mm

Roy E. Appleman, James M. Burns Russell A* Gugeler, and John Stevens

UNITED STATES ARMY IN WORLD WAR II

The War in the Pacific OKINAWA: THE LAST BATTLE

by

Roy E. Apple-man, James M. Burns Russell A. Gugelcr, and John Stevens

CENTER OF MILITARY HISTORY UNITED STATES ARMY WASHINGTON B.C., 1993

Library of Congress Catalog Card Number: 49-45742

First Printed 1948— CMH Pub 5-11-1

For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402

UNITED STATES ARMY IN WORLD WAR II

Kent Roberts Greenfield, General Editor

Advisory Committee

James P. Baxter President, Williams College

Henry S. Commager Columbia University

Douglas S. Freeman Richmond News Leader

Pendleton Herring Social Science Research Council

John D. Hicks University of California

William T. Hutchinson University of Chicago

S.L.A. Marshall Detroit News

Col. Thomas D. Stamps United States Military Academy

E. Dwight Salmon Amherst College

Charles H. Taylor Harvard University

Walter L. Wright Princeton University

Historical Division, SSUSA

Chief, Historical Division Chief Historian Chief, Editorial Branch Chief Cartographer

Brig. Gen. Harry J. Malony Kent Roberts Greenfield Lt. Col. John M. Kemper Wsevolod Aglaimoff

111

. . . to Those Who Served

Foreword

The conflict with the Axis Powers confronted the United States Army with problems on a scale never faced before — problems as great in adminis- tration, training, supply, and logistics as in strategy and tactics. THE UNITED STATES ARMY IN WORLD WAR II sets forth in detail the nature of the problems faced, the methods used to solve them, and the mistakes made as well as the success achieved. The object is to provide a work of reference for military and civilian students as well as a record of achievements which deserve an honorable place in the pages of history. Its value to the thoughtful citizen as an aid to his comprehension of basic problems of national security has been a major consideration. Its preparation has also been prompted by the thought that in a faithful and comprehensive record all who participated in the Army's vast effort would find a recognition merited by their service and sacrifice.

The advantage to the Army and the scholar has been the decisive factor in proceeding with the least possible delay to the publication of such a series. No claim is made that it constitutes a final history. Many years will pass before the record of the war can be fully analyzed and appraised. In presenting an organized and documented narrative at this time, the Historical Division of the War Depart- ment has sought to furnish the War Department and the Army schools an early account of the experience acquired, and to stimulate further research by provid- ing scholars with a guide to the mountainous accumulation of records produced by the war.

The decision to prepare a comprehensive account of military activities was made early in the war. Trained historians were assigned to the larger units of the Army and War Department to initiate the work of research, analysis, and writing. The results of their work, supplemented by additional research in records not readily available during the war, are presented in this series. The general plan provides for a division into subseries dealing with the War Department, the Army Air, Ground, and Service Forces, the technical services, and the theaters of operations. This division conforms to the organization of the Army during

vii

World War II and, though involving some overlapping in subject matter, has the advantage of presenting a systematic account of developments in each major field of responsibility as well as the points of view of the particular commands. The plan also includes volumes on such topics as statistics, order of battle, military training, the Women's Army Corps, and other subjects that transcend the limits of studies focused on an agency or command. The whole project is oriented toward an eventual summary and synthesis.

The present volume concerns one of the most bitterly fought battles of the Pacific war, in which the Army, the Marine Corps, and the Navy all played a vital part. In order to make the Army's role and the campaign as a whole as intelligible as possible the historians have treated in detail the operations of the Marine Corps units attached to Tenth Army, and have also sketched the con- tribution of the Navy both in preliminary operations against Okinawa and in the campaign itself. Another characteristic of this as of other volumes on Pacific campaigns is that tactical action is treated on levels lower than those usually presented in the history of operations in the European theaters. The physical limitations of the terrain fought over in the Pacific restricted the number and size of the units which could be employed and brought into sharp focus the operations of regiments, battalions, and smaller units. A wealth of verified material on such operations is available for all theaters, but it is only that of the Pacific which can be used extensively, since in other theaters the actions of smaller units are lost in the broad sweep of great distances and large forces. The description of small-unit action has the merit of giving the non- professional reader a fuller record of the nature of the battlefield in modern war, and the professional reader a better insight into troop leading.

Okinawa: The Last Battle is the work of combat historians of the ist In- formation and Historical Service, Tenth Army. The practice of dispatching trained historians to accompany troops into combat grew out of earlier experi- ence, both in World War I and in the early part of World War II, which demon- strated that the paper records produced by units in battle were rarely, if ever, adequate for the writing of military history. Lower units, such as the infantry company and very often the battalion, do not write as they fight; hence the details of combat are not in their records. Even at higher levels many significant orders and reports, because they are communicated orally and by telephone, are noted in the record only sketchily if at all. An equally serious gap arises

viii

from the fact that the "why" behind the decision is almost never discernible in the documents.

The records must be supplemented by interviewing key participants in the action at all levels if anything approaching complete understanding of what happened is to be attained. Unless such quick on-the-spot study is made, memories will grow dim or the man who knows the answer may become a casualty in a subsequent operation. Thus the historians who took the field were given the mission of noting the messages, reports, and orders as they came in, of spotting the gaps in the story as it was thus unfolded, and of taking prompt steps to fill those gaps by asking questions.

At first, historians were sent to the theaters as individuals or teams. Later they were organized into units called Information and Historical Services, one of which was assigned to each field army. Though the ist Information and Historical Service was the first of these to be activated, all the others were called on to deal with operations earlier. As a consequence the ist Information and Historical Service not only benefited in some measure by the lessons they learned, but was the first which was fully organized and prepared to take the field at the very start of a major operation, with plans laid for a systematic coverage of the campaign.

In an organizational sense, therefore, the preparations for historical coverage of the Okinawa campaign were better than those for earlier operations. This explains why the history of the last operation has been issued first.

Washington, D. C. i July 1947

HARRY J. MALONY Brigadier General, USA Chief, Historical Division War Department Special Staff

ix

Preface

Okinawa: The Last Battle was written by U. S. Army historians who partici- pated in the Ryukyus campaign as members of a group organized to accompany the American forces to the Ryukyus and secure at first hand the materials for a history of their operations. This group was formed in Hawaii as a section of the i st Information and Historical Service, which was attached to Tenth Army in January 1945.

Before the embarkation of troops for Okinawa, most of the Tenth Army's combat historians, as they were called, had joined at various points in the Pacific the units whose part in the coming battle they were to record. Similarly, Marine historians were already with III Amphibious Corps headquarters and the Marine divisions which were to take part in the action. Lt. Col. John Stevens was in command of the Army historians; his chief assistant was M/Sgt. James M. Burns, the author of Guam in the series AMERICAN FORCES IN ACTION* Colonel Stevens and Sergeant Burns accompanied Tenth Army headquarters. Capt. Donald L. Mulford came from Leyte with XXIV Corps and remained with it until late in May, when he was assigned to the 96th Division to replace its his- torian, Sgt. Bert Balmer, who had been wounded in action. At XXIV Corps headquarters Maj. Roy E. Appleman succeeded Captain Mulford. Capt. Edmund G. Love, an experienced historian of operations in the Central Pacific, was attached to the 27th Division. Capt. Russell A. Gugeler and Capt. Paul R. Leach, who had served respectively with the 7th and 77th Divisions on Leyte, accom- panied these divisions to Okinawa. Capt. Jesse L. Rogers, on his arrival at Oki- nawa in June, was assigned to the 96th Division to assist Captain Mulford. The Marine historians on Okinawa were Maj. Almet Jenks, III Amphibious Corps; Sgt. Kenneth Shutts and Sgt. Paul Trilling, 1st Marine Division; and Capt. Phillips D. Carleton, 6th Marine Division.

Army historians held frequent conferences during and after the campaign for the purpose of coordinating their work. Liaison with the Marine historians

* Published by the Historical Division, War Department Special Staff.

XI

was established soon after the initial landings at the target and was maintained throughout the operation. Further information and perspective were gained through conferences with Navy personnel at Okinawa and with Navy historians in Hawaii and Washington.

After the campaign, histories of the operations of the four Army divisions and of the 6th Marine Division were written by the respective division historians; a history of the XXIV Corps on Okinawa was written by Major Appleman; and a history of the ist Marine Division on Okinawa was compiled by Capt. James R. Stockman, USMCR, from division records and from material supplied by the division historians.

In July 1945, after the battle of Okinawa ended, Colonel Stevens and Ser- geant Burns were detached from the ist Information and Historical Service and returned to Oahu to write the history of the Okinawa operation at Fort Shafter, where the records of all Amy units which had fought on Okinawa were subse- quently brought together. Captain Love, who had completed his history of the operations of the 27th Division by July 1945, returned to Washington. The other Army historians remained with their units to complete their interrogations of the men who fought, write the division and corps histories for which they were responsible, and be available for prospective new assignments.

After the war ended, Captain Leach completed the history of 77th Division operations, and Captain Mulford and Captain Rogers the account of 96th Division operations; these three historians were then separated from the Army. Major Appleman and Captain Gugeler, who accompanied the XXIV Corps and the 7th Division to Korea, were ordered to Oahu late in the fall of 1945 to complete their respective corps and division histories at Fort Shafter. Ser- geant Burns returned to the United States early in December and was separated from the Army.

By March 1946 Major Appleman had completed the narrative of XXIV Corps operations on Okinawa, and Captain Gugeler the history of the 7th Division in the campaign. At that time, although Colonel Stevens, Major Appleman, and Captain Gugeler were all eligible for separation, they returned with the Okinawa records to Washington to continue work in the Historical Division, WDSS, on the history of the Okinawa campaign. Together with Sergeant Burns, now a civilian, they completed the Okinawa manuscript by the end of June. Organization of the volume was developed at conferences of all the Army historians during and after the battle on the basis of studies by Sergeant Burns.

Xll

The manuscript was turned over to the Pacific Section of the Historical Division, WDSS. Dr. Charles B. Hirschfeld, a member of the Section, added material on high-level planning and logistics, revised and condensed certain portions of the manuscript, and aided in the preparation of the maps. The authors are especially indebted to Dr. Louis Morton, Chief of the Pacific Section, who supervised the preparation of the final manuscript and represented the authors during the editing process. The editing was performed by Dr. Albert K. Wein- berg of the Editorial Branch, assisted by Miss Edith M. Poole and Miss Grace T. Waibel. The maps were prepared under the direction of Mr. Wsevolod Aglaimoff. Col. Allison R. Hartman acted as military editor, Major Charles F. Byars prepared the list of Tenth Army units in Appendix A, and Mr. George R. Powell compiled the charts and tables in Appendix C. Mr. W. Brooks Phillips prepared the index.

Capt. Robert L. Bodell selected the illustrations in this volume from material in the possession of the Signal Corps, Army Air Forces, U. S. Navy, U. S. Marine Corps, U. S. Coast Guard, and Yan\ magazine. The sketches on pp. 244-45 and 292-93 were drawn by S/Sgt. T. King Smith of the XXIV Corps Historical Section.

Washington, D. C. 1 July 1947

ROY E. APPLEMAN JAMES M. BURNS RUSSELL A. GUGELER JOHN STEVENS

xm

Contents

Chapter Page

I. OPERATION ICEBERG 1

The Strategic Decision 1

Nature of the Target 7

The Plan of Attack 17

Mounting the Attack 36

II. INVASION OF THE RYUKYUS 44

Preliminary Neutralization of Enemy Strength 44

Seizure of the Kerama Islands 51

Softening Up the Target 63

III. WINNING THE OKINAWA BEACHHEAD 68

The Landing 69

Moving Inland 74

Organising the Beachhead 79

IV. WHERE IS THE ENEMY? 84

The Japanese Forces 84

The Japanese Plan of Defense 92

Enemy Counterattacks by Air and Sea 96

V. COMING TO GRIPS WITH THE ENEMY 103

Through the Outposts, 4-8 April 104

Assaulting the Shuri Defenses, 9-12 April 113

The Enemy Takes the Offensive 130

VI. THE CONQUEST OF NORTHERN OKINAWA 138

Drive up the Ishikawa Isthmus, 4-7 April 138

Probing the Motobu Defenses, 7-13 April 141

Closing In on Yae-Take, 14-15 April 144

Conquest of Motobu Peninsula, 16-18 April 146

VII. THE CAPTURE OF IE SHIM A 149

Plans and Preparations of the Enemy 150

American Plans and Preparations 153

Invasion of le Shima, 16-17 April 156

Stalemate at Bloody Ridge, 18-19 April 163

Capture of legusugu, 20-21 April 173

Last Phase 181

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Chapter Page

VIII. THE ATTACK OF 19 APRIL ON THE SHURI DEFENSES 184

Plans and Preparations 184

Preliminary Attack of the 27th Division, 18 April 190

The General Attack 194

IX. FALL OF THE FIRST SHURI DEFENSE RING 208

Item Pocket 208

Assaulting the Outer Shuri Defense King 219

X. TACTICS AND TACTICAL DECISIONS 249

Tactics and Weapons on Okinawa 249

Tactical Decisions 258

XL ASSAULTING THE SECOND SHURI DEFENSE RING 265

Stalemate on the West Coast 267

The 7th Division at Kochi Ridge 269

The Maeda Escarpment Barrier 274

XII. THE JAPANESE COUNTEROFFENSIVE AND ITS AFTERMATH . 283

Planning the Offensive 283

The Offensive Under Way 286

Japanese Penetration to Tanabaru, 5 May 294

The Americans Resume the Offensive 302

XIII. THE MAY ATTACK ON THE SHURI DEFENSES 311

The Attack in the West 313

The Attack in the Center 332

Opening the East Coast Corridor 351

XIV. BATTLE IN THE RAIN 360

Enemy Air Attacks 360

Stalemate in the Center 364

The 6th Marine Division Occupies Naha 372

The 7th Division Bids for Envelopment 377

XV. THE FALL OF SHURI 383

Exodus From Shuri 387

American Occupation of Shuri 394

XVI. BEHIND THE FRONT 403

Supply Operations 405

Hospitalization and Evacuation 412

Military Government • 415

Base Development 419

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Chapter Page

XVII. THE ENEMY'S LAST STAND 422

The Push South to the Yaeju-Dake-Yu^a-Dake Barrier 422

The Capture of Oroku Peninsula 427

Assaulting the Last Defense Line 434

XVIII. THE BATTLE ENDS 455

End of Organised Resistance 455

Surrender and Suicide 462

Final Mop-up 471

Victory: Cost and Value 473

APPENDIX A. MAJOR TACTICAL UNITS OF TENTH ARMY IN THE

RYUKYUS CAMPAIGN 475

APPENDIX B. JAPANESE 32d ARMY UNITS IN THE RYUKYUS CAM- PAIGN 483

APPENDIX C . STATISTICS OF THE RYUKYUS CAMPAIGN 487

BIBLIOGRAPHICAL NOTE 503

INDEX 513

Tables

No. Page

1. Strength of Army, Marine, and Naval Forces of Tenth Army in the

Ryukyus Campaign, 30 April-30 June 1945 488

2. Comparative American and Enemy Major Losses in the Ryukyus Cam-

paign, 1 April-30 June 1945 489

3- Casualties Sustained by Tenth Army, 1 April-30 June 1945 490

4. Troops and Supplies Loaded for the Initial Assault on the Ryukyus . . 492

5. Personnel and Supplies Loaded for Assault and for First Echelon Garri-

son in the Ryukyus Campaign, by Point of Embarkation 493

6. Comparison of Estimated Capacities for Unloading at Okinawa Beaches

and Quantities Actually Unloaded, 1 April-30 June 1945 494

7. Cargo Unloaded at Okinawa Beaches, 1 April-30 June 1945 496

8. Ammunition Expended by Tenth Army Field Artillery, 1 April-30 June

1945 498

9. Ammunition Expended by the U. S. Navy in the Ryukyus Campaign,

March-June 1945 500

10. Ammunition Expended by XXIV Corps, by Type of Weapon, 4 April-21

June 1945 501

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Charts

No. Page

I. Organization of Allied Forces for the Ryukyus Campaign, January 1945. 20 II. Organization of Central Pacific Task Forces for the Ryukyus Campaign,

January 1945 22

III. Organization of Expeditionary Troops for the Ryukyus Campaign,

January 1945 24

IV. XXIV Corps Assignment of Shipping for the Assault on Okinawa. . . 43 V. Organization of the Japanese 62d Division in Okinawa 88

1. Tenth Army Weekly Battle Casualties, 1 April-30 June 1945 491

2. Comparison of Estimated Capacities for Unloading at Okinawa Beaches

and Quantities Actually Unloaded, 1 April-20 June 1945 495

3. Average Daily Volume of Supplies Unloaded in the Ryukyus, 1 April-16

May 1945 ' 497

4. Ammunition Expended by Tenth Army Field Artillery, 1 April-30 June

1945 499

Maps

No. Page

1. Ryukyu Islands 5

2. Okinawa Island Group 6

3. The Plan of Attack 30

4. Advance in the North: 6th Marine Division, 4-8 April 1945 140

5. Kakazu Pocket, 21 April 1945 240

Maps I-XLIX are in accompanying map envelope

I. Strategic Situation in the Pacific

II. Island of Okinawa

III. Southern Okinawa

IV. Kerama Islands: 77th Division, 26-29 March 1945 V. Tenth Army Advance, 1-3 April 1945

VI. Japanese Defensive Positions, 1 April 1945

VII. Through the Outposts: XXIV Corps, 4-8 April 1945

VIII. The Pinnacle: 1st Battalion, 184th Infantry, 6 April 1945 IX. Kakazu Ridge: Attack of 9 April 1945

X. Kakazu Ridge: Attack of 10 April 1945

XI. XXIV Corps Advance, 9-12 April 1945

XII. Japanese Plan of Attack, 12 April 1945

XVlll

No.

XIII.	Japanese Attack, 12-14 April 1945
XIV.	Yae-Take: 6th Marine Division, 8-20 April 1945
XV.	Landings on Ie Shima: 77th Division, 16 April 1945
XVI.	Ie Shima, 18 April 1945
XVII.	Ie Shima, 19 April 1945
XVIII.	Ie Shima, 20-21 April 1945
XIX.	XXIV Corps Attack, 19 April 1945
XX.	Fire Plan of 272d Independent Infantry Battalion: Kakazu Area, 19 April
	1945
XXI.	Item Pocket: 165th Infantry, 20 April 1945
XXII.	Item Pocket, 21 April 1945
XXIII.	Item Pocket, 22-25 April 1945
XXIV.	Skyline Ridge: 7th Division, 19 April 1945
XXV.	Skyline Ridge: 32d Infantry, 21 April 1945
XXVI.	96th Division, 20-24 April 1945
XXVII.	Fight for the Pinnacles, 20 April 1945
XXVIII.	Through the Outer Shuri Defenses, 19-24 April 1945
XXIX.	Stalemate at Kochi: 7th Division, 25 April-3 May 1945
XXX.	Maeda Escarpment, 25-29 April 1945
XXXI.	Attack on Shuri Defenses, 25 April-3 May 1945
XXXII.	Japanese Plan of Attack, 4 May 1945
XXXIII.	Japanese Attack, 4-5 May 1945
XXXIV.	American Advance, 3-10 May 1945
XXXV.	Tenth Army Advance, 11-21 May 1945
XXXVI.	Sugar Loaf Hill: 6th Marine Division, 14-15 May 1945
XXXVII.	Sugar Loaf Hill: 6th Marine Division, 16-17 May 1945
XXXVIII.	Sugar Loaf Hill: 6th Marine Division, 18 May 1945
XXXIX.	Flattop and Dick Hills, 11-12 May 1945
XL.	Flattop and Dick Hills, 13-14 May 1945
XLI.	Flattop and Dick Hills, 15 May 1945
XLII.	Conical Hill, 11-16 May 1945
XLIII.	Conical Hill, 17-21 May 1945
XLIV.	Closing in on Shuri, 22-29 May 1945
XLV.	Fall of Shuri, 30-31 May 1945
XL VI.	The Push South, 1-3 June 1945
XL VII.	Oroku and Yaeju-Dake, 4-11 June 1945
XL VIII.	Breaching Yaeju-Dake, 12-17 June 1945
XLIX.	End of Organized Resistance, 18-21 June 1945

XIX

Illustrations

Page

Okinawans and Okinawan Customs 8

Okinawa's Landscape 11

Village on Okinawa 12

American Commanders 18

Loading Supplies for Okinawa 42

Preliminary Bombardment 47

Japanese Kamikaze Attacks 48

Terrain in the Kerama Retto 53

Landings in the Keramas 59

"Suicide Boats" 61

Softening Up the Target 62

Bombarding the Beaches 71

The Landings 73

Moving Inland 78

Supplying and Developing the Beachhead 82

Japanese Commanders 86

Japanese Weapons 90

Kamikaze Attacks 98

Sinking of the Yamato 100

XXIV Corps Turns South 106

East Coast Battles 109

Kakazu West 114

Kakazu Gorge 122

Tombstone Ridge Area 128

Saddle Between Kakazu West and Kakazu Ridge 136

Fire Bombing 142

Pushing to Yae-Take 145

Ie Shima 151

Rockets Over Ie Shima 155

Invasion of Ie Shima 158

Fighting Toward Ie 161

Death of Ernie Pyle 165

Ie and the Southern Beaches 166

Typical Defense System 168-69

Attack on Bloody Ridge 174

Government House Hill 179

Strategic Area of Southern Okinawa 186

Ouki Hill-Skyline Area and Machinato Inlet 188

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Page

Opening Action, 19 April 195

Battle for Tombstone Ridge 199

Death of a Tank 201

West End of Urasoe-Mura Escarpment 206

Item Pocket Area 212

Heart of Item Pocket 216

Skyline Ridge 221

Rocky Crags 229

Nishibaru Escarpment Area 233

The Pinnacles 239

Urasoe-Mura Escarpment 244-45

Kakazu Village and Kakazu Pocket 246

Japanese Fortifications 251

Naval Fire and Air Support 252

Blowtorch and Corkscrew 254

Southern Coast Line 261

Asa River Area 266

Kochi Area ; 270

Maeda Escarpment and Tank-Infantry Attacks 277

Maeda Escarpment Strong Points 278

Japanese Sea and Air Attack 288

Japanese Position at Tanabaru Escarpment, 4-7 May 292-93

Japanese Land Offensive 294

Tanabaru Escarpment 298

Attacks on Hill 60 305

American Advance Down the Center 308

West Flank Zone 315

Sugar Loaf and Horseshoe Hills 316

Fighting at Sugar Loaf and Crescent Hills 324

Dakeshi Ridge 327

Reverse Slope of Wana Ridge 331

Ishimmi Ridge 335

Chocolate Drop Hill 340

Dick Hills and Flattop 345

Advance Around Dick Hills and Flattop 350

Conical Hill and East Coast Flatlands 354

Japanese Air Raids on Okinawa 363

Wana Draw 367

Mud and Flood 368

"Three Sisters" and Oboe 371

Crossing the Asato River and Entering Naha 374

East Coast Corridor and Yonabaru-Naha Valley 380

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Page

Casualties 385

Secret Retreat 390

Shuri Heights 395

Shuri 399

Shuri Castle Bell 401

Supply and Communications Installations 404

Moving Supplies 408

Movement of Wounded 413

Military Government 416

Development of Airfield and Rehabilitation of Port 418

Mud and Supply 426

Advancing to Yaeju-Dake 429

Last Point of Resistance 430

Base of Oroku Peninsula 435

Yaeju-Dake and Hill 95 437

Flame Through a Hose 444

Night Attack on Yaeju-Dake 448

Yuza Peak and Kunishi Ridge 453

Fighting Toward Hill 89 457

Lt. Gen. Simon B. Buckner 460

Overcoming the Last Resistance 464

Surrender 466

Last Japanese Command Post 469

Raising the American Flag 472

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The U.S. Army Center of Military History

The Center of Military History prepares and publishes histories as required by the U.S. Army. It coordinates Army historical matters, including historical proper- ties, and supervises the Army museum system. It also maintains liaison with public and private agencies and individuals to stimulate interest and study in the field of military history. The Center is located at 1099 14th Street, N.W., Washington, D.C. 20005-3402.

xxin

OKINAWA: THE LAST BATTLE

CHAPTER I

Operation ICEBERG

On 3 October 1944 American forces in the Pacific Ocean Areas received a directive to seize positions in the Ryukyu Islands (Nansei Shoto). Okinawa is the most important island of the Ryukyu Group, the threshold of the four main islands of Japan. The decision to invade the Ryukyus signalized the readiness of the United States to penetrate the inner ring of Japanese defenses. For the enemy, failure on Okinawa meant that he must prepare to resist an early invasion of the homeland or surrender.

The Strategic Decision

Operation ICEBERG, as the plan for the Okinawa campaign was officially called, marked the entrance of the United States upon an advanced stage in the long execution of its strategy in the Pacific. Some 4,000 miles of ocean, and more than three years of war, separated Okinawa from Pearl Harbor. In 1942 and 1943 the Americans had contained the enemy and thrown him back; in 1944 their attack gathered momentum, and a series of fierce island campaigns carried them toward the Japanese inner stronghold in great strides.

The Allied advance followed two main axes, one through the islands of the Central Pacific, the other through the South and Southwest Pacific. Navy task forces and some other elements operated on both fronts as needed. The result was "unremitting pressure" against Japanese military and naval might, a major objective of American strategy.

Near the close of 1943, a thrust at the Gilbert Islands from the Central Pacific, in which Tarawa, Makin, and Apamama were seized, paved the way for the assault on the Marshalls on 31 January 1944. American forces captured Kwajalein, Majuro, and Eniwetok, and their fleet and air arms moved forward. At the same time, American carriers heavily attacked Truk, and that formidable enemy naval base in the Carolines was thenceforth immobilized. Saipan, Tinian, and Guam in the Marianas fell to American arms in the summer of 1944, and, in the First Battle of the Philippine Sea, the U. S. Navy administered a crushing

OKINAWA: THE LAST BATTLE

defeat to the Japanese fleet that tried to interfere with the American push west- ward. In September and October the Americans occupied Uhthi in the western Carolines for use as an anchorage and advanced fleet base, and took Angaur and Peleliu in the Palau Islands, situated close to the Philippines.

Meanwhile, American forces in the South and Southwest Pacific were approaching Mindanao, southernmost of the Philippine Islands, by advances through the Solomons and New Guinea in which Japanese armies were neu- tralized and isolated on Bougainville, New Ireland, and New Britain. The capture of Wakde on the northeastern coast of New Guinea in May 1944 was followed by the seizure of Biak and Noemfoor. During the summer a Japanese army attempting to break out from Wewak in Australian New Guinea was subdued. The invasion of Morotai in September placed American forces within

300 miles of Mindanao.1 (See Map No. I

The ultimate goal of American operations in the Pacific was the industrial heart of Japan, along the southern shores of Honshu between the Tokyo plain and Shimonoseki. American strategy aimed to reach this objective by successive steps and to take advantage, on the way, of Japan's extreme vulnerability to submarine blockade and air bombardment. Throughout most of 1944 Army and Navy staffs in the Pacific Ocean Areas had been planning for the invasion of Formosa (Operation CAUSEWAY) in the spring of 1945. On the basis of the Joint Chiefs of Staff directive of March 1944, the general concept of this operation had been outlined, the availability of troops considered and reviewed many times, and the assignment of task force commanders announced. On 23 August, a joint staff study for CAUSEWAY had been published. It was clear that Admiral Chester W. Nimitz, Commander in Chief, U. S. Pacific Fleet and Pacific Ocean Areas, intended to invade Formosa after Southwest Pacific forces had established positions in the Central and Southern Philippines; CAUSEWAY, in turn, was to be followed by operations against the Ryukyus and Bonins, or against the China coast. Either course would lead eventually to assault on the Japanese home islands.2

On 15 September the Joint Chiefs directed Gen. Douglas MacArthur to seize Leyte on 20 October, instead of 20 December as planned, and to bypass

1 Biennial Report of the Chief of Staff of the United States Army, July i, 1943 to June 30, 1945 . . ., pp. 71, 73; see also maps, pp. 66-68.

2 U. S. Army Forces, Middle Pacific, History of G— 5 Section, pp. 169-76; JCS 713/4, 12 Mar 44; JCS 924, 30 Jun 44: Opns against Japan Subsequent to Formosa.

*All maps numbered in Roman are placed m accompanying map envelope.

OPERATION ICEBERG

3

Mindanao. At the same time, Admiral Nimitz was instructed to bypass Yap.3 On the next day Admiral Nimitz reconsidered the Formosa operation. He believed that the early advance into the Central Philippines, with the opportunity of acquiring the desired fleet anchorages there, opened up the possibility of a direct advance northward through the Ryukyus and Bonins rather than through Formosa and the China coast. He reviewed the objectives of CAUSEWAY — the establishment of air bases from which to bomb Japan, support China, and cut off the home islands from resources to the south — with reference to the new possibility and in a letter to his Army commanders requested their opinions on the subject.4

Lt. Gen. Robert C. Richardson, Jr., Commanding General, U. S. Army Forces, Pacific Ocean Areas, replied that only those steps should be taken which would lead to the early accomplishment of the ultimate objective — the invasion of Japan proper. From this point of view the occupation of Formosa as a stepping stone to an advance on Japan via the China coast did not, in his opinion, offer advantages commensurate with the time and enormous effort involved. He proposed instead, as a more economical course, a dual advance along the Luzon- Ryukyus and the Marianas-Bonins axes. He fully agreed with General Mac- Arthur's plan to seize Luzon after Leyte. The seizure of Luzon would provide air and naval bases in the Philippines from which enemy shipping lanes in the China Sea could be blocked and, at the same time, Formosa effectively neu- tralized. From the ample bases in Luzon, it would be possible and desirable to seize positions in the Ryukyus for the prosecution of air operations against Kyushu and Honshu. The occupation of bases in the Bonins would open another route from the Marianas for bomber operations against Japan. The air assaults on Japan would culminate in landings on the enemy's home islands.5

Lt. Gen. Millard F. Harmon, Commanding General, U. S. Army Air Forces, Pacific Ocean Areas, in his reply to Admiral Nimitz referred to a previous letter which he had written to the Admiral, recommending, as an alternative to the invasion of Formosa and the China coast, the seizure of islands in the Ryukyu chain, for development as air bases from which to bomb Japan. He restated these views and emphasized his opinion that if the objective of CAUSEWAY was the

3 Biennial Report Chief of Staff, p. 71.

4Ltr CINCPOA to USAFPOA, Serial 000113, 16 Sep 44, sub: CAUSEWAY Objectives, cited in USAFMIDPAC G-5 Hist, pp. 176-77.

5 Ltr HUSAFPOA to CINCPOA, Serial 0003, 27 Sep 44, sub: CAUSEWAY Objectives.

4

OKINAWA: THE LAST BATTLE

acquisition of air bases it could be achieved with the least cost in men and materiel by the capture of positions in the Ryukyus.6

The commander of the ground troops designated for CAUSEWAY, Lt. Gen. Simon B. Buckner, Jr., Commanding General, Tenth Army, presented the primary objection to the entire Formosa operation. He informed Admiral Nimitz that the shortages of supporting and service troops in the Pacific Ocean Areas made CAUSEWAY unfeasible. General Buckner added, about a week later, that if an invasion of Luzon was planned the need for occupying Formosa was greatly diminished.7

Admiral Nimitz communicated the substance of these views to Admiral Ernest J. King, Commander in Chief, U. S. Fleet. The latter, who had been the chief proponent of an invasion of Formosa, proposed to the Joint Chiefs of Staff on 2 October 1944 that, in view of the lack of sufficient resources in the Pacific Ocean Areas for the execution of CAUSEWAY and the War Department's inability to make additional resources available before the end of the war in Europe, operations against Luzon, Iwo Jirria, and the Ryukyus be undertaken successively, prior to the seizure of Formosa. Favorable developments in the Pacific and in Europe might make CAUSEWAY feasible at a later date.8 On the next day, 3 October, the Joint Chiefs of Staff issued a directive to Admiral Nimitz to seize one or more positions in the Ryukyu Islands by 1 March 1945.9 On 5 October Admiral Nimitz informed his command that the Formosa opera- tion was now deferred and that, after General MacArthur invaded Luzon on 20 December 1944, the Pacific Ocean Areas forces would seize Iwo Jima on 20 January 1945 and positions in the Ryukyus on 1 March.10

The projected Ryukyus campaign was bound up strategically with the operations against Luzon and Iwo Jima; they were all calculated to maintain unremitting pressure against Japan and to effect the attrition of its military forces. The Luzon operation in December would allow the Southwest Pacific forces to continue on the offensive after taking Leyte. The occupation of Iwo Jima in January would follow through with another blow and provide a base

8Ltr Hq AAFPOA to CINCPOA, 24 Sep 44, sub: CAUSEWAY Objectives, cited in USAFMIDPAC G— 5 Hist, p. 177; USAFPOA Participation in the Okinawa Operation Apr-Jun 45, 1, 143.

7Ltr Hq Tenth Army to CINCPOA, 26 Sep 44, sub: Feasibility of CAUSEWAY Opn; Ltr Hq Tenth Army to CINCPOA, 4 Oct 44, sub: CAUSEWAY Objectives. Both cited in USAFMIDPAC G-5 Hist, pp. 177, 179.

8JCS 713/18, 2 Oct 44. 9JCS 713/19, 3 Oct 44.

10 CINCPOA dispatch 050644,— Oct 44, cited in USAFMIDPAC G-5 Hist, p. 180.

RYUKYU ISLANDS

100

100

MILES

125°

MAP NO. 1

6

OKINAWA: THE LAST BATTLE

MAP NO. 2

for fighter support for the B-29's operating against Japan from the Marianas. The seizure of Okinawa in March would carry the war to the threshold of Japan, cut the enemy's air communications through the Ryukyus, and flank his sea communications to the south. Okinawa was, moreover, in the line of advance both to the China coast and to the Japanese home islands.11

The direct advance to the Ryukyus-Bonins line from the Luzon-Marianas was thus conceived within the framework of the general strategy of destroying by blockade and bombardment the Japanese military forces or their will to resist. The Ryukyus were within medium bomber range of Japan, and it was estimated that 780 bombers, together with the necessary number of fighters, could be based there. An advanced fleet anchorage was available in Okinawa. From these air- fields: and naval bases American air and naval forces could attack the main islands of Japan and, by intensified sea and air blockade, sever them from the Japanese conquests to the south. The captured bases could also be used to sup- port further operations in the regions bordering on the East China Sea. Finally,

nJCS 713/18, 2 Oct 44.

OPERATION ICEBERG

7

the conquest of the Ryukyus would provide adequate supporting positions for the invasion of Kyushu and, subsequently, Honshu, the industrial heart of Japan.12

Nature of the Target

The Islands

The Ryukyu Islands lie southwest of Japan proper, northeast of Formosa and

the Philippines, and west of the Bonins, (See Map No. l.)The islands, peaks of

submerged mountains, stretch in an arc about 790 miles long between Kyushu and Formosa and form a boundary between the East China Sea and the Pacific Ocean. The archipelago consists of about 140 islands, only 30 of which are large enough to support substantial populations. The climate is subtropical, the tem- perature ranging from about 60 0 F. to 83 0 F. Rainfall is heavy, and the high humidity makes the summer heat oppressive. The prevailing winds are mon- soonal in character, and between May and November each year the islands are visited by destructive typhoons.13

Approximately in the center of the arc is the Okinawa Group (Gunto) of some fifty islands clustered around the island of Okinawa. The Kerama Islands lie in an area from ten to twenty miles west of southern Okinawa. Kume, Tonachi, Aguni, and Tori form a rectangle to the north of the Kerama Group. Ie Shima stands off the jutting tip of the Motobu Peninsula on northern Okinawa, while farther to the north lie the Iheya Islands and Yoron. A chain of small islands, called by the Americans the Eastern Islands, extends along the eastern shore of southern Okinawa. Lying in the path of the Japan Current, the entire Okinawa Group is surrounded by seas warm enough to allow the growth of coral, and hence all the islands are surrounded by fairly extensive reefs, some

of which extend several miles ofT shore. (See Map No. 2.)

Okinawa is the largest of the islands in the Ryukyus. Running generally north and south, it is 60 miles long and from 2 to 18 miles wide, with an area of

12 JPS 404/14, 7 Oct 44.

13 The description of the terrain of Okinawa is taken from the following sources: CINCPAC-CINCPOA Bull No. 161-44, 15 Nov 44: Okinawa Gunto; Office of the Chief of Naval Opns, Civil Affairs Handbook Ryukyu Islands, Op Nav 13-31, 15 Nov 44; Joint Amph Force Int Sec-Tenth Army G-2 Info Bull, Feb 45: Hagushi Landing Area; USAFPOA G-2 Objective Data Section, 1 Feb 45: Study of Okinawa Gunto; Tenth Army Tentative Opn Plan ICEBERG 1-45, 6 Jan 45, Annex 3; Tenth Army G-2 Int Monograph Ryukyus Campaign, Aug 45, Pt. I, Sec. A, p. 4; Interv 1st I & H Service Off with 1st Lt Robert Seeburger, Photo Interp Off, G-2 XXIV Corps, 4 Jul 45; personal obsn from air by Lt Col John Stevens, Tenth Army Historian, 9 Jun 45. All interviews and notes of personal observation are recorded in the Okinawa Diary kept by Lt Col John Stevens and M/Sgt James M. Burns of the 1st Information and Historical Service. The diary is on file in the Historical Division, WDSS.

OKINAWAN CUSTOMS include the burial tomb and the veneration of ancestors. The burial tombs characteristic of the Okjnawan landscape stand out clearly in this aerial view {above) just north of Shuri.

OKINAWANS, their head man, and a native priest ( white hat ) gather around an American soldier-interpreter as he asl^s questions.

OPERATION ICEBERG

9

485 square miles. It is entirely fringed with reefs: on the western side the reef lies fairly close to shore and is seldom over a mile wide; on the eastern side, where the coast is more sheltered, the reef extends for some distance off shore, the widest and shallowest points being north of Nakagusuku Bay. (See Maps NosTTllancfTlL]

When Commodore Perry's ships sailed into Naha Harbor, on 26 May 1853, Okinawa was a semi-independent country, paying tribute to China and Satsuma. It was annexed in 1879 by Japan, which integrated the Okinawan people almost completely into the Japanese governmental, economic, and cultural structure. The racial origins of the Okinawans are similar to, but not identical with, those of the Japanese, and the Okinawan stock and culture had been subject to exten- sive Chinese influence. While the Okinawans generally resemble the Japanese in physique, they differ appreciably in their language, the native Luchuan tongue. The predominant religion among the Okinawans is an indigenous, animistic cult, of which worship of fire and the hearth is typical ; veneration of ancestors is an important element in this religion and the burial tomb the most characteristic feature of the Okinawa landscape — a feature which the Jap- anese were to convert into a formidable defensive position.

The standard of living of the Okinawan people is low; the Japanese made no attempt to raise it, regarding the Okinawans as inferior rustics. Most of the inhabitants subsist on small-scale agriculture. When the invading Americans climbed up from the beaches, they found every foot of usable land cut into small fields and planted with sugar cane, sweet potatoes, rice, and soy beans. In 1940 the population of the island was 435,000.

The terrain in northern Okinawa, the two-thirds of the island above the Ishikawa Isthmus, is extremely rugged and mountainous. A central ridge, with elevations of 1,000 feet or more, runs through the length of the region; the ridge is bordered on the east and west by terraces which are dissected by ravines and watercourses, and it ends at the coast in steep cliffs. About 80 percent of the area is covered by pine forests interspersed with dense undergrowth. Troop move- ments are difficult in the region as the use of vehicles is confined to the poor road that hugs the western shore. The Motobu Peninsula, which is nearly square in shape and juts to the west, has also a mountainous and difficult terrain. Two mountain tracts separated by a central valley run east and west the length of the peninsula. Successive coastal terraces are well developed on the north, east, and west of the peninsula. About three and one-half miles off the northwest end of the Motobu Peninsula is the small flat-topped island of Ie Shima, with a sharp pinnacle about 500 feet high at the eastern end.

10

OKINAWA: THE LAST BATTLE

The southern third of Okinawa, south of Ishikawa, is rolling, hilly country, lower than the north but broken by terraces, steep natural escarpments, and ravines. This section is almost entirely under cultivation and contains three- fourths of the population of the island ; here, too, are the airfields and the large towns — Naha, Shuri, Itoman, and Yonabaru. It was in this area that the battle for Okinawa was mainly fought. The limestone plateau and ridges are ideal for defense and abound in natural caves and burial tombs, easily developed into strong underground positions. Generally aligned east and west, the hills offer no north-south ridge line for troop movement, and thus they provide successive natural lines of defense, with frequent steep slopes created by artificial terracing. Rice paddies fill the lowlands near the coasts. The roads are more numerous than in the north, but, with the exception of those in Naha and its vicinity, they are mostly country lanes unsuited for motorized traffic. Drainage is generally poor, and heavy rains turn the area into a quagmire of deep, clay-like mud.

South of Zampa Point on the west there is a 15,000-yard stretch of coast line which includes nearly 9,000 yards of beaches, divided by the Bishi River. These are known as the Hagushi beaches, deriving their name from a small village at the mouth of the river. The beaches are not continuous but are separated by cliffs and outcropping headlands. They range from 100 to 900 yards in length and from 10 to 45 yards in width at low tide, and some are completely awash at high water. A shallow reef with scattered coral heads borders the entire stretch of beach and, in many places, is almost a barrier reef, with deeper water between its crest and the shore line than immediately to seaward. The beaches are for the most part coral sand and most have at least one road exit. A low coastal plain flanks the beaches from Zampa Point south to Sunabe; it is dominated by rolling hills which afford excellent observation, good fields of fire along the beaches, and extensive cover and concealment. Less than 2,000 yards inland on the plain lie the Yontan and Kadena airfields, north and south of the Bishi River. A 400- foot-high hill mass, rising southeast of Sunabe and extending across the center of the island, dominates the entire beachhead area. Composed of innumerable sharp ridges and deep ravines, it is a major obstacle to rapid troop movements and can be used effectively for a strong delaying action.

South of the Sunabe hills, down to the Uchitomari-Tsuwa line, the island narrows to 5,500 yards. The terrain is essentially similar to that behind the Hagu- shi beaches, with heavily wooded uplands and extensively terraced and cultivated valleys and lower slopes. The hills and ridges are generally low except for some high peaks in the general vicinity of Kuba on the east coast, from which observa-

OKINAWA'S LANDSCAPE in the south is marked by fields of grain and vegetables, broken only by humps oj coral, farmhouses, and villages. Navy plane flying over such terrain is shown dropping supplies to the fast-moving American troops early in the campaign.

VILLAGES ON OKINAWA consist of small clusters of houses surrounded by vegetation- covered stone and mud walls. Note camouflaged Japanese Army trucks.

OPERATION ICEBERG

J3

tion of the area is excellent. Roads are adequate for light Japanese transport but not for the heavy strain of American military traffic.

On the east coast, the Katchin Peninsula on the north and the Chinen Penin- sula on the south extend into the ocean to inclose the spacious fleet anchorage of Nakagusuku Bay, called by the American troops "Buckner" Bay. A low coastal plain from one-fourth to one mile wide runs along the shore of the bay from the Katchin Peninsula to Yonabaru. At Yonabaru the plain extends inland to the west through an area of moderate relief and joins another coastal flat extending northeastward from Naha. A cross-island road follows this corridor and connects the two cities. Naha, the capital of the island, with a population of 65,000, is Okinawa's chief port and can accommodate vessels up to 3,000 tons. Southwest of the city, on the Oroku Peninsula, was the Naha airfield, the most highly developed field on the island.

In the region north of the Naha- Yonabaru corridor and in the vicinity of Shuri, the ancient capital of Okinawa, lies the most rugged terrain in the south- ern part of the island. From the high ground near Shuri and from many other vantage points in this area observation is excellent to the north and south and over the coastal regions. At the highest point the hills rise about 575 feet, but the lack of pattern, the escarpments, steep slopes, and narrow valleys characteristic of the region make the major hill masses ideal territory for defense. Many of the escarpments are sheer cliffs without topsoil or vegetation. The low ground is filled with twisting ridges and spotted with small irregular knolls, rendering observation difficult and providing excellent locations for minor infantry and antitank positions. The most prominent features of the region are the strong natural defensive line of the Urasoe-Mura Escarpment, rising from the west coast above the Machinato airfield and running for 4,500 yards across the island in a southeasterly direction, and the chain of hills through Tanabaru and Minami- Uebaru to the east coast southwest of Tsuwa.

South of the strong Shuri positions the terrain is rough, but there are few large escarpments. There are some broad valleys and an extensive road net which would facilitate troop movements. The terrain in the southern end of the island consists of an extensive limestone plateau, surrounded by precipitous limestone cliffs. The northern side of the plateau is a 300-foot escarpment which rises vertically from the valley floor in a jagged coral mass. On the top of the plateau major hills — Yuza-Dake and Yaeju-Dake — cover all approaches from the north, east, and west. Along the southeastern coast, much of the stretch from Minatoga to the eastern end of the Chinen Peninsula consists of beaches.

*4

OKINAWA: THE LAST BATTLE

These are dominated by the rolling dissected terrace forming the body of the peninsula and by the high plateau to the southwest.

American Intelligence of the Enemy

American knowledge of the enemy and of the island of Okinawa was acquired slowly over a period of many months and in the face of many diffi- culties. With Okinawa isolated from the world by the Japanese, information of military value concerning this strategic inner defense line of the Empire was scarce and difficult to obtain. Limited basic intelligence was garnered from documents and prisoners captured on Pacific island battlefields, from interro- gation of former residents of the Ryukyus, and from old Japanese publications. The great bulk of the data was obtained through aerial photographic recon- naissance. This, however, was often incomplete and inadequate, particularly for terrain study and for estimating enemy strength and activity. The distance of the target from American air bases — 1,200 nautical miles — necessitated the use of B-29's and carrier planes for photographic missions; the former afforded only high-altitude, small-scale coverage, while the latter depended on the scheduling of carrier strikes. The relatively large land masses involved and the prevalence of cloud cover added to the difficulty of obtaining the large-scale photographs necessary for detailed study of terrain and installations.14

The target map prepared by American intelligence represented all that was known of the terrain and the developed facilities of the island. This map, scale 1 : 25,000, was based on aerial photographs obtained on 29 September and 10 October 1944 and was distributed about 1 March 1945. Incomplete coverage, varying altitudes of the planes, and cloudiness over parts of the island at the time prevented clear delineation, and certain portions of the map, including that of the high ground north of Shuri, had either poor topographic detail or none at all. Additional photographic coverage of the island was obtained on 3 and 22 January, 28 February, and 1 March 1945; that of 22 January was excellent for the proposed landing beach areas. To supplement aerial photography a submarine was sent from Pearl Harbor to take pictures of all Okinawa beaches. The sub- marine never returned.15

14 Comdr Task Force 51, Comdr Amph Forces, U S Pac Fit. Rpt on Okinawa Gunto Opn from 17 Feb to 17 May 45, 25 Jul 45 (hereafter cited as CTF 51 Actn Rpt), Pt. V, Sec. A, Int Rpt; Tenth Army Actn Rpt Ryukyus 26 Mar to 30 Jun 45, 3 Sep 45, Ch. 11, Sec. II, G-2 Rpt; interv 1st I & H Service Off with Lt Col James R. Weaver, G-2 Sec, Tenth Army, 10 Jul 45.

is Q-pp Actn Rpt, Pt. V, Sec. A, p. 6 (hereafter cited bv part, section, and page as follows: V-A-6); interv 1st I & H Off with Lt Col James R. Weaver, G— 2 Sec, Tenth Army, 10 Jul 45.

OPERATION ICEBERG

J5

Hydrographic information was complete, but its accuracy could not be checked until the target was reached. As the data agreed with a captured Japanese map they were presumed to be accurate. The most reliable information on the depth of the water over the reefs was obtained from Sonne Strip photography and was made available to the troops in March.16

The first estimate of enemy strength, made in October 1944, put the number of Japanese troops on Okinawa at 48,600, including two infantry divisions and one tank regiment.17 In January 1945 this estimate was raised to 55,000, with the expectation that the Japanese would reinforce the Okinawa garrison to 66,000 by 1 April 1945. At the end of February, however, the January estimate was still entertained. All these figures were based on interpretation of aerial photographs and on the use of standard Japanese Tables of Organization: there was no docu- mentary evidence corroborating the estimate of the number of troops on the island.18

It was believed that the Japanese had moved four infantry divisions to the Ryukyus during 1944. These were identified as the gth, 62d, 24th, and 28th Divisions. Army intelligence learned that one division, perhaps the gth, had been moved from Okinawa to Formosa in December 1944. In March 1945 American intelligence estimated that the Japanese forces on Okinawa consisted of the following troops, which included 26 battalions of infantry :

Headquarters 32c! Army 625

24th Division (triangular) 15, 000-17, 000

62c! Division (square) n, 500

44th Independent Mixed Brigade 6, 000

One independent mixed regiment 2, 500

One tank regiment 750

One medium artillery regiment, two mortar battalions, one anti- tank battalion, three antitank companies, and antiaircraft

units 5, 875

Air-ground personnel 3, 500

Service and construction troops 5, 000-6, 000

Naval-ground troops 3, 000

Total 53, 000-56, 000

10 III Amph Corps Actn Rpt Ryukyus, I Jul 45, p. 10.

17Comdr in Chief Pacific Ocean Areas (CINCPOA) Joint Staff Study ICEBERG, Serial 00031, 25 Oct 44, p. 8.

18 Tenth Army Tent Opn Plan 1-45, 6 Jan 45. Annex 3, G-2 Current Estimates, p. 10; CINCPAC- CINCPOA Bull No. 53-45, 28 Feb 45: Okinawa Gunto. p. 14. The only mention of possible civilian con- scription is in Tenth Army Estimate of the Situation, 3 Nov 44, p. 2.

i6

OKINAWA: THE LAST BATTLE

It was considered possible that elements of the gth and 28th Divisions might also be present on Okinawa proper. Enemy forces were known to be organized under the -p.d Army, commanded, it was thought, by General Watanabe, with headquarters at Naha. Shortly before the landings the estimate of Japanese troops was raised to 65,000 on the basis of long-range search-plane reports of convoy movements into Naha.19

Calculations based on Japanese Tables of Organization indicated that the enemy could be expected to have 198 pieces of artillery of 70-mm. or larger caliber, including twenty-four 150-mm. howitzers.20 The Japanese were presumed to have also about 100 antitank guns of 37-mm. and 47-mm. caliber in addition to the guns carried on tanks. The tank regiment on Okinawa had, according to Japanese Tables of Organization, 37 light and 47 medium tanks, but one estimate in March placed the total number of tanks at 90. Intelligence also indicated that rockets and mortars up to 250 mm. could be expected.21

Aerial photographs disclosed three main defense areas on Okinawa, center- ing in Naha, the Hagushi beaches, and the Yonabaru-Nakagusuku Bay area on the east coast. Prepared positions for four infantry regiments were noted along the bay; for one regiment, behind the Hagushi beaches; and for one battalion, along the beaches at Machinato above Naha. It was believed that a total of five or six battalions of troops would be found in the northern part of Okinawa and Ie Shima and that two divisions would be concentrated in southern Okinawa. The main strength of the Japanese artillery was believed to be concentrated in two groups — one about two miles east of Yontan airfield and the other about three miles due south of Shuri; the probable presence of guns was deduced from the spoil which had been deposited in front of cave or tunnel entrances on the slopes of ridges in a manner suitable for gun emplacements.22

At the end of March 1945 intelligence indicated that there were four opera- tional airfields on Okinawa — at Naha, Yontan, Kadena, and Machinato; the first two were the best. All were heavily defended with numerous antiaircraft and dual purpose gun emplacements. The Yonabaru strip, which had been in an initial stage of construction in October 1944, was reported as having been aban-

19 XXIV Corps G-2 Summary No. 3 ICEBERG, 6 Mar 45; XXIV Corps Actn Rpt Ryukyus, 1 Apr 45- 30 Jun 45, p. 116.

20 CINCPAC-CINCPOA Bull No. 53-45, p. 14.

21 XXIV Corps G-2 Summary No. 3; CINCPOA Joint Staff Study ICEBERG; Comdr Amph Forces Pacific Fleet (CTF 51) Opn Plan Ai-45, 16 Feb 45, Annex B: Int Plan.

22CTF 51 Opn Plan Ai-45, Annex B: Int Plan; CINCPAC-CINCPOA Bull No. 53-45, PP- 8~12', CINCPAC-CINCPOA Bull No. 161-44, 15 Nov 44, pp. 110-12.

OPERATION ICEBERG

17

doned by February 1945. Apparently not intending to defend Ie Shima very determinedly, the Japanese, in the latter part of March, were reported to have rendered the airfield there unusable by digging trenches across the runways.23 Land-based enemy aircraft on Okinawa was not expected to constitute a danger; the Americans fully expected that the airfields would be neutralized by the time they invaded the island. It was reported on 29 March, however, that enemy fighter and transport planes were being flown in at night to the Kadena airfield. On 31 March no activity was observed on any of the Okinawa airfields. It was constantly stressed that heavy enemy air attacks would probably be launched from Kyushu, 350 miles to the north. The potential threat of small suicide boats against shipping was also pointed out.24

Tenth Army believed that the most critical terrain for the operation was the area between the Ishikawa Isthmus and the Chatan-Toguchi line, particularly the high ground inland which dominates the Hagushi beaches and the valley of the Bishi River. The enemy could defend the beaches from prepared positions with one regiment, maintaining mobile reserves in the hills north and south of the river. Other reserves could be dispatched to the landing area within a few hours. It was expected that the Japanese would wait until the night of L Day to move their artillery. Alerted by American preliminary operations, they might have a division in position ready for a counterattack on the morning of the land- ings. From terrain 3,000 yards inland that offered both cover and concealment, the Japanese could launch counterattacks of division strength against both flanks of the landing area simultaneously. If the landings were successful, the enemy's main line of resistance, manned by a force of from nine to fifteen battalions, was expected to be at the narrow waist of the island, from Chatan to Toguchi, south of the landing beaches.20

The Plan of Attack^

The plan for the conquest of the Ryukyus was in many respects the culmi- nation of the experience of all previous operations in the Pacific war. It em- bodied the lessons learned in the long course of battle against the Japanese out-

23 CINCPAC-CINCPOA Bull No. 53-45, pp. 15-24; USAFPOA G-2 Objective Data Section, 1 Feb 45: Study of Okinawa Gunto; Tenth Army Actn Rpt, Ch. 7, Sec. IV, p. 1 (hereafter cited by chapter, section, and page as follows: 7— IV— 1).

24 Tenth Army Tent Opn Plan 1-45, Annex 3: G-2 Current Estimates; 96 Div FO No. 12, 5 Mar 45, Annex 4, App. 1, p. 3; Tenth Army Opns Summary No. 10, 29 Mar 45, and No. 16, 31 Mar 45.

25 Tenth Army Tent Opn Plan 1-45, Annex 3 : G-2 Current Estimates.

AMERICAN COMMANDERS in Operation ICEBERG: Admiral Raymond A. Spruance, Fleet Admiral Chester W . Nimitz, and Lt. Gen. Simon B. Buc\ner.

OPERATION ICEBERG

r9

posts in the Pacific — lessons of cooperation and combined striking power of the services, of the technique of amphibious operations, and of Japanese tactics and methods of meeting them. The plan for ICEBERG brought together an ag- gregate of military power — men, guns, ships, and planes — that had accumulated during more than three years of total war. The plan called for joint operations against the inner bastion of the Japanese Empire by the greatest concentration of land, sea, and air forces ever used in the Pacific. Basic Features of the Plan

The immediate task imposed upon the American forces by the terms of the general mission was the seizure and development of Okinawa and the estab- lishment of control of the sea and air in the Ryukyus. The campaign was divided into three phases. The seizure of southern Okinawa, including Keise Shima and islands in the Kerama Group, and the initiation of the development of base facilities were to constitute the first phase. In the next phase Ie Shima was to be occupied and control was to be established over northern Okinawa. The third phase consisted of the seizure and development of additional islands in the Nansei Shoto for use in future operations. The target date of the operation was set at i March 1945.26

Planning began in October 1944. The general scheme for Operation ICE- BERG was issued in the fall of 1944 by Admiral Nimitz as Commander in Chief, Pacific Ocean Areas (CINCPOA). The strategic plan outlined was based on three assumptions. First, the projected campaign against Iwo Jima would have progressed to such an extent that naval fire-support and close air-support units would be available for the assault on Okinawa. Second, the necessary ground and naval combat units and assault shipping engaged in the Philippines would be released promptly by General MacArthur for the Okinawa campaign. Third, preliminary air and naval operations against the enemy would ensure control of the air in the area of the target during the operation.27

Air superiority was the most important factor in the general concept of the operation as outlined by Admiral Nimitz's staff. The CINCPOA planners be- lieved that American air attacks on Japan, from carriers and from airfields in the Marianas, combined with the seizure of Iwo Jima, would force a concen- tration of enemy air strength around the heart of the Empire — on the home islands, Formosa, the China coast, and the Ryukyus. From these bases, strong

29 CINCPOA Joint Staff Study ICEBERG, p. i. This was not a directive but a basis for planning the operation. 27 Ibid.

TWENTIETH AIR FORCE

GEN. it. H. ARHOLD

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OPERATION ICEBERG

21

and continuous air attacks would be made against the forces invading the Ryukyus. It would be necessary, therefore, to neutralize or destroy enemy air installations not only at the target but also at the staging areas in Kyushu and Formosa. All available carrier- and land-based air forces would be called on to perform this task and give the Americans the control of the air required in the area of operations. On Okinawa itself, the scheme of maneuver of the ground troops would be such as to gain early use of airfields that would enable land- based planes to maintain control of the air in the target area. Control of the sea was to be maintained by submarine, surface, and air attacks on enemy naval forces and shipping.28

The American Forces

The isolation of Okinawa was to be. effected with the aid of land-based air forces of commands outside the Pacific Ocean Areas (POA). Planes from the Southwest Pacific Area (SWPA) were to engage in searches and continuous strikes against Formosa as soon as the situation on Luzon permitted. Twentieth Air Force B-29's from China and the Marianas were to bomb Formosa, Kyushu, and Okinawa during the month preceding the landings. The China-based XX Bomber Command was to concentrate on Formosa, while the XXI Bomber Command from the Marianas would attack Okinawa and then shift to Kyushu and other vulnerable points in the home islands during the fighting on Okinawa. The Fourteenth Air Force was to conduct searches along the China coast and also, if practicable, bomb Hong Kong.29

All the forces in Admiral Nimitz's command were marshaled in support

of the ICEBERG Operation. |(See Chart The Strategic Air Forces, POA

was assigned the task of neutralizing enemy air bases in the Carolines and the Bonins, of striking Okinawa and Japan when practicable, and of providing fighter cover for Twentieth Air Force bombing missions against Japan. The Commander, Forward Areas Central Pacific, was to use his naval air strength to provide antisubmarine coverage, neutralize bypassed enemy bases, and, in general, furnish logistic support. Provision of intelligence on enemy naval units and interdiction of the sea approaches from Japan and Formosa were the tasks of the Submarine Force, Pacific Fleet. The enemy was to be contained in the North Pacific Area, and the lines of communication were to be secured in the Marshalls-Gilberts area. Logistic support was to be provided by General Rich-

28 Ibid., pp. 2—4.

29 Fifth Fleet Opn Plan 1-45,3)3045, Annex E : Air Plan.

CHART H

on of Central Pacific Tas{ Forces for the Ryukjus January 1945

CENTRAL PACIFIC TASK. FORCES

ADMIRAL R, A, SPRUANCE

COVERING FORCES AND SPECIAL GROUPS {TASK FORCE SO)

ADMIRAL R, A, SPRUASCE

FAST CARRIER FORCE (TASK FORCE IB) HRITISH CARRIER FORCE (TASK. FORCE 57)

JOfNT EXPEDITIONARY FORCE (TASK FORCE Si)

VICE ADMIRAL R. fc TURNER

AMPHIBIOUS SUPPORT FORCE (task. ruRCE m

RE4R ADMIRAL V. tt. P. BLANDY

WESTERN ISLANDS ATTACK GROUP

REAR 4HMIRAL

i, ,v ku.aivp

LANDING FORCE 77TH DJ VISION

CUNFIRt AND COVERING FORCt (TASK FORCF. S4j

REAR AOMIRAL M. L. UHYO

(TASK FOHt* vii REAR A0MIRAI

LANDING FORCE ill AMPHIBIOUS CDflPS

(TASK FORCfi 1«)

1ST, GEN. J. B. BUCKS CRr JR.

SOUTH ERN ATTACK FORCE

(TASK FOR IE S<>\ RLAtt AOM IRAL

/. I , HALL, IR.

LANDING FORCE SXJV LOR PS

DEMONSTRATION GROUP

REAR ADMIRAL

j. Wright

LANDING EOR'GS 315 MARINE DIVISION

SWii,- Comnundcr in Chtff, U. S. Pi.lIi. Fke. arid Piiirii O^an Areas, Op<rjti«n* in the PldfrL Gam Artai, April l<W>. PIil« J ind If. ottP. [J. ^0 iwith ndppliliuilO.

OPERATION ICEBERG

23

ardson's United States Army Forces, POA (USAFPOA), the Air and Service Forces, Pacific Fleet, and the South Pacific Force. All the armed forces in the Pacific Ocean Areas, from the West Coast to Ulithi and from New Zealand to the Aleutians, were directed to support the attack on Okinawa.30

The principal mission in seizing the objective was assigned to a huge joint Army-Navy task force, known as the Central Pacific Task Forces and com- manded by Admiral Raymond A. Spruance, Commander of the Fifth Fleet. (See Chart II. )| Admiral Spruance's forces consisted of naval covering forces and special groups (Task Force 50), which he personally commanded, and a Joint Expeditionary Force (Task Force 51), commanded by Vice Admiral Richmond K. Turner, Commander, Amphibious Forces Pacific Fleet. General Buckner, Commanding General, Tenth Army, was to lead the Expeditionary Troops (Task Force 56) under Admiral Turner's direction.31

Command relationships prescribed for the operation differed in some respects from those in previous operations against island positions remote from Japan. Because the campaign would entail prolonged ground combat activities by a field army on a large island close to the enemy's homeland, it was necessary to define clearly the relationships between Army and Navy commanders for the successive phases of the operation. Admiral Nimitz accordingly provided that initially the chain of command for amphibious operations would be Admiral Spruance, Admiral Turner, General Buckner. However, when Admiral Spru- ance determined that the amphibious phases of the operation had been success- fully completed, General Buckner was to assume command of all forces ashore. He was thereafter to be directly responsible to Admiral Spruance for the defense and development of the captured positions. In time, Admiral Spruance would be relieved by Admiral Nimitz of these responsibilities, and General Buckner would take over complete command of the forces in the Ryukyus. As Com- mander, Ryukyus Force, a joint task force of ground, air, and naval garrison troops, he would be responsible only to CINCPOA for the defense and develop- ment of the newly won bases and for the protection of the sea areas within twenty-five miles.32

Admiral Spruance, as commander of Task Force 50, had at his disposal Vice Admiral Mitscher's Fast Carrier Force (Task Force 58), a British Carrier Force

30 CINCPOA Opn Plan 14-44, 31 Dec 44, with changes to 20 Jul 45, p. 3; CINCPAC-CINCPOA Opns in the Pacific Ocean Areas during Apr 45, 16 Oct 45, Plate I.

31 Rad CINCPOA to CG Tenth Army, 9 Oct 44, cited in Tenth Army Actn Rpt, 3-0-1.

32 CINCPOA Opn Plan 14-44, Annex F: Command Relationships in Ryukyus Opn.

CHART III

Organization of Expeditionary Troops for the Ryukyus Campaign,

EXPEDITIONARY TROOPS (TASK FORCE 56)

LT. GEN. S. B. BUCKNER, JR

ISLAND COMMAND (ARMY GARRISON FORCE)

MAJ. GEN, F. G. WALLACE, USA

T.

XXIV CORPS (SOUTHERN LANDING FORCE)

MAJ. GEN. J. R. HODGE. USA

TACTICAL AIR FORCE RYUKYUS

MAJ. GEN. F. P. MULCAHY, VSMC

111 AMPHIBIOUS CORPS

(MARINE) (NORTHERN LANDING FORCE)

R^GEIGER

NAVAL FORCES RYUKYUS

REAR ADMIRAL C H. COBB,

7TH DIVISION (RE1NF)

MAJ. GEN, A. V. ARNOLD, USA

96TH DIVISION (RE INF)

MAJ. GEN. J. C BRADLEY, USA

2D MARINE DIV (DEMONSTRATION LANDING FORCE)

MAJ. GEN. T. E. WATSON, USMC

1ST MARINE DIV

MAJ. GEN. P. A. DEL VALLE, USMC

6TH MARINE DIV

MAJ, GEN L, C SHEPHERD. JR. USMC

27TH DIVISION (FLOATING RESERVE)

MAJ, GEN. G. W. GRtNER, JR., USA

Scmrf. Commander T?i4t Forte ?l, Commander Amphibiou* Fum-i, U. S. pacific Fl*«, Reporp tm Okirmw* fcumn Oprrimini from 17 February In 17 May Lftft, Put I, pp. 1-4; Tenth Army Atriin Bejwrt ft} ukyus. It, Mar.h u> JO June 19-1%, Ch, i; Commander in Chief, U S. Pai-ibi FJcce ind P*rlfc Ocean At cm. Ofwmicn, in the Pteifir Cheap Art*,, April )<HS,

77TH DIVIS (REINF) (WESTERN ISLANDS LANDING FORCE)

MAJ, GEN. A, D. BRUCE, USA

S 1ST DIVISION (AREA RESERVE UNDER CINCPOA)

MAJ. GEN, P.J. MUELLER, USA

OPERATION ICEBERG

25

(Task Force 57), special task groups for aerial search and reconnaissance and antisubmarine warfare, and fleet logistic groups. Task Force 58 had a major share of the mission of neutralizing Japanese air strength. Its fast carriers were to strike Kyushu, Okinawa, and adjacent islands in the middle of March, to remain in a covering position east of the target area during the week preceding the invasion, to support the landings with strikes and patrols, and to be prepared for further forays against Kyushu, the China coast, or threatening enemy sur- face forces. The British carriers, the first to participate in Pacific naval actions with the American fleet, were given the task of neutralizing air installations on the Sakishima Group, southwest of the Ryukyus, during the ten days before the landings.33

The Joint Expeditionary Force (Task Force 51) was directly charged with the capture and development of Okinawa and other islands in the group. It was a joint task force of Army, Navy, and Marine units and consisted of the Expe- ditionary Troops (Task Force 56 — |see Chart III}, shipping to transport them,

and supporting naval and air units. Direct naval and air support for Task Force 51 was to be furnished by its Amphibious Support Force (Task Force 52), made up of escort carriers, gunboat and mortar flotillas, mine sweepers, and under- water demolition teams, and by the Gunfire and Covering Force (Task Force 54) of old battleships, light and heavy cruisers, destroyers, and destroyer escorts. The transports and tractor units of the Northern Attack Force (Task Force 53) and Southern Attack Force (Task Force 55) were to land the ground troops in the main assault on the Okinawa beaches, while a number of task groups were assigned the task of transporting the troops for subsidiary landings and the float- ing and area reserves. Task Force 51 also included a transport screen, a service and salvage group, and several specialized naval units.34

The troops who would assault the objectives constituted a field army, the Tenth Army, which had been activated in the United States in June 1944 and shortly thereafter had opened headquarters on Oahu. General Buckner formally assumed command in September 1944, having come to the new assignment from the command of the Alaskan Department, where for four years he had been organizing the American defenses in that area. His new stafT included many officers who had served with him in Alaska as well as some from the European Theater of Operations. The major components of Tenth Army were

33 Fifth Fleet Opn Plan 1-45, pp. 1, 5, Annex E: Air Plan.

34 CTF 51 Opn Plan Ai-45, 16 Feb 45, p. 1.

26

OKINAWA: THE LAST BATTLE

XXIV Army Corps and III Amphibious Corps (Marine). The former con- sisted of the 7th and 96th Infantry Divisions and was commanded by Maj. Gen. John R. Hodge, a veteran leader of troops who had met and defeated the Japanese on Guadalcanal, New Georgia, Bougainville, and Leyte. Ill Amphibious Corps included the 1st and 6th Marine Divisions and was headed by Maj. Gen. Roy S. Geiger, who had successfully directed Marine operations on Bougainville and Guam. Three divisions, the 27th and 77th Infantry Divisions and the 2d Marine Division, were under the direct control of Tenth Army for use in special operations and as reserves. The area reserve, the 81st Infantry Division, was under the control of CINCPOA. Also assigned to Tenth Army for the pur- pose of defense and development of the objectives were a naval task group, the Tactical Air Force, and the Island Command.35

A total of 183,000 troops was made available for the assault phases of the operation.36 About 154,000 of these were in the seven combat divisions, excluding the 81st Division, which remained in New Caledonia; all seven divisions were heavily reinforced with tank battalions, amphibian truck and tractor battalions, joint assault signal companies, and many attached service units. The five divisions committed to the initial landings totaled about 116,000. The 1st and 6th Marine Divisions, with 26,274 and 24,356 troops, respectively, each carried an attached naval construction battalion and about 2,500 replacements in addition to their other supporting combat and service units. The reinforced 7th, 77th, and 96th Divisions averaged nearly 22,000 men per division but each was about 1,000 understrength in organic infantry personnel. The 27th, a reserve division, was reinforced to a strength of 16,143 but remained nevertheless almost 2,000 under- strength organically. The 2d Marine Division, also in Army reserve, numbered 22,195/

(See Appendix C, Table No. 4.)

Tenth Army, as such, had never directed any campaigns, but its corps and divisions had all been combat-tested before the invasion of the Ryukyus. XXIV Corps had carried out the conquest of Leyte, and III Amphibious Corps had captured Guam and Peleliu. The 7th Division had seen action on Attu, Kwajalein, and Leyte, the 77th on Guam and Leyte, and the 96th on Leyte. The 27th had taken part in the battles for the Gilberts and Marshalls and for

3° Tenth Army Tent Opn Plan 1-45, 6 Jan 45, pp. 1-1 o.

36 CTF 51 Actn R ;;,!.. Pt. V, Table 1.

37 Ibid., Tables 2a-2g: III Amph Corps Actn Rpt Ryukyus, 1 Jul 45, p. 28; XXIV Corps Actn Rpt Ryukyus, p. 6; 7th Div Actn Rpt Ryukyus, 30 Jul 45, Annex I, App. B, pp. 1, 2; 27th Div Actn Rpt Ryukyus, 19 Jul 45, p. 10: 96th Div Actn Rpt Ryukyus, Ch. IX, p. 21.

OPERATION ICEBERG

27

Saipan. The 1st Marine Division had been one of the first to see action in the Pacific, on Guadalcanal, and had gone through the campaigns of Western New Britain and Peleliu. The 6th Marine Division had been activated late in 1944, but its regiments were largely made up of seasoned units that had fought on Guam, the Marshalls, and Saipan. The 2d Marine Division had participated in the fighting on Guadalcanal, Tarawa, Saipan, and Tinian.

Plan for the Capture of Okinawa

Using the CINCPOA Toint Staff Study as a basis, each of the major com- manders prepared his plans and issued his operation orders. Although each plan and operation order was derived from that of the next superior echelon, planning was always concurrent. The joint nature of the operation also required extensive coordination of the three services in all operational and logistical problems. Joint conferences thrashed out problems of troop lists, shipping, supplies, and strategy. Corps and task force commanders worked together on the plans for amphibious operations. Corps and division staffs were consulted and advised by Army for purposes of orientation and planning. To ensure interservice coordination, Navy and Marine officers were assigned to work with Tenth Army general and special staff sections. ih In some cases planning was facilitated by utilizing the results of work on other operations. Thus the naval staff developing the gunfire support plans was able to use the operations at Iwo Jima to test and strengthen the general command and communications framework, which was generally similar for both operations; in the same way Tenth Army logistical planners took advantage of their work on the canceled Formosa operation, adapting it to the needs of the Okinawa campaign.39

Out of these planning activities came extremely important decisions that modified and expanded the scope of proposed operations. Tenth Army found it necessary to enlarge the troop list by about 70,000 to include greater numbers of supporting combat elements and service units. Its staff presented and sup- ported a plan for initial assault landings on the west coast of Okinawa, just north and south of Hagushi, as the most feasible logistically and as consonant tactically with the requirements of CINCPOA. The naval staff insisted on the necessity of a sustained week-long naval bombardment of the target and on the consequent need for a protected anchorage in the target area where the fleet units could refuel and resupply. As a result it was decided to capture the Kerama Islands

38 Tenth Army Actn Rpt, Ch. 3: Preliminary Planning.

>!' CTF 51 Actn Rpt, V-C-i ; Tenth Army Actn Rpt, 11-IV-3, 4.

28

OKINAWA: THE LAST BATTLE

just west of Okinawa, a week before the main landings, and the 77th Division was assigned this task. At the suggestion of Admiral Turner a landing was to be feinted on the eastern coast of the island, and the 2d Marine Division was selected for this operation. The commitment of these two reserve divisions impelled Tenth Army to secure the release of the area reserve division to the Expeditionary Troops, and the 27th Division was designated the floating reserve. In its place, as area reserve, the 81st Division was ordered to stand by in the South Pacific. Finally, CINCPOA was twice forced to set back the target date because delays in the Luzon operation created difficulty in maintaining shipping sched- ules and because unfavorable weather conditions appeared likely in the target area during March. L Day (landing day) was set for 1 April 1945.40

As finally conceived, the plan for the capture of Okinawa gave fullest opportunity for the use of the mobility, long range, and striking power of combined arms. After the strategic isolation of Okinawa had been effected by land- and carrier-based aircraft, the amphibious forces were to move forward to the objective. Task Force 52 (the Amphibious Support Force) and Task Force 54 (the Gunfire and Covering Force), assisted by the fast carriers of Task Force 58, were to begin operations at Okinawa and the Kerama Group on L minus 8 (24 March). They were to destroy the enemy defenses and air installa- tions by naval gunfire and air strikes, clear the waters around the objective and the beaches of mines and other obstacles, and provide cover and protection against hostile surface and air units to ensure the safe and uninterrupted approach of the transports and the landings of the assault troops. After the landings they were to furnish naval support and air cover for the land operations.41

Mine sweepers were to be the first units of the Amphibious Support Force to arrive in the target area. Beginning on L minus 8, they were to clear the way for the approach of the bombardment units and then to sweep the waters in the landing and demonstration areas to the shore line/2 Underwater demolition teams were to follow the mine sweepers, reconnoiter the beaches, and demolish beach obstacles.43

Naval gunfire was to support the capture of Okinawa by scheduled destruc- tive bombardment in the week before the landings, by intensive close support

40 Tenth Army Actn Rpt, Ch. 3 : Preliminary Planning.

41 CTF 51 Opn Plan Ai-45, p. 35.

,2 Ibid., Annex A; CTF 52 Actn Rpt Okinawa, 1 May 45, V-H-i. 43 CTF 52 Actn Rpt, V-G-i.

OPERATION ICEBERG

29

of the main and subsidiary landings and the diversionary feint, and thereafter by delivering call and other support fires. The fire support ships with their 5- to 16-inch guns were organized into fire support units, each consisting of 2 old battleships, 2 or 3 cruisers, and 4 or 5 destroyers, that were to stand off the southern part of the island in accordance with definite areas of responsibility. In view of the size of the objective and the impossibility of destroying all targets, fire during the prelanding bombardment was to be laid on carefully selected targets; the principal efforts were to be directed to the destruction of weapons threatening ships and aircraft and of the defenses opposing the landings. Profitable targets were at all times to be sought by close observation, exploratory firing, and constant evaluation of results. Covering fires were to be furnished in conjunction with fire from gunboats and mortar boats in support of mine-sweeping operations and beach demolitions.44

On L Day, beginning at 0600, the naval guns were to mass their fires on the beaches. Counterbattery and deep supporting fires were to destroy the defense guns and keep enemy reinforcements from moving up to oppose the landings. As the assault waves approached the beaches, the fires of the big guns would lift to targets in critical areas inland and to the exterior flanks of the troops. Mortar boats and gunboats were to lead the boat waves to the shore, delivering mortar and rocket fire on the beaches. All craft would begin 40-mm. fire on passing the line of fire support ships and would fire at will until H Hour.45 After the landings scheduled fire on areas 1,000 yards inland and on the flanks would be continued, but top priority would be given to call fires in direct support of the assault elements.46

All scheduled bombardments until H minus 35 minutes were to be under control of the commander of Task Force 52. After that time, because of the size of the landing forces and the extent of the beaches, the commanders of the Northern and Southern Attack Forces would assume control of the support of their respective landing forces. The commander of Task Force 51 was to remain responsible for the general coordination as well as the actual control of bombard- ment in the Army zone. By 1500 each day he would allocate gunfire support vessels for the succeeding twenty-four hours in accordance with approved requests from Army and Corps.47

44 CTF 51 Opn Plan Ai-45, Annex G: Ship's Gunfire Support Plan.

45 Ibid., App. III.

4B Tenth Army Tent Opn Plan 1-45, Annex 6: Naval Gunfire Support. 41 Ibid., CTF 51 Opn Plan Ai-45, Annex G: Ship's Gunfire Support Plan.

MAP NO. 3

OPERATION ICEBERG

31

Air support was to be provided largely by the fast carriers of Task Force 58 and by the escort carriers of Task Force 52. The fast carriers were for the first time to be available at the target area for a prolonged period to furnish support and combat air patrols. They were to cover mine-sweeping operations, hit targets on Okinawa which could not be reached by naval gunfire, destroy enemy defenses and air installations, and strafe the landing beaches. The escort car- riers would provide aircraft for direct support missions, antisubmarine patrols, naval and artillery gunfire spotting, air supply, photographic missions, and the dropping of propaganda leaflets. After L Day additional support was to be furnished by seaplane squadrons based on the Kerama Islands and by the shore- based Tactical Air Force of the Tenth Army.48 The latter was eventually to be responsible for the air defense of the area, being charged with gaining the neces- sary air superiority and giving tactical support to the ground troops.41'

Provision was made for the careful coordination of all naval gunfire, air support, and artillery both in the assault and in the campaign in general. Target information centers, to be established at army, corps, and division levels, would collect and disseminate data on all targets suitable for attack by the respective arms and keep a record of attacks actually carried out. In addition, at every echelon, from battalion to army, representatives of each support arm — artillery, naval gunfire, and air — were to coordinate the use of their respective arms for targets in their zones of action and advise their commanders on the proper employment of the various types of supporting fires. Requests for support would thus be coordinated and screened as they passed up through the various echelons for approval.50

Under cover of the sustained day and night attacks by the naval and air forces, the first phase of the campaign — the capture of the Kerama and Keise Islands and of the southern part of Okinawa — was to begin. On L minus 6, the Western Islands Attack Group was to land the reinforced 77th Division on the Kerama Islands. The seizure of these islands was designed to give the Joint Expeditionary Force, prior to the main assault on Okinawa proper, a base for logistic support of fleet units, a protected anchorage, and a seaplane base. Two regimental combat teams were to land on several of the islands simultaneously and to proceed from the southeast end of the group to the northeast by island-

48 Q-pp Qpn pian A 1-45, Annex H: Air Support Plan.

49 Tenth Army Tent Opn Plan 1-45, Annex 7: Air Support Plan.

50 Tenth Army Tent Opn Plan 1-45, Annex 5: Planning and Coordination of Artillery, Naval Gunfire and Air Support.

32

OKINAWA: THE LAST BATTLE

hopping maneuvers, capturing Keise Island by L minus i. All hostile coastal defense guns that could interfere with the construction of the proposed naval bases were to be destroyed. Organized enemy forces would be broken up without attempting to clear the islands of snipers. Two battalions of 155-mm. guns were to be emplaced on Keise in order to give artillery support to the landings on the coast of Okinawa. Then, after stationing a small garrison force in the islands, the division would reembark and be prepared to execute the Tenth Army's

reserve plans, giving priority to the capture of Ie Shima.51 (See Map No. 3.)

While the 77th Division was taking the lightly held Kerama Islands the preliminary operations for softening up Okinawa would begin; they would mount in intensity as L Day approached. Beginning on 28 March fire support units would close in on the island behind the mine sweepers and demolition teams. The Northern and Southern Attack Forces would arrive off the west coast early on L Day and land their respective ground forces at H Hour, tenta- tively set for 0830. Ill Amphibious Corps would land, two divisions abreast, on the left flank, north of the town of Hagushi at the mouth of the Bishi River: XXIV Corps would land, two divisions abreast, on the right flank, south of Hagushi. The four divisions in landing would be in the following order from north to south; 6th Marine Division, 1st Marine Division, 7th Division, and 96th Division. The two corps were then to drive across the island in a coordinated advance. The 6th Marine Division was first to capture the Yontan airfield and then to advance to the Ishikawa Isthmus, the narrow neck of the island, secur- ing the beachhead on the north by L plus 15. The 1st Marine Division was to head across the island and drive down the Katchin Peninsula on the east coast. South of the Corps' boundary, which ran eastward from the mouth of the Bishi, the 7th Division would quickly seize the Kadena airfield and advance to the east coast, cutting the island in two. The 96th was required initially to capture the high ground commanding its beaches on the south and southeast; then it was to move rapidly down the coastal road, capture the bridges near Chatan, and protect the right of the Corps. Continuing its attack, it was to pivot on its right flank to secure the beachhead on the south by L plus 10 on a line running across the isthmus below Kuba and Futema.52

The choice of the beaches north and south of Hagushi for the initial assault was made after a study by Tenth Army of all the landing beaches in southern

n CTF 51 Opn Plan Ai-45, Annex A, pp. 35, 38; 77th Div Opn Plan ICEBERG, 18 Feb 45, Opn Plan I (Preferred Plan).

"Tenth Army Tent Opn Plan 1-45, pp. 12-13; XXIV Corps FO 45, 8 Feb 45: Preferred Plan, pp. 2-6.

OPERATION ICEBERG

33

Okinawa and a survey of several plans of action. The various plans were weighed in the light of the requirements of the CINCPOA Joint Staff Study and consid- erations of tactical and logistical feasibility. The preferred plan was finally chosen for a number of reasons. First, it would secure the necessary airfields by L plus 5. Second, it would provide the unloading facilities to support the assault. The Hagushi beaches were considered the only ones capable of handling suffi- cient tonnage to sustain a force of two corps and supporting troops, and this seemed to outweigh the disadvantages of not providing for the early capture of the port of Naha and the anchorage in Nakagusuku Bay. Third, the plan would result in separating the enemy forces. Fourth, it would concentrate the troops on one continuous landing beach opposite the point where the greatest enemy resistance was expected. Fifth, it would use the terrain least advantageous for enemy resistance to the landings. Finally, it would permit maximum fire support of the assault.53

The scheme of maneuver was designed to isolate the initial objective, the southern part of the island, by seizing the Ishikawa Isthmus, north of the land- ing beaches, to prevent enemy reinforcement from that direction. At the same time the establishment of a general east-west line from Kuba on the south would prevent reinforcement from the south. Thereafter, the attack was to be continued until the entire southern part of the island was occupied.54 Ground commanders hoped that, for the first time in the Pacific, maneuver could be used to the utmost. The troops would cut across the island quickly, move rapidly to the south, break up the Japanese forces into small segments, bypass strong points, and mop up at leisure.55

While the troops were landing on the west coast, the 2d Marine Division would feint landings on the southeast coast. This demonstration, scheduled for L Day and to be repeated on L plus 1, would be as realistic as possible in order to deceive the enemy into believing that landings would be made there as well as on the Hagushi beaches. After the demonstration the division would be prepared to land on the Hagushi beaches in support of the assault forces.56

The 27th Division, as floating reserve, was to arrive at Ulithi not later than L plus 1 and be on call of the Commander, Joint Expeditionary Force. It was

53 Tenth Army Estimate of the Situation ICEBERG, 3 Nov 44, pp. 6-1 1.

54 Tenth Army Tent Opn Plan 1-45, p. 12.

65 Interv 1st I & H Off with Gen Buckner, CG Tenth Army, 21 Mar 45, and with Gen Hodge, CG XXIV Corps, 12 Mar 45.

56 Tenth Army Tent Opn Plan 1-45, p. 13.

34

OKINAWA: THE LAST BATTLE

to be prepared to seize the islands off the east coast of Okinawa and then to land on that coast in support of XXIV Corps.07

In case the preferred plan for landing on the west coast proved impracticable, an alternate plan was to be used. In this plan, the capture of the Kerama Islands was to be followed by a similar sweep through the small islands east of southern Okinawa that guarded the entrance to Nakagusuku Bay. On L Day two Marine divisions would land on the southeast coast of Okinawa, between Chinen Point and the town of Minatoga. During the next three days the marines were to seize high ground in the area in order to support a landing by two divisions of XXIV Corps on the lower part of Nakagusuku Bay, between Kuba and Yonabaru. Although the alternate plan met most of the requirements for a successful landing operation, it was distinctly a second choice because it would allow the enemy reserves to offer maximum opposition to the second landings and would require a prolonged assault against all the enemy forces on the island to complete the first phase of the mission.58 Psychological Warfare and Military Government

Despite general skepticism as to the effectiveness of psychological warfare against the Japanese,09 an attitude which resulted from its failure in many previous operations, the American plan called for an intensive effort to weaken the enemy's will to resist. Intelligence agencies prepared 5,700,000 leaflets to be dropped over Okinawa from carrier planes. More millions of leaflets were to be printed at the target and scattered over specific areas by bombs and shells. Tanks with amplifiers, an airplane with an ultraloud speaker, and remotely controlled radios dropped behind enemy lines would also tell the enemy why and how he should surrender.60

The plans for psychological warfare were also directed toward influencing the Okinawans, and in this connection there was greater optimism. Because the Okinawans were of a different stock and culture from the Japanese, and had been treated by their rulers as inferiors rather than as elements to be assimilated to Japanese nationalism and militarism, it was hoped that the civilians would not be as hostile, or at any rate as fanatical, as the Japanese.

'"' Ibid., pp. 13-14.

'"slbid., Annex 18; Tenth Army Estimate of the Situation ICEBERG, pp. 9, 11. Plan Baker was the basis for the alternate plan.

^Interv with Gen Buckner, CG, Tenth Army, 21 Mar 45, Command Ship El Dorado, off Leyte, and with Gen Hodge, CG, XXIV Corps, 12 Mar 45, Leyte; interv with 2d Lt Alfred S. Yudkoff, Combat Propaganda Team en route to Okinawa, — Mar 45.

60 Tentative Opn Plan, ICEBERG, Annex 5, "Intelligence Plan," pp. 1-15.

OPERATION ICEBERG

35

The Okinawans also presented the American planners with the problem of military government. The problem was twofold — that of removing the Okinawans from the front lines and that of caring for them; it was necessary to handle the problem in such a way as to facilitate military operations and to make available to the occupying forces the labor and economic resources of the areas. Approximately 300,000 natives lived in southern Okinawa; thousands of others were in the north and on near-by islands. Never before in the Pacific had Americans faced the task of controlling so many enemy civilians.

Basic responsibility for military government in the conquered Japanese islands devolved on the Navy, and Admiral Nimitz was to assume the position of Military Governor of the Ryukyus. However, in view of the fact that most of the garrison forces were Army troops, Admiral Nimitz delegated the responsi- bility to General Buckner. The latter planned to control military government operations during the assault phase through his tactical commanders; corps and division commanders were made responsible for military government in the areas under their control and were assigned military government detachments whose mission was to plan and organize civilian activities behind the fighting fronts. As the campaign progressed and increasing numbers of civilians were encountered, teams attached to military government headquarters of Tenth Army would assume charge, organize camps, and administer the program on an island-wide basis. During the garrison phase the Island Commander, on order of General Buckner, would exercise command over all military government personnel. Maj. Gen. Fred C. Wallace would act through a Deputy Commander for Military Government, Brig. Gen. W. E. Crist.61

The major problem of Military Government was to feed and provide emer- gency medical care for the approximately 300,000 civilians who were expected to be within the American lines by L plus 40. Each of the combat divisions mounted out with 70,000 civilian rations of such native staples as rice, soy beans, and canned fish and also with medical supplies. Military Government personnel would land in the wake of assault units to handle a huge "disaster relief" pro- gram. Additional supplies of all kinds were to be included in the general main- tenance shipments.02

61 CINCPOA Opn Plan 14-44, Annex G; Tenth Army Tent Opn Plan 1-45, Annex 15: Military Government; Tenth Army Opnl Directive No. 7, 6 Jan 45; Tenth Army Tech Bull Mil Govt, 25 Feb 45, p. 5; Tenth Army Mil Govt Opn Rpt, 2 Aug 45.

'Tentative Opn Plan, ICEBERG, "Military Government Plan," Annex 15, pp. 1-5. Cf. App. I, Table of Population.

36

OKINAWA: THE LAST BATTLE

Mounting the Attac\

Organizing the Supply Line

The planning and execution of ICEBERG presented logistical problems of a magnitude greater than any previously encountered in the Pacific. For the assault echelon alone, about 183,000 troops and 747,000 measurement tons of cargo were loaded into over 430 assault transports and landing ships at 11 differ- ent ports, from Seattle to Leyte, a distance of 6,000 miles. (See Appendix C,

Tables Nos. 4 and^i After the landings, maintenance had to be provided for the combat troops and a continuously increasing garrison force that eventually numbered 270,000. Concurrently, the development of Okinawa as an advanced air and fleet base and mounting area for future operations involved supply and construction programs extending over a period of many months subsequent to the initial assault. Close integration of assault, maintenance, and garrison ship- ping and supply was necessary at all times.63

Factors of distance dominated the logistical picture. Cargo and troops were lifted on the West Coast, Oahu, Espiritu Santo, New Caledonia, Guadalcanal, the Russell Islands, Saipan, and Leyte, and were assembled at Eniwetok, Ulithi, Saipan, and Leyte. The closest Pacific Ocean Area bases were at Ulithi and the Marianas, 5 days' sailing time to Okinawa (at 10 knots). The West Coast, which furnished the bulk of resupply, was 6,250 nautical miles away, or 26 days' sailing time. Allowing 30 days to prepare and forward the requisitions, 60 days for pro- curement and loading on the West Coast, and 30 days for sailing to the target, the planners were faced with a 120-day interval between the initiation of their calculations and the arrival of supplies. This meant in practice that requisitioning had to be started before a Troop Basis had been fixed and the details of the tactical plans worked out. Distance, moreover, used up ships and compelled the adoption of a schedule of staggered supply shipments, or "echelons," as well as a number of other improvisations. Mounting the troops where they were sta- tioned, in the scattered reaches of the Pacific Ocean and Southwest Pacific Areas, required close and intricate timing to have them at the target at the appointed moment.64

Broad logistic responsibilities for the support of ICEBERG were assigned by Admiral Nimitz to the various commanders chiefly concerned. Admiral Turner, as commander of the Amphibious Forces Pacific Fleet, furnished the

63 CTF 51 Actn Rpt, I-5, 6, 7, and V-I-12; Tenth Army Actn Rpt, 11-IV-1, 2.

64 CINCPOA Joint Staff Study, p. 29; Tenth Army Actn Rpt, n-IV-1-12; Com Phibs Pac Op Ord Ai-45.

OPERATION ICEBERG

37

shipping for the assault troops and their supplies, determined the loading sched- ules, and was responsible for the delivery of men and cargo to the beaches. Gen- eral Buckner allocated assault shipping space to the elements of his command and was responsible for landing the supplies and transporting them to the dumps. The control of maintenance and garrison shipping, which was largely loaded on the West Coast, was retained by CINCPOA. Responsibility for both the initial supply and the resupply of all Army troops was assigned to the Com- manding General, Pacific Ocean Areas, while the Commanders, Fleet Marine Force, Service Force, and Air Force of the Pacific Fleet were charged with logistic support of Marine, Navy, and naval aviation units. The initial supplies for the troops mounting in the South Pacific and the Southwest Pacific were to be furnished by the commanders of those areas.65

The first phase of supply planning involved the preparation of special lists of equipment required for the operation, which included excess Tables of Equip- ment items, equipment peculiar to amphibious operations, and base development materials. Such lists, or operational projects as they were known, had been pre- pared for the projected Formosa operation; when this was canceled the projects were screened and reduced to meet the needs of ICEBERG.68

At a very early stage in the planning it became evident that there was a short- age of available shipping. The number of combat and service troops included in the initial Troop Basis far exceeded the capacity of allocated shipping. As a result, tonnage had to be reduced for some units while other units were elim- inated entirely from the assault echelon and assigned space in the next echelon. Later, in January 1945, it became apparent that there was still not enough ship- ping space in the assault echelon to transport certain air units and base develop- ment materials designed for early use. It was necessary to request CINCPOA to increase the over-all allocation of LST's and LSM's, as well as to curtail cargo tonnage and provide for the quick return of LST's to Saipan to load eight naval construction battalions.67

Providing the assault troops with their initial supplies was not a difficult problem as generally there were sufficient stocks on hand at each of the mounting areas. When the assault units embarked, they took with them a 30-day supply of rations, essential clothing and equipment, fuel, and medical and construction

66 CINCPOA Opn Plan 14-44, Annex D, pp. 1, 2, 20, 21. 66 Tenth Army Actn Rpr, 11-IV-3, 4. "Ibid., 5-0-4, u-IV-8.

3«

OKINAWA: THE LAST BATTLE

supplies. Initial ammunition quotas consisted of five CINCPOA units of fire.68 On Leyte, XXIV Corps found that SWPA logistics agencies did not have suffi- cient rations on hand to supply it as required, and the shortage was overcome by having the Corps joined at Okinawa by two LST's loaded with rations from Tenth Army reserve stocks in the Marianas.09

Equipment issued to the troops included weapons and instruments of war never before used against the Japanese. New-type flame-thrower tanks, with an increased effective range and a larger fuel capacity, were available for the invasion. Each division was issued no sniperscopes and 140 snooperscopes, devices for seeing in the dark by means of infrared radiation; the former were mounted on carbines and permitted accurate night firing, while the latter were on hand-held mounts and could be used for night observation and signaling. Army artillery and antiaircraft units used proximity (VT) fuzes over land areas for the first time in the Pacific. During the campaign tests were conducted with a new mortar-locating device, the Sound Locator Set GR-6, and the 57-mm. and 75-mm. recoilless rifles and 4.2-inch recoilless mortars.70

Supplies to maintain the troops at the target were scheduled to arrive in twenty-one shipments from the West Coast. Loaded ships were to sail from Pacific ports at 10-day intervals, beginning on L minus 40 (20 February 1945), and to arrive at the regulating stations at Ulithi and Eniwetok beginning on L minus 5, there to await the call of General Buckner. These maintenance shipments, planned to provide automatic resupply until L plus 210 (31 October 1945), were based on the estimated population build-up at the scheduled time of arrival. The principal emergency reserves were kept at Saipan and Guam.71

The main logistical task of the operation, in Admiral Nimitz's opinion, was the rapid development of air and naval bases in the Ryukyus to support further operations against Japan. The Base Development Plan for Okinawa, published by CINCPOA, provided for the construction of eight airfields on Okinawa, two of which were to be operational by L plus 5, a seaplane base, an advanced fleet

68 A CINCPOA U/F was a balanced assortment of ammunition based on Central Pacific experience. It included, among other types, 100 rounds for the Mi Rifle, 1,500 for the .30-caliber machine gun, 600 for the .50-caliber machine gun, 275 for the 60-mm. and 81-mm. mortars, 250 for the 105 -mm. howitzer M2, and 150 for the 155-mm. howitzer. See Tenth Army Tent Opn Plan 1-45, Annex 13, A,pp. B, Incl 1, for the complete description of CINCPOA U/F, 6 Dec 44.

69 CINCPOA Opn Plan 14-44, Annex D, pp. 4-11; Tenth Army Actn Rpt, 11-IV-11; interv 1st I & H Off with Brig Gen David H. Blakelock, ACofS G-4, Tenth Army, 22 May 45.

70 Tenth Army Actn Rpt, 1 1— III— 8, 9; u-XIV-15; USAFPOA, Participation in the Okinawa Opera- tion, I, 63, 240. See also below, [pp. 256-57. |

73 CINCPOA Opn Plan 14-44, Annex D, pp. 8-12; Tenth Armv Actn Rpt. 11-IV-5.

OPERATION ICEBERG

39

base at Nakagusuku Bay, and the rehabilitation of the port of Naha to accom- modate support shipping. Base development responsibilities also included immediate support of the assault by the early construction of tank farms for the bulk storage of fuel and for the improvement of waterfront unloading facilities and of roads. Later a large construction program was planned that included roads, dumps, hospitals, communications facilities, water supply systems, and housing and recreational facilities. A plan for the development of Ie Shima as an advanced air base was also prepared.72

General Buckner was charged with the responsibility for base development in the Ryukyus. Assigned to Tenth Army for the execution of the Base Develop- ment Plan was the Island Command Okinawa, or Army Garrison Force, with Maj. Gen. Fred C. Wallace in command. Some of the Island Command troops were to land in the assault echelon and to provide logistic support for the assault troops during and immediately after the landings. At the conclusion of the am- phibious phase, the Island Command was to act as Tenth Army's administrative and logistical agency, operating in effect as an Army service command and an advanced section of the communications zone. As such, it was to be in charge of the base development program as well as of the garrisoning and defense of the captured positions. Garrison troops and base development materials were scheduled to arrive at Okinawa in seventeen echelons. These were based pri- marily on the unloading capacity of the Hagushi beaches; the tonnage in each echelon was kept within the estimated discharge capacity between the arrivals of the echelons. Most of this garrison shipping was loaded on the West Coast and Oahu, but some originated in the South Pacific and the Marianas.73

Training and Rehearsal of Troops

The great distances that separated the elements of its command, together with the limited time available, precluded combined training or rehearsal by Tenth Army of the maneuver which would land two corps abreast on a hostile shore. To the extent that circumstances permitted, however, the scattered units of the Tenth Army engaged in individual training, combined-arms training, and special training in amphibious, cave, and mountain warfare. Particular efforts were made to train ground troops in the use of the new snooperscopes

" CINCPAC-CINCPOA Opns in the POA during May 45, p. 46; CINCPOA Joint Staff Study, App. E; CINCPOA Base Development Plan LEGUMINOUS, Serial 000221, 10 Feb 45 (LEGUMINOUS was the code name for the base development of Okinawa); Tenth Army Actn Rpt, 11— IV— 7.

73 CINCPOA Opn Plan 14-44, Annex D, p. 36, and Annex F, pp. 1,2; Tenth Army Tent Opn Plan 1-45, Annex 12: Island Command Plan; Tenth Army Actn Rpt, 5-0-8, 9; 11-IV-6, 9, 10; ii-XXVI-i.

40

OKINAWA: THE LAST BATTLE

and sniperscopes, and the one standard tank battalion which was converted to an armored flame thrower battalion received instruction in the use and main- tenance of its tanks. Many service units received little specialized training because of the pressure of their regular duties and, in some cases, the circum- stance that they had been released to Tenth Army only a few days before mounting from Hawaii.74

When, in December 1944, XXIV Corps received its warning order, it was in action over a large part of southern Leyte, engaged in virtually separate operations on the east and west coasts of the island. The Corps was not released from tactical responsibility until 10 February 1945, and it did not complete the assembly of all its units in the staging area at Dulag until 18 February. Training and rehearsals had to be sandwiched between the rehabilitation program for its combat-weary units and the mounting-out for the new operation. The 7th, 77th, and 96th Divisions were able to engage only in a very limited amount of training specifically oriented to the Okinawa operation, but all managed to train in the use of the sniperscope and of flame throwers. The Corps was, however, able to engage in a full-scale nonfinng rehearsal with the 7th and 96th Divisions and amphibious elements of the Southern Attack Force in Leyte Gulf from 15 to 19 March 1945. In addition to training in the techniques of amphibious landings, the troops practiced the breaching and scaling of sea walls. Assault regiments of the two divisions landed and moved inland for 1,000 yards in a simulated attack, after which critiques were held and the exercise repeated. The 77th Division conducted practice landings separately in Leyte Gulf from 9 to 16 March. The 27th was able to engage in intensive training in Espiritu Santo between October 1944 and 25 March 1945, when it embarked for the target; four landing rehearsals were also held between 20 and 25 March.75

All the Marine divisions scheduled for the Okinawa campaign had sev- eral months in which to train and rehearse. The 1st Marine Division, finding training facilities restricted in the Russell Islands, arranged for each of its regi- ments to take a month's training on Guadalcanal, where adequate artillery, mortar, and small-arms ranges were available. The 6th Marine Division trained on Guadalcanal, conducting numerous division problems and field exercises. On Saipan the 2d Marine Division had the advantage of practicing against the Jap- anese still holed up in the hills. The III Amphibious Corps conducted a combined

14 Tenth Army Actn Rpt, 4-0-1-6, 1 1— III— 8, 9.

75 XXIV Corps Actn Rpt, pp. 4, 6, 8, 18; 7th Div Actn Rpt, pp. 4, 28, 29; 96th Div Actn Rpt, Ch. V, pp. 1, 2; 77th Div Actn Rpt, pp. 8, 19; 27th Div Actn Rpt, pp. 18-21.

OPERATION ICEBERG

41

rehearsal with the ist and 6th Marine Divisions at Guadalcanal from 2 to 7 March; full-scale problems were worked out, troops and token supplies were landed, and a communications net established.70

Mounting Out

Responsibility for the loading of the assault units was decentralized through delegation to the commanders at the various mounting points; the Commanding General, Tenth Army, however, retained control of the mounting of units from Oahu. The commanders of the III Amphibious Corps and XXIV Corps were responsible for embarking their respective troops in the South Pacific and Leyte. The 2d Marine Division supervised the loading of its own troops and other units mounting from Saipan. Units which originated on the West Coast were moved to the assigned mounting points for integration with the assault echelon.77

All loading was conducted according to the transport doctrine of the Am- phibious Forces Pacific Fleet and the logistical directives published by Tenth Army. One transport squadron of fifteen APA's (transports) and six AKA's (cargo ships), together with the requisite number of LST's and LSM's, was allocated to each division, and additional allocations were made for Corps and Army troops.|(See Chart IV.)| Altogether, 111 APA's, 47 AKA's, 184 LST's, and 89 LSM's were loaded in mounting the Joint Expeditionary Force. Transport Quartermaster Teams were activated and assigned to Army units to load their troops and equipment, while Marine units used the teams which had functioned in previous operations. Admiral Turner also sent two combat loading teams, trained in embarkation procedures and familiar with the policies of his com- mand, to aid in the loading of the two corps at Leyte and the Guadalcanal- Russells area and of the 27th Division at Espiritu Santo. All loading plans and operations were subject to the approval of the captain of each ship as well as of the transport squadron commander concerned.78

Tenth Army headquarters and most of its attached troops mounted out of Hawaii, while the 7th, 77th, and 96th Divisions embarked at Leyte, where the largest number of ships was loaded. Each division did its own loading under general supervision of the Corps. The chief difficulty encountered was the necessity of loading across the open beaches in the Dulag area on the east coast of Leyte. Piers were nonexistent or of too flimsy a construction to withstand the battering which they took in the high surf and tide. LST's and LSM's were

76 III Amph Corps Actn Rpt, pp. 23, 24. 7' Tenth Army Actn Rpt, 5-0-1, 2, 6.

78CTF 51 Actn Rpt, V-I-14, 21: Tenth Army Actn Rpt, 5-0-1, 3. 6, 7.

LOADING SUPPLIES FOR OKINAWA — not only arms, ammunition, and food but also great quantities of construction material {above). Barrels of fuel and boxes of other materiel are shown below being loaded at Leyte.

CHART IV

XXIV Corps Assignment of Shipping for the Assault on Okinawa

purple

/ AM TRAC

77* AM TK COL

A

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I opj> p. II.

LJVI

OPERATION ICEBERG

43

beached as near shore as possible and vehicles had to be driven through the water; 105-mm. artillery was loaded by means of DUKW's and ponton cause- ways. Transports were loaded in the stream by ships' boats, LCT's, and LSM's. Many lighters and landing craft on Leyte had been diverted to the needs of the Luzon campaign in February when loading began, and a hurry call was sent to Tenth Army for additional lighterage. Loading plans also went awry because of the lack of accurate advance information on the characteristics of ships to be loaded. Much time was consumed by the necessity of unloading newly arrived supplies across the open beaches and reloading them in the assault shipping. The 27th Division loaded separately at Espiritu Santo, where it met difficulties of transportation and misunderstandings with naval officials.79

Ill Amphibious Corps and its units mounted out in the Guadalcanal- Russells area. Loading was out in the stream but was facilitated by an ample supply of lighterage and by excellent sandy beaches. Assault troops were em- barked on transports initially and were transferred to landing ships at the staging point at Ulithi, a method which shortened the time to be spent in the uncomfortable, crowded LST's and LSM's.80

Movement to the target got under way on 18 March 1945, when the slow tractor group carrying the assault troops which were to take the Kerama Islands left San Pedro Bay, Leyte. Transports with other 77th Division troops sailed from Leyte three days later, and the remainder of the division followed on 24 March. The tractor groups of the Southern Attack Force sailed from Leyte on 25 March, and the faster transports followed two days later. The course from Leyte was approximately NE by N to a point about 300 miles south of Okinawa, when it was changed to N by NW directly to the target. Units of III Amphibious Corps in the Northern Attack Force sailed from the Guadal- canal area on 12 March, arriving on 21 March at Ulithi, where four days were spent in topping off supplies and effecting the transfer of troops to landing ships. The Northern Tractor Flotilla left from Ulithi on 25 March. The tractor groups carrying the 2d Marine Division to the demonstration beaches left Saipan the same day. When the remainder of the Northern and Southern Attack Forces and the Demonstration Group set forth on 27 March, Americans and Japanese were already engaged in land fighting in the Kerama Islands.81

TO Ibid.; see also sections on loading in the Actn Rpts of XXIV Corps and the 7th, 27th, 77th, and 96th Divisions.

80 III Amph Corps Actn Rpt, pp. 31, 32.

81 CTF 51 Actn Rpt, II-7-13; XXIV Corps Actn Rot. Ch. VI.

CHAPTER II

Invasion of the Ryukyus

Operations preliminary to the landing on Okinawa were as protracted and elaborate as the tactical and logistical planning. From October 1944 to April 1945 American forces from the Pacific Ocean Areas, the Southwest Pacific Area, and the China Theater conducted an intensive campaign to neutralize Jap- anese air and naval strength.1 In the last week of March, while the Kerama Islands were being seized, the Navy concentrated on a furious bombardment of the main target. Before the troops for the assault mounted out American forces had invaded Luzon and Iwo Jima.

Preliminary Neutralization of Enemy Strength

The first attack on Okinawa was made by Vice Admiral Marc A. Mitscher's Fast Carrier Task Force, operating as part of the Third Fleet, in the preliminary operations for the landings on Leyte. Nine carriers, 5 fast battleships, 8 escort carriers, 4 heavy cruisers, 7 light cruisers, 3 antiaircraft cruisers, and 58 destroyers arrived off Okinawa early on 10 October. Admiral Mitscher made every effort to achieve surprise. The force followed the track of bad weather caused by a typhoon moving toward Okinawa from the southeast. A smaller force of cruisers and destroyers made a diversionary attack on Marcus Island, 1,500 miles to the east, in such a way as to simulate a large force. Aircraft based on the Marianas intensified attacks on Iwo Jima, to hamper searches from that direction, and flew interdiction patrols ahead of the Third Fleet forces.

Wave after wave of carrier planes swept over Okinawa shortly after dawn of 10 October. The first strikes bombed, rocketed, and strafed airfields at Yontan, Kadena, Ie Shima, and Naha. Later waves made intensive attacks on shipping, installations, harbor facilities, and similar targets. The attack con-

1The data for this account were taken from monthly reports of operations by Admiral Nimitz

entitled "Operations in the Pacific Ocean Areas during the Month of ." Copies of the reports

are available in the Historical Division, WDSS.

INVASION OF THE RYUKYUS

45

tinued throughout the day. Many enemy aircraft were caught on the ground, dispersed and revetted, but only a few in the air. A fighter-bomber from the Bunker Hill dropped a bomb between two midget submarines moored side by side. Other islands in the Ryukyus were reconnoitered and attacked, including Kume, Miyako, Amami-O, Tokuno, and Minami.

The attack was one of the heaviest delivered by the Fast Carrier Force in a single day up to that time. In 1,356 strikes, the planes fired 652 rockets and 21 torpedoes and dropped 541 tons of bombs. Naha was left in flames; four- fifths of the city's 533 acres of closely built-up area was laid waste. Twenty- three enemy aircraft were shot down and 88 more destroyed on the ground or water. Twenty cargo ships, 45 smaller vessels, 4 midget submarines, a destroyer escort, a submarine tender, a mine sweeper, and miscellaneous other craft were sunk. "The enemy is brazenly planning to destroy completely every last ship, cut our supply lines, and attack us" was the gloomy observation of a Japanese soldier on the island on that day.2

Admiral Mitscher's estimate of results was probably conservative. A Jap- anese Army report on the attack listed in addition a destroyer and a mine sweeper as sunk. According to the report, almost 5,000,000 rounds of machine- gun ammunition and 300,000 sacks of unpolished rice were among the supplies destroyed. The report noted that antiradar "window" had been used by the Americans, and that propaganda leaflets had been dropped. Nowhere did the Japanese report mention one of the most significant accomplishments of the task force during the day — photographic coverage of important areas through- out the Ryukyus.3

Okinawa was not assaulted again until 1945, when carrier planes raided the Ryukyu and Sakashima Islands on 3 and 4 January during a heavy attack on Formosa by the Fast Carrier Task Force. The primary objective of the task force was the destruction of enemy air strength on Formosa in preparation for the invasion of Luzon, and the attack on Okinawa was limited in extent be- cause of the long distance the fighters had to fly to the target. On 22 January, Admiral Mitscher's carrier force moved a second time against the Ryukyus, with the primary mission of photographing the islands. Unfavorable weather inter- fered with some of the sorties, but pilots obtained photographic coverage of 80

2 ONI Weekly, Vol. IV, No. 30, 25 Jul 45, pp. 2276-77, Translated Diary of Miyashita Kuraji.

3 CINCPAC-CINCPOA Bull No. 170-45, 7 Jul 45, Transl and Interrog No. 35: Effects of First Carrier Plane Attack on Okinawa, Ishi Condition Rpt No. 1, 62/I Div Hq, 17 Oct 44, pp. 89-93.

46

OKINAWA: THE LAST BATTLE

percent of priority areas and attacked ground installations, aircraft, and ship- ping. The operations were small compared to those of 10 October but to the enemy they must have seemed impressive. A Japanese superior private in the infantry wrote indignantly in his diary on 22 January :

Grumman, Boeing, and North American Planes came over one after another con- tinuously. Darn it, it makes me mad! While some fly around overhead and strafe, the big bastards fly over the airfield and drop bombs. The ferocity of the bombing is terrific. It really makes me furious. It is past 1500 and the raid is still on. At 1800 the last two planes brought the raid to a close. What the hell kind of bastards are they? Bomb from 0600 to 1800! I have to admit, though, that when they were using tracers this morning, it was really pretty.4

On 1 March the Fast Carrier Task Force, now operating as Task Force 58, a part of Admiral Spruance's Fifth Fleet, delivered another strike on the Ryukyus at the end of a 3-week battle cruise in Japanese home waters which included an attack on Tokyo. Sweeping down the long Ryukyu chain, American planes hit Amami, Minami, Kume, Tokuno, and Okino as well as Okinawa. Cruisers and destroyers shelled Okino Daito, 450 miles from Kyushu, in the closest surface attack to the Japanese homeland made by the fleet up to that time. The carrier planes sank a destroyer, 8 cargo ships, and 45 more craft of various sizes, destroyed 41 enemy planes, and attacked airfields and installations, particularly in the Okinawa Group. Enemy opposition was meager and American losses were small.

During February and March 1945, aircraft based in the Southwest Pacific and in the Marianas made almost daily runs over the Ryukyus and adjacent waters. Army and Navy search planes and patrol bombers hunted the waters for Japanese shipping and helped to isolate Okinawa by destroying cargo vessels, luggers, and other craft plying between Okinawa and outlying areas. One or two bombers flying high over Okinawa became so familiar a sight to the Japa- nese that they called it the "regular run" and dispensed with air raid alarms.5 During March American submarines also tightened the shipping blockade around the Ryukyus.

On 14 March 1945, Task Force 58 steamed out of Ulithi and headed north. Its objective was the Inland Sea, bounded by Kyushu, western Honshu, and Shikoku ; its mission was to prepare for the invasion of the Ryukyus by attacking

4 CINCPAC-CINCPOA Bull No. 147-45, 16 Jun 45, Transl and Interrog No. 32: Translation of Diary Captured on Okinawa, p. 71.

5 Ibid., Extracts from an. Okinawa Diary, p. 49.

PRELIMINARY BOMBARDMENT of Okjnawa and supporting islands began months in advance of the landings. Naha ( above ) was a prize target because of its port installations and was leveled long before the invasion. Also important were bridges (below) along the island's lines of supply.

JAPANESE KAMIKAZE ATTACKS were a constant menace to the American fleet. Here a Kamikaze plane, jailing short of its target, plunges into the sea after being riddled by antiaircraft fire from an American cruiser. But the aircraft carrier Franklin (below} was not as fortunate. Hit off Kyushu by two 550-pound armor-piercing bombs, the Franklin's fuel, aircraft, and ammunition went up in flame; more than a thousand of her crew were lost. Gutted and listing badly, the carrier limped bac\ to New Yor\ for repairs.

INVASION OF THE RYUKYUS

49

airfields and naval bases in the Japanese homeland. The formidable task force was composed of 10 large aircraft carriers, 6 smaller carriers, 8 fast battleships, 16 cruisers, and dozens of destroyers and other vessels; included were famous names like Hornet, Yorktown, Enterprise, New Jersey, and Missouri?

As Task Force 58 neared Kyushu on 17 March, it was spotted by Japanese search planes but was not attacked. At dawn on the 18th the destroyers formed two radar patrol groups, one 30 miles north and the other 30 miles west of the main force, each with carrier-based fighter protection. At 0545, when Task Force 58 was about 100 miles east of the southern tip of Kyushu, the first fighters took off from their carriers and headed for Kyushu airfields. Within an hour more fighters were launched, then the bombers and torpedo bombers. During the forenoon American planes attacked aircraft and fields near the coasts of Kyushu. When the enemy air opposition proved ineffective, the planes were ordered to strike farther inland, at targets originally scheduled for the next day. The move was profitable; during the day 102 aircraft were shot down, 275 more on the ground damaged or destroyed, and hangars, shops, and other airfield installations heavily bombed.

The Japanese counterattacked during the day. Their attack was not heavy, but it was carried out in an aggressive and determined manner. Single enemy aircraft using cloud cover effectively launched bombing attacks on American carriers. Radars were not of much help, but visual sightings by destroyers were invaluable. Although patrol planes shot down twelve of the enemy, and anti- aircraft fire accounted for twenty-one more, the Yorhtown and Enterprise were hit by bombs. Fortunately, damage to the former was minor, and the bomb that hit the Enterprise failed to explode. Both could continue flight operations.

The next day, 19 March, Admiral Mitscher concentrated the attack on the enemy warships at Kobe, Kure, and Hiroshima in western Honshu, as well as on the airfields in Honshu and Shikoku. Major Japanese fleet units, including the battleship Yamato, were at Kure and Hiroshima harbors. The attack against the enemy fleet was only moderately effective, mainly because of extremely heavy and accurate antiaircraft fire. One group alone lost thirteen planes over Kure. The Yamato was slightly damaged, an escort carrier severely damaged, and fourteen other warships damaged in varying degrees. Merchant ships and coastal vessels were sunk or damaged in the Inland Sea.7

6 CTF 58 Actn Rpt, pp. 2-3, Incl A, p. 1. ''ibid., pp. 4-5.

50

OKINAWA: THE LAST BATTLE

Soon after the first planes were launched on 19 March, enemy aircraft appeared over Task Force 58, concentrating their attack as usual on the carriers. Two 550-lb. bombs hit the Franhlin while she was in the course of launching a strike. She burned fiercely amid shattering explosions and enveloping clouds of black smoke, finally becoming dead in the water. A bomb hit the Wasp and exploded between her second and third decks, but the fire was quickly put out and the carrier was able to work her aircraft within an hour. The weather was perfect for the enemy: a thin layer of clouds at 2,500 feet. Antiaircraft gunnery was, however, excellent. Six Japanese planes attacked one group, coming in at cloud level at an angle of 45 degrees ; all six were blown to pieces.

Task Force 58 retired during the afternoon of 19 March. Carriers covered the burning Franklin, which was being towed at five knots, and launched fighter sweeps against Kyushu airfields in order to disrupt any planned attack on the force as it withdrew slowly south. Eight enemy planes attacked in the evening but were intercepted 80 miles away; five were shot down. The total number of Japanese planes shot out of the air during the day by planes and anti- aircraft fire was 97, and approximately 225 additional enemy aircraft were de- stroyed or damaged on the ground. Installations at more than a score of air bases on Honshu, Shikoku, and Kyushu were left in ruins by the operations of the day.

Japanese "bogeys" shadowed Task Force 58 on 20 March, and enemy planes attacked during the afternoon and evening. The Enterprise was hit by American gunfire which started a fire. Eight planes were destroyed and flying operations were halted. A plane narrowly missed the Hancoc\ and hit and crippled a destroyer. The Japanese delivered an 8-plane torpedo strike against the force during the night, without success. On the 21st the enemy launched a final heavy attack on the retiring ships, with a force of 32 bombers and 16 fighters. Twenty- four American fighters intercepted the enemy planes about sixty miles from the force and quickly shot down every enemy plane, with the loss of only two American fighters. Task Force 58 met its supply ships south of Okinawa on 22 March, and spent a busy day fueling, provisioning, and taking on replacement pilots and aircraft, in preparation for the decisive phase of the campaign soon to come. In the entire course of its foray from 18 to 22 March, Admiral Mitscher's force had destroyed 528 enemy planes, damaged 16 surface craft, and hit scores of hangars, factories, warehouses, and dock areas. The success of the operation was indicated by the subsequent failure of the Japanese to mount a strong air attack for a week after the American landing on Okinawa.

INVASION OF THE RYUKYUS

51

Seizure of the Kerama Islands

The first landings in the Ryukyus were on the Kerama Islands, fifteen miles west of Okinawa. The boldly conceived plan to invade these islands six days prior to the landing on Okinawa was designed to secure a seaplane base and a fleet anchorage supporting the main invasion. An additional pur- pose was to provide artillery support for the Okinawa landing by the seizure of Keise Shima, eleven miles southwest of the Hagushi beaches, on the day preceding the Okinawa assault. The entire operation was under the control of the Western Islands Attack Group. The force selected for the landings in the Keramas was the 77th Division, commanded by Maj. Gen. Andrew D. Bruce; the 420th Field Artillery Group was chosen for the landing on Keise Shima.8

Steaming from Leyte, where the 77th Division had been engaged in combat since November 1944, the task force moved toward the objective in two convoys. The 22 LST's, 14 LSM's, and 40 LCI's, organized into a tractor flotilla with its own screen, left on 20 March. Two days later twenty trans- ports and large cargo vessels followed, screened by two carrier escorts and destroyers. En route, the training begun on Leyte was continued. Opera- tional plans were discussed and the men were thoroughly briefed with the aid of maps, aerial photographs, and terrain models. Booklets on habits, cus- toms, government, and history of the Okinawans were distributed. After an uneventful voyage, broken only by false submarine alarms, the entire task force arrived on 26 March in the vicinity of the Kerama Islands.

Naval and air operations against the Keramas had begun two days earlier. Under the protection of the carriers and battleships of Task Force 58, which was standing off east of Okinawa, mine sweepers began clearing large areas south of the objective area on 24 March. On 25 March Vice Admiral William H. Blandy's Amphibious Support Force arrived, and mine sweeping was intensified. By evening of 25 March a 7-mile-wide lane had been cleared to Kerama from the south and a slightly larger one from the southwest. Few mines were found. Underwater demolition teams came in on the 25th and found the approaches to the Kerama beaches clear of man-made obstacles, though the reefs were studded with sharp coral heads, many of which lay only a few feet beneath the surface at high tide and were flush with the surface at low tide.9

CTF 51. 1 R,pt, I-1-19, III-5-17.

9CTF 52 Actn Rpt Okinawa, II-C-i, 4; V-H-i; V-G-i.

52

OKINAWA: THE LAST BATTLE

While the demolition teams surveyed the approaches, observers from 77th Division assault units studied their objectives. A fringing reef of irregular width surrounds each island. The coasts of the islands are generally steep and irreg- ular. Narrow benches of coral rock lie along the coasts in many places. The beaches are narrow and are usually bulwarked by 4-foot sea walls. The only beaches of any considerable length are at the mouths of steep valleys or within small bays. All but the smallest of the islands are for the most part masses of steep rocky slopes, covered with brush and trees and from about 400 to 800 feet in height. Wherever possible the inhabitants grew sweet potatoes and rice on the terraced slopes of the hills and in small valley flats near the beaches. There are no roads and only a few pack-animal trails. No island in the group is suitable for an airstrip; none can accommodate large masses of troops or extensive base facilities. The military value of the Keramas lies in two anchor- ages, Kerama Kaikyo and Aka Kaikyo, separated from each other by Amuro Islet, in the center of the group, and bounded on the east by Tokashiki and on the west by Aka, Geruma, and Hokaji. These anchorages inclosed 44 berths, from 500 to 1,000 yards long, ranging in depth from 13 to 37 fathoms.10 (See Map No. IV.TI

Four battalion landing teams (BLT's) of the 77th Division made the first landings in the Kerama Islands on the morning of 26 March. The sky was clear, visibility good, and the water calm. Escorted by Navy guide boats, waves of amphibian tractors moved from LST's to four central islands of the group — Aka, Geruma, Hokaji, and Zamami. Cruisers, destroyers, and smaller naval craft swept the beaches with 5-inch shells, rockets, and mortar shells. Carrier planes strafed suspected areas and guarded against interference by enemy sub- marines and aircraft. Amphibian tanks led the amtracks to the beaches.11

The first unit ashore was the 3d BLT of the 305th Regimental Combat Team (RCT). At 080412 the 3d BLT hit the southern beaches of Aka, an island of irregular shape, measuring 3,400 by 3,000 yards at its extreme dimensions and rising in a series of ridges to two peaks, one 539 feet and the other 635 feet high. Aka, "Happy Corner Island," lies near the center of the group. The 200 boat operators and Korean laborers on Aka put sporadic mortar and machine-gun fire on the Americans, without inflicting damage, and then re-

10 CINCPAC-CINCPOA Info Bull No. 161-44, 15 Nov 44; Okinawa Gunto, pp. 56-58; Supplement, 17 Dec 44: Okinawa Gunto, pp. 35-46.

11 CTF 52 Actn Rpt Okinawa, II— C— 3 ; 77th Div Opn Rpt, pp. 25-26.

12 77th Div G-3 Jnl and Msg File, 26 Mar 45. This time is erroneously reported as 0904 in the Opn Rpt.

TERRAIN IN THE KERAMA RETTO was rugged. In particular the coastal terrain was precipitous, appearing formidable to the 2d BUT , 306th Infantry, yyth Division, as it approached Ho\aji Island on 26 March. Below is an aerial view of To\ashi\i Island.

54

OKINAWA: THE LAST BATTLE

treated into the steep central area as the invaders rapidly overran the beaches and the town of Aka.

The next island invaded — and the first to be secured — was Geruma, a circular island five-eighths of a mile in diameter, lying south of Aka. The ist Battalion Landing Team of the 306th Regimental Combat Team landed on the narrow beach at 0825, meeting no opposition except for long-range sniper fire. Within three hours it wiped out a score of defenders and secured the island. Before the engagement was over, DUKW's began unloading 105-mm. howitzers of the 304th and 305th Field Artillery Battalions for use in operations scheduled for the next day.

The easiest conquest of the day was that of Hokaji, an island one mile by 800 yards, lying a few hundred yards south of Geruma and linked to it by an encircling reef that follows the contours of the two land masses. The 2d BLT of the 306th landed on Hokaji at 0921 and secured it without resistance.

At 0900 on 26 March the ist BLT of the 305th invaded Zamami, initially meeting little resistance. A two-legged, humpbacked island, approximately 5,500 yards long east-west and 400 yards at its narrowest point, Zamami is formed, except for a few low flat areas along the southern coast, by a group of wooded hills which rise about 450 feet. Amtracks carried the troops ashore in a deep bay that cuts into the southern coast. A sea wall fifteen feet from the water's edge held up the amtracks and forced the men to continue by foot. The assault elements received sporadic mortar and sniper fire until they reached the town of Zamami, just to the rear of the beach. Then a group of Japanese estimated to be of com- pany strength, together with about 300 Korean laborers, fled north from the town to the hills.

It became apparent to General Bruce by late morning of 26 March that the rapid progress of the landing teams would permit the seizure on the first day of an additional island. Accordingly the 2d BLT of the 307th, a reserve unit, was directed to seize Yakabi, northwesternmost islet of the Keramas, which was nearly oval in shape and a little more than a mile long. At 134 1 the battalion landed on Yakabi and, meeting only slight opposition, quickly overran it.13

On both Aka and Zamami the invading forces met stiffer resistance as they pressed up the steep slopes into the interior of the islands. On Aka a group of Japanese of platoon strength was routed by naval gunfire. During the afternoon the troops killed fifty-eight Japanese in a series of brief skirmishes

13 77th Div Opn Rpt, p. 25.

INVASION OF THE RYUKYUS

55

on the eastern heights of the island. Though the enemy fought from caves and pillboxes with small arms, he had no effective defense. By 1700 of 26 March two-thirds of Aka was secured; 300 Japanese troops and 400 civilians were still at large on the island.

On Zamami advance elements of the 1st BLT of the 305th pushed up into the high ground during the afternoon without closing with the enemy. From midnight until dawn of the next day, however, groups of Japanese armed with rifles, pistols, and sabers tried to break into the American peri- meters near the beach. Company C bore the brunt of the attack, repulsing nine local thrusts supported by automatic weapons and mortars. One Amer- ican machine gun changed hands several times. In a series of night fire fights that at times developed into savage hand-to-hand combat, the 1st Battalion killed more than 100 of the enemy at a cost of 7 Americans killed and 12 wounded.14

On 27 March the Americans took without opposition Amuro, an islet between the two anchorages and Kuba, the southwesternmost of the Keramas. Fitful action was still in process on Aka and Zamami on the morning of 27 March. On Aka the 3d BLT of the 305th isolated seventy-five Japanese who were dug in on a ridge and its reverse slope and were fully supported by mortars and automatic weapons. After a period of aerial strafing, bombing, rocketing, and mortar fire, the Americans drove the enemy from their posi- tion into the brush. On Zamami patrols of company size reconnoitered the island and eliminated scattered groups of the enemy. One organized position was located but could not be assaulted until the following day, when amtracks blasted frontally the caves where the last Japanese to be found were dug in.

After a preparation by artillery firing from Geruma, the 1st BLT of the 306th landed on the west coast of Tokashiki at 091 1 of 27 March, and a few minutes later the 2d BLT landed to the south of the 1st. Tokashiki was the largest island in the group, six miles long from north to south and aver- aging about one mile in width. Closest of the islands to Okinawa, it formed the eastern barrier of the Kerama anchorages. Its coasts rise for the most part as cliffs or steep slopes cut by narrow ravines, the hill masses reaching heights of more than 650 feet in the center of the island and at the northern and

14 Terrain descriptions are from 77th Div G-2 Estimate of the Situation ICEBERG, 15 Mar 45; Capt Paul R. Leach (77th Div Historian), Opns of 77th Div in Kerama Retto; Narrative of Actn from 77th Div Opn Rpt Kerama Retto; G-2 and G-3 Periodic Rpts, 27-31 Mar 45; and G-2 and G-3 jnls and msg files for the same period.

56

OKINAWA: THE LAST BATTLE

southern ends. At the backs of two sheltered bays near the center of the west coast there are two settlements, Tokashiki and Aware; the sandy beaches near these bays were selected by the invaders for the landings.

Operations on Tokashiki followed the pattern of those on the other major islands of the Keramas. Resistance at first was negligible, the Americans being hindered more by the rugged terrain than by the scattered sniper fire. The two battalions abreast drove north over narrow trails. The 3d BLT of the 306th, initially in reserve, was landed with the mission of clearing the southern por- tion of the island. By nightfall the 1st and 2d Battalions were set for the next day's attack on the town of Tokashiki on the east coast; 3d Battalion patrols had reached the southern tip of the island.

On the following day, 28 March, the two battalions of the 306th renewed their drive to the north. After a 500-round artillery preparation the troops occupied Tokashiki, which had previously been leveled by air and surface bombardment. The area near the bay was overrun without opposition. The advance continued to the north, meeting only scattered resistance. On 29 March, after the three battalions had sent patrols throughout the island, Tokashiki was declared secured.

By the evening of 29 March all islands in the Kerama Retto were in American hands. In all, combat elements of the 77th had made fifteen separate landings, involving five ship-to-shore movements by LVT's, two ship-to-shore movements by DUKW's, three ship-to-shore movements by LCVP's with subsequent transfer to LVT's, and five shore-to-shore movements by LVT's. Despite the complexity of the maneuvers, the veterans of Guam and Leyte operated with little confusion. Casualties were low. From 26 to 31 March the 77th killed 530 of the enemy and took 121 prisoners, at a cost of 31 Americans killed and 81 wounded.10

The operations on Aka and Tokashiki had interesting consequences. Al- though 77th Division patrols scoured the islands, hundreds of Japanese soldiers and civilians managed to evade discovery in caves, ravines, and brush through- out the hilly central parts of the islands. After the Okinawa operation, representa- tives from Tenth Army tried unsuccessfully to induce the Japanese commander on Aka to surrender. The Japanese soldiers and sailors were not as stubborn, and most of them escaped from the island and surrendered. On Tokashiki teams of Nisei and Japanese officer prisoners negotiated with the Japanese commander, who refused to surrender his garrison of 300 officers and men. He offered, how-

15 77th Div Opn Rpt, pp. 26, 30-32, 41.

INVASION OF THE RYUKYUS

57

ever, to allow Americans to swim on Tokashiki beaches provided they kept away from the Japanese camp in the hills. Only after many months, when he was given a copy of the Imperial rescript announcing the end of hostilities, did the Japanese commander surrender, claiming that he could have held out for ten more years.16

The capture of the Kerama Islands was followed by the landings on Keise Shima. Lying about eleven miles southwest of the Hagushi beaches and about eight miles west of Naha, the group of four tiny coral islets that make up Keise had an importance in the attack on Okinawa far out of proportion to its size and topography. From Keise 155-mm. guns could command most of southern Oki- nawa. Employing tactics used with great success on Kwajalein, Tenth Army ordered XXIV Corps artillery to emplace two battalions of 155-mm. guns on Keise to support the attack.

On 26 March the Fleet Marine Force Amphibious Reconnaissance Battalion, attached to the 77th Division, scouted Keise without encountering enemy troops or civilians. On the morning of 31 March a convoy of LST's and LSM's bearing the 420th Field Artillery Group and attachments arrived off the islets. Over floating caisson docks set up by Seabees the heavy guns and other equipment were unloaded. Twenty-four 155-mm. guns were emplaced on the low, sandy islets, and a cub strip and a bivouac area were established. By dawn of L Day the batteries were ready to execute their mission of firing counterbattery, interdiction, and harassing fires deep into enemy territory.

The guns were set up in full view of the Japanese occupying high ground on Okinawa. General Ushijima ordered a "surprise shelling" of Keise to begin at midnight of 31 March, after which army and navy commands were to dispatch "raiding infiltration units" to Keise, "thereby wiping out the enemy advanced strong point in one blow." 17 For an hour after midnight, Japanese 150-mm. shells exploded on the islets. There were no casualties or damage. The infiltration party never appeared. This attempt to destroy the artillery on Keise was only the first of several, the enemy being keenly aware of the threat offered by the artillery in this flanking position.18

The assault on Kerama and Keise had come as a surprise to the Japanese commanders on Okinawa Gunto. The enemy commanders on Okinawa had

10 77th Div Opn Rpt, pp. 33, 35; 870th AAA AW Bn Actn Rpt Kerama Retto, p. 5.

17 Tenth Army TransI No. 248, 8 Jul 45 : j2d Army Ord, 3 1 Mar 45.

18 420th FA Gp Actn Rpt, 31 Mar to 30 Jun 45, pp. 4-6; 531st FA Bn Actn Rpt, pp. 1-2; 532c! FA Bn Actn Rpt, p. 1.

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OKINAWA: THE LAST BATTLE

expected that the Americans would land first on the Hagushi beaches and that their ships would deploy just east of the Kerama Islands.19

Since the enemy considered the Keramas as bases for special attack units rather than as defensive positions, there were few prepared defenses on the beaches or inland when the Americans appeared. At one time 2,335 Japanese troops occupied the islands, engaged in installing and operating facilities for the Sea Raiding units. When, in late 1944 and early 1945, the need for combat troops on Okinawa became acute, most of these troops were moved to the larger island. There remained on the Kerama group only about 300 boat operators of the Sea Raiding Squadrons, approximately 600 Korean laborers, and about 100 base troops. The garrison was well supplied not only with the suicide boats and depth charges but also with machine guns, mortars, light arms, and ammunition.20

In Kerama Retto, "Island Chain between Happiness and Good," the Japa- nese tradition of self-destruction emerged horribly in the last acts of soldiers and civilians trapped in the hills. Camping for the night of 28 March a mile from the north tip of Tokashiki, troops of the 306th heard explosions and screams of pain in the distance. In the morning they found a small valley littered with more than 150 dead and dying Japanese, most of them civilians. Fathers had systematically throttled each member of their families and then disemboweled themselves with knives or hand grenades. Under one blanket lay a father, two small children, a grandfather, and a grandmother, all strangled by cloth ropes. Soldiers and medics did what they could. The natives, who had been told that the invading "barbarians" would kill and rape, watched with amazement as the Americans provided food and medical care; an old man who had killed his daughter wept in bitter remorse.21

Only a minority of the Japanese, however, were suicides. Most civilians straggled into American positions, worn and dirty. In all, the 77th took 1,195 civilian and 121 military prisoners. One group of 26 Koreans gave up on Zamami under a white flag. On Aka one Japanese lieutenant surrendered voluntarily be- cause, he said, it would be "meaningless" for him to commit suicide.22 A Japanese

19 Interrog Yahara; 77th Div G-2 Periodic Rpt No. 4, 30 Mar 45; XXIV Corps PW Interrog No. 71, 20 Apr 45.

20 77th Div Opn Rpt Kerama Retto, pp. 38-39; G-2 Periodic Rpt, 26-31 Mar 45.

21 Personal Obsn of Capt Leach, 77th Div Historian, and Cpl Alexander Roberts, 1st I & H Service.

22 XXIV Corps PW Interrog No. 71, 20 Apr 45; 77th Div G-2 Periodic Rpt No. 3, 29 Mar 45: Order of Battle Rpt.

LANDINGS IN THE KERAMAS, made by the yyth Division, met little opposition. Zamami Island (above) was taken by the ist BLT, 3o$th Infantry, some soldiers of which are shown just before they started inland. Amtrac^s were unable to negotiate the seawall and were left at the beach. Below is a scene on a beach at T okashikj , captured by the ist BLT , 306th, on 2j March. Soldier {right) seems puzzled by the absence of opposition.

6o

OKINAWA: THE LAST BATTLE

major captured by a patrol on Zamami late in May assisted in efforts to induce Japanese remaining in the islands to surrender.

More than 350 suicide boats were captured and destroyed by the 77th in the Kerama Islands. They were well dispersed throughout the islands, many of them in camouflaged hideouts. These plywood boats were 18 feet long and 5 feet wide. Powered by 6-cylinder Chevrolet automobile engines of about 85 horsepower, they were capable of making up to 20 knots. Two depth charges weighing 264 pounds each were carried on a rack behind the pilot and were rolled off the stern of the boat when released. According to captured instructions, three boats would attack a ship simultaneously, each seeking a vital spot to release its charge. Strictly speaking, manning the boats was not suicidal in the same sense as pilot- ing the Kamikaze planes or the "Baka" bombs. Delay time for the depth-charge igniters was five seconds. According to a Japanese officer, it was considered pos- sible to drop the depth charges against a ship and escape, but the fragility of the boats made survival highly unlikely. As a result, the pilots were promoted two grades upon assignment and received preferential treatment. After com- pletion of their missions they were to receive promotion to second lieutenant; obviously, most such promotions would be posthumous.

From hideouts in the small islands, the "Q-boats" with their charges were to speed to the American anchorages. "The objective of the attack," General Ushijima ordered, "will be transports, loaded with essential supplies and material and personnel. . . . The attack will be carried out by concentrating maximum strength immediately upon the enemy's landing." 23 The Japanese had carefully mapped out possible assembly areas of American transports and had prepared appropriate routes of approach to each area, especially those around Keise.24 The initial thrust into the Keramas completely frustrated the enemy's plan. In the opinion of General Bruce, the destruction of the suicide boat base alone was well worth the cost of reducing the Kerama Islands.20

In a campaign that found the Japanese prepared for the major moves of the invading forces, the initial seizure of their "Western Islands" not only caught them off guard but frustrated their plan of "blasting to pieces" the American transports with a "whirlwind" attack by suicide boats.20 The Americans gained

23 Tenth Army Transl No. 231, 6 Jul 45 : j2d Army Opn Ord No. 115,23 Mar 45.

24 Tenth Army Transl No. 210, 11 Jul 45: 20th Sea Raiding Bn Opn Ord No. 26, 16 Feb 45. 2° 77th Div Opn Rpt, p. 40.

26 77th Div Opn Rpt Kerama Retto [n. d.], p. 38; Interrog Yahara; Tenth Army G-2 CICA Trans] No. 231, 6 Jul 45: 3 2d Army Opn Ord No. 115.

"SUICIDE BOATS" wrecked by their crews were found by the yjth Division as it mopped up in the Keramas. They looked like small speedboats but were poorly constructed and quite slow. These two craft (below) were captured in their cave shelters by American troops on Okinawa. Note booby trap warnings and crude depth charge rac\s at stern.

SOFTENING UP THE TARGET was the tas\ of the Allied fleet. It stood off Okinawa to place accurate fire on \nown Japanese installations and to support underwater demolitions teams clearing the beaches. At the same time the fleet ' s air arm conducted aerial bombard- ment. This low-level bombing attac\ on L minus I {below) hit enemy shipping in the mouth of the Bishi River.

INVASION OF THE RYUKYUS

63

even more than the Japanese lost. In American hands, this sheltered anchorage became a miniature naval base from which seaplanes operated and surface ships were refueled, remunitioned, and repaired.

Softening Up the Target

While operations were proceeding in the Kerama Islands, Task Force 52, under the command of Admiral Blandy, supervised the specialized tasks that were an essential prelude to the invasion of Okinawa itself — the mine sweeping, underwater demolition work, and heavy, sustained bombardment of the target by ships and aircraft. Task Force 58 stood off to the north and east of Okinawa, ready to intercept any Japanese surface force approaching from the east, while Task Force 52 guarded against enemy attack from the west and against any "express runs" from the north either to reinforce or to evacuate Okinawa. During the day the ships bombarding Okinawa stayed close enough together to be able to concentrate for surface action without undue delay. At night 80 percent of Task Force 52 deployed to the northwest of Okinawa and 20 percent to the northeast. The northwest group was con- sidered strong enough to cope with any surface force which the Japanese could bring against it; the northeast element was to deal with "express runs," and could count on the support of Task Force 58 if the enemy dispatched a larger, slower, and more easily detected force to the area east of Okinawa. In case of emergency, one force could join the other by passing through the unswept waters north of Okinawa.27

Bombardment of Okinawa began on 25 March when ships of the Amphib- ious Support Force shelled the southeast coast. The fire was executed only at long range, however, for mine-sweeping operations which had commenced the previous day were still proceeding well offshore. During the following days, as the mine sweepers cleared areas progressively nearer the coast of Okinawa, the bombardment ships were able to close in for heavier and more accurate fire. The Japanese had planted a mine field of considerable strength along the approaches to the Hagushi beaches, and until mine-sweeping opera- tions were completed the American ships could not bring the beaches within range. Not until the evening of 29 March were the approaches to Hagushi and other extensive areas cleared in what Admiral Blandy called "probably the largest assault sweep operation ever executed." Operating under inter-

27 CTF 52 Actn Rpt Okinawa, I-C-i, 2.

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OKINAWA: THE LAST BATTLE

mittent air attack, American mine sweepers cleared about 3,000 square miles in 75 sweeps.

From 26 to 28 March the naval bombardment of Okinawa was at long range; targets were located with difficulty because of the range and occasional poor visibility, and few were reported destroyed. Effective bombardment of the island did not begin until 29 March when battleships, cruisers, destroyers, and gunboats closed the range and hit their objectives with increasing effec- tiveness. Then for the first time the large concentration of targets in the Naha- Oroku Peninsula area was taken under effective fire. On the 30th heavy shells breached the sea walls along the coast line in many places. Ten battleships and eleven cruisers were now participating in the attack. On 31 March four heavy ships, accompanied by destroyers and gunboats, supported the final underwater demolition operation off the Hagushi beaches. This was completed before noon. Then the ships concentrated on sea walls and on defensive installations behind the beaches. Even at the shortest range, however, it was difficult to locate impor- tant targets, and ships had to explore with gunfire for emplacements and similar structures.

During the seven days before L Day, naval guns fired more than 13,000 large-caliber shells (6-inch to 16-inch) in shore bombardment. Including sev- eral thousand 5-inch shells, a total of 5,162 tons of ammunition was expended on ground targets. All known coast defense guns in the area were destroyed or severely damaged. The enemy had established a few heavy pillbox-type installations and numerous emplacements along the beaches and farther inland, but most of them were empty. Naval guns fired extensively into cliffs and rocky points overlooking and flanking the beaches to disclose defensive posi- tions such as the enemy had frequently used in the past; few, however, were found.28 By the afternoon of 31 March, Admiral Blandy could report that "the preparation was sufficient" with the exception of certain potentially dan- gerous installations still in the Naha area. Enemy shore batteries did not open up on ships during the preliminary bombardment.29

Aircraft from Task Force 58 and from the escort carriers flew 3,095 sorties in the Okinawa area prior to L Day. Their primary objective was enemy air- craft based on the islands. Second priority was given to small boats and "amphibian tanks," which later were discovered to be suicide attack boats

23 Ibid., V-C 1, 7.

20 CINCPAC-CINCPOA Opns in POA, Apr 45, pp. 35-36. See below under "The Japanese Plan of Defense," p. 93.

INVASION OF THE RYUKYUS

65

fitted with depth charges. After these, they gave preference to installations such as coastal defense guns, field artillery, antiaircraft guns, floating mines, communications facilities, and barracks areas.

Planes from Task Force 58 concentrated on targets that could not be reached by naval gunfire. Escort carrier aircraft protected the mine sweepers and under- water demolition teams, conducted preliminary attacks against Kerama and Keise, and supported the assault generally. The preliminary air assault got under way on 25 March with bombing, napalm, and rocket attacks on Tokashiki Island in thz Keramas and attacks on air installations on Okinawa. On the 26th, 424 sorties were made against suicide boat and midget submarine bases, airfields, and gun positions. On the following day attacks continued on these targets, and barracks areas were also worked over with bombs, napalm, and rockets.

From 28 to 31 March air missions were closely coordinated with projected ground operations as the escort carriers executed missions requested by Tenth Army. Aircraft concentrated on gun positions at scattered points throughout southern Okinawa. They bombed a bridge along the northern shore of Nakagu- suku Bay and broke it in ten places. They scored fifteen direct hits with napalm on installations near the Bishi River. Operations against enemy air and naval bases continued. On 29 March carrier planes destroyed 27 enemy planes on Okinawa airfields and probably destroyed or damaged 24 more; planes hit on the ground during the period totaled 80. Barges, wooden boats, and other small enemy craft were systematically gutted. At least eight submarine pens were demolished at Unten Ko on the north coast of Motobu Peninsula.30

Under cover of carrier planes and naval gunfire, underwater demolition teams performed reconnaissance and necessary demolitions on Keise, on the demonstration beaches of southeastern Okinawa, and on the Hagushi landing beaches. Planes made strafing, bombing, and rocket runs on the beaches, and smoker planes, where needed, concealed the teams with smoke. Three lines of ships, increasing in fire power from the beach out, gave the underwater demoli- tion teams formidable support. LCI(G)'s (Landing Craft, Infantry, Fire Sup- port) armed with 40-mm. guns stood approximately 1,200 yards off the beach; then a line of destroyers at about 2,700 yards covered the shore to 300 yards inland with 40-mm. and 5-inch gunfire; and 1,000 yards behind the destroyers were battleships and cruisers ready with secondary and antiaircraft batteries to neu- tralize all ground from 300 to i,coo yards inland.

30 CTF 52 Actn Rpt, pp. V-E-1-7; CINCPAC-CINCPOA Opns in POA, Apr 45, pp. 37-38.

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OKINAWA: THE LAST BATTLE

Underwater demolition teams first reconnoitered the Hagushi beaches on 29 March, after a delay of a day because of the large number of mines found in the areas off the beaches. Three battleships, 3 cruisers, 6 destroyers, and 9 LCI(G)'s supported the operation. The machine-gun and mortar fire encoun- tered was silenced by the fire support units. The swimmers found approximately 2,900 wooden posts, from 6 to 8 inches in diameter and from 4 to 8 feet high, most of them off beaches north of the Bishi River. In some places there were four rows of these posts. On 30 and 31 March underwater demolition teams destroyed all but 200 of the posts, using tetratol tied in with primacord. A demolition operation was carried out on the demonstration beaches under gun- fire coverage; several tons of tetratol were detonated on the edge of the reef even though no obstacles had been found.31

As the Americans closed in on Okinawa from 26 to 31 March, the enemy suddenly found itself confronting another adversary — the Royal Navy. A British carrier force, under the command of Vice Admiral H. B. Rawlings and assigned to the Fifth Fleet, struck at the Sakishima Islands on 26, 27, and 31 March. Its planes made 345 sorties over Sakishima, dropped more than 81 tons of bombs, and fired more than 200 rockets. The British labored under several handicaps. They lacked night fighters, and their ships carried a much smaller number of planes than did the large American carriers. Also, their supply resources afloat were rudimentary. Nevertheless, the British rendered valuable assistance to the assault forces by considerably reducing the magni- tude and number of enemy air attacks staged from Sakishima airfields.32

Task Force 58 remained in a constant state of readiness, and on 28 March it demonstrated its fast striking power in convincing fashion. Word was received from Admiral Spruance of a reported sortie of enemy fleet units from the Inland Sea on a southwesterly course. Immediately a task group headed north at high speed to attack the enemy ships. The Japanese force, however, was not found. On the 29th another task group joined in the search, but without success. The foray was not allowed, however, to be useless. On their way back to the carriers, planes from both groups bombed airfields in the Kagoshima Bay area of Kyushu and attacked miscellaneous shipping with good results.33

31 CTF 52 Actn Rpt, V-G-i, 2, 3; CINCPAC-CINCPOA Opns in POA, Apr 45, pp. 32-33.

32 CINCPAC-CINCPOA Opns in POA, Apr 45, pp. 67-68. 83 Ibid., p. 61.

INVASION OF THE RYUKYUS

67

Despite American attacks on enemy airfields and installations, approxi- mately 100 Japanese planes made 50 raids in the Okinawa area during the period from 26 to 31 March. Many of the attacking planes tried to suicide- crash the American ships — an omen of the basic Japanese tactics in the tre- mendous sea-air war soon to come. With few exceptions, the attacks came during early morning or by moonlight. Already the Japanese were using a considerable assortment of new- and old-type planes. As they approached, the enemy raiders generally split up into single planes or 2-plane groups, which made individual, uncoordinated attacks. There was some evidence that planes flew in from outlying bases and landed on fields in Okinawa at night. Favorite targets of the Japanese were pickets and patrols, including small craft, but several planes attacked formations of heavy ships. Of the enemy planes that suicide-crashed, nine hit their targets and ten made near misses. Much of the damage from these attacks was superficial, but several ships suffered serious damage and casualties. Ten American ships, including the battleship Nevada and the cruisers Biloxi and Indianapolis , were damaged in the period from 26 to 31 March, eight of them by suicide planes; two other vessels were destroyed by mines. The defending ships and planes shot down approximately forty-two of the attackers.34 In addition to the suicide attacks the Japanese con- ducted a few bombing, strafing, and torpedo attacks during the period, but these were without significant results.

On the afternoon of 31 March naval auxiliary vessels delivered the latest aerial photographs of the beaches to the transports approaching the target area. As night fell, the vast armada of transports, cargo ships, landing craft, and war ships ploughed the last miles of their long voyage. Before dawn they would rendezvous off the Hagushi beaches in the East China Sea. Weather for 1 April promised to be excellent.

84 Com Amphib-Gp i, CTF 52 Actn Rpt, IV-B-10.

CHAPTER III

Winning the Okinawa Beachhead

Dawn of Easter Sunday, i April 1945, disclosed an American fleet of 1,300 ships in the waters adjacent to Okinawa, poised for invasion. Most of them stood to the west in the East China Sea. The day was bright and cool — a little under 75 °; a moderate east-northeast breeze rippled the calm sea; there was no surf on the Hagushi beaches. Visibility was 10 miles until 0600, when it lowered to from 5 to 7 miles in the smoke and haze. More favorable conditions for the assault could hardly be imagined.

The Japanese doubtless marveled at the immensity of the assemblage of ships, but they could not have been surprised at the invasion itself. The Kerama Islands had been seized; Okinawa had been heavily bombarded for days; and underwater demolition teams had reconnoitered both the Hagushi beaches and the beaches above Minatoga on the southeast coast, indicating that landings were to be expected at either place or both. Moreover, Japanese air and submarine reconnaissance had also spotted the convoys en route.1

The Japanese had been powerless to interfere with the approach to the Ryukyus. Bad weather, however, had caused not only seasickness among the troops but also concern over the possibility that a storm might delay the land- ings. It was necessary for some convoys to alter their courses to avoid a threaten- ing typhoon. The rough seas caused delays and minor damage and resulted in other deflections from planned courses. Thus on the evening before L Day various task forces converging on Okinawa were uncertain of their own positions and those of other forces. All arrived on time, however, and without mishap.2

For the men, observing the outline of the strange island in the first rays of light before the beaches became shrouded in the smoke and dust of naval and air bombardment, this Easter Sunday was a day of crisis. From scale models

1 Comdr Amph Gp 12 (CTF 55), Actn Rpt Okinawa, II-2; Comdr Transport Sq 14, Actn Rpt Okinawa, II— 5.

2 Capt Donald Mulford and 1st Lt Jesse Rogers (96th Div Historians), 96th Div Actn. on Okinawa (cited hereafter as Mulford and Rogers, 96th Div Hist), Introduction, p. 6 (available in Hist Div WDSS); 381st Inf Actn Rpt Okinawa, p. 15; CTF 53 Actn Rpt, II-B-i; CTF 55 Actn Rpt Okinawa, II-2.

WINNING THE OKINAWA BEACHHEAD

69

of Okinawa studied on shipboard they had seen that the rising ground behind the landing beaches, and even more the island's hills and escarpments, were well suited for defense. They had read of the native houses, each protected by a high wall, and of the thousands of strange Okinawan tombs which might serve the enemy as pillboxes and dugouts. They had been encouraged by the weakness of Kerama Retto's defenses, but the generally held expectations of an all-out defense of the beaches on the first Japanese "home" island to be invaded was one to appall even the dullest imagination. And behind the beaches the men were prepared to meet deadly snakes, awesome diseases, and a presumably hostile civilian population.3

The Landing

H Hour had been set for 0830. At 0406 Admiral Turner, Commander of Task Force 51, signaled, "Land the Landing Force." 4 At 0530, twenty minutes before dawn, the fire support force of 10 battleships, 9 cruisers, 23 destroyers, and 177 gunboats began the pre-H-Hour bombardment of the beaches. They fired 44,825 rounds of 5-inch or larger shells, 33,000 rockets, and 22,500 mortar shells. This was the heaviest concentration of naval gunfire ever to support a landing of troops. About seventy miles east of Okinawa, Task Force 58 was deployed to furnish air support and to intercept attacks from Kyushu. In addition, support carriers had arrived with troop convoys. At 0745 carrier planes struck the beaches and near-by trenches with napalm.5

Meanwhile LST's and LSM's, which had carried to the target both the men composing the first assault forces and the amphibian vehicles in which they were to ride, spread their yawning jaws and launched their small craft, loaded and ready for the shore. Amphibian tanks formed the first wave at the line of departure, 4,000 yards from the beach. Flagged on their way at 0800, they proceeded toward land at four knots. From five to seven waves of assault troops in amphibian tractors followed the tanks at short intervals.6

3Capt Russell Gugeler (7th Div Historian), The Opns of the 7th Inf Div on Okinawa (hereafter cited as Gugeler, 7th Div Hist), pp. 10-11.

4 Tenth Army Actn Rpt, 7— III— 1 ; 1st Marine Div Actn Rpt, Nansei Shoto Opn, 1 Apr-30 Jun 45, Ch. VII, p. 2; CTF 51 Actn Rpt, V-B-II-2, 3; Comdr Amph Gp 4 Pac Fit (CTF 53), Actn Rpt Okinawa Gunto, 20 Jul 45, III— 1 2 ; III Amph Corps Actn Rpt, p. 69.

5 CTF 51 Actn Rpt, II— 1 5 ; Tenth Army Actn Rpt. 11-V-6; CTF 58 Actn Rpt Okinawa, Incl A, p. 3, and II— 5 ; CTF 53 Actn Rpt, III— 13.

"Gugeler, 7th Div Hist, p. 17; III Amph Corps Actn Rpt, p. 69; CTF 53 Actn Rpt, III— 13; XXIV Corps Actn Rpt, Fig. 3, following p. 19.

7o

OKINAWA: THE LAST BATTLE

Opposite each landing beach, control craft, with pennants flying from the mast, formed the assault waves of amphibious vehicles in rotating circles. At 0815 tne leading waves of amtracks uncoiled and formed a line near their mother control craft. Five minutes later the pennants were hauled down and an almost unbroken 8-mile line of landing craft moved toward the beaches.

Gunboats led the way in, firing rockets, mortars, and 40-mm. guns into prearranged target squares, on such a scale that all the landing area for 1,000 yards inland was blanketed with enough 5-inch shells, 4.5-inch rockets, and 4.2-inch mortars to average 25 rounds in each 100-yard square. Artillery fire from Keise added its weight. After approaching the reef, the gunboats turned aside and the amphibian tanks and tractors passed through them and pro- ceeded unescorted, the tanks firing their 75-mm. howitzers at targets of oppor- tunity directly ahead of them until landing. Simultaneously, two 64-plane groups of carrier planes saturated the landing beaches and the areas immediately behind with machine-gun fire while the fire from supporting ships shifted inland. When the assault wave moved in, the landing area had been under constant bombardment for three hours.7

As the small boats made their way steadily toward the shore the men kept expecting fire from the Japanese. But there was no sign of the enemy other than the dropping of an occasional mortar or artillery shell, and the long line of invasion craft advanced as though on a large-scale maneuver. The offshore obstacles had either been removed by the underwater demolition teams or were easily pushed over by the amphibian tractors. Some concern had been felt as to whether, despite the rising tide, the Navy landing boats would be able to cross the coral reef, and the first waves were to inspect the reef and send back information. The reef did not hinder the first waves, in amphibian vehicles, but those who followed in boats had difficulty and were therefore ordered to transfer at the edge of the reef and cross in LVT's.

Beginning at 0830, the first waves began to touch down on their assigned beaches. None was more than a few minutes late. The volume of supporting fire had increased until a minute or two before the first wave landed; then suddenly the heavy fire on the beach area ended and nothing was to be heard except the rumble of the shells that were shifted inland. Quickly the smoke and dust that had shrouded the landing area lifted, and it became possible for the troops to see the nature of the country directly before them. They

7CTF 51 Actn Rpt, V-C-7 and III— 9, 10; III Amph Corps Actn Rpt, pp. 70, 76; XXIV Corps Actn Rpt, p. 34; 1st Mar Div Actn Rpt, Ch. VII, p. 2.

BOMBARDING THE BEACHES directly preceded the landings. It was carried on at closest range by roc\et gunboats of the U. S. fleet. These boats led the way to the Hagushi beaches, turned aside just outside the reefs, and alloived amphibian tan\s and tractors (below) to proceed ashore unescorted. Meanwhile the Tennessee and other American battleships kept up a steady support barrage.

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OKINAWA: THE LAST BATTLE

were on a beach which was generally about twenty yards in depth and which was separated by a io-foot sea wall from the country beyond. There were few shell holes on the beach itself, but naval gunfire had blown large holes in the sea wall at frequent intervals to provide adequate passageways.8 Except at the cliff-bordered Bishi River mouth, in the center of the landing area, the ground rose gradually to an elevation of about fifty feet. There was only sparse natural vegetation, but from the sea wall to the top of the rise the coastal ground was well cultivated. In the background, along the horizon, hills showed through the screen of artillery smoke. Farther inland, in many places, towns and villages could be seen burning and the smoke rising above them in slender and twisted spires. These evidences of devastation, however, made less impres- sion upon the men than did the generally peaceful and idyllic nature of the country, enhanced by the pleasant warmth, the unexpected quiet, and the absence of any sign of human life.

New waves of troops kept moving in. Before an hour had passed III Am- phibious Corps had landed the assault elements of the 6th and ist Marine Divisions abreast north of the Bishi River, and XXIV Corps had put ashore those of the 7th and 96th Infantry Divisions abreast south of that river. The 6th Marine Division and the 96th Division were on the flanks. Two battalion landing teams from each of two assault regimental combat teams in the four divisions, or more

than 16,000 troops, came ashore in the first hour.9 (See Map No. V.)

The assault troops were followed by a wave of tanks. Some were equipped with flotation devices, others were carried by LCM(6)'s which had themselves been transported by LSD's, and still others were landed by LSM's. After debark- ing the assault waves, the amphibian tractors returned to the transfer line to ferry support troops, equipment, and supplies across the reef onto the beach. LVT, DUKW, and small-boat control points were established at the transfer line. Amphibian vehicles preloaded with ammunition and supplies proceeded inland as needed.10

The entire landing on Okinawa had taken place with almost incredible ease. There had been little molestation from enemy artillery, and on the beaches

8 Tenth Army Actn Rpt, 7— III— i and 11-IX-7; III Amph Corps Actn Rpt, pp. 69, xoi; XXIV Corps Actn Rpt, p. 24; ist Mar Div Actn Rpt, Ch. VII, p. 3; 32c! Inf Actn Rpt, p. 3; 780th Tank Bn Actn Rpt, p. 24.

9 Maj Roy E. Appleman (XXIV Corps Historian), The 'XXIV Corps in the Conquest of Okinawa (hereafter cited as Appleman, XXIV Corps Hist), p. 89; III Amph Corps Actn Rpt, p. 69; ist Mar Div Actn Rpt, Ch. VII, p. 3.

10Gugeler, 7th Div Hist, p. 18; Appleman, XXIV Corps Hist, p. 91; Tenth Army Actn Rpt, n-IX-6; III Amph Corps Actn Rpt, pp. 69, 70, 99, 101.

THE LANDINGS were made in amphibian craft which were shepherded to shore by control craft (arrows). Heavy support fire which had blanketed the beaches with smo\e and dust lifted seconds before the first troops touched down. Absence of enemy opposition to the landings made the assault seem li\e a large-scale maneuver as troops ( below ) left their craft and quickly consolidated. Other waves followed closefa.

74

OKINAWA: THE LAST BATTLE

no enemy and few land mines had been encountered. The operation had taken place generally according to plan ; there was little disorganization and all but a few of the units landed at the beaches assigned to them. The absence of any but the most trivial opposition, so contrary to expectation, struck the men as ominous and led them to reconnoiter suspiciously. After making certain that they were not walking into a trap, the troops began moving inland, according to plan, a very short time after they had landed.

Spirits rose as the marines and soldiers easily pushed up the hillsides behind the beaches. The land was dry and green with conifers and the air bracing — a welcome change from the steaming marshes and palm trees of the islands to the south. An infantryman of the 7th Division, standing atop a hill just south of the Bishi River soon after the landing, expressed the common feeling when he said, "I've already lived longer than I thought I would." 11

Simultaneously with the landing Maj. Gen. Thomas E. Watson's 2d Marine Division feinted a landing on Okinawa's southeast coast, above Minatoga, with the hope of pinning down the enemy's reserves in that area. This diversion simu- lated an actual assault in every respect. The first part of the demonstration group left Saipan on 25 March, and the main body arrived at Okinawa early in the morning of L Day. The Japanese attacked the force with their suicide planes, and one transport and an LST were damaged. Under cover of a smoke screen, seven boat waves, each composed of twenty-four LCVP's, carried 2d Marine Division troops toward the beach. As the fourth wave crossed the line of depar- ture at 0830 — H Hour for the main assault on the Hagushi beaches — all boats reversed course. By 1500 all the landing vessels had been recovered by their parent vessels. The only enemy reaction to the demonstration was one salvo of four rounds. The next day the demonstration was repeated, and the marines retired from the area. Proudly the Japanese boasted that "an enemy landing attempt on the eastern coast of Okinawa on Sunday morning [1 April] was completely foiled, with heavy losses to the enemy." 12

Moving Inland

Having ascended the slight hills at the landing beaches, the troops moved inland cautiously. Their immediate objectives were the two airfields, Kadena and Yontan, each about a mile inland. At 1000 the 17th RCT of the 7th Divi-

"Gugeler, 7th Div Hist, p. 24; Tenth Army Actn Rpt, 11-IX-6; III Amph Corps Actn Rpt, p. 99. 12 CINCPOA Operations in POA, April 1945, p. 42.

WINNING THE OKINAWA BEACHHEAD

75

sion had patrols on Kadena airfield, which was found to be deserted, and at 1030 the front line was moving across the airstrip. A few minutes later it was 200 yards beyond. With similar ease the 4th Marines of the 6th Marine Division captured the more elaborate Yontan airfield by 1130. Wrecked Jap- anese planes and quantities of supplies were strewn about on both fields.13

By nightfall the beachhead was 15,000 yards long and in places as much as 5,000 yards deep. More than 60,000 men were ashore, including the reserve regiments of the assault divisions. All divisional artillery landed early, and, by dark, direct-support battalions were in position. Numerous tanks were ashore and operating, as well as miscellaneous antiaircraft artillery units and 15,000 service troops. Kadena airfield was serviceable for emergency landings by the evening of the first day. The 6th Marine Division halted for the night on a line running from Irammiya to the division boundary below Makibaru. The 7th Division had pressed inland nearly three miles, knocking out a few pillboxes and losing three tanks to mines. On the southern flank, the 96th Division had established itself at the river south of Chatan, on the high ground northwest of Futema, in the outskirts of Momobaru, and in the hills northwest and southwest of Shido. There were gaps in the lines in many places, but before nightfall they had been covered by reserve units or by weapons.14

Although in the hills around Shuri the enemy had superb observation of the Hagushi beaches and of the great American armada that stood off shore, he had been content for the time being to leave the burden of opposition to the Japanese air force. Some delaying actions were fought by small groups of Japanese, and some rounds of artillery and mortar fire were directed at the landing craft and the beaches, but the total resistance was negligible.

In the air the enemy did his best, but did not inflict much damage. Thrown off balance by the strikes of Task Force 58 against the airfields on Kyushu on 18-19 March, Japanese air resistance to the landings was aggressively pressed home but was small in scale. Suicide hits were scored on the battleship West

"Gugeler, 7th Div Hist, p. 25; Capt Phillips D. Carleton (6th Mar Div Historian), The 6th Marine Div in Northern Okinawa (hereafter cited as Carleton, 6th Mar Div Hist), p. 11; Steven-Burns, Okinawa Diary, entry 15 Apr 45; III Amph Corps Actn Rpt, p. 33.

14CTF 51 Actn Rpt, III— 9, and Tenth Army Actn Rpt, 7— III— 2, give the number of troops landed as 50,000. A survey of unit reports indicates a figure of 60,000 as more accurate. See 382d Inf (96th Div) Actn Rpt, Ch. VII, p. 1; 7th Div Opn Rpt, p. 38; III Amph Corps Actn Rpt, p. 33; 1st Mar Div Actn Rpt, Ch. VII, p. 3; Gugeler, 7th Div Hist, p. 26. On the Kadena airfield, see CTF 55 Actn Rpt, III — 7. For the front lines at the end of L Day, see III Amph Corps G-3 Periodic Rpt, 1 Apr 45; 1st Mar Div Actn Rpt, Ch. VII, pp. 2, 3; 17th Inf (7th Div), Actn Rpt, map opp. p. 14, Ch. VII; 32d Inf (7th Div) G-3 Periodic Rpt, 1 Apr 45; Mulford and Rogers, 96th Div Hist, Pt. I, pp. 5, 7, and Pt. II, pp. 5, 9, 10.

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OKINAWA: THE LAST BATTLE

Virginia, two transports, and an LST; another LST was damaged by a suicide plane's near miss, and two ships were damaged in other ways.15 An indefinite number of Japanese planes were shot down during the day by ships' fire and defending fighters.16

Favored by perfect weather and light resistance, American forces moved swiftly during the next two days, 2 and 3 April. By 1400 on 2 April the 17th Infantry, 7th Division, had established itself on the highlands commanding Nakagusuku Bay, on the east coast, and had extended its patrols to the shore of the bay. The speed of its advance had left the units on its flanks some distance behind. To the south the 32d Infantry came abreast late in the after- noon of 2 April, after reducing a strong point south of Koza with tanks. To the north, where the 1st Marine Division had encountered rugged terrain and difficult supply problems, a 6,000-yard gap was taken over by the 184th Infantry. Okinawa was now cut in two, and units of the Japanese Army in the northern and southern parts of the island were separated.17

The 96th Division made slow progress during the morning of 2 April in the country around Shido. Here it found heavily forested ridges, empty caves and dugouts, and mines and tank traps along the rough trails. Before evening the 381st Infantry had pushed through Shimabuku but had been stopped by enemy opposition in and around Momobaru. After a sharp fight the 383d In- fantry took a hill just south of Momobaru, and with the help of an air strike, artillery, and tanks it reduced a ridge northeast of Futema. That night its lines stretched from the west coast just north of Isa to a point southwest of Futema on the Isa-Futema road and along the northern edge of Futema.18

On 3 April XXIV Corps turned its drive southward. Leaving the 17th Infan- try to guard and consolidate its rear, the 32d Infantry pushed all three of its bat- talions southward along Nakagusuku Bay. After gaining 5,000 yards it occupied Kuba and set up its lines in front of Hill 165, the coastal extremity of a line of hills that swept southwest of the village. Fire was received from the hill, and a few Japanese were killed in a brief fire fight. Ten rounds of enemy artillery were received in the regiment's sector, a sign of awakening resistance.19

15CINCPAC-CINCPOA Opns in POA, Apr 45, p. 42; CTF 51 Actn Rpt, IV-75H; CTF 58 Actn Rpt, I-7. 16CTF 51 Actn Rpt, IV-75ff; CTF 53 Actn Rpt, I-A-i; XXIV Corps Actn Rpt, p. 24; 1st Mar Div Actn Rpt, Ch. VII, p. 2.

1T Gugeler, 7th Div Hist, p. 29.

18 Mulford and Rogers, 96th Div Hist, Pt. I, pp. ioff, and Pt. II, pp. 1 iff.

19 Gugeler, 7th Div Hist, pp. 32ff.

WINNING THE OKINAWA BEACHHEAD

77

Coordinating their advance with that of the 326. Infantry on their left, elements of the 96th Division moved toward Hill 165 and Unjo. An unsuccessful attempt was made to take the hill. Other 96th Division units advanced to posi- tions in the vicinity of Kishaba and Atanniya and northeast of Nodake. Futema and the high ground 600 yards south of it were taken. On the west flank the division's line went through Isa to the southeastern edge of Chiyunna.20

Having completed its wheeling movement to the right, the 96th Division was ready to drive south in conjunction with the 7th Division. Civilians and prisoners of war stated that Japanese troops had withdrawn to the south. XXIV Corps now changed the boundary line between its two assault divisions. On the next day, 4 April, four regiments were to move into line across the narrow waist of the island — the 32d and the 184th of the 7th Division on the east, and the 382d and the 383d of the 96th Division on the west. The real battle for Okinawa would then begin.21

Meanwhile, in the zone of III Amphibious Corps, the 1st Marine Division continued on 2 April 1945 to the line Ishimmi-Kutoku and Chatan. It met a few small pockets of resistance but was slowed mainly by the primitive roads and rough terrain. On the following day this division again advanced against little opposition, its forward elements reaching Nakagusuku (Buckner) Bay by 1600. At the same time its reconnaissance company explored Katchin Peninsula and the east coast roads north to Hizaonna. On 4 April all three regiments of the 1 st Marine Division were on the eastern shore of Okinawa, and the division's zone of action was completely occupied.22

On L plus 1, the 6th Marine Division continued its advance into the foot- hills of Yontan-Zan, patrolled the peninsula northwest of the Hagushi beaches, and captured the coastal town of Nagahama. In this mountainous sector, well-worn trails crisscrossed the wooded hills and ridges, and caves pitted the coral walls and steep defiles. By manning both ridge tops and caves, the Jap- anese put up tenacious resistance. The 6th Marine Division killed about 250 of the enemy in two such strong points on 2 April. Next day it advanced 7,000 yards, the 22d Marines on the left maintaining supply through rough wild country by "weasels." One more day's march would bring this division to the L-plus-15 line drawn from Nakodamari to Ishikawa.23

20 Mulford and Rogers, 96th Div Hist, Pt. I, pp. 12H.

21 Gugeler, 7th Div Hist, p. 35; Mulford and Rogers, 96th Div Hist, Pt. I, pp. 17, 18. 23 1st Mar Div Actn Rpt, Ch. VII, pp. 4-5, and maps.

23 Carleton, 6th Mar Div Hist, pp. 15-18; Tenth Army Actn Rpt, 7— III— 3 .

MOVING INLAND, American troops at first met little or no opposition. South of Kadena airfield, in coral crags deeply scarred by naval bombardment, 96th Division infantrymen engaged in their first hill and cave fighting in Okinawa. Other 96th Division troops, in am- phibian tanks (below), turned south on the right flank and paused just north of Sunabe to reconnoiter; here they raised the American flag.

WINNING THE OKINAWA BEACHHEAD

79

The tempo of Japanese air attacks increased somewhat during the first three or four days after L Day, and many ships were damaged and some lost during this period. Vessels not actually engaged in unloading withdrew some distance from Okinawa each night, but this did not make them proof against attack. The Henrico, an assault transport carrying troops and the regimental staff of the 305th Infantry, 77th Division, was crashed by a suicide plane south of the Keramas at 1900 on 2 April. The plane struck the commodore's cabin and plunged through two decks, its bomb exploding on the second deck. The com- modore was killed, as were also the commanding officer, the executive officer, the S-i, and the S-3 of the 305th. The ship's total casualties were 30 killed, 6 missing, and 50 injured.24

Organizing the Beachhead

The first waves of the troops were no sooner across the beaches and moving up the slopes than the complex machinery of supplying them, planned in intri- cate detail over long months, went into action. The problem was to move food, ammunition, and equipment for more than 100,000 men across beaches with a fringing reef from 200 to 400 yards wide 20 to dumps in rear areas, and then to the troops; to widen the native roads; to repair the captured airfields; and to alleviate the inevitable distress of the civilian population while rendering it incapable of interference.

While the beaches varied widely in serviceability, they were in general well adapted to unloading purposes. LCM's and LCVP's could cross the reef for four or five hours at each flood tide and unload directly on the beach; during middle and low tides their cargoes had to be transferred to amphibian vehicles at transfer barges. LST's, LSM's, and LCT's were beached on the reef at high tide to enable vehicles and equipment to be discharged during the next low tide, and the bulk cargo by DUKW's and LVT's at any tide. Various expedients were used to hasten the unloading. Night unloading under floodlights began on 2 April, and the work proceeded without interruption except when enemy aircraft was in the vicinity. Ponton causeways accommo- dating LST's were established at predetermined sites. By 4 April a T-pier, with a 300-foot single-lane approach and a 30- by 170-foot head, and a U-pier,

2i Fifteen ships of Task Force 51 were damaged and three others lost from 2 to 5 April. CTF 51 Actn Rpt, IV-75ff, 94-98, and III— 1 0, 12, 13; 305th Inf Opn Rpt, 1-27 Apr 45, p. 3. 25 III Amph Corps Actn Rpt, p. 125.

8o

OKINAWA: THE LAST BATTLE

with two 500-foot approaches and a 60- by 175-foot wharf section, had been set up on the beaches. The piers were soon supplanted by six single-lane cause- ways. By the same day an L-shaped pier, with a 1,400-foot single-lane approach and a 45- by 175-foot head, had been completed. Several sand piers were also constructed. As the marines rolled northward, additional unloading points were established as far north as Nago. Ponton barges carried to Okinawa on cargo ships were assigned varying jobs from day to day. By 11 April, 25 had been equipped with cranes and were operating as transfer barges, 53 were operating as lighters, and 6 as petroleum barges, while 8 were being used for evacuating casualties. A crane barge was capable of handling 400 tons in a 20-hour day when enough amphibian vehicles were available to make the runs ashore.26

Control of operations on the beaches, initially in the battalion landing teams, passed step by step through the echelons of command until Tenth Army, acting through the Island Command and the 1st Engineer Special Brigade, assumed responsibility on 9 April. Navy beachmasters maintained liaison with the ships and scheduled the beaching of landing ships and the assignment of lighterage. General unloading began on 3 April. It was soon apparent that the limiting factor was the availability of transport from the beaches to the dumps. The shortage of service units and equipment due to space limitations was immediately felt, especially in the Army zone; the problem was eased for the Marines by the use of 5,000 replacements landed with the Marine divisions. The rapidity of the advance and the immediate uncovering of Yontan and Kadena airfields required a rearrangement of supply priorities. The difficulties in initiating so intricate an undertaking near the enemy's homeland were prodigious, and it required time and the process of trial and error to overcome them. Suicide planes and suicide boats were a con- stant menace, and on the afternoon of 4 April the weather came to the aid of the enemy. A storm, bringing with it from 6- to 10-foot surf on the Hagushi beaches, lasted through the night and the following day. All unloading ceased, and some landing craft hit against the reef and were damaged. Again on 10 April surf backed by a high wind brought work to a standstill, and on 11 April conditions were but slightly improved. Rain accompanying these storms made quagmires of the roads and further complicated the supply problems. Despite these handicaps, the assault shipping was 80 percent unloaded by

"Ibid., CTF 51 Actn Rpt, V-I-23-26 and V-J-14-16; Tenth Army Actn Rpt, n-IV-14.

WINNING THE OKINAWA BEACHHEAD

81

16 April, and 577,000 measurement tons had crossed the Hagushi beaches, a larger amount than had been anticipated in the plans.27

In addition to beach installations, base facilities necessary for the immediate success of the operation had to be developed quickly. Existing roads had to be improved and new roads built; the two airfields required repairs and expansion; and facilities for bulk storage of petroleum products, especially aviation gas, with connections to tankers off shore, were urgently needed. It was not long before the road down the west coast of Okinawa blossomed with markers which pro- claimed it "US 1," and route numbers were similarly assigned to all main roads as they were taken, in accordance with the Engineers' plans. Okinawa's roads were, for the most part, unsurfaced and only one or one and one-half lanes in width. On L Day beach-exit and shore-party dump roads were improved; next, the main supply routes to the troops and roads to permanent and semipermanent supply installations. During the rains of 4-5 and 10-11 April the spinning wheels of endless lines of trucks soon tore through the crusts of the more traveled high- ways and became mired. In dry weather the surface became pulverized, and the heavy military traffic raised clouds of dust that sometimes cut visibility to the length of the hood. Engineers widened and resurfaced the main thoroughfares, using coral from existing and newly opened pits, coral sand, rubble from de- stroyed villages, and limestone. Bridges that were too narrow or too weak to carry American trucks and tanks were soon replaced by Bailey bridges, which could be set up and taken down much in the fashion of an Erector span. It was late in April before equipment was available for the construction of gasoline tank farms.28

An area 30 feet by 3,000 feet on the Yontan runway was cleared and the bomb craters filled on L Day; by the evening Kadena was also ready for emer- gency landings.29 Nineteen artillery spotting planes were flown in from CVE's and LST's on 2 April and began operations on 3 April.30 The work of condition- ing the two fields began in earnest the following day.31 Land-based fighter groups arrived at Yontan on 7 April and at Kadena two days later, improving local control of the air and making more aircraft available for support. Air

27 CTF 51 Actn Rpt, V-I-22-26; Tenth Army Actn Rpt, 11-IV-12, 14, 17; personal observation of road conditions by Lt Col John Stevens.

28 Tenth Army Actn Rpt, 11-IV-24-29 and 11-XI-7; personal observation of traffic conditions by Lt Col John Stevens.

29 Tenth Army Actn Rpt, 1 1-VII-3; CTF 55 Actn Rpt, III— 7. 80 CINCPAC-CINCPOA Opns in POA, Apr 45, pp. 47, 48.

31 III Amph Corps Actn Rpt, p. 114; personal observation at Kadena airfield by Lt Col John Stevens.

SUPPLYING AND DEVELOPING THE BEACHHEAD had by L plus 3 made sub- stantial progress. Supply ships were run in to the reefs edge, where they unloaded into trucks or amphibian vehicles. Indentation in shore line is Bishi River mouth, with Yontan airfield on horizon beyond; one runway (below) had been sufficiently repaired to allow use of land-based fighter planes.

WINNING THE OKINAWA BEACHHEAD

83

evacuation of the wounded to the Marianas by specially equipped C-54's began on 8 April.32 At the same time a C-47 equipped for spraying DDT was brought into Yontan to take over the sanitation mission performed since 2 April by carrier-based aircraft.33 The 69th Field Hospital landed on 3 April and received its first casualties two days later. Until it was established, the divisions had evacuated their casualties immediately by LCVP's and DUKW's to one of eight LST(H)'s lying off the Hagushi beaches. Each hospital ship could take care of 200 patients and perform emergency surgery. By 16 April Army and Marine hospitals ashore had a capacity of 1,800 beds.34

Thousands of destitute Okinawans, dazed by the preinvasion bombard- ment of their island and the swift advance of the Americans, entered the custody of the Military Government authorities almost at once. Initially placed in stockades to keep them out of the way, they were quickly moved to selected villages which had escaped destruction. Thus by 5 April 1,500 civilians held in a barbed wire enclosure just south of Kadena were being moved by truck to Shimabuku, where they would have freedom of movement within bound- aries established by the military police. Other collection points were similarly emptied and closed.35

Thus, in an amazingly short time the beachhead had been won and the supply lines established. By 4 April Tenth Army held a slice of Okinawa 15 miles long and from 3 to 10 miles wide. The beachhead included two air- fields of great potentialities, beaches that could take immense tonnage from the cargo ships, and sufficient space for the dumps and installations that were rapidly being built. The months of planning and preparation had borne their first fruit.

82 Apple nan, XXIV Corps Hist, p. 136.

33 Tenth Army Actn Rpt, 11-VII-4.

34 Tenth Army Actn Rpt, n-XV-8.

36 Stevens-Burns, Okinawa Diary, 5 Apr 45.

CHAPTER IV

Where Is the Enemy?

The ease with which American forces landed and established themselves on Okinawa gave rise to widespread speculation as to the whereabouts of the Japanese Army. The most optimistic view was that the enemy had been stra- tegically outguessed and had prepared for the Americans at some other island, such as Formosa. Or, if Okinawa was not to be another Kiska, there was the possibility that the Marine diversion in the south had drawn the Japanese forces to that area. While the real attack forces approached by a roundabout route, covered by an early morning fog and artificial smoke, the approach of the diversion troops had been in full view of the enemy. Again, the Jap- anese might be conserving their strength for a bold counterattack as soon as American forces should be irrevocably committed to the beaches; but the time for such a counterattack came and went and still the enemy gave no sign.

The truth was, as the Americans were soon to discover, that the enemy was indeed on Okinawa in great strength, and that he had a well-thought-out plan for meeting the invasion.1

The Japanese Forces

The task of defending the Ryukyus was entrusted to the Japanese jid Army, commanded by Lt. Gen. Mitsuru Ushijima.2 General Ushijima had assumed command in August 1944, relieving Lt. Gen. Masao Watanabe who had activated the yid Army in the preceding April. On assuming command, General Ushijima and his chief of staff, Lt. Gen. Isamu Cho, had reorganized the staff of the Army, replacing the incumbents with bright young officers from Imperial Headquarters. As reconstituted, the staff was distinguished by its youth, low rank, and ability. Col. Hiromichi Yahara, the only holdover from the old staff, was retained as senior staff officer in charge of operations.

1 Stevens-Burns, Okinawa Diary, entries for 3 and 4 April.

1 Unless otherwise noted, the account of the Japanese units and weapons on Okinawa was taken from Tenth Army G-2 Combat Intelligence Collecting Agency (CICA), Prisoner of War Interrogation Sum- maries, Nos. 1— 19, Jul— Aug 45. These summaries are based on extensive interrogations of a large number of prisoners captured for the most part at the end of the campaign. A good deal of the material in Tenth Army G—2 Intelligence Monograph, Ryukyus Campaign, Aug 45, Pts. I-V, is based on these summaries. The original typescript summaries are, however, fuller and more accurate sources.

WHERE IS THE ENEMY?

85

General Ushijima, according to the members of his staff, was a calm and very capable officer who inspired confidence among his troops. He had com- manded an infantry group in Burma early in the war and came to his new assignment from the position of Commandant of the Japanese Military Academy at Zama. General Cho was a hard-driving, aggressive officer who had occupied high staff positions with the troops in China, Malaya, and Burma and had come to Okinawa from the Military Affairs Bureau of the War Department in Tokyo. Colonel Yahara enjoyed the reputation of being a brilliant tactician, conservative and calculating in his decisions. The combination of Ushijima's mature judgment, Cho's supple mind and aggressive energy, and the shrewd discernment of Yahara gave the yid Army a balanced and impressively able high command.3

Prior to the activation of the jzd Army on 1 April 1944, Okinawa had been defended by a small and poorly trained garrison force. In June, before the Amer- ican landings in the Marianas, the Japanese planned to reinforce the garrison with nine infantry and three artillery battalions.4 The first reinforcement to reach Okinawa was the 44th Independent Mixed Brigade, which arrived late in June. The gth Division landed on the island in July and was followed in August by the 6id Division and the 24th Division. Artillery, supporting troops, and service elements arrived during the summer and fall of 1944.

The Japanese plans for the defense of the Ryukyus were disrupted when the veteran 9th Division left Okinawa for Formosa early in December, as part of the stream of reinforcements started toward the Philippines after the invasion of Leyte. It was intended to replace the division, but shortage of shipping made this impossible. Of the remaining combat units, the 6id Division was considered by the commanding general and his staff to be the best in the 32^ Army. Com- manded by Lt. Gen. Takeo Fujioka, the division was formed from the 63d and 64th Brigades, each consisting of four independent infantry battalions which had fought in China since 1938. It lacked divisional artillery but by April 1945 had been brought up to a strength of about 14,000 by the addition of two inde- pendent infantry battalions and a number of Boeitai (Okinawa Home Guards).

8 See Tenth Army G-2 PW Interrog Rpt No. 28, 6 Aug 45 (hereafter cited as Interrog Yahara). This is a verbatim report of the interrogation of Col. Hiromichi Yahara, senior staff officer, the most important Japanese officer captured on Okinawa. Also Tenth Army G-2 PW Interrog Rpt No. 27, 24 Jul 45 (hereafter cited as Interrog Shimada), a verbatim report of the interrogation of Akira Shimada, civilian secretary to General Cho.

4 CINCPAC-CINCPOA Bull No. 194-45: Empire Defense Opns Plan, Special Transl No. 86, 7 Aug 45. PP- 5> 6. The Japanese plan was dated 15 Jun 44.

JAPANESE COMMANDERS on Okinawa (photographed early in February 1^4$). In center: (1) Admiral Minora Ota, (2) Lt. Gen. Mitsuru Ushijima, (3) Lt. Gen. Isamu Cho} (4) Col. Hitoshi Kanayama, (5) CoL Kifyuji Hongo, and (6) Col. Hiromicki Yahara.

WHERE IS THE ENEMY?

87

As finally organized, each of the independent infantry battalions was composed of five rifle companies, a machine gun company, and an infantry gun company,

with a total battalion strength of approximately 1,200 men. (See Chart V.)

Unlike the 62^ Division, the 24th was a triangular division, consisting of the 22^, ^2d, and 8gth Infantry Regiments and the qui Field Artillery Regiment; it had never seen combat. In January 1945 each of the infantry regiments had incorporated 300 Okinawan conscripts into its ranks and had been reorganized. After the reorganization a regiment consisted of three battalions of three rifle companies each, with each company reduced from 290 to 180 men. The total strength of the division, including Okinawans, was more than 15,000.

The 44th Independent Mixed Brigade consisted of the 2d Infantry Unit and the i$th Independent Mixed Regiment and had a strength of about 5,000 men. The brigade had lost most of its original personnel by American sub- marine action while en route to Okinawa in June 1944, and it had been recon- structed around a nucleus of 600 survivors. The latter, plus replacements from Kyushu and conscripted Okinawans, were reorganized into the 2d Infantry Unit, of approximately regimental strength but without a full complement of weapons and equipment. The i$th Independent Mixed Regiment was flown to Okinawa at the end of June 1944 and assigned to the brigade. In addition to its three battalions of infantry, it had engineering troops and an antitank company; by the addition of native conscripts and Boeitai it had been brought by April 1945 to a strength of almost 2^800 men.

To add to the three major combat infantry units, General Ushijima in February 1945 converted seven sea-raiding battalions, formed to man suicide boats, into independent battalions for duty as infantry troops to fill the serious shortage resulting from the withdrawal of the gth Division. These battalions had a strength of approximately 900 men each and were divided among the major infantry commands. Counting these additions there was a total of thirty-one battalions of infantry on Okinawa, of which thirty were in the southern part.

Independent artillery units constituted an important part of the reinforce- ments sent to Okinawa. Two regiments of 150-mm. howitzers, one regiment of 75-mm. and 120-mm. guns, and one heavy artillery battalion of 150-mm. guns were on the island by the end of 1944 to supplement the organic divisional artil- lery and infantry cannon. For the first time in the Pacific war, Japanese artillery was under a unified command; all artillery units, with the exception of divisional artillery, were under the control of the $th Artillery Command. Most of the personnel of the command, which numbered 3,200, had served in other cam-

CHART V

uzaiton of the Japanese 6zd Division in Okinawa

62D DIV HQ

DIV TRANS UNIT

FLD HOSP

S3D BRIG HQ

MTR TRANS CO

HORSE CO

X HMGS

I 100

1ST IND INF BN

iST RIFLE CO

DIV ENGR UNIT

64TH BRIG HQ

15TH IND INF BN

DIV

SIG UNIT

21

VET HOSP

L LOU

21ST IND INF BN

INF BN

23D IND INF BN

273D IND INF BN

{ATTACHED*

\ 2XH IND INF BN

I MtfJ

13TH

IND INF BN

now

MTU

IND

650

IND INF BN

(ATTACHED)

2D RIFLE CO

3D RIFLE CO

4TH RIFLE CO

9 LMC'S 9 KNEE MOKTAKS

5TH RIFLE CO

MG CO

INF GUN CO

10 HMG S

losrrf.' Tcnili Army C-J DlUili^tUt MonDi(riph Ryukym Cimp^pn, Pirc L. Srt. H. p. 10.

2 GUNS (7S-MM) 2 HOWS (?(^MM)

WHERE IS THE ENEMY?

89

paigns and had been with their units for three or four years. They were well trained by Japanese standards and were considered among the best artillerymen in the Japanese Army.

About 10,000 naval personnel were organized into the Okinawa Naval Base Force, commanded by Rear Admiral Minoru Ota, which had control of all naval establishments and activities in the Ryukyus. The unit was largely concentrated on Oroku Peninsula