Number 38111

SUPPLEMENT
to

The London Gazette

Of TUESDAY, the 28th of OCTOBER, 1947

LIBERATION OF EUROPE (OPERATION "OVERLORD")
OPERATIONS OF COASTAL COMMAND, ROYAL AIR FORCE,
FROM MAY TO AUGUST 1944

The following despatch was submitted to the Secretary of State for Air on November 1st, 1944, by Air Chief Marshal Sir Sholto Douglas, K.C.B, M.C, D.F.C., Air Officer Commanding-in-Chief, Coastal Command, Royal Air Force.

I have the honour to submit a despatch on the preparations for and results of operations by my Command for the period May to the end of August 1944. By September the successful progress of our Armies during the three months that they had been established on the Continent had denied the enemy the effective use of the Bay of Biscay ports as submarine bases from which to conduct his war against our shipping. This marked the end of an important phase in  the U-Boat war.

PLANNING AND PREPARATION.
Preparations by the Enemy and Ourselves.

2. At the end of March 1944, there were signs that the enemy was reducing the number of U-Boats operating in the Atlantic, presumably with the intention of conserving his forces for the forthcoming assault. This was confirmed in April, when the number operating in this area was very small .The lull continued during May, with large concentrations of U-Boats in the Bay of Biscay ports. This policy of the enemy's, while it reduced our opportunities for killing U-Boats, permitted an intensive training programme for the Leigh Light squadrons in the United Kingdom—which I had started at the end of March—to proceed without hindrance. The urgent need for Leigh Light aircraft over the past two years had meant that aircrews turned over to this role had had insufficient time to devote to training, and the standard of homing and Leigh Light manipulation was not as high as it might have been. Ten weeks' intensive training was carried out by the U.K.-based Liberator and Wellington searchlight squadrons, and when D-day came the standard was much improved.

Directive for "Overlord".

3. In April 1944, I issued to my Groups a directive which set out the tasks of each Group for the Overlord operation that was shortly to take place, and outlined the action that the Admiralty anticipated would be taken by the enemy.

ANTI-U-BOAT.
Appreciation of Enemy Intentions.

4. On the assumption that the enemy would direct his U-Boat offensive principally against our cross-channel convoys, the Admiralty appreciated that the bulk of his U-Boats would operate from the Bay ports and endeavour to penetrate the S.W. Approaches to the Bristol, St. George's and English Channels, and that he would maintain only comparatively small forces in the Atlantic convoys would be drastically reduced. It was also necessary to provide to some extent against the passage of U-Boats through the Northern Transit Area and also against the possibility of the movement of U-Boats through the North Sea. These areas had however to be regarded as of secondary importance when compared with the S.W. Approaches, and it was not intended to provide permanently for more than thin cover in the Northern Transit Area. The North Sea area would be covered only if the situation demanded it, and my plans allowed for four anti-U-Boats squadrons to be drawn from those

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allotted to the S.W. Approaches and to be transferred to bases on the East coast should the necessity arise.

Tasks of Coastal Groups.

5. The tasks of my various Groups in the United Kingdom in the anti-U-Boat role were briefly as follows:—

19 Group (Plymouth).
  1. To provide adequate air cover in the S.W. Approaches to protect the flanks of the Allied Assault Convoys.
  2. To provide cover or close escort to Allied Assault Convoys in the S.W. Approaches.
  3. To hunt and destroy enemy U-Boats attempting to attack Allied Assault Convoys in the S.W. Approaches.
16 Group (Chatham).
  1. In the event of a threat by U-Boats to the Eastern flank of the Allied Liberation Forces by way of the North Sea, to hunt and destroy enemy U-Boats attempting to enter the English Channel from the east.
  2. To provide cover or close escort by Fleet Air Arm Squadrons allocated to the Group to Allied Liberation Convoys on passage between The Nore and Beachy Head.
15 Group (Liverpool).
  1. To provide cover to threatened Atlantic Shipping.
  2. To cover the entrances of the North Channel against the passage of enemy U-Boats.
  3. To provide A/U cover in the Northern Transit Area.
18 Group (Rosyth).
  1. To provide A/U cover in the Northern Transit Area.
  2. To provide aircraft for Fleet Reconnaissance duties.
The Main Threat

6. In the main area of the S.W. Approaches, the first principle adopted was that of "the cork in the bottle", the object being to flood an area of sufficient depth to kill or keep submarines submerged from the Western limits of the St. George's and Bristol Channels and the English Channel up to a point as near as possible to the route of our cross-channel convoys. The patrols were so calculated as to provide a cover of thirty minutes density in the area. By this plan I expected a high percentage of kills if the U-Boats came through on the surface, or, alternatively, it would, force upon them maximum caution tactics throughout their passage. In the latter even there would be a zone to the East of the flooded area in which U-Boats would be forced to surface for prolonged periods to recharge their batteries, and in which they could be attacked and hunted by air and surface forces with good prospects of success. Moreover, individual patrol areas were so designed as to be readily removable from one part of the main area to another, so that one portion could be immediately strengthened at the expense of another in the light of the situation as it developed. Further, the "cork" could be pushed home or withdrawn at will. In this way the plan preserved flexibility without detriment to the principle upon which it was based.

The Need for Fighter Cover.

7. The extent to which the "cork" could be inserted was considered dependent upon the degree of fighter cover that could be provided by A.E.A.F., since the Southern boundaries of our patrols ran close in to the coast of France along which the enemy was expected to move his U-Boats under cover of his fighters and shore defences. Once the assault was launched it was expected that the enemy fighters would be heavily engaged in the area of the main battle and that no substantial numbers of S.E. fighters would be able to be spared for the protection of U-Boats. The commitment for providing fighter cover was not therefore likely to be a prolonged or heavy one, but it was reasonable to expect from the enemy some early reactions to the preparations in progress and also to any exercises which took place before D-Day. One such exercise, known as FABIUS, was considered sufficient in scope to make it possible that the enemy might believe the assault was startling. Should this happen, I considered that it might be necessary prematurely to implement the plans of my Command in full, and in this case the requirement for S.E. fighter cover would become much more serious. I considered, however, that at this stage our fighters would not be heavily committed elsewhere, and the Air Commander-in-Chief, A.E.A.F., confirmed that full scale fighter support could be provided any time up to D-day. Provision for the protection of A/U aircraft against enemy long range fighters (Ju 88s) was to be most allotting Mosquito and Beaufighter aircraft of my own Command for this task.

Convoy Cover.

8. In addition to flooding the selected area, plans were made for the protection of our cross-channel convoys sailing along the South coast of England. I allotted this task principally to the Fleet Air Arm Squadrons (eight of which were placed under my operational control for "Overlord"), backed by such 19 Group aircraft as I could spare from their main task.

Operation of Surface Hunting Groups

9. Surface hunting groups were to be operated under the control of the Naval Commander-in-Chief, Plymouth and Portsmouth, Cooperation between these Groups and aircraft was arranged between A.O.C. 19 Group and C-in-C Plymouth, who coordinated his own requirements and those of C-in-C Portsmouth.

ANTI-SHIP OPERATIONS
Tasks of 16 and 19 Groups

10. It was expected that the enemy would launch an offensive with destroyers and light surface craft against our convoys sailing to and from their assembly ports and on passage across the Channel. Air operations to meet this threat were to be conducted by 16 and 19 Groups, whose tasks were as follows:—

19 Group.
  1. To hunt and destroy E-Boats and destroyers in the S.W. Approaches and Western Channel.
  2. To provide anti-E-Boat and destroyer reconnaissance in conjunction with Naval Surface Force operating in the area in (i).

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16 Group.
  1. To hunt and destroy E-Boats and destroyers in the Southern North Sea.
  2. To provide anti-E-Boat and destroyer reconnaissance in conjunction with Naval Surface Forces operating in the Southern North Sea.
Form of Operations.

11. It was correctly appreciated that anti-ship operations would take place mostly at night and at dawn and dusk, and these were to take the following forms:—

At night.
  1. Operation of Albacore and Swordfish under G.C.I. control of 10 and 11 Groups.
  2. Reconnaissance by Wellington flare-dropping A.S.V. aircraft operating under 16 and 19 Groups, and the subsequent direction of  Naval Surface Craft and/or Coastal Command Beaufighters to the target.
At dusk and dawn.

Beaufighter sweeps with the object of destroying enemy Light Surface Craft when leaving harbour at dusk or returning from patrol at dawn.

12. As in the case of anti-U-Boat measures, I was prepared to implement these plans as a result of enemy reaction to exercises such as "Fabius", or to any other event which might have led him to believed that the assault was imminent.

Main Battle Zone.

13. In agreement with the Admiralty and the Air Commander-in-Chief, A.E.A.F., I demarcated an area between the lines Portland to Jersey on the West and North Foreland to Calais on the East, as the main battle zone. Coastal Command aircraft were to operate primarily on the flanks of this area and only to a limited extent within it. This was an important point. I expected such a concentration of shipping of all sorts in this zone which even by day I considered it would be difficult to distinguish friend from foe, and at night almost impossible. As it turned out, however, it became possible, by special briefing at Area Combined Headquarters, for my anti-shipping aircraft to operate within the Battle Zone outside the central area containing the cross-channel shipping lanes.

Order of Battle.

14. The Order of Battle, as it stood on 6th June, 1944, shows that, in order to make the flooded area in the S.W. Approaches effective, I deployed no less than 21 of my A/U squadrons together with 4 Fleet Air Arm squadrons in this area. My ant-shipping striking force consisted of seven Beaufighter squadrons, of which I allotted initially five to the east of the main battle zone where the threat of E-Boats was considered greater, and two to the west.

CONDUCT AND RESULTS OF OPERATIONS.
U-Boat Operations in the North.

15. Intensive operations for Coastal Command began in mid-May, although only the Anti-U-Boat squadrons in the North were involved. At this time the enemy decided hurriedly to reinforce his U-Boat flotillas in the Bay of Biscay by moving a number of his Norwegian-based boats into the Atlantic and thence southwards to the Channel and French West Coast ports. The U-Boats were presumably in too much of a hurry to proceed submerged, and their Commanding Officers were apparently confident in the efficiency of their anti-aircraft defences, for they remained on the surface and shot it out with the aircraft to their own detriment. Every opportunity was taken to bring to bear on the enemy the fullest weight of attack without reducing the forces preparing for the vital struggle which was shortly to take place in the S.W. Approaches, and I therefore moved detachments of squadrons from Iceland and Northern Ireland to airfields and flying boat bases in northern Scotland and the Shetlands, to supplement the aircraft at the disposal of the A.O.C. 18 Group. All through June and July these Northern operations went on, and towards the end of July they extended into Arctic waters, where the enemy seemed to be trying to work round into the Atlantic out of aircraft range. This meant that operations were being conducted at no less than 850 miles from the aircraft's bases. At the end of June, however, I had moved the whole of the VLR* Liberator squadron from Iceland to Tain, and this squadron bore the brunt of the operations conducted in these very far Northern regions.

16. During June perhaps three or four boats in all got through to the Bay of Biscay. The rest were either destroyed or damaged and forced to put back to Norway. In those Northern latitudes at the time of year there was no darkness, and, at the beginning of the battle at any rate, few of the Northern U-Boats had been fitted with "schnorkel". these two factors were largely responsible for the opportunities for so many attacks.

17. During the period mid-May to the end of July, we sighted seventy-five U-Boats in Northern Waters and attacked fifty-one. Of these sixteen were sunk or probably sunk and twelve damaged. These success were not achieved without cost. 162 Canadian Squadron sank four U-Boats and lost three Catalinas in June alone. Two Victoria Crosses were awarded to officers taking part in these operations, one posthumously to the Captain  of a Catalina of the aforementioned 162 (R.C.A.F.) Squadron, and a second to the Captain of a Catalina of 210 Squadron.

U-Boat Operations in the South.

18. Despite the importance of these far away operations, it was inevitable that the main attention should be concentrated on the beaches of Normandy and the English Channel. The preparations for the assault and the large scale exercises during the last few days of May and the beginning of June did not produce any reactions form the enemy, and on 6th June the majority of the enemy's operational U-Boats were still assembled in the Biscay ports. They were not offensively deployed on that date, so there can be no doubt that the enemy had been unable to discover the date of our landing. On D-Day however, he reacted swiftly. It soon became clear that the U-Boats were making for the assault area with the utmost speed—that is, on the surface whenever possible. The air patrols which had been planned to counter this move were already being flown and successes soon materialised. Off the Brest Peninsula and in the mouth of the


* Very Long Range.

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Channel, thirty-six U-Boats were sighted by Coastal Command in the first four days of the assault and twenty-three were attacked. Six were destroyed and four seriously damaged. Sixteen of the attacks were at night. Two of the U-Boats destroyed were sunk on one sortie within 20 minutes by a Liberator of No. 224 Squadron, piloted by Flying Officer Moore. In almost every case the enemy fought back desperately with his anti-aircraft armament, for in those four days the U-Boats were in too much of  a hurry to be able to proceed submerged. They inflicted a high proportion of casualties on our attacking aircraft, but very few got through. Prisoners of war from the U-Boats have told us that the penetration of the Channel was a nightmare.

19. After D plus 4 the enemy was forced to change his tactics. During their sojourn in the Bay ports almost all the U-Boats had been fitted with the exhaustible air intake (Schnorkel), and from the fourth day of the assault until the end of June sightings mainly consisted of periscopes and "Schnorkels" of U-Boats trying to get through by remaining submerged continuously and by relying on "Schnorkels" to ventilate the boat and charge batteries. The "Schnorkel" is a most difficult target for airborne radar, and it cannot be denied that the enemy's recourse to this cautious method of approach reduced his losses. At the same time, however, the effect of remaining submerged had an adverse effect on the morale of the U-Boat crews and their achievements were notable by their absence. Between D plus 4 and the end of June forty-seven sightings of U-Boats were made by Coastal Command in southern waters and twenty-four were attacked. During this period at least one more U-Boat was sunk by aircraft and two kills were shared with ships of the Royal Navy, who were taking an ever increasing part in the policing of the Channel and its approaches. In addition, aircraft damaged another four U-Boats and shared with the Navy in damaging a fifth.

20. In July the picture was the same. The enemy was still trying to get in amongst our shipping by making the fullest use of his schnorkel device. In all, twenty-two sightings were made and fifteen U-Boats attacked during this months, of which two were sunk and another damaged.

21. By the end of July there was no doubt that the enemy's threat had been beaten. Only a small number of U-Boats had got through to our shipping lanes, and, in the three months from D-Day to the end of August, of the thousands of merchant ships taking part in the Channel operations, only nine were sunk by U-Boat action.

22. Finally, the steady progress of our armies made it obvious to the enemy that he would soon lose the use of the Bay ports. He therefore began to evacuate them during August and to send U-Boats northward to his Norwegian bases. During the month some ferocious actions were fought in the Bay of Biscay almost within sight of land with U-Boats trying to escape, and six were accounted for by Coastal Command aircraft, three of these being shared with the Navy. By early September, the Biscay U-Boat force had withdrawn and was making its passage, underwater nearly all the time, to the Norwegian ports.

23. In the whole battle in the North and the South from mid-May to the end of August, Coastal Command sank twenty-seven U-Boats, damaged another so badly that when it reached its base it was paid off, shared in five more sunk, and damaged another twenty-nine, including two shared with the Royal Navy.

24. In these operations, where skill counted as much as courage and where both were indispensable, we lost thirty-eight anti-U-Boat aircraft by enemy action and another twenty-two through the hazards of maintaining our patrols in fair weather and foul. A high proportion of these aircraft were four-engined heavies with large crews.

Anti-Shipping Operations.

25. While the U-Boats were being defeated in the south-west and the north-est, Coastal Command was also in action against enemy surface forces. Soon after the assault began, the enemy tried to reinforce his surface craft in the assault areas by bring up three destroyers from the Gironde. These vessels were attacked by our aircraft while still south of Brest on 6th June, but the damage inflicted did not prevent the enemy from making port. Two days later the ships tried to round the Brest Peninsula, but were brought to action by the Royal Navy. One Seetier class destroyer was driven ashore, the Tjerk Hiddes was sunk, and the second Seetier was forced back to Brest. The beached destroyer was later attacked by Beaufighters with rockets and bombs, and became a total loss. After this the enemy made no further attempts to reinforce his surface craft from the west, and the only serviceable Seetier and Elbing destroyers were withdrawn to the Gironde.

26. In the early stages, as was expected, the enemy operated his light forces on quite a considerable scale against our assault forces in the assault area. E-Boats were the main weapons. Some thirty of these vessels were based between Boulogne and Cherbourg, but the number was later reduced by air attack, by surface action, and by the outstandingly successful attack by Bomber Command against Le Havre and Boulogne.

27. The operations of Coastal Command against these light forces consisted mainly of continuous anti-shipping patrols in the Channel Albacores, Avengers, Swordfish, Beaufighters and Wellingtons made a great many attacks, mostly at night, against E-Boats, R-Boats, "M" class minesweepers and trawlers. Wellingtons did a great deal of reconnaissance work, dropping flares and directing naval forces to their targets. Results were naturally extremely difficult to assess, but we know from prisoners of war that hardly an E-Boat put to sea without being spotted and attacked from the air. In the darkness and in the face of flak from other vessels it is almost impossible to investigate the result of a bombing attack on an E-Boat flotilla, but there is no doubt that the menace of the enemy's light forces was held in check by the operations of the Royal Navy and Coastal Command.

28. The enemy made no use of his major units in the Baltic. Moreover, with the exception of one or two flotillas of E-Boats, he never attempted to reinforce the Channel from the East, in spite of the fact that he had a

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number of heavy destroyers and about twenty torpedo boats available in the Baltic. It is probable that he realised our combined sea and air defences made the Southern North Sea and the English Channel a very unpleasant area for operations by the German Navy. In any case, it is certain that, despite the few positive results of our night attacks, the enemy was so harassed by them that he was unable seriously to interfere with our "Overlord" shipping.

29. This success meant that, from the end of June, my anti-shipping aircraft were able to devote more of their time to the second of their two tasks—the interruption of German coastal shipping. In June, I directed the greater part of my effort to the naval targets in the Channel, and only a few attacks were made on convoys. These, however, included some very successful engagements, the most important of which occurred on 15th June north of the Dutch island of Schiermonnikoog, when Beaufighters sank a merchantman of 8,000 tons, a naval auxiliary of 4,000 tons and a minesweeper, besides damaging four more of the escort vessels.

30. In July I kept up the Channel protection, but diverted all but one of the Beaufighter Squadrons to convoy strikes off the coasts of South Norway and the Low Countries. There is no doubt that these strikes proved most harassing to the enemy, and he was obliged to divert to this purely defensive task numbers of minesweepers and naval escort craft which he urgently required elsewhere.

31. The beginning of August saw a new phase open in the shipping war. As our tanks swept through North-Western France, enemy coastal craft broke for th comparative safety of the North Sea ports; one night alone saw 70 of them attacked from the air. Moreover, the enemy in the Brest Peninsula was cut off by land. He as therefore obliged to squeeze yet more work from his seaborne supply services. Every available ship in Western France from Brest to Bordeaux was pressed in service to keep the beleaguered garrisons supplied. Coastal Command made the best of this opportunity. Mosquitoes based in Cornwall, Halifaxes, previously operating in an Anti-U-Boat role, and a Wing of Beaufighters which I transferred from the East Coast convoy routes, operated all along the Biscay coast. Merchant ships, sperrbrechers, minesweepers and coasters of all kinds were sunk, and a fitting climax was reached on 24th August when the last of the larger German warships in this area, a Seetier and an Elbing class destroyer were sunk in the Gironde by the rockets of the Beaufighter Wing

32. At the beginning of September, the area of anti-shipping activity had moved eastward in the wake of the Allied armies. There were no more attacks in the Bay of Biscay or in the Channel. As the enemy-occupied ports fell into our hands, the night patrols of the Beaufighters, Avengers and Wellingtons moved eastwards along the coast. This happened so quickly that there were no attacks off the Belgian Coast after 7th September, and our attention was turned completely to the intensification of the offensive against the enemy's shipping operating off the Dutch and Norwegian coasts.

33. This concluded three months of intensive operations in which the German naval units and merchant shipping in Western Europe had been hammered unmercifully.

CONCLUSION.

34. I wish to end this despatch by paying tribute to all personnel in Coastal Command who by their tireless endeavour and concerted efforts helped to bring about the victory over the enemy sea opposition to the liberation of Europe. In addition to the operations of my Anti-U-Boat and Anti-Shipping aircraft ,whose activities have been recounted, the photographic reconnaissance squadrons, the meteorological squadrons and the air/sea rescue air and surface craft all carried out their arduous tasks with skill and resolution.

35. I would like to mention particularly the Fleet Air Arm Squadrons which were incorporated in my Command for operation "Overlord". They performed their varied duties with outstanding keenness and precision.

36. A tribute must also be paid to the Liberator Squadrons of the U.S. Navy, under Commodore Hamilton, U.S.N., which, working under the operational control of 19 Group, did invaluable work, particularly during the "cork in the bottle" operations.

37. Two Norwegian Squadrons, a Czech and a Polish Squadron were also distinguished for their gallantry and enthusiasm in the combined team.

38. Finally, it will not be forgotten that the success of our operations could not have come about but for the skill in planning and organisation of the Command and Group Staffs who—with the invaluable and enthusiastic cooperation of the Staffs of the Naval Commands—worked long and hard to perfect our preparations; and but for the ceaseless energies of the ground personnel at Stations who provided our aircrews with the means to reap their victories.

I have the honour to be,                
Sir,              
Your obedient Servant,
SHOLTO DOUGLAS,
Air Chief Marshal,
Air Officer Commanding-in-Chief,
Coastal Command, Royal Air Force.

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Transcribed and formatted for HTML by David Newton for the HyperWar Foundation