Assault on Shuri

The Tenth Army's Action Report for the battle of Okinawa paid this understated compliment to the Thirty-second Army's defensive efforts: "The continued development and improvement of cave warfare was the most outstanding feature of the enemy's tactics on Okinawa." In their decision to defend the Shuri highlands across the southern neck of the island, General Ushijima and his staff had selected the terrain that would best dominate two of the island's strategic features: the port of Naha to the west, and the sheltered anchorage of Nakagusuku Bay (later Buckner Bay) to the east. As a consequence, the Americans would have to force their way into Ushijima's preregistered killing zones to achieve their primary objectives.

Everything about the terrain favored the defenders. The convoluted topography of ridges, draws, and escarpments served to compartment the battlefield into scores of small firefights, while the general absence of dense vegetation permitted the defenders full observation and interlocking supporting fires from intermediate strongpoints. As at Iwo Jima, the Japanese Army fought largely from underground positions to offset American dominance in supporting arms. And even in the more accessible terrain, the Japanese took advantage of the thousands of concrete, lyre-shaped Okinawan tombs to provide combat outposts. There were blind spots in the defenses, to be sure, but finding and exploiting them took the Americans an inordinate amount of time and cost them dearly.

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The bitterest fighting of the campaign took place within an extremely compressed battlefield. The linear distance from Yonabaru on the east coast to the bridge over the Asa River above Naha on the opposite side of the island is barely 9,000 yards. General Buckner initially pushed south with two Army divisions abreast. By 8 May he had doubled this commitment: two Army divisions of the XXIV Corps on the east, two Marine divisions of IIIAC on the west. Yet each division would fight its own desperate, costly battles against disciplined Japanese soldiers defending elaborately fortified terrain features. There was no easy route south.

By eschewing the amphibious flanking attack in late April, General Buckner had fresh divisions to employ in the general offensive towards Shuri. Thus, the 77th Division relieved the 96th in the center, and the 1st Marine Division began relieving the 27th Division on the west. Colonel Kenneth B. Chappell's 1st Marines entered the lines on the last day of April and drew heavy fire from the moment they approached. By the time the 5th Marines arrived to complete the relief of 27th Division elements on 1 May, Japanese gunners supporting the veteran 62d Infantry Division were pounding anything that moved. "It's hell in there, Marine," a dispirited soldier remarked to Private First Class Sledge as 3/5 entered the lines. "I know," replied Sledge with false bravado, "I fought at Peleliu." But soon Sledge was running for his life:

As we raced across an open field, Japanese shells of all types whizzed, screamed, and roared around us with increasing frequency. The crash and thunder of explosions was a nightmare . . . . It was an appalling chaos. I was terribly afraid.

General del Valle assumed command of the western zone at 1400 on 1 May and issued orders for a major attack the next morning. That evening a staff officer brought the general a captured Japanese map, fully annotated with American positions. With growing uneasiness, del Valle realized his opponents already knew the 1st Marine Division had entered the fight.

An Okinawan civilian is flushed from a cave into which a smoke grenade had been thrown. Many Okinawans sought the refuge of caves in which they could hide while the tide of battle passed over them. Unfortunately, a large number of caves were sealed when Marines suspected that they were harboring the enemy. Department of Defense Photo (USMC) 125697

The division attacked south the next day into broken country there after known as the Awacha Pocket. For all their combat prowess, however, the Marines proved to be no more immune to the unrelenting storm of shells and bullets than the soldiers they had relieved. The disappointing day also included several harbingers of future conditions. First, it rained hard all day. Second, as soon as the 5th Marines seized the nearest high ground they came under such intense fire from adjacent strongpoints and from higher ground within the 77th Division's zone to the immediate southeast they had to withdraw. Third, the Marines spent much of the night engaged in violent hand-to-hand fighting with scores of Japanese infiltrators. "This," said one survivor, "is going to be a bitch."

The Peleliu veterans in the ranks of the 1st Marine Division were no strangers to cave warfare. Clearly, no other division in the campaign could claim such a wealth of practical experience. And while nothing on Okinawa could match the Umurbrogol's steep cliffs, heavy vegetation, and endless array of fortified ridges, the "Old Breed" in this battle faced a smarter, more numerous foe who had more artfully prepared each wrinkle in the moonscape. In overcoming the sequential barriers of Awacha, Dakeshi, and Wana, the 1st Marine Division faced four straight weeks of hell. The funneling effects of the cliffs and draws reduced most attacks to brutal frontal assaults by fully-exposed tank-infantry-engineer teams. General del Valle characterized this small unit fighting as "a slugging match with but temporary and limited opportunity to maneuver."

A "Ronson" tank, mounting a flame thrower, lays down a stream of fire against a position located in one of the many Okinawan tombs set in the island's hillsides. Department of Defense Photo (USMC) 122153

General Buckner captured the fancy of the media with his metaphor about the "blowtorch and corkscrew" tactics needed for effective cave warfare, but this was simply stating the obvious to the Army veterans of Biak and the Marine veterans of Peleliu and Iwo Jima. Flamethrowers were represented by the blow torch, demolitions, by the cork screw — but both weapons had to be delivered from close range by tanks and the exposed riflemen covering them.

On 3 May the rains slowed and the 5th Marines resumed its assault, this time taking and holding the first tier of key terrain in the Awacha Pocket. But the systematic reduction of this strongpoint would take another full week of extremely heavy fighting. Fire support proved excellent. Now it was the Army's time to return the favor of interservice artillery support. In this case, the 27th Division's field artillery regiment stayed on the lines, and with its forward observers and linemen intimately familiar with the terrain in that sector, rendered yeoman service.

Marine Artillery at Okinawa The nature of the enemy defenses and the tactics selected by the Tenth Army commander made Okinawa the biggest battle of the war for Marine artillery units. General Geiger landed with 14 firing battalions within IIIAC; the total rose to 15 in June when Lieutenant Colonel Richard G. Weede's 2/10 came ashore in support of the 8th Marines. Brigadier General David R. Nimmer commanded III Corps Artillery, and Lieutenant Colonel Curtis Burton, Jr., commanded the 2d Provisional Field Artillery Group, which contained three batteries of 155mm howitzers and three of 155mm "Long Tom" guns. Colonel Wilburt S. ("Big Foot") Brown commanded the 11th Marines and Colonel Robert B. Luckey, the 15th Marines. The Marine divisions had greatly enhanced their firepower since the initial campaigns in the Pacific. While one 75mm pack howitzer battalion remained (1/11), the 105mm howitzer had become the norm for division artillery. Front-line infantry units also were supported by the 75mm fire of medium tanks and LVT-As, 105mm fire from the new M-7 self-propelled "siege guns," 4.5-inch multiple rocket launchers fired by the "Buck Rogers Men," and the attached Army 4.2-inch mortar platoons. Lieutenant Colonel Frederick R. Henderson described this combination of fire support: "Not many people realize that the artillery in Tenth Army, plus the LVT-As and naval gun fire equivalent gave us a guns/mile of front ratio on Okinawa that was probably higher than any U.S. effort in World War II." General Buckner urged his corps commanders to integrate field artillery support early in the campaign. With his corps artillery and the 11th Marines not fully committed during the opening weeks, General Geiger quickly agreed for these units to help the XXIV Army Corps in their initial assaults against the outer Shuri defenses. In the period of 7 April-6 May, these artillery units fired more than 54,000 rounds in support of XXIV Corps. This was only the beginning. Once both Marine divisions of IIIAC entered the lines, they immediately benefited from Army artillery support as well as their own organic fire support. As one example, prior to the 5th Marines launching a morning attack on the Awacha Pocket on 6 May, the regiment received a preliminary bombardment of the objective from four battalions — two Army, two Marine. By the end of the battle, the Tenth Army artillery units would fire 2,046,930 rounds down range, all in addition to 707,500 rockets, mortars, and shells of five-inch or larger from naval gunfire ships offshore. Half of the artillery rounds would be 105mm shells from howitzers and the M-7 self-propelled guns. Compared to the bigger guns, the old, expeditionary 75mm pack howitzers of 1/11 were the "Tiny Tims" of the battlefield. Their versatility and relative mobility, however, proved to be assets in the long haul. Colonel Brown augmented the battalion with LVT-As, which fired similar ammunition. According to Brown, "75mm ammo was plentiful, as contrasted with the heavier calibers, so 1/11 (Reinforced) was used to fire interdiction, harassing, and 'appeasement' missions across the front." Generals Geiger and del Valle expressed interest in the larger weapons of the Army. Geiger particularly admired the Army's eight-inch howitzer, whose 200-pound shell possessed much more penetrating and destroying power than the 95-pound shell of the 155mm guns, the largest weapon in the Marines' inventory. Geiger recommended that the Marine Corps form eight-inch howitzer battalions for the forthcoming attack on of Japan. For his part, del Valle prized the accuracy, range, and power of the Army's 4.2-inch mortars and recommended their inclusion in the Marine division. Department of Defense Photo (USMC) 12446 On some occasions, artillery commanders became tempted to orchestrate all of this killing power in one mighty concentration. "Time on target" (TOT) missions occurred frequently in the early weeks, but their high consumption rate proved disadvantageous. Late in the campaign Colonel Brown decided to originate a gargantuan TOT by 22 battalions on Japanese positions in the southern Okinawan town of Makabe. The sudden concentration worked beautifully, he recalled, but "I neglected to tell the generals, woke everyone out of a sound sleep, and caught hell from all sides." General Geiger insisted that his LVT-As be trained in advance as field artillery. This was done, but the opportunity for direct fire support to the assault waves fizzled on L-Day when the Japanese chose not to defend the Hagushi beaches. Lieutenant Colonel Louis Metzger commanded the 1st Armored Amphibian Battalion and supported the 6th Marine Division up and down the length of the island. Metzger's LVT-As fired 19,000 rounds of 75mm shells in an artillery support role after L-Day. The Marines made great strides towards refining supporting arms coordination during the battle for Okinawa. Commanders established Target Information Centers (TICs) at every level from Tenth Army down to battalion. The TICs functioned to provide a centralized target information and weapons assignment system responsive to both assigned targets and targets of opportunity. Finally, all three component liaison officers — artillery, air, and naval gunfire — were aligned with target intelligence information officers. As described by Colonel Henderson, the TIC at IIIAC consisted of the corps artillery S-2 section "expanded to meet the needs of artillery, NGF, and CAS on a 24-hour basis . . . . The Corps Arty Fire Direction Center and the Corps Fire Support Operations Center were one and the same facility — with NGF and air added." Such a commitment to innovation led to greatly improved support to the foot-slogging infantry. As one rifle battalion commander remarked, "It was not uncommon for a battleship, tanks, artillery, and aircraft to be supporting the efforts of a platoon of infantry during the reduction of the Shuri position."

At this point an odd thing happened, an almost predictable chink in the Japanese defensive discipline. The genial General Ushijima permitted full discourse from his staff regarding tactical courses of action. Typically, these debates occurred between the impetuous chief of staff, Lieutenant General Isamu Cho, and the conservative operations officer, Colonel Hiromichi Yahara. To this point, Yahara's strategy of a protracted holding action had prevailed. The Thirty-second Army had resisted the enormous American invasion successfully for more than a month. The army, still intact, could continue to inflict high casualties on the enemy for months to come, fulfilling its mission of bleeding the ground forces while the "Divine Wind" wreaked havoc on the fleet. But maintaining a sustained defense was anathema to a warrior like Cho, and he argued stridently for a massive counterattack. Against Yahara's protests, Ushijima sided with his chief of staff.

Marines of the 1st Division move carefully toward the crest of a hill on their way to Dakeshi. The forwardmost Marines stay low, off of the skyline. Department of Defense Photo (USMC) 120412

The greatest Japanese counterattack of 4-5 May proved ill-advised and exorbitant. To man the assault forces, Ushijima had to forfeit his coverage of the Minatoga sector and bring those troops forward into unfamiliar territory. To provide the massing of fires necessary to cover the assault he had to bring most of his artillery pieces and mortars out into the open. And his concept of using the 26th Shipping Engineer Regiment and other special assault forces in a frontal attack, and, at the same time, a waterborne, double envelopment would alert the Americans to the general counteroffensive. Yahara cringed in despair.

In the end, victory was achieved at Okinawa by well-trained assault troops on the ground, like this Marine flamethrower operator and his watchful rifleman. Marine Corps Historical Center

The events of 4-5 May proved the extent of Cho's folly. Navy "Flycatcher patrols on both coasts interdicted the first flanking attacks conducted by Japanese raiders in slow-moving barges and native canoes. Near Kusan, on the west coast, the 1st Battalion, 1st Marines, and the LVT-As of the 3d Armored Amphibian Battalion greeted the invaders trying to come ashore with a deadly fire, killing 700. Further along the coast, 2/1 intercepted and killed 75 more, while the 1st Reconnaissance Company and the war dog platoon tracked down the last 65 hiding in the brush. Meanwhile the XXIV Corps received the brunt of the overland thrust and contained it effectively, scattering the attackers into small groups, hunting them down ruthlessly. The 1st Marine Division, instead of being surrounded and annihilated in accordance with the Japanese plan, launched its own attack instead, advancing several hundred yards. The Thirty-second Army lost more than 6,000 first-line troops and 59 pieces of artillery in the futile counterattack. Ushijima, in tears, promised Yahara he would never again disregard his advice. Yahara, the only senior officer to survive the battle, described the disaster as "the decisive action of the campaign."

Men of the 7th Marines wait until the exploding white phosphorous shells throw up a thick-enough smoke screen to enable them to advance in their drive towards Shuri. The smoke often concealed the relentlessly attacking troops. Department of Defense Photo (USMC) 120182

At this point General Buckner decided to make it a four-division front and ordered General Geiger to redeploy the 6th Marine Division south from the Motobu Peninsula. General Shepherd quickly asked Geiger to assign his division to the seaward flank to continue the benefit of direct naval gunfire support. "My G-3, Brute Krulak, was a naval gun fire expert," Shepherd said, noting the division's favorable experience with fleet support throughout the northern campaign. Unspoken was an additional benefit: Shepherd would have only one adjacent unit with which to coordinate fire and maneuver, and a good one at that, the veteran 1st Marine Division.

On the morning of 7 May General Geiger regained control of the 1st Marine Division and his Corps Artillery from XXIV Corps and established his forward CP. The next day the 22d Marines relieved the 7th Marines in the lines north of the Asa River. The 1st Marine Division, which had suffered more than 1,400 casualties in its first six days on the lines while trying to cover a very wide front, adjusted its boundaries gratefully to make room for the newcomers.

Heading south toward Shuri Castle, a 1st Marine Division patrol passes through a small village which had been unsuccessfully defended by Japanese troops. Department or Defense Photo (USMC) 119485

Yet the going got no easier, even with two full Marine divisions now shoulder-to-shoulder in the west. Heavy rains and fierce fire greeted the 6th Marine Division as its regiments entered the Shuri lines. The situation remained as grim and deadly all along the front. On 9 May, 1/1 made a spirited attack on Hill 60 but lost its commander, Lieutenant Colonel James C. Murray, Jr., to a sniper. Nearby that night, 1/5 engaged in desperate hand-to-hand fighting with a force of 60 Japanese soldiers who appeared like phantoms out of the rocks.

The heavy rains caused problems for the 22d Marines in its efforts to cross the Asa River. The 6th Engineers fabricated a narrow foot bridge under intermittent fire one night. Hundreds of infantry raced across before two Japanese soldiers wearing satchel charges strapped to their chests dashed into the stream and blew themselves and the bridge to kingdom come. The engineers then spent the next night building a more substantial Bailey Bridge. Across it poured reinforcements and vehicles, but the tanks played hell traversing the soft mud along both banks — each attempt was an adventure. Yet the 22d Marines were now south of the river in force, an encouraging bit of progress on an otherwise stalemated front.

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The 5th Marines finally fought clear of the devilish Awacha Pocket on the 10th, ending a week of frustration and point-blank casualties. Now it became the turn of the 7th Marines to engage its own nightmare terrain. Due south of their position lay Dakeshi Ridge. Coincidentally, General Buckner prodded his commanders on the 11th, announcing a renewed general offensive along the entire front. This proclamation may well have been in response to the growing criticism Buckner had been receiving from the Navy and some of the media for his time-consuming attrition strategy. But the riflemen's war had progressed beyond high-level exhortation. The assault troops knew fully what to expect — and what it would likely cost.

Marine Tanks at Okinawa The Sherman M-4 medium tank employed by the seven Army and Marine Corps tank battalions on Okinawa would prove to be a decisive weapon — but only when closely coordinated with accompanying infantry. The Japanese intended to separate the two components by fire and audacity. "The enemy's strength lies in his tanks," declared Lieutenant General Mitsuru Ushijima before the invasion. Anti-tank training received the highest priority within his Thirty-second Army. These urgent preparations proved successful on 19 April when the Japanese knocked out 22 of 30 Sherman tanks of the 27th Division, many by suicide demolitionists. The Marines fared better in this regard, having learned in earlier campaigns to integrate infantry and artillery as a close, protective overwatch to their accompanying tanks, keeping the "human bullet" suicide squads at bay. Although enemy guns and mines took their tool of the Shermans, only a single Marine tank sustained damage from a Japanese suicide foray. Lieutenant Colonel Arthur J. Stuart commanded the 1st Tank Battalion during the Okinawa campaign. The unit had fought with distinction at Peleliu a half-year earlier, despite shipping shortfalls which kept a third of its tanks out of the fight. Stuart insisted on retaining the battalion's older M-4A2 Shermans because he believed the twin General Motors diesel engines were safer in combat. General del Valle agreed: "The tanks were not so easily set on fire and blown up under enemy fire." By contrast, Lieutenant Colonel Robert L. Denig's 6th Tank Battalion preferred the newer M-4A3 model Shermans. Denig's tankers liked the greater horsepower provided by the water-cooled Ford V-8 engine and considered the reversion to gasoline from diesel an acceptable risk. The 6th Tank Battalion would face its greatest challenge against Admiral Minoru Ota's mines and naval guns on Oroku Peninsula. The Sherman tank, much maligned in the European theater for its shortcomings against the heavier German Tigers, seemed ideal for island fighting in the Pacific. By Okinawa, however, the Sherman's limitations became evident. The 75mm gun proved too light against some of Ushijima's fortifications; on these occasions the new M-7 self-propelled 105mm gun worked better. And the Sherman was never known for its armor protection. At 33 tons, its strength lay more in mobility and reliability. But as Japanese anti-tank weapons and mines reached the height of lethality at Okinawa, the Sherman's thin-skinned weak points (1.5-inch armor on the sides and rear, for example) became a cause for concern. Marine tank crews had resorted to sheathing the sides of their vehicles with lumber as a foil to hand-lobbed Japanese magnetic mines as early as the Marshalls campaign. By the time of Okinawa, Marine Shermans were festooned with spot-welded track blocks, wire mesh, sandbags, and clusters of large nails — all designed to enhance armor protection. Department of Defense Photo (USMC) 123166 Both tank battalions fielded Shermans configured with dozer blades, invaluable assets in the cave fighting to come, but — surprisingly — neither outfit deployed with flame tanks. Despite rave reports of the success of the USN Mark I turret-mounted flame system installed in eight Shermans in the battle of Iwo Jima, there would be no massive retrofit program for the Okinawa-bound Marine tank units. Instead, all flame tanks on Okinawa were provided courtesy of the U.S. Army's 713th Armored Flamethrower Battalion. Company B of that unit supported the IIIAC, with brand-new H-1 flame tanks. Each carried 290 gallons of napalm-thickened fuel, good for two-and-a-half minutes of flame at ranges out to 80 yards. The Marines received consistently outstanding support from this Army company throughout the battle. The Marines employed the newly developed T-6 "Tank Flotation Devices" to get the initial assault waves of Shermans ashore on L-Day. The T-6 featured a series of flotation tanks welded all around the hull, a provisional steering device making use of the tracks, and electric bilge pumps. Once ashore, the crew hoped to jettison the ungainly rig with built-in explosive charges, a scary proposition. The invasion landing on 1 April for the 1st Tank Battalion was truly "April Fools Day." The captain of an LST carrying six Shermans equipped with the T-6 launched the vehicles an hour late and 10 miles at sea. It took this irate contingent five hours to reach the beach, losing two vehicles on the reef at ebb tide. Most of Colonel Stuart's other Shermans made it ashore before noon, but some of his reserves could not cross the reef for 48 hours. The 6th Tank Battalion had better luck. Their LST skippers launched the T-6 tanks on time and in close. Two tanks were lost — one sank when its main engine failed, another broke a track and veered into an unseen hole — but the other Shermans surged ashore, detonated their float tanks successfully, and were ready to roll by H plus 29. Japanese gunners and mine warfare experts knocked out 51 Marine Corps Shermans in the battle. Many more tanks sustained damage in the fighting but were recovered and restored by hard-working maintenance crews, the unsung heroes. As a result of their ingenuity, the assault infantry battalions never lacked for armored firepower, mobility, and shock action. The concept of Marine combined-arms task forces was now well underway.