The Battle for Iwo Jima

(See my previous post for more information on the Japanese preparation for the assault on Iwo Jima.)

Black and white image taken from Mt Suribachi on Iwo Jima after the end of World War II, with two ships in the sea and rocky mountain in the foregroundOn 7 October 1944 Admiral Chester W. Nimitz and his staff had issued a staff study for preliminary planning of ‘Detachment’ to maintain constant military pressure against Japan, to extend US control over the western reaches of the Pacific Ocean and, from mid-July 1944 and the capture of Saipan, to provide the USAAF with a forward base. General Henry H. Arnold, commanding the USAAF, urged the paramount importance of acquiring Iwo Jima’s airfields for offensive purposes, and a defensive need soon became apparent as Japanese bombers staging through the island attacked the Marianas and caused great damage, including the destruction of 15 B-29 bombers and the damaging of more than another 40. Air attacks failed to neutralise Iwo Jima’s airfields and early warning radar, so it became clear that an amphibious assault would be required. In American hands, Iwo Jima could be turned into a base from which to attack the Japanese home islands, protect bases in the Marianas, cover naval forces, conduct search operations of the approaches to the Japanese home islands, and provide fighter escort for long-range bomber operations. Three tasks specifically envisaged in the study were the reduction of Japanese naval and air strengths and also of industrial capacity in the home islands; the destruction of Japanese naval and air strength in the Bonin islands; and the capture, occupation and subsequent defence of Iwo Jima for development as a major air base.

On 9 October, Lieutenant General Holland M. Smith, heading the Fleet Marine Force, Pacific, received the staff study, accompanied by a directive from Nimitz ordering the seizure of Iwo Jima. This directive designated specific commanders for the operation. Admiral Raymond A . Spruance, commanding the 5th Fleet, was placed in overall command of Task Force 50. Under Spruance, Vice Admiral Richmond K. Turner, commanding the Amphibious Forces, Pacific, was to lead the Joint Expeditionary Force (TF51) and had under his command some 1,300 ships for the movement, landing and support of the invasion force. Second in command of the JEF was Rear Admiral Harry W. Hill. Smith was designated as commander of the Expeditionary Troops (TF56). All of these men had shown their exceptional capabilities in previous campaigns. TF56 was centred on Major General Harry Schmidt’s V Amphibious Corps, comprising Major General Graves B. Erskine’s 17,715-man 3rd Marine Division (3rd, 9th and 21st Marines plus the 12th Marine Artillery), Major General Clifton B. Cates’s 18,241-man 4th Marine Division (23rd, 24th and 25th Marines plus the 14th Marine Artillery) and Major General Keller E. Rockey’s 18,311-man 5th Marine Division (26th, 27th and 28th Marines plus the 13th Marine Artillery).

Schmidt’s plan for the landings was straightforward: the 4th and 5th Marine Divisions were to land side-by-side on the eastern beaches, the former on the right and the latter on the left, and when released to the V Amphibious Corps, the 3rd Marine Division, as Expeditionary Troops Reserve, was to land over the same beaches to take part in the attack or play a defensive role as demanded by the tactical situation. The plan called for a rapid exploitation of the beach-head with an advance in a north-easterly direction to capture the entire island. One regiment of the 5th Marine Division was assigned to the capture of Mt Suribachi in the south. Since there was a possibility of unfavourable surf conditions along the eastern beaches, the V Amphibious Corps issued an alternative plan on 8 January 1945 for a landing on the western beaches. However, since predominant northerly or north-westerly winds caused hazardous swells almost continuously along the south-western side of the island, it appeared unlikely that this alternative plan would be put into execution. The detailed plan for the landings provided for two battalions of Colonel Harry B. Liversedge’s 28th Marines of the 5th Marine Division to land on the extreme left of the corps on Green 1 beach. On the right of the 28th Marines, Colonel Thomas A. Wornham’s 27th Marines was to land single battalions on Red 1 and Red 2 beaches, and then attack toward the western coast of the island before wheeling north to seize the western end of the O-1 Line between the East Boat Basin and the western coast via Motoyama Airfield No. 2. Action by the 27th and 28th Marines was designed to drive the Japanese from the commanding heights along the southern portion of Iwo Jima, simultaneously securing the flanks and rear of the V Amphibious Corps. As far as the 4th Marine Division was concerned, Colonel Walter W. Wensinger’s 23rd Marines was to land single battalions on Yellow 1 and Yellow 2 beaches, seize Chidori Airfield No. 1, then turn north-east and seize that part of Motoyama Airfield No. 2 and the O-1 Line within its zone of action. After landing on Blue 1 beach, two battalions of Colonel John R. Lanigan’s 25th Marines were to assist in the capture of Motoyama Airfield No. 2, the capture of Blue 2 beach just south of the East Boat Basin and thus on the extreme right of the V Amphibious Corps, and the O-1 Line within its zone of action. Colonel Walter I. Jordan’s 24th Marines was to be held in 4th Marine Division reserve during the initial landings. Colonel Chester B. Graham’s 26th Marines was to be released from corps reserve on D-day and be prepared to support the 5th Marine Division. Divisional artillery was to go ashore on order from the respective division commanders. The 4th Marine Division was to be supported by Colonel Louis G. DeHaven’s 14th Marines, and Colonel James D. Waller’s 13th Marines was to furnish similar support for the 5th Marine Division.

The operation was to start with the simultaneous arrival on the assault beach of the 68 LVTs (Landing Vehicles Tracked) carrying the first wave of men. These vehicles were to advance inland until they reached the first terrace beyond the high-water mark. The LVTs were to use their 75-mm (2.95-in) howitzers and machine guns to keep the heads of the Japanese down, thus giving some measure of protection to succeeding waves of marines, who would be most vulnerable to Japanese fire as they disembarked from their LVTs. Early versions of the V Amphibious Corps’ operations plan had called for tanks of the 4th and 5th Marine Tank Battalions to be landed at H+30, but later consideration of the beaches made it necessary to adopt a more flexible schedule. The possibility of congestion at the water’s edge also contributed to this change in plans. In the end, the time for bringing the tanks ashore was left to the discretion of the regimental commanders.

American battleship bombarding Iwo JimaIn the period leading up to ‘Detachment’, the US forces undertook ‘Jamboree’ as their first major raid on Tokyo with carrierborne aircraft. The final preparations for ‘Detachment’ had meanwhile been completed on 16/19 February. On 16 February Rear Admiral Bertram J. Rodgers’s TF54, comprising the battleships Tennessee, Idaho, Nevada, Texas, New York and Arkansas, cruisers Chester, Salt Lake City, Pensacola, Tuscaloosa and Vicksburg and 16 destroyers of Destroyer Squadron 51 and Destroyer Divisions 91 and 112, approached Iwo Jima and started a gunfire bombardment of the designated areas in preparation for the assault. Rear Admiral William H. P. Blandy’s TF52 (Support Force), with the Minesweeper Group 52.3, Frogman Group 52.4 and LCI Support Group 52.5, and Rear Admiral Calvin T. Durgin’s TG52.2 Escort Carrier Group 52.2, with the escort carriers Sargent Bay, Natoma Bay, Wake Island, Petrof Bay, Steamer Bay, Makin Island, Lunga Point, Bismarck Sea, Saginaw Bay and Rudyerd Bay, with their escort of destroyers and destroyer escorts, provided air cover and flew 158 attack sorties. The effect of the gunfire bombardment was slight because of inadequate observation in poor weather, but a repetition on 17 February in better weather was deemed to be more successful. The Japanese coastal batteries obtained one hit on Tennessee, six on Pensacola and one on the destroyer Leutze. After disembarkation from the APDs (high-speed transports) Bull, Bates, Barr and Blessman, the underwater demolition teams stated on the task of removing underwater obstacles. All 12 LCIs (Landing Craft Infantry) used for support were hit by the Japanese coastal batteries, and nine of them were put out of action. The escort carriers flew off 226 sorties, some with napalm. Forty-two B-24 Liberator heavy bombers of Major General Thomas D. White’s 7th AAF also made attacks. On 18 February the shelling and air attacks were continued, the latter totalling only 28 heavy bomber sorties. Including air escorts, the escort carriers’ aircraft flew 612 sorties in all and lost three of their number. The destroyer minesweeper Gamble was damaged beyond repair by a Japanese naval aeroplane during this day, and the high-speed transport destroyer Blessman was damaged.

On the following day, 19 February, the landings on Iwo Jima got under way as Turner’s TF51 delivered and disembarked Schmidt’s V Amphibious Corps. TF51 consisted of 495 ships allocated four task groups (TG52, TG53, TG54 and TG56). On 19 February Rodgers’s TF54, reinforced by the battleships North Carolina and Washington, cruisers Indianapolis, Santa Fe and Biloxi, and 10 destroyers from two destroyer divisions of TF58, completed a heavy preliminary gunfire bombardment of the assault areas, this being interspersed with attacks by the carrierborne aircraft of TG58.2 and TG58.3. The landings were effected by Rear Admiral Harry W. Hill’s TF53: in the north the 4th Marine Division was landed by Commodore H. C. Flanagan’s TG53.2 from 15 attack troop transports, six attack transports, two dock landing ships, 19 tank landing ships and 12 medium landing ships, and in the south the 5th Marine Division by Commodore J. B. McGovern’s TG53.1 from 15 attack troop transports, six attack transports, one dock landing ship, 19 tank landing ships and 16 medium landings ships. Each of these two task groups was escorted by one destroyer squadron. Another task group had the 3rd Marine Division on board as a floating reserve, of which part had to be landed on the first day. On 19 February the Americans landed some 30,000 men, and these had the support of the aircraft of the fleet and light carriers of TG58.2 and TG58.3 as well as of the escort carriers of TG52.2. The marines faced determined opposition, and carrierborne aircraft thus flew 606 sorties on the first day, using 274 tons of bombs, 2,254 rockets and more than 100 napalm bombs. Japanese shore batteries damage the destroyer John W. Weeks and four LSMs, and damage also resulted from collisions involving the cruiser Chester with the amphibious force flagship Estes, the cruiser Indianapolis with the ammunition ship Shasta, the destroyer escort Finnegan with LCI(L)-627, and the cruiser Salt Lake City with the transport Starr. On 21 February TG58.1 and TG58.4 provided support for the disembarked forces while TG58.2 and TG58.3 moved farther offshore to replenish. The only Japanese response from anywhere off Iwo Jima was a kamikaze attack by 32 aircraft on 21 February: the escort carrier Bismarck Sea was sunk and the fleet carrier Saratoga, light carrier Langley and escort carrier Lunga Point, the transport Keokuk , and LST-477 and LST-809 were damaged. Saratoga sustained severe damage, her casualties totalling 123 dead and 192 wounded, and Bismarck Sea lost 218 men. There were several further collisions, causing damage to destroyers and auxiliaries. The Japanese submarine Ro-43 and ‘Kaiten’-carrying I-368, I-370 and I-44 were deployed as the ‘Chihaya’ Group, and later I-36 and I-58 were ordered into the area as the ‘Kamitake’ Group. The escort carriers Tulagi and Anzio led carrier/destroyer escort groups in the submarine hunter/killer role, and on 25/26 February aircraft from Anzio sank Ro-43 and I-368, and the destroyer escort Finnegan, part of a convoy escort, sank I-370. Ro-43 managed to attack an escort, torpedoing the destroyer Renshaw on 21 February.

As noted above, on 16 February 1945 the US forces started a massive three-day air and naval bombardment of Iwo Jima. The second day of bombardment was so furious that the Japanese thought the invasion was imminent and many of the gunners forgot Kuribayashi’s orders to hold their fire. The Japanese thus opened a furious fire on the closer American warships and the specialised landing craft undertaking tasks such as the bombardment of the shoreline with rockets and the delivery of frogmen for underwater reconnaissance of the beaches and their approaches. The cruiser Pensacola was hit by six shells which killed 17 men and wounded more than 100 others, a destroyer took a direct hit which killed seven men and wounded another 33, and the landing craft suffered badly. The US ships pulled back under cover of a smokescreen, and the Japanese concluded that they had beaten off an invasion attempt. The Americans now realised that the earlier bombings and the first two days of the naval bombardment had not been as effective as anticipated, and also that many artillery positions had not yet been pinpointed. The third day of the air and naval barrage therefore saw the bombardment force, including five old battleships, close to within 1.5 miles (2.4 km) of the beach to attempt the destruction of all the defensive positions threatening the next day’s assault area: many of these positions were destroyed, but many others survived as poor weather prevented accurate aerial spotting. After a 72-day aerial bombardment (mostly by B-24 Liberator bombers occasionally supplemented by B-29 Superfortress bombers) and a three-day naval bombardment, D-day was signalled at 02.00 on 19 February by warship guns in a 30-minute barrage that saw the arrival of more than 8,000 shells ranging in calibre from 5 to 16 in (127 to 406 mm). Soon 100 bombers attacked the island, followed by another barrage from the naval guns.

Marines burrow in the volcanic sand on the beach of Iwo JimaAt 08.29, the first of an eventual 30,000 marine riflemen of the 3rd, 4th, and 5th Marine Divisions landed and ‘Detachment’ had truly started. The first of four assault waves landed in LVTs and landing craft, the troops immediately running into problems as they tried to scale the soft embankment behind the beach while still carrying their heavy equipment packs; at first it seemed that this would be the marines’ only difficulty, for they were greeted only by sporadic fire. After 20 minutes, however, the Japanese recovered from the daze into which they had been stunned by the 30-minute naval bombardment and opened fire with every weapon that would bear on the men of the four infantry regiments landed by the 4th and 5th Marine Divisions. The assault forces were soon pinned down on the beach, and this greatly increased the problems faced by the landing craft bringing in the assault divisions’ two artillery regiments and the bulldozers tasked with creating the beach exits needed by the tanks that would now be the only way for the US forces to break out of their very shallow beach-head. Some units did achieve this feat, and by the end of 19 February elements of the 5th Marine Division had managed to advance right across the island at its narrowest point just north of Mt Suribachi. Almost 30,000 US Marines were landed on the first day, and of these some 2,500 were killed or wounded.

On 20 February the US position across the island’s neck and on the south-western shore was consolidated, the US Marines started to fight their way into the defences on the northern side of Mt Suribachi, and the advance north began but soon stalled in the face of a Japanese defence that was, as always, extraordinary determined, but in this particular instance also very effective. At the end of the day it was decided that the 3rd Marine Division should also be committed. Men of the 28th Marines completed their encirclement of Mt Suribachi on 21 February, and began their assault up the northern slope on the following day. The first men reached the edge of the crater at the top on 23 February, but it was another six days before this southern pocket of Japanese resistance could be declared secure. Meanwhile the 23rd and 25th Marines of the 4th Marine Division and the 27th Marines of the 5th Marine Division were battling their way north over very difficult terrain and against fanatical resistance, both of which caused a stream of casualties. On 22 February Schmidt ordered the replacement of the hard-hit 25th Marines, on the right wing of the 4th Marine Division, by the 3rd Marine Division’s fresh 21st Marines, but in fact this unit relieved the 23rd Marines on the boundary between the 4th and 5th Marine Divisions. At much the same time Rockey replaced the exhausted 27th Marines with the 26th Marines, and this fresh strength allowed the Americans to push forward over a distance of between 200 and 1,000 yards (180 and 915 m) during the day.

The marines’ next objective was Motoyama Airfield No. 2, and the assault for this important tactical objective began on 24 February after an air attack, a 75-minute naval bombardment and a barrage from the marines’ own artillery. As a result largely of armoured support, the marines advanced some 500 yards (460 m) before being checked by the Japanese anti-tank guns and minefields on the southern side of the airfield. Schmidt decided to commit the 3rd Marine Division’s last unit, the 9th Marines, in an effort to maintain the momentum of the American advance. In the morning of 25 February, the 9th Marines attacked through the depleted 21st Marines, and there followed three days of bloody combat before the 9th Marines had taken all of Motoyama Airfield No. 2 and the hills just to its north. The somewhat rested 21st Marines then returned to the fray in place of the 9th Marines, and pushed the edge of the American progress through the village of Motoyama to the high ground just south of Airfield No. 3. The fighting was bitter in the extreme, and as the Japanese made effective and full use of the area’s caves, which were all but impervious to artillery fire, the marines found that their most effective weapons were the flamethrower and satchel charge. The former either killed the Japanese defenders or drove them underground, whereupon satchel charges could be placed to seal the entrance of any cave. As the 3rd Marine Division was pressing forward from Motoyama Airfield No. 2 to Airfield No. 3, the 4th and 5th Marine Divisions were also driving slowly forward to take Hill 362A and Hill 382 respectively. Neither could be bypassed, and the marines suffered very heavy casualties in taking both hills: Hill 362A fell to the 28th Marines, which suffered 224 casualties, and in two days of dire fighting that ended on 1 March the regiment cleared the hill and reached the ridge to its north. Hill 362A was an isolated defensive feature, but Hill 382 was just the core of a defensive complex that included an outer line of dug-in tanks and bunkers for artillery and anti-tank guns, and then the defences proper on Hill 382, the ridges and ravines of Turkey Nob, and the large depression of the Amphitheater, all three features soon becoming known as the Meat Grinder. The battle for the Meat Grinder lasted two weeks and was extremely costly in lives on both sides, though ultimately it was the Japanese who suffered the heavier casualties as the Americans gained the ascendancy.

As the 4th Marine Division fought the Meat Grinder battle, the 3rd and 5th Marine Divisions were pressing forward. The 3rd Marine Division captured Hill 362C in a surprise night attack which caught the Japanese completely unaware on 7 March, even though it was mid-afternoon before the whole feature had been taken, and the 5th Marine Division took Hill 362B. The Americans had now broken through Kuribayashi’s semi-circle of interlocking defensive features extending from Hills 362A, B and C to the Meat Grinder, and also severed all communication between Kuribayashi and his soldiers. In these circumstances some of the Japanese soldiers attempted a suicide charge against the 4th Marine Division during the night of 8 March. The eventuality that Kuribayashi had feared now came to pass, and by mid-morning on 9 March the Japanese had suffered 650 dead as they tried to break though the junction between the 23rd and 24th Marines. Followed by the capture of the Meat Grinder on the following day, this signalled the end of organised Japanese resistance on Iwo Jima.

It did not signal the end of unorganised resistance, however, for the surviving Japanese were still determined to sell their lives as expensively as possible in three strongpoints, one in front of each marine division. In front of the 3rd Marine Division, south-west of Hill 362C, was Cushman’s Pocket named for Lieutenant Colonel Robert E. Cushman, commander of the 2/9th Marines. It required the efforts of three marine battalions before this 450-man pocket was eliminated on 15 March when the last 60 men attempted a suicide change. In front of the 4th Marine Division was a comparable tangle of Japanese holding caves and pillboxes in the ravines extending from the northern plateau to the island’s eastern coast. The men of the 4th Marine Division attacked on 12 March, and finally reduced the Japanese pocket in four days of fighting. In front of the 5th Marine Division was the Bloody Gorge pocket near Kitano Point on the island’s north-western tip. The 5th Marine Division attacked on 11 March, and by 25 March had eliminated this last vestige of Japanese resistance.

B-29 at Iwo Jima after an emergency landing The battle for Iwo Jima was finally over, the Japanese having lost all but 216 of their 22,000-man garrison and the US Marine Corps having suffered just under 25,000 casualties (6,891 men killed and 18,070 wounded). There were also losses among the US Navy personnel involved in ‘Detachment’, for on 21 February the Japanese had launched a kamikaze mission against the warships supporting the land fighting with their carrierborne warplanes: of the 50 aircraft despatched by the Japanese, three hit the fleet carrier Saratoga causing considerable damage, including 42 aircraft, and inflicting 315 casualties (123 dead and 192 wounded), one hit the escort carrier Lunga Point causing only modest damage, and two hit the escort carrier Bismarck Sea causing fatal damage and another 300 or so casualties. Other kamikaze aircraft sank an LST and the auxiliary vessel Keokuk. Yet the value of the island in American hands was amply proved as early as 4 March, while the fighting was still raging, for on this day the first B-29 landed on Chidori Airfield No. 1 as it ran short of fuel while returning from Japan with a weapons bay door jammed open. Eventually 2,251 B-29 bombers, carrying more than 24,500 aircrew, made emergency landings on Iwo Jima.

[First photo by John Anderson, courtesy of bunnygoth]