The large scheme of visual misdirection inaugurated by COSSAC in the autumn of 1943 depended, on the one hand, upon the concealment or display of real warlike preparations and, on the other, upon additions to these preparations made for the sole purpose of deceiving German spies and reconnaissance aircraft. The policy of ‘concealment and display’ had been set in motion in September and was now being actively pursued by the Commands affected. Permission to embark on the ‘false’1 preparations had been given by the Chiefs of Staff at the end of November when they reviewed APPENDIX ‘Y’, and by the end of February 1944, when the Joint Commanders were entrusted with the detailed planning, some progress had been made. It was recognised at the outset that these ‘false’ preparations were bound to compete with the mounting of the real invasion in the demands that they made on manpower, materials and movement facilities. In October 1943, when APPENDIX ‘Y’ was still being written, the Director of Movements at the War Office had sounded a warning note: ‘I must stress that this paper, as it stands, suggests the provision of additional shipping and movement activities which are impracticable.’2 When the time came, however, for the Q (Ops) Committee at the War Office to allocate the administrative resources available, their deliberations were characterised by efforts, not so much to settle rivalries between real and cover demands, as to discover what the cover demands were. These proved extraordinarily difficult to formulate. On 9th February SHAEF issued a guidance letter to the War Office3 indicating the movement and administrative preparations required in the East and South-East in addition to those required for the embarkation of the OVERLORD forces. Constructional work undertaken for the purpose of deception was to continue ‘as far as Command resources allowed’, but until OVERLORD D minus 30, the main effort would be directed towards completing the real preparations. After that date the effort was to be transferred to the cover programme. This fitted in with the later target date for the Pas de Calais and avoided a direct conflict between the demands for real and ‘false’ preparations, since it was hoped that construction for the real operation would have been completed, or very nearly so, a month before the invasion date. The guidance letter of 9th February contained a number of miscellaneous provisions, some of them repeated from APPENDIX ‘Y’, which, it was felt, would add realism. Preparations were to be made for the reception of casualties and prisoners-of-war in South-Eastern Command. Military stores were to be displayed in the ‘cover’ areas. Members of the National Fire Service were to be moved in. Training units were to be evacuated.
The letter did not omit a reference to the conflict arising from our adherence to a postponed D Day, which affected this aspect of the plan just as it complicated every other. The story which would be told until the invasion took place was of an attack in July. From D Day onwards the Germans were to believe that the second assault might be launched at any moment. ‘It will be seen that the two stories are in conflict as the first has a target date of NEPTUNE D plus 45, while the post D Day operation has a target date of, or just after, NEPTUNE D Day. Long-term preparations should therefore indicate the later target date while those final preparations, which take a comparatively short time to complete, should be delayed until the last possible moment compatible with apparent completion by D Day.’ This may be taken to mean that while such things as road-making and building should be proceeding apace during the month of May, such last-minute preparations as the appearance of convoys on the roads and the sweeping of shingle off the hards should be left as late as possible and, presumably, until after the real invasion had begun.
The letter also gave an indication of movement requirements. Until the invasion day it would be unnecessary to introduce real troops for deceptive reasons into the South-East of England for if they were not to embark until the middle of July, there would be no need for them to move into their concentration areas until June. Directly after the invasion date, however, when the story had changed, troops would be needed immediately and in strength. It was therefore proposed that as soon as operations in Normandy began, two real build-up divisions, one British and the other American, should move into the ‘cover’ area and ‘spread themselves about’ to make each camp look as if it were filling up.4
The directive of 26th February, relating to the command and control of FORTITUDE, informed the Joint Commanders that the guidance letter of 9th February ‘had been issued to the War Office, which was interpreting this direction in detail to Commands through General Headquarters, Home Forces, Q (Ops) and Q (M) channels’. When 21 Army Group, together with the Naval and Air Commanders, took charge of the detailed planning, the fulfilment of many of its provisions still lay in the future and were, therefore, as yet no more than topics of active discussion at the Service Ministries, GHQ, Home Forces, and the Commands. On the other hand, some positive visual deception was already being practised on the ground. Thus, on 9th February, GOC in C, South-Eastern Command, reported to GHQ, Home Forces, as follows: ‘The picture that I wish to convey to the Germans at this date is that although the camps are not being allowed to fall into disrepair, there is at present no sign of their being occupied by troops in the near future. This is being effected by small routine repair parties of Royal Engineers or Pioneers carrying out work in the camps, and also by some camps being occupied from time to time for a few days by troops who may be training near them. As embarkation areas are for the most part in built-up areas, there is at present nothing for German reconnaissance to note and I am content that this should be so for the present. Some of the Hards have been covered with shingle washed up by the tides. The Navy has so far taken no steps to remove this shingle which should be a further pointer to the Germans that no immediate use of the Hards is contemplated. At some Hards, embarkation extension piers are being built and this will show up to any German air reconnaissance, and will give the correct impression that these Hards are to be used sometime in the future and are not being allowed to become derelict.’5
21 Army Group had never agreed with this extensive programme of physical deception. The presence of shipping in the ports rather than the construction of camps round these ports, they argued, would be looked for by the enemy as an indication of where the attacking forces would be coming from and of the scale of the attack. The enemy had made no inland air reconnaissance and even if he did, owing to the character of the British landscape, with its woods, towns and villages, he would be unlikely to discover much, providing that camouflage discipline was strictly enforced. So far as the enemy agent was concerned, they argued that the omission of preparations was less dangerous than the inclusion of those which the spy might recognise as deceptive. These costly measures would do little good and might do much harm.6
About the middle of February, when it had became clear that the Joint Commanders were to be entrusted with the detailed planning, 21 Army Group decided to translate their views into action. At a meeting held on 23rd February the Chief of Staff, 21 Army Group, stated that the cover plan would now be governed by the following principles:
(i) There would be no camouflage policy of concealment in one area and display in another.
(ii) Concealment would be obtained by strict unit and formation camouflage.
(iii) Where possible new construction would be concealed, but not if it impaired the efficient working of camps or prevented their erection by the target date.
(iv) There would be no requirement for troops, camps or special preparations for cover purposes.
(v) the method of implementing the cover plan would be confined to –
The display of dummy craft.
The clearing of such hards as would not be employed in OVERLORD.7
On the following day 21 Army Group requested SHAEF to cancel any instructions which the latter had issued in connection with the camouflage, administration and movement preparations for the cover plan and to inform the War Office accordingly.8 This meant the abolition of ‘discreet display’ in Eastern and South-Eastern Commands and the substitution of normal camouflage discipline, which was now to be practised in all areas. Maximum concealment was to give way only to operational necessity. The two divisions, one British and one American, and all the ancillary preparations which were to herald their arrival in the ‘cover’ area would no longer be required. Only the display of dummy craft and the clearing of hards were to remain.
Having considered 21 Army Groups request, SHAEF replied on 4th March.9 In its view, the course proposed by 21 Army Group would expose us to unacceptable risks, both with regard to enemy air reconnaissance and to leakage through agents. Referring to air reconnaissance: ‘Although there has been no extensive enemy overland air reconnaissance since 1941 either by day or night, the enemy is capable of obtaining photographic cover of a coastal belt of about fifteen to twenty miles deep, from the Wash to Land’s End in about ten days of fine weather. Such cover would reveal the extent to which particular areas have been, and are being, developed for the movement and embarkation of troops…. If no preparations other than those required for NEPTUNE are made, it is considered that the enemy could deduce that no large-scale operation involving a high rate of build up was contemplated in the Pas de Calais.’ With reference to enemy agents: ‘The relative absence of preparations in Kent and East Sussex compared to the rest of the Channel coast is very obvious at the present time, and must be corrected. It is considered that information disclosing lack of essential preparations is more prejudicial than information suggesting that preparations are of a deceptive nature. The enemy will require confirmation, and if air reconnaissance discloses the presence of extensive preparations despite any reports he may have about their deceptive nature, he cannot afford to neglect the fact that these preparations have been made.’ The letter concluded with the direction that the policy initiated on 22nd September, 1943, with regard to ‘concealment and display’ and that for the extension of movement and administrative preparations laid down in the letter of 9th February should be carried out. ‘It is considered that failure to carry out any preparations essential to an operation in the Pas de Calais, when our resources allow such preparations, is an unacceptable breach of security, both from the point of view of enemy air reconnaissance and leakage.’
Under the FORTITUDE directive of 26th February 21 Army Group was entitled to deal directly with the War Office and GHQ, Home Forces. Doubt having been expressed10 as to whether the latter were clear about this, SHAEF on 15th March wrote a letter for the guidance of those concerned. Having recited the policy letters of 22nd September, 1943, and 9th February, 1944, the FORTITUDE Directive of 26th February, 1944, and the letter of 4th March, 1944, upholding the existing policies, SHAEF concluded: ‘21 Army Group is therefore now empowered to arrange direct with the War Office and GHQ, Home Forces, for the continuation of the measures already initiated, adjusted as may be desirable and feasible with the resources and time available to support the detailed plan of the Joint Commanders, prepared under the directive given them and executed within the framework of the policies mentioned above.’11 The only adjustment which seemed desirable and feasible to 21 Army Group was a return to the policy which had been put forward by them on 23rd February and rescinded by SHAEF on 4th March; in fact this paragraph was treated as an escape clause. Ten days later an instruction12 issued to Commands through GHQ, Home Forces, gave effect to 21 Army Group’s wishes.
This may seem a free interpretation of SHAEF’s letter of 15th March. But the days were passing, the invasion was now little more than two months away, and the German spies and reconnaissance aircraft had not appeared. And so this reversal of camouflage policy was now found acceptable by all concerned.