The Invasion of Normandy: Operation NEPTUNE

United States Naval Administration in World War II


Commander, U.S. Naval Forces in Europe: Volume V

Table of Contents United States Naval Forces Europe, 7 vols.

Editor's Note

Index to Volume V

Table of Contents Operation NEPTUNE
Naval Aspects of Operation OVERLORD

Section Title Pages
Chapter I     THE STRATEGIC BACKGROUND OF OVERLORD 1
  Part 1   Introductory: Policy and Strategy in World War II 1
    A. Definition of Operation OVERLORD 1
    B. U.S. Policy and Grand Strategy 2
    C. American-British Combined Strategy (ARCADIA Conference Decisions, Washington, January 1942) 5
    D. The War Situation in 1942: Allocation of U.S. Forces 6
  Part 2   Combined Strategy in the European Theater 10
    A. Combined Planning of Future Operations (January-July 1942) 10
    B. Mediterranean Strategy 1942-1943 (British Strategic Concepts) 14
    C. Planning the Assault On Germany: (OVERLORD and American Strategic Concepts) 21
    D. Planning Offensive Operations: 1943 British Proposals 25
  Part 3   Grand Strategy of the OVERLORD Plan 29
    A. Quebec Conference Decisions: Views of British Chiefs of Staff 29
    B. Strategical Implications of OVERLORD: The American Position 32
    C. The General War Situation November 1943 33
  Part 4   Tripartite Strategic Agreements: The EUREKA Conference (Teheran) 41
    A. Soviet Strategic Concepts 41
    B. U.S.-British Positions At Teheran 44
    C. Final Approval of OVERLORD At Teheran 45
    D. Allied Program for Victory in Europe: Political Implications 47

Chapter II     PLANNING AND PREPARATIONS FOR CROSS-CHANNEL (OVERLORD) OPERATIONS 51
  Part 1   Early Plans for Cross-Channel Operations 51
    A. Introduction: British Planning 1940-1941 51
    B. Combined Planning, January-June 1942 58
    C. Preliminary Cross-Channel Plan: ROUND-UP 1943 65
    D. Plan for a Sacrifice Operation: SLEDGEHAMMER 1942 70
    E. Build-up of U.S. Forces in the United Kingdom (Operation BOLERO) 72
  Part 2   The OVERLORD Plan: COSSAC Appreciation and Outline, 1943 79
    A. Casablanca Conference Decisions: January 1943 79
    B. COSSAC: Functions and Organization 83
    C. The COSSAC Appreciation and Outline Plan for OVERLORD, July 1943 89
  Part 3   OVERLORD and ANVIL: Planning the 1944 Grand Assault 98
    A. Quebec Conference Approval of OVERLORD, August 1943 98
    B. Plans for Landings On the French Mediterranean Coast (ANVIL Operation) 102
    C. Strategy and Logistics of 1944 Amphibious Operations 105
    D. 1944 Modifications of OVERLORD and ANVIL Plans: December 1943-March 1944 110
  Part 4   Air Operations in Relation to OVERLORD 120
    A. COSSAC Plan for Air Operations 120
    B. Plans for Combined SICKLE-POINTBLANK Air Operations 123
    C. Coordination of U.K. and Mediterranean Air Operations - 1943 126
    D. OVERLORD Plan for the Air Offensive in 1944 128
  Part 5   OVERLORD Cover and Deception Operations 133
    A. COSSAC Cover Plan 134
    B. British and Combined Organization for Cover and Deception Operations 137
    C. OVERLORD Cover Plans: JAEL and BODYGUARD 139
    D. Outline of OVERLORD Deception Operations 145
    E. Operations VENDETTA (and ZEPPELIN) in the Mediterranean (ANVIL) 149
    F. Operation FORTITUDE (and TINDEL) in Relation to OVERLORD in North Europe 151
    G. Operation FORTITUDE SOUTH in Relation to NEPTUNE) Pas de Calais Threat 156
    H. Organization of Radio Deception Operation 152
    I. Results of Cover and Deception Operations 166

Chapter III     THE STRATEGIC BACKGROUND OF OVERLORD 170
  Part 1   Formation of the OVERLORD System of Command 171
    A. Unity of Command: U.S. and British Systems 171
    B. 1942 Plans for a Supreme Allied Command 174
    C. 1943 Discussions of Combined Command Systems (Casablanca Conference: COSSAC Proposals) 179
    D. Quebec Conference Decisions: Delay in Designation of Supreme Allied Commander 182
    E. Establishment of OVERLORD Command: General Eisenhower Designated S.A.C. 186
  Part 2   Developments of OVERLORD System of Naval Command. 193
    A. Designation of Allied Naval Commander-in-Chief (ANCXF) 193
    B. Relations of Royal Navy and U.S. Navy Organizations With ANCXF 195
    C. Organization of the TWELFTH U.S. Fleet and of Task Force 122 202
    D. Command Arrangements and Operation Plan, Task Force 122 207
  Part 3   NEPTUNE Naval Command 213
    A. Pre-NEPTUNE Phase (25 Oct 1943 - 27 May 1944) 213
    B. NEPTUNE Phase (May 27 to July 10, 1944) 217
    C. Post-NEPTUNE Phase (10 July 1944 - 14 July 1944) 220
    D. Chronological Summary of Naval Command Developments -- OVERLORD Operation 222
  Part 4   Integrated Command of Allied Forces OVERLORD Operations 226
    A. Chain of Integrated Command 226
    B. Division of Responsibilities for Planning 228
    C. Division of Responsibility between Army and Navy 230
    D. Division of Responsibility for the Build-up 232

Chapter IV     NEPTUNE OPERATIONS PLANS 233
  Part 1   The Enemy Situation 233
    A. German Land Forces 233
    B. The German Defense Plans 234
    C. Coastal Defenses, Fortifications and Obstacles 235
    D. German Coastal Batteries and Mobile Artillery 241
    E. Disposition of Garrison Troops and Mobile Forces 243
    F. German Naval Forces 246
    G. German Air Forces 250
  Part 2   The Assault Area: Allied Method for Assault 253
    A. Basis of the NEPTUNE Plan 253
    B. Landing Beaches and Lodgment Areas 254
    C. Anticipated Development of the Land Campaign 262
    D. NEPTUNE Method for Amphibious Assault 263
    E. Timing of the NEPTUNE Assault 273
    F. Plans for Movement of Forces 276
  Part 3   General Plan for the Normandy Landings 279
    A. The Preliminary Phase 279
    B. The Preparatory Phase 279
    C. The Assault Phase 281
    D. The Build-up Phase 285
  Part 4   Composition and Organization of Forces 287
    A. Army Forces, Allied Expeditionary Force 287
    B. Air Forces, Allied Expeditionary Force 289
    C. Naval Forces, Allied Expeditionary Force 291
    D. Chain of Combined High Command
    E. Chain of Naval Command
    F. Army Order of Battle
    G. Integrated Chain of Command
    H. Organization of Western Task Force
    I. Organization of Eastern Task Force
    J. Composition of Naval Forces
  Part 5   The Naval Plan 301
    A. Outline Review of NEPTUNE Operation 301
    B. Loading and Assembly of Forces 305
    C. Program of Assault and Follow-Up Forces 308
    D. The Build-up for Offensive Land Operations 311
    E. Supporting Naval Operations 313
      (1) Minesweeping 313
      (2) Bombardment 316
      (3) Diversions 319
      (4) Covering Forces 319
      (5) Defence of the Assault Area 320
      (6) Minelaying 322
    F. Supporting Air Operations 323
      (1) Command 323
      (2) Forces Available 323
      (3) Fighter Protection 324
      (4) Coastal Air Operations 324
      (5) Smoke-laying 325
      (6) Mine-laying 325
      (7) Air Spotting 325
      (8) Air Bombardment 325
      (9) Expected Scale of German Air Effort 325
    G. Ancillary Operations 325
      (1) Mulberries 325
      (2) Gooseberries 325
      (3) Pluto, Tombola and Amathea 328
      (4) Buoy Laying 329
      (5) Surveying 329
      (6) Moorings 330
      (7) Salvage 330
      (8) Rescue Tugs 330
      (9) Colliers, Oilers, and Water Tankers 331
      (10) Cable Laying 331
      (11) Despatch Boat Service 331
      (12) Ammunition Barges 331
      (13) Sunken Causeway 331
      (14) Minor Landing Craft 331
      (15) Coast Guard Cutters 331
    H. Chronological Order of Events 332

Chapter V     NAVAL PREPARATIONS FOR CROSS-CHANNEL OPERATIONS 338
  Part 1   U.S. Naval Preparations 338
    A. ComNavEu Organization and Action 338
    B. Twelfth Fleet and Task Force 122 341
    C. Establishment of Eleventh Amphibious Forces 343
    D. Landing Craft and Bases (LanCrabEu) 346
  Part 2   Preparations of Bases for Amphibious Forces 348
    A. Naval Bases and Training Areas in Southwest England: Relations with C-in-C Plymouth 348
    B. Repair and Port Facilities 351
    C. Arrival and Organization of Amphibious Forces 355
  Part 3   Organization and Training of U.S. Naval Forces 358
    A. Organization and Activities, Eleventh Amphibious Forces 358
    B. Coordination in Training with U.S. Army Formations 359
    C. Amphibious Training Exercises -- 1944 360
    D. Organization and Training of U.S. Naval Assault Forces 362
  Part 4   Details of U.S. Naval NEPTUNE Forces 367
    A. Table of Numbmers of Vessels present by Months
    B. Table and Disposition of U.S. Vessels for OVERLORD
    C. Case History of U.S. Ships and Major Craft
    D. Detailed Task Organization, Western Task Force
  Part 5   Brief Review of Royal Navy Preparations 371
  Part 6   Loading and Assembly: NEPTUNE Forces 375

Chapter VI     THE OPERATION BEGINS 381
  Part 1   Developments During May 1944 381
    A. The Naval Assault Forces 381
    B. Enemy Reactions 382
    C. Promulgation of Operation Orders 384
    D. Security Problems and Measures 386
    E. Command Questions 387
    F. Questions of Air-Navy Coordination 388
    G. MULBERRY Problems: Tug Shortage 389
    H. Visits of Important Personages 390
  Part 2   Designation and Postponement of D-Day 392
    A. 5 June Designated as D-Day 392
    B. NEPTUNE Forces in Movement 393
    C. Weather Intervenes: Postponement of Assault 394
    D. The Supreme Commander's Dilemma: 6 June Fixed as D-Day 396
  Part 3   The Assault Movement of NEPTUNE Forces 400
    A. General Outline of the Movement 400
    B. Composition and Timing of Convoys 401
    C. Routing and Navigation 405
    D. The Assault Forces Reach the Beaches 407

Chapter VII     DEFENSIVE MEASURES -- NEPTUNE OPERATION 410
  Part 1   Enemy Naval Dispositions, 1944 410
  Part 2   Minelaying (Operation MAPLE) 412
    A. Plan for Minelaying 412
    B. Minelaying Operations 413
  Part 3   Naval Cover for NEPTUNE 416
    A. Countering the German Heavy Fleet 416
    B. Countering U-Boat Movements from the North 417
    C. Sealing the Western Channel 418
    D. Sealing the Straits of Dover 421
    E. Patrols Along the Convoy Flanks 422
  Part 4   Assault Area: Screen and Escorts 425
    A. Allied Naval Dispositions 425
    B. Eastern Task Force 426
    C. Western Task Force 428
    D. Convoy Escort Forces 432
  Part 5   NEPTUNE Minesweeping Operations 433
    A. Plans for Sweeping German Minefields 433
    B. Minesweeping Arrangements in the Assault Area 435
    C. The Passage and False Start 437
    D. The Approach 438
    E. Sweeping Inshore Waters 442
    F. The Enemy's Minelaying Counter-Attack 443
    G. Minesweeping at Cherbourg 444
    H. The Score 446
  Part 6   Air Cover Forces for NEPTUNE 449
    A. Coordination of Coastal Command and Naval Operations 449
    B. Air Defense by Combined Allied Air Forces 454

Chapter VIII     BOMBARDMENT AND OTHER DEFENSIVE OPERATIONS AGAINST ENEMY LAND FORCES 458
  Part 1   General Bombardment Plans 458
    A. Coordination of Naval and Air Bombardment 458
    B. Air Bombardment Program 462
  Part 2   Naval Bombardment Operations 464
    A. Naval Bombarding Forces 464
    B. Pre-Arranged Bombardment Schedule 468
    C. Post H-Hour Aimed Bombardment 469
    D. Ammunition Supplies 473
    E. Results of Naval Bombardment 474
  Part 3   Bombardment of Cherbourg 477
    A. Bombardment of Cherbourg 477
  Part 4   Radar Counter Measures 479
  Part 5   Naval Diversions 483

Chapter IX     THE NEPTUNE ASSAULTS 487
  Part 1   General Conditions for the Assault 487
    A. Reasons for Success of NEPTUNE Operation 487
    B. The Effect of Surprise 488
    C. The Normandy Landings 490
  Part 2   Western Task Force: Force U 493
    A. General Situation, Western Task Force 493
    B. Assault Force U: Organization and Assembly 493
    C. Assault Force U: The Channel Passage 500
  Part 3   Western Task Force: Force O 507
    A. Organization and Assembly 507
    B. OMAHA Beach: Plan for the Assault 511
    C. Assault Force O: Organization and Assembly 514
    D. Assault Force O: The Channel Passage 515
    E. The Assault on OMAHA Beach 518
    F The Battle on OMAHA Beach 526
  Part 4   Eastern Task Force: Forces G, J, S 534
    A. The Channel Passage 534
    B. The Assaults: General Narrative 542
    C. Force G: GOLD Area 546
    D. Force J: JUNO Area 548
    E. Force S: SWORD Area 553
  Part 5   The Assault Ends: The Situation at H Plus 24 Hours 559

Chapter X     THE BUILD-UP FOR THE BATTLE OF FRANCE 563
  Part 1   The Post-NEPTUNE Naval Task 563
  Part 2   Far Shore Organization 565
    A. Plans and Preparations for Naval Far Shore Service 565
    B. British Area: Far Shore Naval Organization 567
    C. U.S. Area: American Far Shore Naval Organization 570
    D. Shore Parties, U.S. Area 571
  Part 3   Naval Far Shore Activities After D-Day
(Extracts from ANCXF NEPTUNE Report)
573

Index       583


Source: Historical Section, COMNAVEU. "Administrative History of U.S. Naval Forces in Europe, 1940-1946." vol. 5. (London, 1946) [This manuscript, identified as United States Naval Administrative History of World War II #147-E, is located in the Navy Department Library's Rare Book Room.]


Note: Indexed at the U.S. Naval War College, Newport, Rhode Island, in connection with the preparation of S.E. Morison's History of U.S. Naval Operations in World War II, Volume 11, by Roger F. Schofield, YN1, USN, 9 December 1954.