THE OPERATION BEGINS
DEVELOPMENTS DURING MAY 1944
A. The Naval Assault Forces
- While the assault forces were rounding off the last stages of their preparation and training, the High Command was equally busy completing the last stages of overall preparation. In April and May, SHAEF, Headquarters 21 A.G. and ANCXF took up their battle headquarters on the Portsdown Hill just behind Portsmouth and on the coast directly opposite the "Assault Area".1 Headquarters A.E.A.F. remained at Stanmore and Uxbridge.
- NCWTF and NCETF hoisted their flags in their respective Flagships, U.S.S. Augusta at Plymouth and H.M.S. Scylla at Portsmouth.2 The assault and follow up forces were then assembled:
- Force U at Plymouth
- Force O at Portsmouth
- Force S at Portsmouth
- Force G at Southampton
- Force J in the Isle of Wight area
- Force B in Milford Haven and
- Force L on the Nore.
- The large concentration of vessels and craft of all descriptions taxed the port capacity to the utmost. Bombardment forces and other large vessels schedule to arrive after H-hour were pushed further and further out to the wings until in the end they were assembled in ports of east and west England, of Scotland, and of North Ireland.
B. Enemy Reactions
- This large concentration of assault forces in the southern ports was expected to provoke enemy reaction. It had been anticipated that, when the enemy appreciated the size and nature of the forces being concentrated against him, he would intensify to his utmost his efforts to cripple it. Minelaying, attacks on exercises, bombing and the employment of V bombs against assembly areas were considered especially likely. Enemy reaction was, however, slow and unexpectedly light.
- Enemy naval activity in the Channel did increase from the end of April onwards. Force U had been attacked during exercise TIGER, on 28th April, but the Germans appear to have been ignorant of the real nature of their target. Their radio reported merely the sinking of two cargo vessels in convoy. The following night H.M.C.S. Athabaskan, which, with H.M.C.S. Haida, was covering the 10th Minelaying Flotilla operating off the Ile de Bas, was sunk in an engagement with Elbing class destroyers. One of the enemy was driven aground by the Haida.1 The loss of the two L.S.T.s in Lyme Bay brought into "sharp focus", in the mind of NCWTF, the risks of attack from German E-Boats. On 28th April he proposed a pre-D-day bombardment of Cherbourg with naval forces including Battleships. This proposal seemed unacceptable to ANCXF for a number of reasons:
- It would involve unjustifiable risk of bombarding ships which, if lost or damaged, would reduce forces allocated to covering the assaults;
- Security would be endangered as the proposed bombardmant would indicate the possible locality of the assault;
- The E-boat menace could be adequately dealt with by existing weapons, if handled with more efficiency and altertness.
- The number of E and R-boats reported to be operating from Cherbourg and Le Havre increased regularly during May. Prior to May 20th, no submarines were known to be operating in the Channel, but on that date a U-Boat was sighted and attacked in the area between Ushant and Guernsey (49° 01'N, 4°09' W) and on the following night another U-boat was sighted in the Channel area. C's-in-C Portsmouth, Plymouth and Coastal Command accordingly put into force special defensive measures to preclude any sustained movement against NEPTUNE convoy routes.
- In the six weeks before D-day, the enemy intensified his minelaying program off the South Coast of England, using aircraft on a larger scale than for over two years. He also employed two new types of mines. Minelaying was, however, confined to moonless periods. As the last week before invasion was in the new moon period, the mines laid were not beyond tha capabillties of the minesweeping resources of the Home Commands. "Had D-day been in such a period it is doubtful whether the Portsmouth channels could have been cleared in time. As it was, no interruption was caused and it was considered that the enemy missed a great opportunity in not still further extending this form of attack. That he did not attempt more was yet another result of the air auperiority we achieved before D-day."1 Toward the end of May, some aircraft minelaying was combined with small scale night bombing attacks on south coast ports, but very few casualties were caused either to ships or personnel.
- The reasons for the German failure to react more effectively have been attributed to a number of causes:
- The effectiveness with which the allied air forces denied enemy air reconnaissance opportunities to observe preparations;
- Security measures which prevented serious leakages of information;
- Deception measures which confused his estimates of the situation and overcame the possible reports of agents;
- The constant protection afforded by allied naval and air forces;
- The fact that by that stage of the war German air and naval capabilities had been reduced to inadequacy.
C. Promulgation of Operating Orders
- On 24th April, ANCXF issued his operation orders. These were called Naval Order, Operation NEPTUNE (short title ON's), The ON's amounted to a total of 700 printed foolscap pages. The Administrative orders, ONAD's, required 100 more pages while ONCO's (Operation NEPTUNE Communication Orders) totalled another 200 pages. These orders, all together, made a book three inches thick. NCWTF, whose orders to the Western Task Force, ONWEST, were only 2½ inches thick,1 was a little critical of the volume and detail of the ON's. The ON's were so arranged, however, that the parts concerning any one ship or command were comparatively small, and the large volume of orders, therefore, have caused no real difficulty.
- The issuance of such a mass of orders at so late a date might very well have proved confusing. In anticipation of this difficulty ANCXF, since his first appointment, had made it an invariable policy to circulate all his plans and intentions as soon as they were known. A series of Planning Memoranda (XFPM issued from time to time from 27 November 1943 to the end of April 1944), the NEPTUNE NAVAL Plan (issued 18 February) and the ANCXF provisional orders (PON's issued 2 April) had been issued concurrently with planning developments. Hence the ON's, when issued 24 April 1944, contained no surprises and required no important action to be taken that was not already known.
- Both ANCXF and NCWTF have commented in their reports on the fact that ON's dealt in detail with many matters, which in U.S. Naval practice, would normally be left to Force, or even Group commanders. ANCXF has pointed out that he had no desire to interfere with matters properly within the competence of lower echelons, but that the peculiarities of the situation in NEPTUNE, in which thousands of ships were to move in congested waters, using inadequate port facilities, and executing a closely integrated operation, required that all details should be carefully coordinated. To achive this required coordination, while
at the same time leaving his commanders as free a hand as possible, ANCXF employed the following methods:
- He early stated his requiremensts and proposals in his planning memoranda;
- Lower echelons were directed to submit objections and detailed plans;
- Differences were ironed out at conferences;
- Revised Planning Memoranda were circulated incorporating changes and details supplied from lower echelons;
- The compiled results were incorporated in the PON's (Provisional ON's);
- The process of raising objections, settling them in conference, filling in detail supplied from the plans of lower commands, was repeated;
- Finally ON's were issued incorporating all materials assembled and coordinated in this way.
- The ON's finally issued were thus in part ANCXF's directives, and in part an encyclopedic collection of the detailed plans of subordinate formations, fitted together so as to produce a coordinated whole.1 While ANCXF did not believe that, under the circumstances, ON's could have been less detailed, he stated that he should have added a ship index, in which every commander could have quickly found, listed under the name of his ship or his command all sections of ON's of direct concern to him. No sooner were the ON's printed than a vast flood of ammendments and changes were proposed. These were due to the late assignment of additional vessels to NEPTUNE, to changes of H-hour and D-day, to changes in army and air plans, to proposed improvements in the naval plans and to the fact that some preparations, particularly those involving the MULBERRIES, were falling behind schedule. While such changes were not confined to ON's, their comprehensive nature necessarily led to more amendments than were required for other Naval orders.
- The prospect of thousands of ships and authorities opening their orders on the eve of D day, only to find a voluminous book with a mass of later corrections to be made, before each commanding officer could learn exactly what was required of him created grave concern. ANCXF therefore gave notice on 9 May that all plans and orders would be frozen as of 0900 on 12 May, after which date no further alterations in plans and orders would be allowed.
D. Security Problems and Measures
- The problem of security was particularly acute during the last month. When ON's and other orders were issued on 24 April 1944, they were distributed in sealed envelopes, not to be opened until so ordered.1 Senior commands which required information immediately were, however, authorized to open and study their copies. The day before ON's were to be generally opened and studied, SCAEF directed the impounding of private correspondence and the prohibition of private use of telephone and telegraph. All personel, army and navy, were "sealed" on their ships. Not until then were they "briefed" on their tasks and duties in the forthcoming operation.2
- To obviate security risks that might result, if a large number of press correspondents disappeared suddenly from their usual haunts when mobilised shortly before D-day, a practice mobilization took place on 22 May. Approximately 80 correspondents, who were to be attached to the assault forces, were collected, briefed on the need of security and sent by road to their respective ships for about 24 hours. When they disappeared again, just prior to D-day, the event could not provide precise information as the same thing had happened before.
- Despite all precautions, some security breaches did occur. On 31 May, charts of the Bay of the Seine were prematurely issued to tugs. To avoid suggesting to the tug masters the exact area of the intended assault, they were subsequently issued with IMMEDIATE TOP SECRET charts of the Boulogne area. On 26 May and again on 29 May,
NCWTF issued despatches of comparatively wide distribution, from which it could be readily inferred that D-day was to be during the first week in June.1 A curious point on security arose on 22 May when the London Daily Telegraph produced a cross word puzzle for which a remarkable number of NEPTUNE code words' formed the correct answer to clues.2 While there were other security breaches, mostly caused by indiscreet talk with "un-bigotted" persons, the secret was kept. The arrival of allied forces off the Normandy beaches came as a surprise to the defenders.
E. Command Questions
- During the last month the planned evolution of command proceeded according to schedule, except for two unexpected developments. The French Admiral d'Argenlieu, commanding all French Naval forces in British waters raised the question on May 17 1944 of having a French Naval Command, both over French ships taking part in NEPTUNE and over French Waters and Ports after the landings. Admiralty also "directed" on the same day that Rear-Admiral Jaujard, who had just arrived from the Mediterranean for this assignment, should assume command of the French division of Cruisers included in the Expeditionary Force. Neither ANCXF nor NCWTF, to whose force the cruisers had been assigned, had any operational requirement for such an appointment. On the understanding that Rear Admiral Jaujard should not, by virtue of his seniority, be considered to be interposed in the chain of command in the Western Task Force, he hoisted his flag in the Montcalm with the intention of transferring to the Georges Leygues at a later date.
- The next day, 18 May, Rear Admiral Bieri, U.S.N., arrived from Washington with orders attaching him to the staff of ANCXF. As no operational requirement for such an appointment then existed, ANCXF did not wish, on the eve of operations, to disturb staff arrangements already completed and functioning smoothly. Rear Admiral Bieri was therefore attached to the ANCXF future planning section at SHAEF, witht the title of Deputy Chief of Staff (U.S.).
F. Questions of Air-Navy Coordination
- Naval authorities had experienced considerable difficulty throughout the entire planning period, through delays in obtaining from the Air Force detailed information regarding:
- Fighter protection
- The routing of airborne forces, and
- The air bombardment program.1
- The air plan, finally received on 12 May 1944, indicated that, contrary to previous understandings, the air force would not provide individual protection to naval units in any part of the assault area. At a meeting on May l6th, C-in-C AEAF explained that air protection was to be organized over the entire channel area on the principle of "unity of operation".2 AEAF also proposed for the first time that an aircraft corridor should be established, in which Naval AA gunfire would be prohibited. This corridor, to be used by the airborne division attacking Caen, passed directly over the Force S lowering position and beach. A route farther to the eastward would have brought the aircraft over the strong German AA defenses of Le Havre. Admiral Ramsay agreed to the restriction of Naval AA fire provided:
- The corridor was moved so as not to be directly above the naval anchorages, and
- That Naval AA fire need not he restrained if the allied air movement coincided with an enemy air attack.3
- When enemy troop movements on the Cotentin Peninsula on 26 May, the U.S. Air Force proposed to route the U.S. troop carrier air forces directly over Utah Beach and Force U anchorages, and to impose restrictions on Naval AA fire in that area. NC Force U and NCWTF protested strongly, but ANCXF decided that, the restrictions would have to be accepted, in the interest of the operation as a whole, provided the route were not directly above naval forces. It was almost impossible at that late date to inform the multitude of ships and craft affected, or to establish adequate measures of AA fire discipline".
- Restrictions of air attack on enemy surface ships in the Channel, to westward of a line from North Foreland to Walcheren Fort (near Dunkirk), was imposed 27 May, on all aircraft except those of Coastal Command. The restriction did not at first apply to a 10 mile strip off the French coast where enemy vessels were still plying. But on 29 May this area was also closed.1
- Another air problem was created by the Army's perplexity on how to take their air observation posts (these were tiny aircraft, Ansters and Piper Cubs used to assist in spotting for artillery) to France. On 5th May, and again on 28th May, the U.S. Army requested SCAEF to provide a naval aircraft carrier to ferry them over. Admiralty made H.M.S. Argus available for this purpose, but on 31 May the Army cancelled the requests, to the great relief of ANCXF who did not relish the prospect of a large and very vulnerable ship in the assault area. In the event, these small craft flew the Channel without difficulty, being led by a British Fleet Air Arm Walrus to their destinations.
G. MULBERRY Problems: Tug Shortage
- It became increasingly apparent throughout April and May that the MULBERRY program was falling behind schedule. Not only had there been delay in delivery of units, but the towing shackles on the MULBERRY units were poorly located, of a construction too light to stand the strain of towing, and towing gear had not been provided. All the riggers in the Chatham dockyards, when put to rectifying these deficiencies, managed to have the first units ready to sail by D-day. The place for assembly of MULBERRY
units, in readiness for towing across the channel, also caused concern. It was decided to "park" them by sinking them in shallow water near Selsey Bill, Dungeness, Peel Bank and Portland.1 Parking operations rapidly revealed:
- That the intake valves were too small to allow units to be sunk rapidly enough to be positioned accurately, and
- That the pumping gear supplied by the War Office to refloat parked units was inadequate for this purpose, which made it necessary to seek a partial remedy for this difficulty by diverting salvage vessels to pumping out PHOENIX.2
- The most acute MULBERRY problem was the tug shortage, which was never satisfactorily remedied. The target date for completing MULBERRY had, as a result, to be postponed. A special body, known as COTUG, was organized on the 24th May under ANCXF to deal with all NEPTUNE tug problems. There were not enough tugs in the country, however, to satisfy all Civil, Naval and Military demands for their services. As late as 31st May only 48 out of 72 large, and only 4 out of 44 small tugs allocated for towage of PHOENIX and WHALE units were available. On that date Admiral Ramsay directed that "the principle, that MULBERRY and construction constituted a vital part of the whole operation, must govern decisions as to the extent that tug assistance could be provided for other purposes".
H. Visits of Important Personages
- The expeditionary forces were honored by a great many visits of Very Important Persons during the last month before sailing. Mr. Churchill and the Dominion Prime Ministers (excluding the Prime Minister of Australia) were shown NEPTUNE preparations in the Solent area on 13 May.
"On 15 May a meeting took place at 21 Army Group headquarters at which a general outline of the complete NEPTUNE plan was presented by each of the respective Commanders-in-Chief and the Task Force Commanders. Included in the audience were H.M. The King, the Prime Minister and General Smuts. Each of them addressed the assembled senior officers, of the three services concerned with the planning and execution of the NEPTUNE Operation. ANCXF outlined the Naval plan, while NCETF and NCWTF added details as to their respective forces. Army and Air Force Commanders-in-Chief and Force Commanders also described their plans and intentions. The Supreme Commander himself summed up the main features of the Operation. Great if sober confidence in the outcome of the Operation was evident throughout the meeting. The need for flexibility to meet events which might not go in accord with plans was emphasized by both Prime Minister and ANCXF."1
- On 24th May H.M. The King visited the Portsmouth area. After being met by Admiral Ramsay, he embarked in each of the three Force Headquarters ships of the Eastern Task Force, and witnessed Assault Landing Craft Flotillas steam past in formation. His Majesty afterwards embarked in the Royal Barge and proceeded past major landing Craft assemblies at Portsmouth and Southampton, and Coastal Craft in Haslar Creek. The next day His Majesty visited Portland, where he was met by Rear Admirals Kirk and Hall, USN, and inspected ships and personnel of the Western Task Force, taking luncheon on board the Flagship, U.S.S. Augusta.
- On May 21st, the First Lord of the Admiralty, Mr. A. V. Alexander, and on June 4th the First Sea Lord, Admiral of the Fleet Sir Andrew Browne Cunningham, paid ANCXF visits at Southwick House. Mr. Churchill and Field Marshall Smuts employed June 4th watching the E.T.F. loading.
DESIGNATION AND POSTPONEMENT OF D-DAY
A. 5 June Designated as D-Day.
- With the approach of the invasion target date (May 31), a definite decision on D-day and H-hour, was required. No single question had been discussed more often. Until obstructions were discovered on the beaches, the number of days when an acceptable combination of tidal and light conditions would obtain was not severely limited. Confirmation of the existence of such beach obstacles required a re-examination of the question of the timing of the initial assault. At a Meeting held at Supreme Headquarters on 1 May, the situation created by the extension of obstacles was discussed. It was decided that they must be dealt with dry shod in areas in which they stood in less than two feet of water.1 This necessitated the adjustment of H-hour, which in turn required the fixing of a target date for D-day. After some days' consideration, Admiral Ramsay decided:
- That five different H-hours would have to be accepted, one for each assault force;
- That the earliest acceptable dates for the assault from the Naval point of view, were the 5th and 6th June, and,
- That the 7th June could be accepted in case of extreme necessity. General Eisenhower was informed of these conclusions at a meeting on 8 May.
- The Supreme Commander, on 23 May, signaled his decision in special code that D-day was provisionally fixed for 5 June,2 At 2330, 25 May, all holders of ON's were
directed to open their operation orders and to "execute operation NEPTUNE". Contrary to original intentions the nomination of D-day and H-hour was withheld in order to avoid announcing the newly decided five differing H-hours until after the orders had been read and understood. Three days later, at 1800 on 28 May ANCXF signalled that D-day was fixed for the 5th and that H-hour for respective assault forces would be:
Force 0 0610 Force U 0600 Forces S and G 0645 Force J, right sector 0655 Force J, left sector1 0705
B. NEPTUNE Forces in Movement
- The naming of D-day and H-hour, with the previous order to "carry out Operation NEPTUNE" was the executive signal which started all the intricate action and movements detailed in ON's. It was intended that no further despatch would be sent unless weather conditions forced a postponement of D-day. As the days went by it became increasingly clear that the long spell of fine weather was showing signs of breaking up, and that an unsettled spell was impending. On 29 May, at a meeting at which the Deputy Supreme Commander (Air Chief Marshall Tedder) was present, it was decided that Commanders Meetings to give critical examination to weather forecasts should be held at ANCXF Battle Headquarters twice daily from D minus 3 (2nd June) onwards. Details of movements of forces, in the event of postponement of D-day were promulgated, on 31 May, amplifying those contained in the ON's.
- The first convoys to sail with destinations in the Assault area left Oban, Scotland, south bound between 0700 and 1030 on the morning of 31 May. These convoys consisted of 54 CORNCOBS (Block ships to be sunk off the beaches on D plus l to form breakwaters). They sailed with sealed orders and under the impression that they were going only to their "southerly anchorages". Concurrently the intricate business of loading and final assembly of
assault forces was proceeding according to plan. The congestion of all the ports necessitated very careful timing and movement of craft, both loaded and unloaded.1 The job of loading and assembly had been well practised and few hitches developed. The overloading of craft continued, despite restrictive orders to prevent it, and some time was lost backing unwieldy vehicles onto the landing vessels. But "the knowledge that they were really "off at last" acted as a great incentive"2 to all hands, and the armada was loaded and assembled in good time. During this most vulnerable period the enemy made no effort whatever to interfere.
- At 1200, 1st June 1944, Admiral Sir Bertram Ramsay assumed operational command of "NEPTUNE" Forces and general control of operations in the Channel.
C. Weather Intervenes: Postponement of Assault
- The Supreme Commander's chief concern after June 1 was the weather dilemma. He presided over the first meeting of the Commanders-In-Chief to consider the weather forecast at ANCXF Headquarters on the morning of 2 June. Less favorable conditions were predicted for June 5th, particularly as regards cloud and cloud base, which was of special concern to the Air Force, since it would affect the passage of the Airborne divisions.
- The first warships to sail for the Assault Area (Bombarding Force D) weighed anchor from the Clyde in the evening (2nd June). The two midget submarines X.23 and
X.20,1 sailed from Portsmouth. H.M.S. Nelson left Scapa for Milford Haven.
- The weather further deteriorated over night. June 3rd was cloudy, with a westerly wind force 3 to 4 backing to S.W. and increasing to force 5. The sea was slight, increasing to moderate, and the cloud base was lowering. Commanders' meetings were held at 0430 and again at 2130 to consider the weather forecast. Further deterioration was predicted for 5th June. Though the wind was expected to increase to force 5 Admiral Ramsay considered that the Navy would be able to undertake its task if reasonable protection could be given from the air. Since the conditions predicted affected the airborne and Air Force plans more unfavorably than the Naval plan, the Supreme Commander decided at the evening meeting to await a possible change in the forecast in the next six hours. Meanwhile the ships continued to put to sea according to schedule. W.T.F. Bombarding Forces sailed from Belfast and the balance of the E.T.F., Bombarding Forces from the Clyde. Late in the afternoon, the little craft of Force U, the first of the Assault Force convoys, put to sea from Dartmouth, Salcombe and Brixham.
- The Supreme Commander again met with his three Commanders-in-Chief, at 0415, 4th June, to consider the weather. The sky was overcast, with the cloud ceiling low, with a wind of force 6 from the south west. The sea was moderate but rain was falling. The forecast for the 5th was for an increase of wind and a further deterioration in cloud conditions. Admiralty promulgated a gale warning for the Irish Sea (wind force 8). The Supreme Commander reluctantly decided to postpone the operation for one day. A general signal ordering the postponement was promulgated from ANCXF Headquarters at 0515.2
- Convoys at sea were ordered to reverse their courses, and to proceed to sheltering anchorages. Those which had not yet sailed were retained in harbor. The CORNCOB
convoys were diverted to Poole Bay. The Bombarding Forces reversed course with the intention of remaining at sea. Movements generally went in accordance with the postponement plan, and at 2250 that evening (4th June), the Commander-in-Chief, Portsmouth, reported all NEPTUNE convoys anchored, except Group U.2.A., still under way off Portland where the harbor was too crowded to permit entry.
- Group U.2.A. was a very large convoy totaling 138 vessels (77 British LCT, 61 U.S. LCT, 4 escorts and one rescue tug). It had progressed some distance ahead of its planned position and apparently did not receive the postponement signal. At 0900 it was 25 miles to the southward of St. Catherines Point and still driving south. Rear-Admiral Moon sent two destroyers to turn the convoy back, and the Commander-in-Chief, Portsmouth, sent a Walrus aircraft. By 0948 all the craft had turned to the northward.1 They were ordered to anchor in Weymouth Bay and refuel. Great difficulty was experienced in proceeding westward against the wind, which was then blowing W.S.W. force 5 to 6, with a short steep sea on the port bow. It was after midnight before any of the craft were anchored in the Bay.
- The two midget submarines, assigned to mark off the assault beaches, reached their positions at about the time that the decision to postpone the operation was taken, when they received the postponement signal, they submerged according to plan and remained on position for 48 hours until the arrival of the forces on June 6th.
D. The Supreme Commander's Dilemma: 6 June Fixed As D-Day
- The Supreme Commander held another meeting with his C-in-C at 2115 on Sunday 4th of June. The existing weather conditions were bad, typical of December rather than of June. The meteorological officers believed that there was a good prospect that the weather would improve
for 12 hours or so during the morning of the 6th of June. The conditions predicted for those hours were:- wind W.S.W., force 5, backing and decreasing slightly but freshening again in the afternoon of the 6th; the weather fair with showers and an overcast developing on the 6th; visibility mainly good; waves six feet in open sea decreasing slowly; outlook unsettled, with westerly weather and further deterioration continuing.
- General Eisenhower, after full consideration of all factors, decided to proceed with the operation on 6 June. There was a prospect of poor but possible water on that day. The weather prospect for the 7th and 8th was worse than that for the 6th. Two weeks postponement would be necessary until the next suitable tidal-daybreak combination if the invasion was not launched on the 6th or 7th.1 Confirmation that D-day was 6th June was therefore signalled to all forces.
- On the new schedule, H-hour for the 5 forces were to be:
Force U 0630 Force O 0630 Forces G and S 0725 Force J, right sector 0735 Force J, left sector 0745
- Admiral Ramsay summarized the situation, on this evening of June the 4th, as follows:
"On this day, the preparatory period of Operation NEPTUNE may be considered concluded, with the following brief picture of the situation:-
- Naval and Military assault and invasion forces had been assembled with all material that could be made available.
- Naval orders had been promulgated to the utmost foreseeable detail, and plans completed, with the exception of certain details concerned with Air Force intentions, which had to be signalled to ships and craft after they had sailed for the assault.
- Assault ships and craft were loading, or preparing to load, at every available berth where facilities existed from the Thames around the South Coast to the Bristol Channel. A broad dividing line between the Allied forces was at Poole; U.S. ships and personnel of Force O and U were being loaded in ports to the west of Poole while British ships and personnel were loading in that port and to the eastward. The assembly of the bombarding forces was complete.
- No serious interference with preparations had been effected by the enemy.
- Air Force Authorities had reported successful attacks on the targets (especially enemy Radar Stations) of naval interest specified by ANCXF and these attacks were continuing.
- The enemy was aware (though imperfectly) that this unparalleled assembly of shipping was approaching its climax, and that the state of preparations for the projected invasion had reached an advanced stage.
- No particular sign was discernible that the enemy had knowledge of the point of attack selected, but since February their defences in the Bay of the Seine had gradually been strengthened in common with all other parts of the coast where assault was practicable.
- Major difficulties which had arisen during the planning and mounting of the project can be attributed, in nearly every case, to the magnitude of the operation, creating strained resources in man-power, material and supplies.
- Problems of concern still remained in weather prospects, shortage of tugs, integration with
Air force plans when finalised, and strain on communications. There were also additional problems in connection with MULBERRIES, through the failure of Army authorities to deliver tows and stores for WHALES and adequate pumping gear for PHOENIX units, on which naval salvage gear had to be utilised.
- Chief problem of all, however, as the specified D-day approached was weather and the chances that suitable conditions for the assault would exist on 5th June. A long spell of fine weather had continued through May, but now the Meteorological Officers found with dismay that the fine spell showed signs of giving way to more unsettled conditions. From 1st June onwards any study of the weather chart could only result in grave concern both as to the prospects ahead and as to the difficulties of accurate forecast."
The Assault Movement of NEPTUNE Forces
A. General Outline of the Movement
- The NEPTUNE assault forces began putting to sea on the new time table during the morning hours of June 5th. By evening of that day the vast concourse of ships and craft were proceeding in accordance with the appointed program of movement toward the Beaches of Normandy. The general scheme of NEPTUNE movements, as shown in the accompanying sketch, may be summarized as follows.1
- The U.S. assault force "U", carrying elements of the VII U.S. Army Corps (two regiments of the 4th division), was loaded at Torquay, Brixham, Dartmouth and Plymouth, assembled in Torbay, Brixham, Dartmouth and Salcombe and was routed via the British coastal channels, cross Channel route "C" 2 swept channels 1 and 2, to the "U" assault area.
- The U.S. assault force "O", carrying elements of the V U.S. Army Corps (two regiments of the 1st division, and two of the 29th division) and certain U.S. Rangers, was loaded at Portland and Weymouth, assembled at Portland, Weymouth and Poole and was routed via the British coastal channels, channel "B", Area Z, cross Channel route "R", and swept channels 3 and 4, to the "O" assault area.
- The R.N. assault force "G", carrying the British 50th Division, was loaded at Southampton, assembled in Southampton harbor and the Western Solent, and routed via channel "B".3
- R.N. assault force "J", carrying the 3rd Canadian division and certain British commands, was loaded at Southampton and Portsmouth, assembled in the Southampton harbor and the Eastern Solent, and routed via channel "F", area "Z" cross Channel route "U", swept channels 7 and 8, and thence to the "J" assault area.
- The British assault force "S", carrying the 3rd British Division, was loaded at Portsmouth, Newhaven and Shoreham, assembled at Portsmouth, Spithead, Newhaven and Shoreham, and routed via the British coastal channels, cross Channel route "J" and swept Channels 9 and 10, to the "S" assault area.
- The U.S. follow up force "B", carrying the remaining regiments of the U.S. 1st and 29th divisions, was loaded at Falmouth and Plymouth, assembled at Falmouth, Fowey and Plymouth, and routed via British coastal channels, channel "C", and the American swept channels to the "O" and "U" areas, where it was to arrive by the second tide of D-day.
- The British follow up force "L", carrying the British 22nd Armoured Brigades and other formations, was loaded at Tilbury and Felixtowe, assembled at Southend, Sheerness and Harwich, and sailed via the British coastal lanes, area "Z", the British cross Channel lanes, and thence to the British assault areas, to arrive on the second tide of D-day.
- The first U.S. build-up convoy (EBP 1), carrying the preloaded U.S. division and supplies, was loaded and assembled in the Bristol Channel, sailed via the British coastal routes, channel "A", area "Z" and the U.S. cross the Channel routes to the "O" and "U" sectors, where it was to arrive by the second tide of D plus 1.
- The first British build-up convoy (ECT 2), carrying the preloaded British division, was loaded and assembled in the Thames estuary, was sailed via the British coastal channels, area "Z", and the British cross Channel lanes, to the British assault area, which it was to reach on the second tide of D plus 1.
B. Composition and Timing of Convoys
- The timing of NEPTUNE shipping movements was governed by the army plan of battle. All sailings were scheduled so as to deliver personnel and cargo on the far shore, at the times and in the sequence required for the land
battle 1 The timing of the cross Channel shipping movements was complicated by the fact that the vessels involved travelled at widely varying speeds. To standardize movements, initial convoys were designated as either slow (5 knots) or fast (12 knots). As each assault force required vessels of both speeds to accomplish its tasks, two convoys were formed for each purpose, both convoys of each "pair" being sailed so that they would arrive on the other side together and at the appropriate time.2
- British and American forces followed somewhat different systems of assault movement. Before leaving English waters, British forces were formed into 16 or 18 convoys, or groups, corresponding to the assault formation which they would assume for the landings. Thus, each assault group (carrying a Brigade landing team) was sailed from England in two convoys (a slow and a fast) as a distinct group, and was not merged in convoy with the other assault groups of the same assault force.
- The American Assault and Follow Up Forces on the other hand, were formed into convoys, in accordance with scheduled times of arrival by tides. Both Force O and U merged
Assault Groups into the same two convoys for the cross Channel passage. On arrival in the assault area, the convoy formation was dissolved and ships proceeded to their assault group stations. Within each convoy, however, vessels were arranged in assault formation. Transition from convoy formation to the assault formation was accomplished by having each assault group stop as the convoy steamed past its assault station.1
- British assault convoys were sailed so that only the leading brigades (regimental combat teams) would arrive in the assault area for H-hour. The supporting brigades of each division followed, in separate convoys close behind, in order to arrive in the assault area after the landing of the leading brigades had begun. All elements of the assault division were to be introduced, however, before the second tide of D-day. The follow-up force brought up a distinct new army division.
- In the American sector the first two R.C.T. of each division were brought into the assault area at the same time. One initiated the attack while the other followed in over the same beach later on. The third R.C.T. of each division was not brought into the assault area until, the second tide of D-day. In fact the last regiments of the assaulting divisions comprised the bulk of the U.S. follow-up force. The American program for assault convoy movements therefore consisted of the sailing of comparatively few very large convoys, 2 while the British program provided for sailing large numbers of comparatively small convoys.
- The American forces had been assembled at a large number of small ports,1 and travelled primarily in large convoys. It was therefore necessary that they sortie from their various ports in convoy sections and rendezvous at sea. The British were able to form up each convoy in its entirety in the assembly areas.
- The initial assaults were primarily infantry. But military vehicles, guns, and special equipment were required at a very early stage. The first convoys to arrive, therefore, carried chiefly personnel. Some military vehicles, guns and equipment were brought up in the earlier convoys, but the greater part was moved in by later convoys of each assault force. The accompanying sketches show the approximate position of convoys at H-hour, H - 6 and H plus 18.
C. Routing and Navigation
- The general plan for routing NEPTUNE convoys was:
- Convoys should move from their assembly anchorages, via the permanent swept channels of the British Coastal Routes, toward Area "Z".
- At an appropriate point, they were to turn out from the established channels and proceed to Area "Z", via routes specially laid out and searched for NEPTUNE (Channels A, B, F and K).
- At Area "Z", which was located a few miles off the British coast and due North of the assault area1 convoys were to turn southward through an area of searched water known as the SPOUT.2
- On reaching the German mine barrier they were to pass into the assault area through ten narrow swept channels, (channels 1 to 10), which were subsequently widened until the entire SPOUT was cleared of mines.
- The increase in the scale of NEPTUNE, from a three to a five divisional assault, required more room for the movement of the two new assault forces than was provided in area "Z". Two additional cross channel routes had therefore been laid out. (Routes C and V). NEPTUNE routes are laid out approximately to scale on the accompanying sketches.3
- A reliable system of navigation was required to locate the swept channels in the proper place, and to make sure that the innumerable NEPTUNE vessels would follow their assigned courses. No special navigational methods were
required for the navigation of ships while in the British coastal channels. A few of the coastal navigation lights and radar beacons, however, were turned on for the occasion.1 The special NEPTUNE routes were marked, at either end and down their center line, with distinctive buoys. The ten channels through the mine barrier were marked at either end, at the elbows and along the eastern edge, by a series of dan buoys. The transport areas were similarly marked.
- In addition to the normal navigational methods, a number of electronic navigational aids were employed:
- On D minus 6, ten sonic underwater buoys were laid at the northern end of the 10 approach channels. These were laid sonically dead to come alive on D minus l. They would then be used by H.D.M.L's acting as marker buoys, to enable the minesweepers to start sweeping the approach channels in the correct positions.2
- All key buoys were equipped with special radar reflectors which gave a distinctive response on ships radar. Ships were thus able to take bearings whether they could see the buoys or not. With SG Radar installed in at least one out of every six LCI's and above, the reflector buoys provided a very great safeguard.2
- The majority of convoys were provided with special navigational leaders equipped with "QH" and "QM".1 This enabled them to determine their position to a high degree of accuracy in any sort of weather.
- Radar stations on the British shore maintained close watch on the channel area. The position of all ships and convoys were plotted on central plotting charts. C-in-C Portsmouth was thus able to discover at once if any ship or convoy was departing from its scheduled route, and to correct its position by a suitable radio message.
D. The Assault Forces Reach the Beaches
- The entire vast program of assault movements proceeded basically according to schedule and along the established routes without serious deviation. Some mistakes, however, were made:
- Four groups of Force J, and one group of Force S, proceeded down channels to the westward of the correct ones. When this was discovered, before the groups reached the lowering positions, they cut across unswept waters to their proper positions. No casualties from mines were sustained, however, and all reached their appointed positions in time to assault as scheduled, except a few LCT of
Assault Group J-1.1
- The tail of convoy O.2 (which was a very long convoy) drifted eastward down wind and down tide, across unswept waters, and into channel 5, where Group G1 was pushed out. When the tide turned, the tail of convoy O.2 drifted off course the other way.2
- Vessels of Convoy U 2 were likewise set to the westward by the strong tide and got into channel 3 where they disturbed the progress of convoy O.1.3
- The waves of assaulting craft were aided, in finding the appointed beaches and the touching down at the right spot, by special devices in addition to normal navigational methods. Two X craft (small submarines) marked the approaches to beaches Sword and Juno. It was very important that Force S should not hit too far to the eastward. The coast in Force J's sector was not distinctive in outline. These craft, which sailed on the night of 2nd - 3rd June, being towed part way, were in position to mark the beaches for the original D-day (June 5th). When they received the postponement signal, they lay on the bottom all the ensuing day, and were able to mark the beaches accurately.
- Certain MLs were designated navigational leaders, and fitted with Type 970 Radar. A projector was fitted to the PPI of this radar, from which a sort of lantern slide could throw an image on to the PPI scope. Predictions
were prepared which cast an image on the PPI scope exactly like that which the radar would show when the ship was located at a certain spot. When the radar image and the predicted image were matched the ship was known to be on the spot indicated. Predictions were made for points on the line of approach 5,000 yards and 1,500 yards (the line of departure) off shore. By use of these predictions, the navigational leaders brought the landing waves and control vessels to the intended line of departure with great accuracy.
- The shoreward movement of assault craft was controlled by primary and secondary control vessels. These were PC's and SC's, in the case of U.S. Forces, and ML's and light destroyers, in the case of the British Forces. Control vessels were equipped, to find and mark the "line of departure" to beaches, so that the assaulting craft would be started shoreward in the right time, place and sequence.
- Despite all of these preparations, however, both the primary and secondary control vessels on one battalion front of Force U became casualties. The U forces finally landed 1,000 to 1,500 yards south of their intended point. This proved a fortunate error, however, since both beach obstacles and land defenses were less formidable at the point of actual landings.
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p.381 #1 ANCXF established his battle headquarters at Southwick House in Southwick Park on 26 April. Previously the premises had been an R.N. Navigational School with the name H.M.S. Dryad. The site was conventiently near the combined Headquarters Portsmouth at Fort Southwick. SHAEF and H.Q. 21 A.G. were under canvas in the woods surrounding Southwick House.
p.381 #2 U.S.S. Augusta arrived at Plymouth on 22 April, and on the 25th Rear Admiral Kirk (NCWTF) hoisted his flag in her.
p.382 #1 A.N.C.X.F. Report, Vol. I. Page 33.
p.383 #1 ANCXF Report, Vol.1. Page 9.
p.384 #1 By way of comparison ONEAST, NCETF's orders were about 3/8" thick.
p.385 #1 While ANCXF was critical of the detail and volume of ON's, he evidently found the necessities of the case compelling same, his own orders are equally voluminous and even more detailed. In fact he followed the similar procedure of having subordinates submit their intentions, of coordinating them, and then incorporating the results in his orders, ONWEST
p.386 #1 Unofficial reports have it that the staff of ANCXF concocted a document entitled "Naval Orders Operation OVERBOARD. American stupid equals British Most Stupid. These orders are so secret that they are to be burned before reading".
p.386 #2 Briefed personnel who became sick were sent to "sealed" hospitals. Despite objections by ANCXF, relatives were allowed to visit them,
p.387 #1 NCWTF despatches 262345 May 1944 and 291341 May 1944.
p.387 #2 NEPTUNE, OVERLORD, OMAHA, UTAH, MULBERRY, WHALE and several others. Investigation by Admiralty N.I.D. resulted in the conclusion that this was purely coincidence.
p.388 #1 ANCXF Report Vol.I, Page 28 Paragraph 27. The production of firm AEAF plans was probably not expedited by the CCS delay in deciding on Air Force Command and the forces to be allotted to the AEAF (See Chapter III).
p.388 #2 ANCXF Report Vol. I, Page 36 Paragraph 30.
p.388 #3 Admiral Ramsay's doubts were based on experience during the Sicilian invasion when allied Naval AA shot down a great many allied troop carrier aircraft which passed over head during an air raid. As predicted the same thing happened on Sword Beach on the evening of June 7/8.
p.389 #1 See ANCXF Report Vol.1, page 39 Paragraph 52 and Page 42 Paragraph 68.
p.390 #1 These areas were chosen for security reasons, in order to prevent the Germans from guessing what they were or where they were going.
p.390 #2 ANCXF Report Vol. 1. Page 35 Paragraph 23.
p.391 #1 ANCXF Report Volume 1, Page 36 Paragraph 29.
p.392 #1 A number of reconnaissance landings, arranged by the Chief of Combined Operations, were carried out to investigate the extent of these obstacles. On the night of 17/18th May, two officers failed to return from one of these missions in the Pas de Calais area.
p.392 #2 As sailing orders to certain units, such as the CORNCOBS (Blockships) at Oban, had to issued as early as D minus 8, it was necessary to fix D-day provisionally as early as possible.
p.393 #1 The basic H-hour for purpose of sailing and general timing was in the ETF 0654, in the WTF 0610.
p.394 #1 In his report C-in-C Portsmouth stated:
"It is a commonplace expression to say that an anchorage is 'full of ships', but in the case of the East and West Solent with an available area of approximately 22 square miles in which to anchor ships, it was literally true. On 18th May the Admiralty offered the Commander-in-Chief, Portsmouth, the services of H.M.S. Tyne, but it was only possible to accept her because H.M.S. Warspite was not being sent to Portsmouth till D-day, which gave one berth in hand". - Report on Operation "OVERLORD".
p.394 #2 Report of NC Force S contained ANCXF Report Vol.II Paragraphs 8 and 9.
p.395 #1 X23 and X20 were towed by H.M. Trawlers Sapper and Darthema till in Lat. 50°22'N Long. 0°50'W, when they were slipped at about 0430, 3rd June. They proceeded under their own power, dived throughout daylight, 3rd June, surfacing after dark to cross the enemy mine barrier, and arrived off the French coast about 0500, 4th June.
p.395 #2 This signal included the revised times of H-hours for 6th June.
p.396 #1 About half an hour later, the 14th Minesweeping flotilla reported mines in approximately lat. 50°15'N., long. 1°16'W, (15 miles south of St. Catherines point). This area was in the route of the Force U convoys. Five mines were cut and two exploded in the sweep - all of the New German X star type.
p.397 #1 In his Report, Admiral Ramsay said that although the unfavorable weather caused difficulties and damage to craft off the beaches later, the advantages gained by surprise were so striking that the decision of the Supreme Commander to go on despite the weather was amply justified. "A postponement of one more day, e.g., till 7th June would, in the event, have proved disastrous owing to the conditions of sea off the beaches. The problems arising out of a postponement of 12 or 14 days to the next suitable period are too appalling even to contemplate." ANCXF Report Vol. 1 Page 10. The great and utterly unexpected and unpredicted storm broke on what would have been the afternoon of D-day.
p.400 #1 The broad scheme was not always followed in detail. Exceptions which are noted elsewhere, were minor.
p.400 #2 The location of these channels are shown on sketch following.
p.402 #1 As has been seen in Chapter IV the broad outline of the time table for delivery of army units on the far shore was as follows: (1) Five divisions were to be delivered on to five selected beaches in the Bay of the Seine in the assault formation at, and shortly after, H-hour. (2) Two further divisions of follow-up troops were to be delivered on the second tide of D-day. (3) Two more divisions plus military cargo were to arrive on D-plus 1. (4) Thereafter army formations were to be delivered at the rate of 1.1/3rd divisions per day until a total strength of 30 divisions was reached. (5) After that, the build up was to proceed at the rate of three or four divisions per month as required.
p.402 #2 Each assault force was provided with two channels through the mine barrier, one for the slow convoys and one for the fast. The far end of the slow channel ran along beside the far end of the fast channel so that at the end of the run any pair of convoys was matched up side by side.
p.403 #1 The first group to stop had been placed at the rear of the convoy and so on.
p.403 #2 Convoy O 2 contained 293 vessels. (See NCWTF Report - in ANCXF Report Vol. III Page 96.
p.404 #1 Force U was loaded in 9 different ports and assembled over a stretch of coast line some 150 miles long. Force O was loaded and assembled at 5 ports.
p.405 #1 Area "Z" was a circle of 5 mile radius centered on a point 15 miles south of Nab light at position 50°25', 0°58' W.
p.405 #2 Four channels (channels R, S, T and U) were laid out across the SPOUT so that the convoys would not intercept one another.
p.405 #3 For the exact definition of Convoy Routes, see ON-17.
p.406 #1 ANCXF Report Vol.1, Page 43 Paragraph 82.
p.406 #2 ANCXF Report Vol.1, Page 42 Paragraph 67.
p.406 #3 See ANCXF (US) Report on Naval Communications in NEPTUNE, Page 29. See also Chapter V, Section for installation program on U.S. vessels.
p.407 #1 "QH" consists of three transmitters located at known positions, each transmitting a pip simultaneously. The difference in time which the pips from the two transmitters are received establish a line of points along which the receiving ship may be located. The difference in time at which another pair of pips is received establishes another line along which the receiving ship may be located. The point at which these two lines intersect, is the location of the ship. In the cross channel operation, "QH" was accurate to within 100 yards and "QM" which is a similar device was accurate to within 50 yards.
p.408 #1 Report of NC Force J, and NC Force S.
p.408 #2 Report of NC Force G.
p.408 #3 Report of CTF 124 (NC Force U) Paragraph 10.