Source: Historical Section, COMNAVEU. "Administrative History of U.S. Naval Forces in Europe, 1940-1946." vol. 5. (London, 1946): 301-337 [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.]

PART III
ORGANIZATION AND TRAINING OF U.S. NAVAL FORCES

A. U.S. Naval Amphibious Force

28. The task of organizing the U.S. assault forces into battle array was carried out by the Commander 11th Amphibious Force. In December, when he began this work, OVERLORD had not yet been expanded to a five-divisional basis, and the U.S. Navy was expected to supply only one assault force with a follow-up component. During the assault phase, it was intended that Admiral Hall would command the amphibious assault,1 while one of his subordinates, COMLANDCRABEU, would provide support and maintenance. In order to supply a follow-up force commander and additional assault or follow-up lift, CominCh assigned Commodore Edgar with three divisions of combat loading transports to the 11th Amphibious Force. Commodore Edgar² had had wide experience as a follow-up force commander, having served in that capacity in the invasions of North Africa, Sicily, and Italy.

29. The organizing and training of U.S. Naval forces was carried out as one process. Since the duty of naval amphibious forces is to deliver the army in order of battle at the assault beaches, the organization and training of naval amphibious forces centers primarily on meeting army requirements. The basic organization of a U.S. naval amphibious force is designed to meet the "standard" requirements of the army when it assault in a "normal" manner. Since the enemy situation, the terrain and other essential factors are different in every assault, it is expected that the "normal" system will be varied in each invasion to meet the special requirements of the case.

30. The 11th Amphibious Force was organized as it arrived, along basically standard lines, with variations designed to meet the special requirements of NEPTUNE as stated:

    1. By Commanders of Army Formations to be embarked;

    2. by ANCXF when he found it necessary to do so to meet the requirements of the overall plan, and

    3. by the Task Force and Assault Force Commanders when it was found necessary to meet special naval problems in the situation.

B. Coordination In Training With U.S. Army Formations

31. During the whole period of training and organizing, the 11th Amphibious Force acted in the closest coordination with the Army formations of parallel echelons of command. The American Army formation, scheduled to execute the initial phases of the invasion, was the FIRST U.S. ARMY under the command of Lt. General Omar N. Bradley, U.S.A. The First Army was composed of the following elements.

    1. FIRST U.S. ARMY

       1. U.S. Army V Corps. Attack on OMAHA

          1. 28th U.S. Inf.Div. (early Build-up division).

          2. 29th U.S. Inf.Div. (OMAHA assault and follow-up division)

          3. 1st U.S. Inf.Div. (OMAHA assault division)

       2. U.S. Army VII Corps. (Attack on UTAH)

          1. 4th U.S. Inf.Div. (assault UTAH beach)

          2. 2nd U.S. Inf.Div. (UTAH follow-up and early build-up)

3. 9th U.S. Inf.Div. (UTAH build-up)

4. 82nd U.S. Airborne Div. (Airborne assault behind UTAH)

5. 101st U.S. Airborne Div. (Airborne assault and follow-up behind UTAH).
3. XIX U.S. ARMY CORPS Build-up.

   1. 2nd U.S. Armored Div. (Build-up)

   2. 3rd U.S. Armored Div.     "

   3. 30th U.S. Inf.Div.     "

4. Army Troops including two Ranger Battalions
32. Early in June 1943, the 29th Division of the V Corps U.S. Army had established itself in Tavistock (a suburb of Plymouth). Between then and April 1944, the following formations took up their positions in close proximity to the naval bases:

    Bristol Taunton Tenby Tavistock Blandford Bremore Tiverton

    1st U.S. Army H.Q. V Corps H.Q. 28th Inf.Div. 29th Inf.Div. 1st Inf.Div. VII Corps. H.Q. 4th Inf.Div.

    Lt.Gen. Bradley Maj.Gen. Gerow Maj.Gen. Maj.Gen. Gerhardt Maj.Gen. Heubuer Maj.Gen. Woodruff Maj.Gen. Barton

C. Amphibious Training Exercises - 1944

33. These Army formations engaged in specialized amphibious training and experimenting in conjuntion with the navy. Prolonged and large-scale experimentation was carried out at the Advanced Amphibious Training Base at Appledore, Devon.¹ Many problems in connection with landings on a hostile beach were investigated, and projects

tried out and solutions found. The experimental work was carried out on the beaches at Instow and Westward Ho! Some of the principal experiments and trials were:

1. Waterproofing of vehicles and tanks, and wading trials to ascertain maximum depth vehicles could wade ashore;

2. Design of and trials with LCT ramp extension.

3. Rhino ferry trials.

4. LCT beaching trials.

5. Trials with minor landing craft in surf.

6. Trials for suitability of LST as a Hospital ship.

7. Most efficient means of discharging stores from a Coaster.

8. Methods for clearing beach obstacles.

9. The quickest way to refloat stranded landing craft.
34. Parties of U.S. troops were taken on special trips at sea aboard escorts, minesweepers, destroyers, and other ships engaged in routine naval duties. Constant practice in driving army vehicles on and off landing vessels was held. All army personnel, engaged in working army equipment while being loaded onto, carried in, or discharged from naval vessels, were given sound practice over many months. Conversely, naval personnel, required to handle army equipment during operation were given specialized practice in doing so. Strictly naval training in boat operation, beaching and retracting, discharging cargo into "ferry craft" from large ships, and all other aspects of amphibious duties was also carried out during the pre-assault period.

35. In addition to training of a purely "practice" type, a series of exercises and rehearsals were executed. The first large-scale amphibious exercise took place on 31 December - 2nd January 1944, with Rear-Admiral Hall, USN, in the U.S.S. Ancon (H.Q.Ship) commanding Force "O".

This exercise (Operation DUCK¹) was mounted at Falmouth. The assault was made on Slapton beach by part of the 29th Infantry Division of the Vth Corps with Major General Gerhardt, U.S. Army in command. Naval bombardment was carried out by 4 HUNT class destroyers who, together with trawlers and minesweepers acted as escort during the passage and while the assault forces were in the area. In this and in later exercises, all bombarding ships and escorts were placed under the direct operational control of the Assault Force commander, while covering forces of destroyers and coastal craft remained under the operational control of Commander-in-Chief, Plymouth.
36. Exercise DUCK marked the beginning of the process of assigning vessels and amphibious parties their assault organization. Rear-Admiral Hall followed the policy of "marrying-up" the naval and army units as early as possible so that the army-naval personnel and commanders on all echelons would be able to work and train together for as long as possible. This could not be done all at one time, since not all the army formations nor all the navy vessels were available at so early a date, while those that were available had to be inter-changed so as to give training to all. Despite these handicaps the process of making definite assignments began early and proceeded as rapidly as the arrival of forces would allow.

D. Organization and Training of U.S. Naval Assault Forces

37. When the CCS authorized the increased scale of assault in March 1944, the U.S. Navy was required to provide a second assault force. CominCh designated Rear-Admiral D.P. Moon to act as commander of the new force.² During the period of the Basic planning for OVERLORD and ANVIL, Captain Moon had served in the Atlantic Section of the C.N.O. Operational Plans Division. When Admiral Hall was transferred from the Mediterranean to England, another Assault

Force Commander was required for operation ANVIL, then scheduled to take place concurrently with OVERLORD. To fill this requirement Captain Moon was promoted to Rear-Admiral and reported to Com 8th FLEET for duty as Commander of a Task Group of 8th Amphibious Force, at the end of January. When ANVIL was postponed, he was transferred to England. On 4 March, 1944, he reported for duty to COM 12th Fleet, and was assigned to CTF 122, who in turn assigned him to Commander 11th Amphibious Force. The latter designated him Commander Group II, 11th PHIB, and second in Command.
38. The 11th Amphibious Force thus became the reservoir cotaining all the components from which the four separate forces were to be built. The Commander of this Force was, therefore, reponsible for allocating vessels to each force, as required by the Naval Plan, and for directing the process of training and preparing of all the Forces to be used in the assault. This now included:

    1. FORCE B, which, under the new arrangement was to bring up the follow-up formations to both assault forces;

    2. LANDCRAB, which was to support all three forces;

    3. FORCE U, under Rear-Admiral Moon; and,

    4. FORCE O, under command of the Amphibious Force Commander himself - Rear-Admiral Hall.

39. With the arrival of Rear-Admiral Moon in early March, Rear-Admiral Hall re-oriented the program of training and organizing to fit the new requirements. As added vessels arrived and training progressed, the four parts of the 11th Amphibious Force gradually assumed their assault organization. Rear-Admiral Moon had a difficult task ahead of him as he had only two months to bring his force into being, to organize it, and to train it with the associated Army formations. The large program of successive exercises to be arranged with concurrent planning of Operation NEPTUNE, this force, working against time, had a formidable task to accomplish. Operation orders for exercises were often finished just prior to the sailing of the participanting forces. The next exercise had to be planned before the previous one had even commenced.

40. The Amphibious exercise "Fox" was carried out by Force "O" soon after the arrival of Admiral Moon, while organization of Force "U" was being made. The troops embarked consisted of part of the V Corps with Major General Gerow, U.S. Army, in command. They were loaded at Weymouth and Portland, the ports which Force "O" was to use for Operation NEPTUNE. In the Operation "Fox", APA's were used for the first time. The bombarding force consisted of two cruisers and eight destroyers, the latter, with additional destroyers and trawlers, forming the escorts. As in DUCK, no attempt was made by the Germans to attack the assault forces by sea or air, either during the sea passage or while off Slapton beach. Seldom can there have been more tempting targets for E-boats than this vast concourse of ships streaming across Lyme Bay at night with escorts of necessity not as numerous as desired. On conclusion of the exercise, the APA's were sailed to the Clyde to safeguard them from any possibility of air attacks.

41. Force "U" commenced intensive training with two medium sized exercises, MUSKRAT (24-27 March) and BEAVER (29-31 March). MUSKRAT I¹ carried out in the Clyde, consisted of ship to shore training from APA of the 12th Regimental Combat Team of the 4th Division, U.S. Army. The APA's then sailed to the Slapton area. MUSKRAT II² concluded this exercise with a landing and assault on the beach. Two cruisers bombarded and escorts were provided by destroyers, corvettes, and trawlers. Rear-Admiral Moon sailed with the Assault Forces in his flagship, USS BAYFIELD - a converted APA - but as a spectator only. Captain Maynard, USN, commanding the APA's of Force "U", was the Task Force Commander. The difficulties in planning with which Force "U" had to contend were illustrated by the fact that the operation orders of MUSKRAT II were written by officers lent from Force "O" without consultation with the Task Force Commander, who was then witnessing MUSKRAT I, and so out of telephonic communication. These same officers, assigned to Admiral Moon's staff, were working night and day preparing for exercise BEAVER, which was to take place shortly.

42. In exercise BEAVER (29th-31st March)¹ the 8th R.C.T. of the 4th Division (Major General Barton) and attached units were loaded and sailed from Plymouth, Dartmouth, and Brixham, in LST's and LCI(L)'s. In order to make a good approach to the Slapton beach, the assault forces took a circular route around the western half of Lyme bay. Bombardment was carried out by two cruisers and four destroyers while all other available ships were used as escorts and covering forces. Two minesweeping flotillas swept ahead of the assault forces.

43. The last exercise in which Force "U" participated before NEPTUNE, was exercise TIGER² (26th-28th April). Though conforming in principle to BEAVER, it was on a larger scale and was carried on, as far as possible, with those landing craft to be used in the actual operation. Army units embarked consisted of part of the 4th Infantry Division, VII Corps, and attached units with Major Generals Collin and Barton in command. The route of the assault force was taken well into the middle of Lyme Bay, so as to give a longer sea passage. The actual approach was marked by lighted dan buoys laid by the minesweeper units. Two cruisers and seven destroyers carried out both bombardment direct and indirect. As in the other exercises, the maximum number of destroyers, corvettes and trawlers available formed the escort group and covering force. The assault took place in the early morning of April 27th. The night before, while the follow-up convoys of LST was crossing Lyme Bay, E-boats succeeded in attacking this convoy. Two LST were torpedoed and sunk, and a third badly damaged, casualties were high. Survivors were landed at Portland.³

44. The last major exercise before NEPTUNE was FABIUS⁴ (3rd-6th May). This was a full-scale dress rehearsal, involving U.S. Assault Force "O" (Fabius I) and British Assault Force "J" and "S" (Fabius II and IV). ANCXF temporarily assumed operational control of the forces

involved and of the Channel during these exercises. NCETF and NCWTF took temporary command of their respective Task Forces, while command of Assault Forces was exercised by the Assault Force Commanders. D-day was considered to be 4 May, after a postponement of 24 hours for bad weather. Force "O", under Rear-Admiral Hall, executed FABIUS I. The landing force consisted of elements of the 1st U.S. Infantry Division commanded by Major Geberal Huebner. As in FOX, the exercise was mounted in the Portland area with the landing at Slapton. The bombarding force was composed of H.M.S. GLASGOW, U.S.S. AUGUSTA, and nine U.S. destroyers. Escorts were particularly strong. The weather was not good, and, on the evening of D-day, the smaller landing craft sheltered in Dartmouth and Brixham. Further landings on the beaches were cancelled and when the wind and sea had moderated on the 6th May, forces were dispersed to their ports of final assembly.
45. In the middle of April, U.S. Rangers embarked in LSI(H) and LSI(S) carried out training off Woolacombe, North Devon. They took part in FABIUS I and after more training at Falmouth sailed to Portland for attachment to Force "O". On completion of the last exercises, the three forces returned to the ports in which they would be loaded and assembled for the final cross-channel operation. During the last month before D-day, U.S. Destroyers, Cruisers, and Battleships, arrived. Many of them took part in the last exercises and then were based either at Plymouth or at Belfast. They were to sail from these ports on the eve of D-day to keep their appointed rendezvous with the rest of the invasion forces.

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Footnotes:

p.358 #1 For the reasons for having Admiral Hall act as both Amphibious Force Commander and as assault force commander see Admiral Cooke's memo to Admiral King; subject - Naval Command Set-up in U.K. for Cross-Channel Operations, dated 7 October 1943. See also CominCh serial 03683 of 24 October 1943 and BuPers despatch 281439 of October 1943.

p.358 #2 See note at end of Chapter.

p.360 #1 Before this base was taken over by U.S. Forces, it was a British Combined Opererations Experimental Establishment.

p.362 #1 11th Phib. Serial 0023 of 26 December 1943, Op-Order A-43. 11th Phib. Serial 001 and 002 of 5 February 1943, Op-Order 1-44.

p.362 #2 Note on Admiral Moon at the end of Chapter.

p.364 #1 11 Phib Serial 00276 of 12 March 1944, Training Order R-44

p.364 #2 11 Phib Serial 00277 of 12 March 1944, Training Order S-44

p.365 #1 11th Phib (Group 2) Serial 0039 of 21 March 1944, Training Order 1-44.

p.365 #2 WNTF Force "U" Serial 0075 of 15 April 1944, Training Order 2-44.

p.365 #3 See ANCXF Report Vol.1, Appx.2.

p.365 #4 WNTF Assault Force "O", Serial 00556 of 24 April 1944, Op.Order 2-44.