The Circus Offensive, 14th June to 31st December 1941
On 14th June an improvement in the weather permitted the resumption of the Circus offensive, and an operation which had been planned towards the end of May was put into effect. A similar operation on 16th June was followed on 17th June by the most ambitious Circus yet attempted. This involved an attack on a Chemical Plant and Power Station near Bethune by eighteen Blenheim bombers, escorted by no less than 22 squadrons of fighters. The enemy fighter force reacted vigorously, and although we lost nine pilots, those who returned reported a very favourable outcome of their combats. It seemed that the long-expected “fighter battle on terms tactically favourable to ourselves” had come at last.
On the same day the Chief of the Air Staff instructed me to devise, in consultation with my colleagues at Bomber and Coastal Commands, the most effective means possible of checking the withdrawal of Luftwaffe Units to the East – where the German attack on Russia was imminent – and, if possible, forcing the enemy to return some of the Units already withdrawn.
A meeting to discuss this question took place at my Headquarters, on 19th June, and was attended by the three Commanders-in-Chief and members of our staffs and by the Air Officer [Trafford Leigh-Mallory] Commanding No. 11 Group and two of his staff.
We came to the conclusion that the best plan would be to attack objectives within range of escorting fighters – in other words, to intensify the Circus offensive. Since the enemy had reacted most energetically so far to the Circus against a target near Bethune on 17th June and another against a target in that area on 21st May, we concluded that the industrial area which included Bethune, Lens and Lille was probably his most sensitive spot. By attacking this area it was hoped to induce him to concentrate in North-East France such fighter units as he still had in the West. Bombers without escort might then hope to reach West and North-West Germany in daylight round the flank of the defences, and this in turn might force the enemy to bring back fighters from the Eastern Front in order to defend the Fatherland.
As a corollary to this offensive, night attacks would be made on communications in the Ruhr, and shipping attempting to pass through the Straits of Dover would also be attacked. This two-pronged offensive would, we thought, constitute a threat to communications between France and Germany which the enemy could not afford to ignore.
These proposals met with the approval of the Air Ministry, and an agreed list of Circus objectives was drawn up. It was arranged that aircraft of No. 2 Group, Bomber Command, should attack them in cooperation with fighters of my Command, and, as a secondary task, should also attack shipping and “fringe targets”.
On 3rd July, the Air Ministry informed me that the formula defining the object of operation Circus, which had been agreed upon in February, must be abandoned and that the object must now be “the destruction of certain important targets by day bombing, and incidentally, the destruction of enemy fighter aircraft”.
Two days later Stirling bombers of No. 3 Group were used in these operations for the first time instead of Blenheims of No. 2 Group. This change, together with the tactical adjustment which the new policy laid down by the Air Ministry made necessary, imposed a slight and temporary handicap on the fighter force. As soon as experience had been gained under the new conditions, a small formation of Stirlings was found to suit the fighters better than a larger formation of Blenheims. Towards the end of the month the Stirlings ceased, however, to be available for Circus operations, as Bomber Command required them exclusively for other purposes.
The Short Stirling’s career in daytime Circus operations lasted only three weeks.
During the first few weeks of the intensive period, which may be regarded as beginning on 14th June, our pilots reported outstandingly good results in combat, and early in July it seemed that something like complete ascendancy had been gained over the opposing fighter force. For a short time in the middle of June the German fighter-pilots had offered determined opposition, but they now seemed, as in the Spring, reluctant to engage unless specially favoured by circumstances.
The results reported by our pilots during the next few weeks were not quite so good, although still much in our favour, and at the end of July the Air Ministry decided to review the results achieved up to this time.
To assess these results with any approach to accuracy was a matter of great difficulty. Our pilots had reported the destruction of enemy fighters in large numbers; but in operations on this scale there is room for much honest error, and even if the claims were accepted at their face value, it was impossible to know how many German pilots had baled out of their damaged aircraft, descended safely by parachute, and lived to fight another day. We believed that our information about the enemy’s Order of Battle was good – as, indeed, it subsequently proved to be – but our knowledge of his capacity to replace losses was scanty. We had good reason to think that so far our attempt to force the Germans to bring back units from the Eastern Front had failed, but suspected that towards the end of July some experienced individual pilots had returned in order to stiffen up the mass. We also had information which suggested that reserve training units in France had been called upon to replace losses. The effect of the bombing attacks was virtually unknown.
As for our own losses, so far as Fighter Command was concerned these had been heavy, but not so heavy as to cause serious embarrassment. Our losses in pilots during the first two weeks of the intensive period had been far lighter than at the height of the Battle of Britain; and our losses in aircraft over the same period not beyond our capacity to replace. Bomber Command had lost 15 aircraft in Circus operations since 14th June, and in the course of a daylight attack on German capital ships at Brest and La Pallice had suffered the rather more serious loss of 16 bombers out of 115 despatched.
Losses like this, incurred when attacking an objective on the left flank of the German defensive system, suggested that attacks round the right flank into Germany might not prove such a practicable undertaking as had been hoped.
It was in these circumstances that a conference was held at the Air Ministry on 29th July to decide whether Circus operations should continue. It was agreed that some of the conceptions formulated at the conference of the Commanders-in-Chief on 19th June had been too sanguine; the daylight bombing of Germany, in particular, no longer looked like being practicable on any appreciable scale for some time to come, and it was agreed that for the medium and heavy bombers of Bomber Command night operations should normally take precedence over day operations. On the other hand it was equally clear that, if anything was to be done to contain the enemy fighter force in the West, offensive operations by Fighters must not cease; and it seemed to me that the cooperation of a bomber force was necessary to make these operations effective. The Chief of the Air Staff upheld this view; and it was decided that the Circus offensive should continue.
Up to this time 46 Circus operations had been carried out since 14th June, In those six weeks escort and support had been given to 374 bomber sorties and over 8,000 fighter sorties flown. We had lost 123 fighter pilots but it was hoped that many more German fighters than this had been destroyed. In addition, over 1,000 fighter sorties had been flown in support of 32 bomber operations against shipping, including the operations against the German capital ships on 24th July and an attack on the docks at Le Havre on 19th June. Fighter sweeps without bombers accounted for approximately another 800 sorties and operation Rhubarb – resumed on 16th July after a month’s pause – for a further 61. Altogether the six weeks’ intensive effort had meant the expenditure of nearly 10,000 offensive sorties by my Command. This was an impressive total, but to preserve perspective it must be remembered that the effort devoted to defensive purposes was still greater, approximately this number of sorties being expended during the same period on the protection of shipping alone.
The Circus offensive was resumed on 5th August and 26 operations were carried out during the month. Blenheims of No. 2 Group provided the striking force for 24 of them and Hampdens of No. 5 Group for the other two. As the enemy gained experience in repelling these attacks his opposition grew more effective and the balance of advantage showed a tendency to turn against us. The being so, it was for, consideration whether the scale of the offensive should be reduced, if not at once, at any rate as soon as there was any sign of a more stable situation on the Eastern Front.
One of the main problems facing the RAF at the verge of the 1941 offensive was lack of suitable bombers for daytime operations. Handley-Page Hampdens (above), originally designed as medium front-line bombers were tried in this role, but once again proved too vulnerable to ground fire and enemy fighters and had to be withdrawn to night and minelaying duties. The burnt of the offensive during 1941 was to be carried by the equally obsolescent Bristol Blenheims (below).
Apparently the same considerations occurred simultaneously to the Chiefs of Staff. Consequently, the problem was studied at the end of August and beginning of September in the Air Ministry as well as at my Headquarters and at Headquarters No. 11 Group. The outcome was that, although it was now clear that the offensive had not succeeded in forcing the return of German units, at any rate in substantial numbers, from the Eastern Front, and could not now be expected to do so, it was generally agreed that it ought to be continued, although on the reduced scale which the declining season was likely to impose in any case. A suggestion made by the Air Officer Commanding No. 11 Group [Leigh-Mallory], which I endorsed, was that, instead of being largely concentrated against the French departments of the Nord and Pas-de-Calais, the attacks should now be delivered over a wider area so as to induce the Germans to spread their fighters more thinly along the coasts of France and the Low Countries.
Accordingly, twelve Circus operations were carried out in September and two during the first week of October. The objectives attacked by the bombers included two targets at Rouen, one at Amiens, one at Le Havre and one at Ostend.
By this time it was clear that demands from other theatres of war were likely to cause a shortage of fighter aircraft at home for some time to come. For this reason, and also because the weather was growing less favourable and the situation on the Eastern Front had reached a stage at which it was unlikely to be materially affected by the Circus offensive, on 12th October I instructed the three Group Commanders concerned with offensive operations that in future Circus operations must only be undertaken in specially favourable circumstances, but that a rigorous offensive should be continued against shipping and “fringe targets”.
Early in October the Hurricane bomber, which had been under development for some time, became available for active operations, and armed with, this weapon the Command assumed responsibility for what was called the “Channel Stop”. The object of this operation, which hitherto had been performed mainly by Blenheims of No. 2 Group with fighter escort, was to close the area between the North Foreland, Ostend, Dieppe and Beachy Head to all hostile shipping by day.
The introduction of fighter-bomber Hurricane Mk. IIB markedly increased the flexibility of Circus operations. However, the offensive power of the two bombs carried was even smaller than that of a Blenheim. In the end, Hurribombers could not compensate for the lack of tactical bomber force, a fact which became painfully obvious during the Dieppe landings the following year.
When the Air Ministry decided to reduce the- scale of the Circus offensive in September, I made arrangements at their instance to increase the scale of scope of operation Rhubarb. Hitherto pilots had seldom been lucky enough to meet German aircraft, so that their only alternative to inaction had been to make rather aimless attacks on surface objectives. I might have taken advantage of this situation by imposing a rigid “target policy”, but up to the present I had judged it inadvisable to lay down any rule which might give the impression that attacks on surface objectives were as important as the destruction of enemy aircraft. Pilots were therefore given a free hand in this matter so long as they observed the general bombardment instructions which reflected the attitude of H.M. Government to questions of humanity and international law.
Although the relative importance of enemy aircraft and surface objectives as objects of attack had not changed, my staff and I felt that the time had come to subordinate the ideal to the real by recognizing that on nine occasions out of ten our pilots were not likely to see any German aircraft and must either attack surface objectives or do nothing.
Accordingly, new instructions for operation Rhubarb were issued in October. Pilots were now to proceed to a selected surface objective, and if they met no German aircraft on the way, that would be their target. If they did meet German aircraft, then the destruction of those aircraft would take priority.
Categories from which the surface objectives were to be selected were drawn up by my staff in consultation with the Air Ministry; they included canal barges, railway tank wagons, electrical transformer stations and, for a season, factories engaged in distilling alcohol from beet. On 20th October, the Government withdrew a long-standing ban on the attack of moving goods trains, so that we could now attack tank wagons on the move as well as in sidings.
Factories distilling alcohol and a number of other targets on land were also attacked in November by fighter-bombers with fighter escort. The fighter-bombers, which attacked from heights below 5,000 feet, suffered rather heavy losses from AA fire in these operations and also in some of their attacks on shipping. In the past the Blenheim bombers used by No. 2 Group for these shipping strikes had come up against the same difficulty, despite attempts by accompanying fighters to silence the German, gunners by attacks with cannon and machine-guns.
Meanwhile, on 21st October, I carried the reduction in the scale of the Circus offensive a stage further by imposing on No. 11 Group, as the Group principally concerned a limit of six such operations a month.
In practice there was only one Circus after this date. This was carried out on 8th November in conjunction with a high-level fighter sweep and a low-level attack by fighters and fighter-bombers on an alcohol distillation plant. An unexpectedly high wind added to the difficulties of the undertaking, which resulted in the loss of 16 fighter aircraft and 13 pilots. Later in the day another aircraft and its pilot were lost in the course of a fighter sweep.
Although not by any means disastrous, losses on this scale were unwelcome in view of the shortage of aircraft that was expected to make itself felt during the next few months. I therefore decided to restrict No. 11 Group to three Circus operations a month in future instead of six.
A few days later the Air Ministry informed me that the War Cabinet had called attention to the desirability of conserving resources in order to build up strong forces by the Spring of 1942. Since the wording of the letter in which the Air Ministry conveyed this information made it clear that no risks must be taken by pressing attacks in unfavourable weather, I now imposed a still more stringent limitation on the Air Officer Commanding No. 11 Group, who was asked to undertake no more Circus operations without reference to me.
The outbreak of War between the United States of America and Japan in December provided still further grounds for conservation, since it was clear that the supply of aircraft from America was likely to cease or at least be greatly reduced for some time to come. Consequently the constant drain imposed by even minor operations could no longer be afforded.
In point of fact, wintry weather was already upon us, and after 8th November no more Circus operations were carried out. The intensity of our other offensive operations was also substantially reduced as the year drew to its close.