by Daniel Wrinn
Army and Marine aviation units composed Mulcahy’s Tactical Air Force. His force had fifteen Marine fighter squadrons, ten Army fighter squadrons, two Marine torpedo bomber squadrons, and sixteen Army bomber squadrons. Marine fighter pilots flew F4U Corsairs and radar-equipped, night-fighting F6F Hellcats. Army pilots flew P-47 Thunderbolts, and their night fighters were P-61 Black Widows.
Allied pilots fought air-to-air duels against kamikazes and plenty of other late-model “Franks” and “Jacks.” Altogether, the Tactical Air Force pilots shot down 627 planes. Colonel Ward Dickey’s Marine Aircraft Group (MAG-33) set the record with 215 kills—more than half claimed by the “Death Rattlers”—Major George Axtell’s squadron VMF-323.
The need to protect the Fleet caused some ground commanders to worry that their own close-in air support would be “short-sheeted.” But escort carrier Naval squadrons picked up the slack. They flew over sixty percent of the close-in support missions between April 1 and the end of June. The combined TAF and carrier pilots flew over 14,000 air support sorties. Over 5,000 of these supported Marines on the ground. Pilots dropped over 150,000 gallons of napalm on enemy positions.
Air Liaison Parties accompanied the frontline divisions and directed aircraft to the target. Coordinating these lower echelon requests became the responsibility of three Marine Landing Force Air Support Control Units. One represented the Tenth Army to the fleet while the others were responsive to IIIAC and the XXIV Corps. This technique refined experiments McGee had started on Iwo Jima. In most cases, close air support for the infantry was extremely effective. Several units reported safe and prompt delivery of ordnance on target within 150 yards. But there were also accidents and delays (less than a dozen) and situations where lines were simply too intermingled for any air support.
Other Marine aviation units helped in the victory on Okinawa. Marine torpedo bomber pilots flew their Avenger “torpeckers” in zero-zero weather. They dropped over 40,000 pounds of medical supplies, rations, and ammunition to forward-deployed ground units. The fragile and small Grasshoppers of the Marine Observation Squadrons flew 3,487 missions of artillery spotting, medical evacuations, and photo-reconnaissance. One artillery officer described the Grasshopper pilots as: “the unsung heroes of Marine aviation. They’d often fly past cave openings and look in to see if the Japs were hiding a gun in there.”
Marine pilots served on Okinawa with panache. During a desperate dogfight, one pilot radioed: “Come on up here and help me. I got two Franks, and a Zeke cornered.” Those were his last words, but his fighting spirit persisted. According to a destroyer skipper who’d just been rescued from swarms of kamikazes by Marine Corsairs: “I’d take my ship to the shores of Japan if I could have those Marines with me.”
Artillery on Okinawa
Because of the tactics selected and the nature of enemy defenses, Okinawa was the most significant battle in the war for artillery units. General Geiger landed with fourteen firing battalions with the IIIAC. And when the 2/10 Marines came ashore to support the 8th Marines—the total rose to fifteen firing battalions.
General David Nimmer commanded the III Corps Artillery with three batteries of 155mm howitzers and three 155mm “Long Tom” guns. The Marines had considerably enhanced their firepower since the initial Pacific campaigns.
While one 75mm howitzer battalion still remained, the 105mm howitzer had become the norm for division artillery. Infantry units on the front line were supported by the 75mm fire of medium tanks and LVT-As. New self-propelled “siege guns” with 4.5-inch multiple rocket launchers fired by the “Buck Rogers” men and attached Army 4.2 mortar platoons caused chaos on Japanese positions.
Colonel Fred Henderson described this devastating array of fire support: “Not many people realize that the Tenth Army’s artillery, plus the LVT-As and naval gunfire gave us a guns/mile of front ratio on Okinawa that was higher than any US effort in all of World War II.”
General Buckner tasked his commanders to integrate field artillery support early in the campaign. General Geiger sent his corps artillery and 11th Marines (not fully committed in the opening weeks) to help the XXIV Army Corps in their early assaults against the outer Shuri defenses. From April 7 to May 6, these artillery units fired over 55,000 rounds in support of the XXIV Corps. But this was only the beginning. Once both IIIAC Marine divisions entered the lines, they benefited from Army artillery support and organic fire support—two Marine and two Army.
By the end, the Tenth Army artillery rockets had fired over two million rounds downrange. In addition, 707,000 mortars, rockets, and five-inch or larger shells were fired from naval gunfire ships offshore. Half of the artillery rounds were from 105mm howitzer shells and the M-7 self-propelled guns. Compared to these bigger guns, the older 75mm pack howitzers were the battlefield’s “Tiny Tims.” Their versatility and mobility proved valuable through the long haul. According to Colonel Brown, who commanded the LVT-As firing similar ammunition: “The 75mm was plentiful and contrasted with the heavy calibers, so we used it for fire interdiction and harassing missions across the front.”
Generals del Valle and Geiger expressed interest in the army’s larger weapons. Geiger respected the Army’s 8-inch howitzer 200-pound shell. It had much more penetrating and destroying power than the 155mm gun’s ninety-five-pound shell—largest in the Marine’s inventory. Geiger urged Marine Corps Headquarters to form 8-inch howitzer battalions for the next attack on Japan. Geiger also praised the accuracy, range, and power of the Army’s 4.2-inch mortars, and recommended their inclusion in the Marine division.
On several occasions, artillery commanders were tempted to orchestrate all this killing power into one mighty concentrated attack. Time on target (TOT) missions frequently occurred in the early weeks, but their high consumption rates were a drawback. Late in the campaign, Colonel Brown coordinated a massive TOT with twenty-two battalions against enemy positions in southern Okinawa. This sudden concentration worked brilliantly, but Brown failed to inform the generals and woke everyone from a sound sleep. Brown “caught hell” from all sides.
Geiger insisted the LVT-As were also trained as field artillery. While this was done, the opportunity for direct fire support in the assault waves fizzled on L-Day when the enemy chose to not defend the Hagushi breaches. Colonel Lewis Metzger’s 1st Armored Amphibian Battalion LVT-As fired over 20,000 rounds of 75mm shells in an artillery support role after L-Day.
Marines made great advances in refining supporting arms coordination during the battle for Okinawa. Commanders established Target Information Centers (TIC) at every level from battalion up to Tenth Army. The TICs provided centralized target information and a weapons assignment system responsive to both assigned targets and targets of opportunity. All three component liaison officers: air, artillery, and naval gunfire, were staffed with target intelligence information officers.
This commitment to innovation led to significant support improvements for the foot-slogging infantry. As one rifle battalion commander later wrote: “It wasn’t uncommon for a battleship, artillery, tanks, and aircraft to be supporting the efforts of a single platoon during the assault on Shuri.”
Sherman M-4 Tanks
Seven Marine and Army tank battalions were deployed on Okinawa. They were a deadly weapon—but only when coordinated with accompanying infantry. The Japanese tried to separate the two components by boldness and fire.
Before the invasion, General Ushijima said: “The strength of the enemy’s forces is with his tanks.” Ushijima’s anti-tank training received the highest priority within his Thirty-second Army. These preparations proved successful on April 19, when the Japanese knocked out twenty-two out of the thirty Sherman tanks of the 27th Division—mostly by suicidal demolitionists.
The Marines fared better. They learned in earlier campaigns how to integrate artillery and infantry in a close protective over-watch of their tanks and to keep the “human bullet” suicide squads at bay. While enemy mines and guns took their toll on the Shermans, only
one Marine tank sustained damage from a Japanese suicide attack.
Colonel Arthur Stewart commanded the 1st Tank Battalion on Okinawa. His unit had fought with distinction at Peleliu six months earlier, despite shipping shortfalls that kept a third of his tanks out of the fight. Stewart insisted on keeping the battalion’s older M-4A2 Shermans because their twin (General Motors) diesel engines were safer in combat: “The tanks were not so easily set on fire and blown up under enemy fire,” Stewart wrote after the war.
Colonel Rob Denig preferred the newer Sherman model M-4A3 for his 6th Tank Battalion. Denig’s tank crews liked the greater horsepower provided by the water-cooled Ford V-8 engines. They considered the reversion to gasoline from diesel an acceptable risk. The 6th Tank Battalion faced its greatest challenge against Admiral Ota’s naval guns and mines on the Oroku Peninsula.
Sherman tanks were harshly criticized in the European theater for coming up short against the heavier German Tiger Tanks. But they were ideal for island fighting in the Pacific. On Okinawa, the Sherman’s limitations were obvious. Their 75mm gun was too light against most of Ushijima’s fortifications. But the new M-7 self-propelled 155mm gun worked well. Shermans were never known for their armor protection. At thirty-three tons, their strength was more in mobility and reliability. Japanese anti-tank weapons and mines reached the height of their deadliness on Okinawa. The Sherman’s thin-skinned weak points (1.5-inch armor on the rear and sides) caused considerable concern.
Marine tank crews sheathed the sides of their tanks with lumber to thwart hand-lobbed Japanese magnetic mines as early as the Marshalls. By Okinawa, the Shermans were draped with spot-welded track blocks, sandbags, wire mesh, and clusters of large nails—designed to enhance armor protection.
Both tank battalions had their Shermans configured with dozer blades (valuable for cave fighting), but neither deployed with flame tanks. Despite the rave reports of the USN Mark I turret-mounted flame system installed on the Shermans in the Iwo Jima battle, there was no retrofit program for the Okinawa-bound Marine tank units. All flame tanks on Okinawa were provided courtesy of the US Army’s 713th Armored Flamethrower Battalion. Company B of that unit supported the Marines with three brand-new H1 flame tanks. Each carried 290 gallons of napalm thickened fuel—good for two-and-a-half minutes of flame at a range of 200 yards.
Marines used the new T-6 “tank flotation devices” to get the initial waves of Shermans ashore on L-Day. The T-6 was a series of floating tanks welded around the hull. They had a provisional steering device that made use of the tracks and electric bilge pumps. Once ashore, the crew jettisoned the bulky rig with built-in explosive charges.
The April 1 landing for the 1st Tank Battalion was truly “April Fool’s Day.” An LST (Landing Ship Tank) captain carrying six Shermans equipped with a T-6 launched the vehicles an hour late and eleven miles out to sea. It took them five hours to reach the beach (losing two tanks on the reef at ebb tide). Most of Colonel Stewart’s other Shermans made it ashore before noon, but some of his reserves could not make it across the reef for another forty-eight hours.
The Sixth Tank Battalion had better luck. Their LST skippers launched their T-6 tanks on time and close in. Two tanks were lost: one sank after its main engine failed, and the other broke a track and swerved into a hole. The other Shermans surged ashore and were ready to roll.
Enemy gunners and mine warfare experts knocked out three Marine Shermans in the battle. Many more tanks took damage from the fighting but were repaired by the hard-working maintenance crews. Because of their ingenuity, the assault infantry battalions never lacked armored firepower, shock action, and mobility.
Amphibious Reconnaissance
A series of smaller amphibious operations around the periphery of Okinawa helped contribute to victory. These landing forces varied in size from the company level to an entire division. Each reflected the apex of amphibious expertise learned in the Pacific theater by 1945. These landings produced fleet anchorages, auxiliary airfields, fire support bases, and expeditionary radar sites, giving an early warning to the fleet against the dreaded kamikazes.
The Amphibious Reconnaissance Battalion commanded by Major James Jones provided outstanding service to landing force commanders in a series of audacious exploits in the Marianas, Marshalls, Gilberts, and on Iwo Jima. Before L-Day on Okinawa, these Marines supported the Army’s 77th Division with stealthy landings on Awara Saki, Keise Shima, and other islands in the East China Sea. Later in the battle, this recon unit executed night landings on the islands guarding the eastern approaches to Nakagusuku Wan (later known as Buckner Bay).
On one of those islands—Tsugen Jima, the main Japanese outpost—Jones and his recon Marines had a ferocious firefight before he could extract his men through the darkness. The Army’s 105th Infantry stormed ashore on Tsugen Jima three days later and eliminated the stronghold and all resistance. On April 13, Jones’ Marines then sailed northwest and executed a night landing on Minna Shima to seize a firebase supporting the 77th’s main landing on Ie Shima.
The post-L-Day amphibious operations with the 27th and 77th Divisions were helpful—but not decisive. By mid-April, the Tenth Army had waged a campaign of massive firepower against the primary Japanese defenses. General Buckner chose not to employ amphibious resources to break the gridlock. Buckner’s long deliberation of whether to use the “amphib card” was not helped by a lack of flexibility by the Joint Chiefs, who kept strings attached to the use of the Marine divisions. The Japanese Thirty-second Army in southern Okinawa was the enemy’s center of gravity in the Ryukyu Islands. But still, the Joint Chiefs let weeks pass before scrubbing earlier commitments to send the 2nd Marine Division into attack Kikai Shima—an obscure island north of Okinawa.
General Buckner used the 8th Marines in a pair of amphibious landings on June 3 to seize outlying islands for early warning radar facilities against the kamikaze raids. Then, the commanding general attached the reinforced regiment to the 1st Marine Division for the final overland assaults on the south.
Buckner consented to the 6th Marine Division’s request to conduct its own amphibious assault below Naha to surprise the Naval Guard Force on the Oroku Peninsula. This was a jewel of an operation in which the Marines used every component of amphibious warfare to their great advantage.
If the 77th Division’s amphibious landings on Ie Shima or the 6th Marine Division’s landing on Oroku had been executed separately from the Okinawan campaign, they would both have received major historical study for the size of forces, brilliant orchestration, and intensity of the fighting.
While both operations provided valuable objectives: unrestricted access to Naha’s ports and Ie Shima airfields. They were only secondary to the more extensive campaign and barely received a passing mention. The Oroku operation would be the final unopposed amphibious landing of the war.
Legacy of Okinawa
The exhausted Marines on Okinawa showed little joy at the official proclamation of victory. The death throes of the Thirty-second Army kept the battlefield deadly. The last of General Ushijima’s infantry may have died defending Yuza Dake and Kunishi Ridge, but the remaining mishmash of support troops sold their lives dearly to the last man.
On June 18, diehard enemy survivors wounded Major Earl Cook, CO of the 1/22 Marines, and Colonel Hunter Hurst, CO of the 3/7. Even Day and Bertoli, who’d survived so long in that crater on Sugar Loaf, watched their luck run out in the final days. Private First Class Bertoli died in action. Corporal Day was seriously wounded by a satchel charge and required urgent evacuation to the hospital ship Solace.
The butcher’s bill on Okinawa was costly to both sides. Over 120,000 Japanese died defending the island, while 7,000 surrendered at the end. The native Okinawans suffered the worst. Recent studies show that over 150,000 civilians died in the fighting—one-third of the island’s population. The Tenth Army suffered over 45,000 combat casualties, including 7,264 dead Americans. An additional 26,000 nonviolent casualties were incurred: primarily c
ases of combat fatigue.
The Marine Corps’ overall casualties: air, ship detachments, and ground were 19,821. In addition, 562 members of the Navy Medical Corps were wounded or killed. General Shepherd described the corpsmen on Okinawa as: “the finest and most courageous men that I’d ever known. They did a magnificent job.”
Losses within the infantry (as usual) were disproportionate with other Allied outfits. Colonel Shapley reported his losses as 110 percent in the 4th Marines. This number represents the replacements and their high attrition in the battle. Corporal Day of the 2/22 Marines experienced the death of his battalion and regimental commanders, plus the killing and wounding of his two company commanders, seven platoon commanders, and every other member of his rifle squad.
The legacy of this epic battle can be defined through the following points:
Foreshadow to the Invasion of Japan
Admiral Spruance described the Okinawan battle as: “the bloody and hellish prelude to the invasion of Japan.” As wicked a nightmare as Okinawa was, every survivor knew the subsequent battles on Honshu and Kyushu would be worse. The operational plans for invading Japan specified the use of surviving veterans from Iwo Jima and Luzon. The reward for the Okinawan survivors would be to land on the main island of Honshu. Most of the men were fatalistic—no man’s luck could last through those hellish infernos.
Mastery of amphibious tactics
The massive and nearly flawless amphibious assault on Okinawa happened thirty years (to the month) after the disaster at Gallipoli in World War I. By 1945, the Allied forces had refined this difficult naval mission into an art form. Admiral Nimitz had every advantage in place for Okinawa: specialized ships and landing craft, a proven doctrine, mission-oriented weapons systems, flexible logistics, trained shock troops, and unity of command. Everything clicked and everything worked. The projection (and execution) of 60,000 combat troops landed ashore on L-Day validated an amphibious doctrine earlier considered suicidal.