchorage for seaplanes and tenders. Japan’s bases and shipping throughout the nearby Bismarck Archipelago were also attacked in order to isolate that area.

On February 25, Allied radio intercepts revealed that a large enemy convoy, traveling to Lae, was scheduled to arrive in the Bismarck Sea early in March. The exact size and composition of the convoy were unknown, but the Allies were confident that they would be carrying both troops and supplies to support an expected push to retake the areas of New Guinea that had been lost.

What was to be called the Battle of the Bismarck Sea began with the sighting of the expected Japanese convoy off the north coast of New Britain on March 1.

General Kenney knew the battle would show what land based airpower could do against naval forces. He had arrived in the southwest Pacific in July 1942 as commanding general of Allied Air Forces under General MacArthur.

While he was en route to the Pacific to his assignment as MacArthur’s chief air officer, he and his aide, Maj. William Benn, commander of the 63d Bomb Squadron, discussed low-altitude bombing of ships. Kenney recalled: “It looked as though there might be something in dropping a bomb with a five-second-delay fuze from level flight at an altitude of about fifty feet and a few hundred feet away from a vessel, with the idea of having the bomb skip along the water until it bumped into the side of the ship. In the few seconds remaining, the bomb should sink just about far enough so that when it went off it would blow the bottom out of the ship. In the meantime, the airplane would have hurdled the enemy vessel and would get far enough away so that it would not be vulnerable to the explosion.”

Innovators, Improvisers

When Kenney arrived in Australia, he found that his flying assets were about 200 fighters–mostly P-39s and P-40s–along with an assortment of A-20s, B-25s, B-26s, B-17s, and C-47s; a high percentage were out of commission for maintenance and parts. His air force units grew during the next few months as he reorganized them and put men in charge who knew how to innovate, improvise, and make do with the supplies available.

In the air, they began to show what could be achieved with a mix of bombardment and fighter aircraft.. With the number of Japanese ships of all types plying their resupply routes, there would be plenty of opportunities to experiment with low-altitude bombing tactics against them.

Major Benn is credited by General Kenney with developing skip bombing into a fine art. He experimented with different bomb sizes, timed fuses, and approaches to targets. He led one skip-bombing raid with a half-dozen B-17s at low altitude and sent six enemy ships to the bottom. According to Kenney, “Skip bombing became the standard, sure way of destroying shipping, not only in Bill’s bombardment squadron but throughout the Fifth Air Force.”

Meanwhile, General Kenney called on Maj. Paul I. “Pappy” Gunn, a pilot whose unorthodox solutions to maintenance problems became legendary. Gunn developed a package of four .50-caliber machine guns for the nose of A-20 light bombers. This impressed Kenney. He directed Gunn to “pull the bombardier and everything else out of the nose of a B-25 medium bomber and fill it full of .50-caliber guns, with 500 rounds of ammunition per gun.”

Kenney said, “I told him I wanted him then to strap some more on the sides of the fuselage to give all the forward firepower possible. I suggested four guns in the nose, two on each side of the fuselage, and three underneath. If, when he had made the installation, the airplane still flew and the guns would shoot, I figured I’d have a skip bomber that could overwhelm the deck defenses of a [Japanese] vessel as the plane came in for the kill with its bombs. With a commerce destroyer as effective as I believed this would be, I’d be able to maintain an air blockade. . . anywhere within the radius of action of the airplane.”

“Pretty Shooting”

The combination of forward-firing 50s and skipping bombs was effective. As fast as planes could be modified, pilots were trained. One of the B-25 squadron commanders who became especially adept at attacking shipping at low altitudes was Maj. Ed Larner. He and his “commerce destroying” squadron had become expert at skipping bombs into ground targets at low altitudes and strafing the nose- and side-gun-firing .50 calibers. Kenney recalled, “I saw a couple of them practicing on the old wreck on the reef outside Port Moresby. They didn’t miss. It was pretty shooting and pretty skip bombing.”

General Kenney added that he had “a hunch” that the enemy’s forces “were going to get the surprise of their lives.”

The battle began on the afternoon of March 1, 1943, when a convoy of seven merchant vessels, six destroyers, and two cruisers was first sighted north of New Britain. Seven additional merchant vessels reportedly joined the convoy en route as the weather closed in.

On March 2, the vessels were again sighted heading from the Bismarck Sea toward the Vitiaz Strait. When a force of twenty-nine B-17s hit the convoy, a large merchant vessel was sunk, two others damaged, and a destroyer was set on fire. The Flying Fortresses were attacked by thirty Japanese fighters, three of which were shot down. Ten Allied bombers were riddled with holes, but all returned to their base at Port Moresby.

Later that day, the convoy consisted of six warships and ten merchant vessels. They were attacked by nine B-17 s that eliminated two merchantmen and damaged another. One intercepting fighter was shot down; again, all bombers returned safely.

Just before daybreak on March 3, reconnaissance airplanes spotted eight enemy warships escorting seven merchant vessels headed south through the Vitiaz Strait. General Kenney explained what happened next:

“At ten o’clock, the big brawl began about fifty miles southeast of Finschhafen, right where we had planned it. Eighteen heavy bombers and twenty medium bombers attacked from 7,000-foot altitude. As the last bombs were dropped, thirteen Australian Beaufighters swept in at deck height, strafing the whole length of the convoy, as Ed Lamer with twelve of my new B-25 commerce destroyers skip-bombed, followed by twelve A-20 light bombers, also down ‘on the deck.’ Sixteen P-38s provided top cover.

“Ed Larner’s squadron dropped thirty-seven 500-pound bombs, scoring seventeen direct hits, and the A- 20s, which also skip-bombed, scored eleven direct hits out of the twenty 500-pounders they let go.

“Twenty minutes from the time the attack started, the battle was just about over. Every. . . merchant vessel was sunk, sinking, or so badly damaged that it was certain they would never reach land. One of the destroyers had been sunk and three others were in bad shape from direct skip-bombing hits.”

During the battle, one B-17 was set on fire, but it continued on its bomb run. Just as the bombs were released, the airplane lost its wing and spiraled seaward out of control. Seven men bailed out successfully, and all were strafed by Japanese fighters as they swung in their parachutes. Three P-38 pilots, seeing what happened, dove on the enemy planes and blasted five of them out of the sky; however, all three P-38s were shot down. Of the thirty Japanese fighters in the engagement, twenty-two were definitely destroyed, two were probables, and four were damaged.

Larner and Henebry

That afternoon, what was left of the Japanese convoy came under attack by a force of sixteen B-17 bombers, five Australian Beaufighters, and ten B-25 “strafers” led by Major Lamer, with Maj. John P. “Jock” Henebry on his wing. Eleven P-38s flew top cover. When the attack was over, three enemy vessels were on fire and sinking fast. One destroyer was set on fire and another was left sinking. When reconnaissance airplanes came over the next morning, only one burned-out Japanese destroyer was visible and it was barely afloat. One of Major Larner’s B-25s skipped a bomb into it and sent it to the bottom.

The Battle of the Bismarck Sea was over. The entire force of Japanese troops, supplies, and equipment had been destroyed; the encounter had cost the enemy an estimated 15,000 lives. US losses came to thirteen men killed and twelve wounded. Four aircraft were shot down and two crash-landed close to base.

The number of ships sunk varied in official reports; poor weather prevented reliable reconnaissance. However, when all the reports were in, the final count, according to the official Summary of Results, was “thirteen to fourteen M/V [merchant vessels] and seven DD [destroyers] sunk and one DD as a possible only. In addition to shipping losses, our fighters shot down twenty-seven fighters, and our bombers destroyed thirty-two planes.”

“Jock” Henebry, who in time became a major general and then, after retirement, the National President of the Air Force Association from 1956 to 1957, summarized the three-day battle this way: “All ships of the convoy were sunk. All landbased Army Air Forces and a few Australian planes did the job. There were no Allied navy surface vessels involved– a ‘first’ in history involving such a large enemy force. No troops or equipment reached their destination.”

In his after-action report, Maj. Gen. Ennis C. Whitehead, then deputy commander of Fifth Air Force, reviewed the battle strategy and results: “Our plan of attack was to begin hitting the convoy as far out as weather and radius of our bombers permitted. In each attack, we used all air force units [that] had sufficient radius in one coordinated attack. Once the convoy was within the operating radius of our attack bombers, we used medium-level bombing to divert AA [antiaircraft artillery] and fighters and the attack bombers to make the ‘kills.’

“The medium-level bombing was surprisingly effective. Strafing by our attack bombers and the RAAF Beaufighter squadron proved adequate in the neutralization of destroyer and light cruiser AA. The fighter cover over each coordinated attack effectively neutralized the enemy fighter force, permitting our bombers to make their runs without enemy fighter interference.”

General Whitehead noted that the 50-caliber “gun is adequate for strafing such targets. The eight-gun B-25C-1 has, however, only half enough firepower. From fifteen to twenty [.50-caliber] guns firing forward would give a suitable covering fire for attack bomber operations against warships.”

They Mean Business

As many as fourteen forward-firing .50-caliber guns were added to some later model B-25s, as well as eight five-inch rockets and a 75-mm cannon, which “Pappy” Gunn had perfected. In addition, the B-25H, the most lethal of all B-25s, also was able to carry a hefty 3,000 pounds of bombs. As General Kenney commented in the Air Force article, “The greatest commerce destroyer of the war had been born. We hurriedly remodeled every B-25 we could get our hands on and made the phrase ‘air blockade’ mean something.”

General MacArthur sent his “gratitude and felicitations on the magnificent victory,” which “cannot fail to go down in history as one of the most complete and annihilating combats of all time.” General Kenney sent a congratulatory message to General Whitehead and added, “Airpower has written some important history in the past three days. Tell the whole gang that I am so proud of them I am about to blow a fuze.”

Since the Bismarck Sea action had proved the concept was sound, all light- and medium-bomber pilots were trained in low-altitude bombing techniques. “Jock” Henebry’s 3d Bomb Group became especially adept. Further proof came in an attack at Rabaul on November 2,1943, a date that ranks with the Bismarck Sea battle in the history of the war in the South Pacific.

While six P-38 squadrons flew top cover, Maj. Ben Fridge, with four squadrons of B-25s, machine-gunned and dropped phosphorous bombs on antiaircraft positions. Henebry led his five squadrons into Rabaul Harbor through the smoke of the phosphorous bombs at masthead height. “Of the thirty-eight vessels. . . and twenty merchant ships. . . in the harbor that day,” Kenney reported, “thirty received direct hits in the toughest, hardest-fought engagement of the war. The list included one heavy cruiser, one destroyer tender, one submarine tender, three destroyers, two naval auxiliary craft, three minesweepers, sixteen merchant vessels, two tankers, and a tug.”

Although from fifty to sixty enemy fighters were expected, 125 to 150 showed up and dove through the P-38s to get at the B-25s. Sixty-eight Japanese fighters were destroyed by the P-38s and B-25s, with twenty-three probables. In addition, Fridge’s B-25s destroyed ten floatplanes sitting at anchor, as well as other aircraft on the Lakunai Airdrome. US losses were six B-25s, with three missing, and nine P-38s, with eight of them missing.

Kenney reported: “In the space of twelve minutes, we had destroyed or damaged 114,000 tons of Japanese shipping, shot down or destroyed on the ground eighty-five. . . airplanes, and burned out half the town of Rabaul, with a loss of supplies to the enemy estimated at 300,000 tons.”

“Jock” Henebry did not escape the enemy’s wrath unscathed. He had to ditch his B-25 after it was riddled with bullet and shell holes and one engine was shot out. He and his crew were rescued later that day.

In writing about the Bismarck and Rabaul battles in his personal history of the war, General Kenney, declared, “Never in the long history of warfare had so much destruction been wrought upon the forces of a belligerent nation so swiftly and at such little cost to the victor.”

General Kenney, a contemporary of Billy Mitchell’s who agreed with the great crusader’s airpower postulates, must have taken special pride in writing that statement. After the 1921 bombing tests off the Atlantic coast, Mitchell had declared, “No surface vessels can exist wherever air forces acting from land bases are able to attack them.” General Kenney’s low-flying B-25 mediums, appropriately named for Mitchell, proved beyond all doubt that he was right.

C. V. Glines is a writer living in Dallas, Tex. His most recent article for Air Force Magazine, “The Son Tay Raid,” appeared in the November 1995 issue.