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Chapter 17: The Night Offensive Against British Industry and Communications*, (14th November 1940–16th May, 1941;, Summary 7th September 1940–16th May 1941)


BY THE late autumn of 1940 no visible ground remained for the belief that repeated night attacks on London might cause a swift collapse of the British will to fight. German estimates of damage to the docks and interference with business and domestic life were on the hopeful side, but did not justify the inference that disintegration of the capital and the country was imminent.1 Accordingly, in early November the Luftwaffe made ready for a new stage of the air offensive.2 If Great Britain could not be bludgeoned into swift surrender, she might have to be worn down by repeated hammering. In any case everything possible must be done to check the expansion of her war production and prevent her from repairing recent losses. Air attacks at night would therefore be extended to the chief industrial centres throughout the country, and to the great commercial ports through which both everyday supplies and special consignments of war material reached her from abroad. London, as both a port and a centre of industry, still qualified for the target-list.

Although the plan adopted by the Luftwaffe early in September had mentioned attacks on the populations of large cities, detailed records of the raids made during the autumn and winter of 1940–1941 do not suggest that indiscriminate bombing of civilians was intended. The points of aim selected were largely factories and docks.3 Other objectives specifically allotted to bomber-crews included the City of London and the government quarter round Whitehall.

The leaders of the German air force, recognising that KNICKEBEIN was not proof against interference, were inclined henceforth to favour

* For statistical summaries, see Appendices 30-32. The equipment and location of British night-fighter squadrons on various dates are given in Appendix 33.

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moonlight for their biggest raids. They had, however, two more radio devices suitable for attacks on unseen targets. Both, like KNICKEBEIN itself, were designed originally for daylight use in cloudy weather. But whereas KNICKEBEIN transmissions were receivable with the ordinary blind-landing equipment fitted to German bombers, the alternative systems called for special apparatus not generally available. Their use was confined, therefore, to selected units whose function was either to undertake special missions on their own account, or more frequently to act as ‘pathfinders’ and target-markers for larger forces.

One system, employing an apparatus called X-Gerät and known to British intelligence officers as ‘Ruffians’, depended on the laying across the target of a main beam or beams cut by two cross-beams at points separated from each other and from the target by fixed intervals.4 By following a main beam, the bomber was assured of a correct track, while the time taken to pass from the first to the second point of intersection gave its ground-speed, from which the proper moment to release bombs could be calculated with great accuracy. The calculation was in fact made automatically by an apparatus carried in the bomber. Certain allowances for the effects of wind were made, however, by the rough-and-ready method of displacing one or more of the beams from its calculated bearing. More precise than KNICKEBEIN, this elegant device nevertheless shared the susceptibility of its cruder partner to interference by a resourceful enemy. Moreover, the practice of laying the beams some hours before the beginning of an attack, presumably for the purpose of making final corrections, quite often enabled the Air Ministry to predict the target and warn the defences accordingly.5

The other system, employing an apparatus called Y-Gerät, was known in the United Kingdom as ‘BENITO’. Essentially it consisted of a ground station emitting transmissions automatically re-radiated by a bomber.6 The time taken for re-radiated signals to return to the ground-station enabled a German controller there to gauge the exact range of the aircraft along a bearing determined by an auxiliary direction-finding system. He could thus direct the aircraft towards the target, make such corrections as errors of navigation or uncharted meteorological conditions might require, and order the dropping of its bombs at the proper moment. The method was potentially very accurate, but could be countered with some chance of success if the appropriate British station picked up the transmissions in sufficient strength.7

By the second week in November the existence of German plans for a new series of night attacks became known in London.8 Counter-measures were thereupon concerted between the Air Ministry and appropriate formations. Where the blow would fall was not precisely

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known, but everything pointed to heavy attacks on centres of industry about the middle of the month. Kampfgeschwader 100, a unit soon famous for its ‘pathfinder’ technique, was expected to lead the raids with the aid of beams. Features of the British counter-plan included a major attack by Bomber Command on a German city; patrols by aircraft of Bomber and Coastal Commands over German bomber bases in France and the Low Countries; and the biggest possible effort by the night defences. Aircraft of day-fighter squadrons would be expected to supplement the effort of regular night-fighter squadrons. In addition No. 420 Flight, a new unit training to trail mines in the path of German bombers, would take part if it were ready.

The new phase opened on the night of November 14th with a memorable raid on Coventry. Out of about five hundred and fifty German aircraft despatched against the United Kingdom and adjacent waters about four hundred and fifty, duly led by Kampfgeschwader 100, attacked the city, dropping some five hundred tons of high-explosive and nearly nine hundred incendiary-canisters over a period of about ten hours.9 Bomber-crews were not told to make an indiscriminate attack on Coventry itself, but to cripple the aircraft industry and its ancillary services there by aiming at specified objectives such as the Standard Motor Car Company’s factory and the like.10 ‘Ruffians’ were laid over the city, but seem to have been scarcely needed, for bright moonlight clearly revealed its main features.11 Fires kindled in the early stages, with flares dropped as markers, acted as further guides for the rank and file. Within an hour of the opening of the raid the centre of Coventry was a sea of fire, clearly visible for many miles.

In such circumstances the city’s ordeal was bound to be severe. Telephone communications failed early in the raid; extensive damage to gas and water-mains increased the difficulty of controlling the two hundred or more fires raging by the early hours of the morning.12 Railway lines from Coventry to Birmingham, Leamington, Rugby and Nuneaton were all blocked; innumerable roads and streets within the city were made impassable by rubble, flames or unexploded bombs. Gravely hampered by these conditions, local Civil Defence workers, reinforced at dawn by parties brought to the outskirts of the city during the night, earned high praise for deeds done in a setting of horror and destruction which few could have imagined before the raid began. In the course of the night five hundred and fifty-four people are believed to have been killed, eight hundred and sixty-five seriously wounded; how many of the latter, and of those more lightly

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injured, owed their lives to anonymous rescuers who carried them from wrecked or blazing buildings to places of relative safety is not recorded.13

As usual, the attackers came to little harm at the hands of the defences. Good weather helped Fighter Command to put up a substantial effort, unhappily without success. On the approaches to Coventry and elsewhere the command flew thirty-five sorties by Blenheims, twelve by Beaufighters, thirty by Defiants, forty-three by Hurricanes and five by Gladiators of No. 247 Squadron at Roborough, these figures including sorties at dusk and dawn. Pilots or other aircrew reported seeing seven enemy machines between them; two Blenheims opened fire, but neither succeeded in bringing down its quarry. Anti-aircraft fire brought down a German bomber on its way to Coventry at Loughborough; at Birmingham gunners claimed to have seen an aircraft break up in mid-air. On the other hand, the deterrent effect of the defences, though it cannot be precisely estimated, may have been substantial, for some sixty aircraft out of about five hundred despatched with orders to bomb Coventry failed to do. so, either attacking alternative targets or breaking off their mission.14 Minor operations, including minelaying and an attack on London by some twenty aircraft, completed the night’s total of just over five hundred and fifty sorties.*

By half-past six on the morning of the 15th the last German aircraft had left a city outwardly stricken almost past repair. Cherished locally as a provincial capital and much-valued religious and commercial centre, but also of wider importance by virtue of its aero engine assembly works and machine-tool industry, Coventry had in fact sustained a fearful blow; but its wounds were far from mortal. Much of the centre of the city was a smoking ruin, where fresh fires continued to blaze up during the day amidst the broken fragments of fallen buildings. Yet by nightfall all fires had been brought under control.15 Between four hundred and five hundred retail shops were out of action; whole streets were rendered difficult of access by ruined masonry and unexploded bombs. By closing the city to all but essential traffic, and with the help of mobile canteens and field-kitchens, the authorities were nevertheless able to keep the wheels of life turning while troops and rescue-parties cleared the ways. Of the railway lines blocked during the night’s bombing, all were repaired

* According to German sources the effort was distributed as follows:

Despatched Reached Primary Target
Coventry 509 449
London 21 18
Minelaying, etc. 22

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by the evening of 18th November except that to Nuneaton, which reopened three days later. Meanwhile the main highways out of the city were found to have suffered no important damage. Transport needed to take people to their work, remove the homeless to places of shelter and shift valuable gear from damaged factories was, however, scarce for several days. Apart from residents transferred to new quarters under the official scheme, a number left Coventry on their own initiative. But by the evening of the 16th confidence had so far returned that means provided to convey ten thousand people from the centre of the city that night were used by only about three hundred.16 A visit by H.M. the King on that day did much to keep up the spirits of the inhabitants.

In some respects the industrial quarters of the city escaped more lightly. Hits were plentiful; but at Coventry as elsewhere factories and plant proved generally less combustible than serried rows of shops and houses, often with much timber in their construction and well stocked with inflammable materials. Twenty-one important factories, twelve of them directly concerned with aircraft production, were severely damaged by fire or direct hits.17 But perhaps a bigger obstacle to production was lack of services through damage to cables, pipes and water-mains. Shortages of gas and water in particular affected most undertakings to some extent. Such interruptions caused a complete stoppage at nine important factories not so severely damaged that they could not have carried on if services had been available. After a general suspension of production on the day after the raid, work was nevertheless resumed as means allowed. Half the staff of the Standard Motor Company were back at their usual tasks on the 16th, though one important building had been completely wrecked; and even the worst-hit factories estimated that production could be resumed in a few weeks.

===> footnote reference location unknown18

The British verdict on the raid was therefore that, while the aircraft industry had suffered a bad setback, so far no irreparable damage had been done. On the other hand, two or three similar raids on Coventry within the next few nights might curtail output over a long period. That these opinions were held in England did not escape the notice of the German Air Staff;19 yet they failed unaccountably to profit by their knowledge. Apparently satisfied that one night’s bombing had achieved its object, they turned their attention to other targets. On the night of the 15th London was the main target and only sixteen bombers were ordered to Coventry. In unfavourable weather less than half of them reached the city, dropping seven tons of high-explosive and thirty-two incendiary-canisters there as compared with some four hundred tons of high-explosive and more than a thousand incendiary canisters aimed at London—a far bigger and less rewarding target, though doubtless easier to hit in conditions

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which forced crews to rely on artificial aids. Similar conditions on the next three nights brought further attacks on London and a fairly big raid on Southampton, where targets included both aircraft factories and the docks. On the 19th, when weather over the Midlands was once more favourable, the opportunity for another devastating raid on Coventry was neglected in favour of an attack on Birmingham.* This raid, with two others on the 20th and 22nd, did much damage; but a similar effort against Coventry would almost certainly have paid the Germans better. Visits to Bristol, Plymouth and the Mersey, with two more to Southampton and one more big raid on London, brought the effort for the last seventeen nights of November to a total of thirteen ‘major’ raids.†

Meanwhile the British bomber-force had embarked on a series of ‘area-attacks’ designed to damage German economy and wear down the spirits of her people by devastating centres of industry and population. Raids in November on Berlin, Essen, Munich, Hamburg and Cologne were the sequel to decisions made by the British Government in October, rather than reprisals for the new series of German attacks which began at Coventry.20 The experience of Coventry did, however, play its part in influencing British estimates of the probable effectiveness of the new policy.21


On 25th November Air Marshal Douglas succeeded Air Chief Marshal Dowding as Air Officer Commanding-in-Chief, Fighter Command. For four years Dowding had headed a command which hitherto had known no other leader, and which bore at almost every point some imprint of his shrewd mind and well-marked personality. Throughout those years he had defended his conception of sound strategy, and had upheld the interests of his command and of all those who served in it, with a pertinacity and vehemence which had brought him often into conflict with the Air Staff. Not many men in British history have shouldered such a burden of responsibility as he had borne in recent months, and few have been privileged to shield their fellow-citizens from so grave a danger. Whether posterity numbers him among the great commanders of all time, or assigns to

* The night was notable for what seems to have been the first successful interception by an aircraft belonging to a Regular first-line squadron using airborne radar. A German bomber was brought down in Oxfordshire after engagement by a Blenheim of No. 604 Squadron whose crew were directed by their sector controller and by searchlight indications. There were no more successes with airborne radar for several months. Aircraft of the Fighter Interception Unit had, however, claimed some successes with airborne radar at an earlier stage.

† A ‘major’ raid by German reckoning was one where a hundred tons or more were aimed at a given target-area.

Map 24: Fighter Command 
Groups and Sectors, Spring 1941

Map 24: Fighter Command Groups and Sectors, Spring 1941

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him a lower place, he will surely be remembered as one of whom it can be truly said that he deserved well of his country.

Three weeks after Douglas moved to Stanmore, Leigh-Mallory, the exponent of large formations for defensive fighting, took Park’s place at Uxbridge. Park had borne the brunt of the fighting in the daylight battle, and that battle had been won; but victory did not silence criticism. Some contemporary observers thought that heavier losses would have been inflicted on the enemy if he had massed his squadrons in greater strength; and while later commentators have generally endorsed his policy of early engagement with single squadrons or pairs of squadrons during the first and second phases of the battle, some have continued to think that in the last phase, when the enemy’s objectives lay further from the coast, a more whole-hearted acceptance of the ‘big-wing’ principle would have paid him better. It is certain, at any rate, that the contribution made by large wings on the few occasions in September when they did come into play, though over-estimated at the time, was not to be despised.

While still a member of the Air Staff, the new Commander-in-Chief had shown where his sympathies lay in this controversy by declaring that ‘it does not matter where the enemy is shot down, as long as he is shot down in large numbers.22 Soon after assuming his new post he made his attitude still clearer by announcing that he had ‘never been very much in favour of the idea of trying to interpose fighter squadrons between enemy bombers and their objective.23 He would rather, he said, shoot down fifty of the enemy when they had bombed their target than ten forward of it. Adopting a suggestion made by the Deputy Director of Air Tactics at a conference held in the closing stages of the Battle of Britain, he made arrangements to re-dispose his day-fighter squadrons in the south-east so that wings could be more readily assembled there in future. A few months later, establishments were created for an officer of Wing Commander rank, immediately subordinate to the Sector Commander and capable of leading a wing in action, at each of fifteen sector-stations in all parts of the country.* Another and less controversial reform which arose out of the recent battle was the reorganisation of fighter squadrons in sections of two aircraft instead of three, to facilitate division into pairs for mutual defence when the need arose.

But for the moment, at least, the enemy had suspended the big daylight attacks which alone could justify the use of large wings for defensive fighting. The task immediately confronting the new Commander-in-Chief was to deal with the night offensive. Like his predecessor (and like his successors throughout the war), he had under

* The stations were Speke (a new sector-station in No. 9 Group.), Colerne (replacing Filton), Middle Wallop, Northolt, Tangmere, Kenley, Biggin Hill, Hornchurch, North Weald, Duxford, Wittering, Digby, Kirton-in-Lindsey, Catterick and Turnhouse. The new arrangement of sectors is shown in Map 24.

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his operational control the guns and searchlights commanded by-General Pile. General Pile’s command was reorganised soon afterwards, when the number of anti-aircraft divisions was raised from seven to twelve and three corps headquarters were interposed between command headquarters and the divisions. These changes lightened the burden borne by command and divisional headquarters and eased co-operation with the fighter groups. But the gunners were still much handicapped by shortages of weapons and ancillary equipment. About the same time Pile and Douglas decided in consultation that searchlights should be redisposed in clusters of three to give more powerful illumination and save manpower. For the rest, the resources at Douglas’s disposal when he assumed command comprised the balloons of Balloon Command (from the beginning of December under Air Vice-Marshal Sir E. L. Gossage, succeeding Air Vice-Marshal Boyd); the various radar devices whose development and shortcomings have been outlined in Chapter XVI; and eleven squadrons of night-fighters. Six of these were the twin-engined squadrons earmarked for re-equipment with Beaufighters instead of Blenheims; the other five consisted of the two Defiant and three Hurricane squadrons whose relegation to night duty was due partly to his advocacy. In addition, elements of the Fighter Interception Unit at Tangmere could still be counted on for active operations; the nucleus of the new aerial mining unit was in being; and a third Defiant squadron was working up. Moreover, a special unit—No. 422 Flight—had been formed recently to study methods of night interception with single-engined fighters, while orders had been given for the creation of an additional Operational Training Unit to specialise in training pilots and other aircrew for night fighting. Measures not under Douglas’s control included the devices worked by No. 80 Wing and various decoys and dummies intended to attract bombs. Smokescreens for the purpose of obscuring vital targets were organised by the Ministry of Home Security with the assistance of up to eight thousand men of the Pioneer Corps provided by the War Office.* In addition, industrial haze was deliberately increased in certain districts by inciting factories to emit more smoke than was allowed by peace-time regulations.†24

For the time being General Pile’s guns were perhaps the most effective of these weapons; for if their tangible achievements were strictly limited, at least they often succeeded in impressing German bomber-crews with the volume and accuracy of their fire.25 The future seemed to lie, however, with the fighter force; and Douglas lost no

* In April 1943, responsibility for smoke-screens was transferred to the War Office and Air Ministry. The work then fell mainly on Anti-Aircraft Command.

† This measure was discontinued in September 1943, in view of the reduced risk of bombing.

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time in stating his view of the measures needed to make that force effective. Like his predecessor, he soon saw that the main obstacle to interception was lack of accurate information about the course and height of German bombers flying to and from their targets. Although worth trying, the Kenley experiment had not brought good results, and in any case its scope was limited. Concluding that concentration of his relatively few G.L. sets in a single sector was uneconomical, he decided to disperse them so as to form a ‘carpet’ of sets in the southern counties.26 But this was only a beginning. In his opinion at least twenty squadrons of night fighters were needed to form a strong defensive belt from Newcastle to Devonshire, with a squadron each near Birmingham and Coventry. Later an additional squadron might be based near Glasgow. Aerodromes with special equipment for night-flying, including blind-landing devices and homing beacons to which airborne radar would respond, were urgently needed, as was an organisation which would relieve sector controllers of direct responsibility for bringing fighters down in safety, thus freeing them for more important tasks. Finally, pilots and other aircrew earmarked for night-flying must be chosen for their eyesight and specially trained to fly and fight in darkness.

Steps already taken to meet these requirements included the formation of the new Night Fighter Operational Training Unit, the posting to twin-engined night-fighter squadrons of experts to look after airborne radar, and the provision of meteorological officers at night-fighter bases. On 9th December the Secretary of State for Air promised Douglas that from twelve to fourteen aerodromes should be fully equipped for night-flying ‘on the highest priority.27 Compliance with his request for a minimum of twenty night-fighter squadrons was more difficult. To make up the number, six new twin-engined squadrons must be formed; but aircraft and pilots were both difficult to find. On the one hand, deliveries of Beaufighters and of the American D.B.7 (the basis of the Havoc and the Boston) were disappointing; on the other, the training organisation was still hard-put to meet demands.28 By early February the strength of the twin-engined fighter force had risen to seven squadrons, with eighty-seven pilots between them instead of nearly twice that number.* Towards a deficiency of seventy-four pilots, twenty-two were due shortly from the new Operational Training Unit and twelve ‘veterans’ with civilian experience would be added to them. The rest would have to be found by combing other commands or waiting for more recruits to come out of the mill.

On the other hand, new prospects of success were opened about the

* The standard establishment of a fighter squadron had been reduced in December from 26 to 23 pilots, the filling of vacancies on the old basis being clearly impossible at a time when new squadrons had also to be manned.

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end of 1940 by delivery of a few of the G.C.I, sets already briefly mentioned.* Designed expressly for the ground control of interception, the new equipment had the advantage of showing the progress of both bomber and intercepting fighter on a fluorescent screen. In their original form the sets failed to read height as accurately as was desirable; until they could be improved the obvious solution was to use them in combination with G.L. sets, whose performance in that respect had been brought to a high pitch. Accordingly, Douglas deployed the first six sets in an area corresponding roughly with that assigned to the G.L. carpet, though his ultimate intention was to cover the whole country.

The coming of the sets not only simplified the mechanics of night interception, but also helped sector controllers by shifting part of their burden to other shoulders. In appropriate conditions the detailed work of interception was now done by special G.C.I. controllers stationed where the apparatus was installed. Again, special aerodrome control officers were henceforth made responsible for landing fighters safely. In these conditions the sector controller’s task, apart from his general responsibility for the smooth working of the system, was to order fighters to their patrol lines, hand them over to the G.C.I, controller when the time was ripe, and order them to make for home or return to their patrol lines when the G.C.I, controller had done with them. Originally intended purely for use at night, the system of G.C.I. control was soon extended to daylight operations in cloudy weather, and later to a variety of circumstances calling for close control of fighters not necessarily equipped with airborne radar.29

Meanwhile Douglas had not relinquished his intention of using substantial numbers of single-seater fighters for night fighting when circumstances were propitious. The G.C.I. system could, of course, be used to guide such aircraft towards their targets in precisely the same way as it guided Beaufighters and Blenheims. But in practice G.C.I. stations were usually fully occupied with twin-engined fighters. A method which relied on G.L. sets to track bonders on behalf of single-seater fighters was tried, but soon abandoned.30 There remained the time-honoured method which relied on searchlights alone; or rather a new version of it modified by re-deployment of the lights and gradual substitution of special radar sets for sound-locators. The S.L.C. sets whose development we have noted on p. 254 were, however, still scarce, and the system was handicapped by inadequate communications.31 Douglas believed that single-seater fighters nevertheless had a good chance of success when visibility was good.32 Should it prove possible to equip them with airborne radar—as then

* See pp. 253-4 and 256.

Map 25: The Bombing of 
London, Night of 29th December 1940

Map 25: The Bombing of London, Night of 29th December 1940

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seemed likely—their chances would become better still. Applying a method used in the spring of 1940 for the defence of Scapa Flow, he ordered that on certain occasions Hurricanes should patrol at various heights over places chosen by the Germans for attack. To give them a free hand, twin-engined fighters (which they might mistake for bombers) would not be allowed within ten miles, while guns in the vicinity would be either forbidden to fire or restricted to a ceiling two thousand feet below the lowest Hurricane. In the second case, if all went well the bombers would be caught between the upper millstone of the Hurricanes and the nether millstone of the guns. The best conditions for a ‘fighter night’, as it was called, were such as might be expected in good weather when the moon was high and full.

Such were the more straightforward of the measures devised at the end of 1940 and the beginning of 1941 to cope with the night bomber. In addition the gravity of the threat and the absence of quick results engendered a number of less orthodox remedies. The formation of a unit for the purpose of trailing mines in the path of the elusive enemy has already been recorded.* A suggestion made by the Admiralty was more comprehensive. Advocating a much bigger minefield than could be sown by a few aircraft, they proposed that balloons carrying explosive charges should be allowed to drift towards the oncoming bomber stream.†33 Clearly the number of balloons required for a barrage of useful size and density would be very great, while an organisation of some complexity would be needed to secure their release at the most auspicious moment. Moreover, the risk that an uncharted wind might carry them away from the predicted course was far from negligible. Yet the prospect of doing lethal damage to the enemy without so much as firing a single gun or sending up a single fighter was undeniably attractive, especially as the scheme might possibly be workable in weather which put more orthodox measures out of court. Accordingly the Air Ministry decided, after a sub-committee of the War Cabinet had drawn attention to the point last mentioned, that the measure was worth trying. A meteorologist was attached to headquarters, Fighter Command, expressly to advise the Commander-in-Chief when conditions were most promising; and No. 30 (Balloon Barrage) Group, Balloon Command, took steps to release a drifting barrage fifty-five miles long, seven miles wide and four thousand feet deep from sites on the outskirts of London when the moment came. On 14th December Douglas was able to tell the Air Ministry that by the 16th preparations would be complete.34

* See pp. 263 and 268.

† A similar suggestion had reached the Air Ministry some years before from a private source.

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In spite of radio beacons, beams, blind-landing devices and a multiplicity of aerodromes, German plans for the night offensive were balked in December by rain, snow, fog, ice and thick clouds.35 On fifteen nights Great Britain was left almost undisturbed. On the other sixteen, eleven major and five moderately heavy attacks were made on British cities. London was the favourite target, with three major attacks and visits by small forces on twelve other nights. Of the seven other places which drew attacks of some weight, the Mersey ports, Manchester, Sheffield and Birmingham attracted most bombs, but Bristol, Southampton and Portsmouth also suffered fairly heavily in relation to their size.*

The most notable of the December raids, though not the largest, was that made on London on the 29th. (See Map 25.) As no bombers operated on the next two nights, it was also the last raid of the year. As in many previous raids on the capital, the principal areas chosen for attack were the City and the government quarter round White-hall.36 The night was dark, the weather indifferent before midnight and worse later. Expecting such a change, the Germans arranged to deliver the bulk of their attack in the early hours of the night. Fresh winds, rising to a velocity of fifty miles an hour or more six thousand feet above the ground, blew from the west and south-west across London.37

Before the raid the Germans laid the main beams of the X-Gerät from south-west to north-east along a line from Battersea Reach to Bloomsbury.38 At the last moment they made a correction, presumably for wind, which placed at least one beam on a roughly parallel course about five-eighths of a mile to the west.39 Ten aircraft of Kampfgeschwader 100, the unit which specialised in X-Gerät, took part in the raid and were almost certainly the leaders.40 They carried incendiary bombs only, presumably to kindle marker-fires. The bulk of the several

* According to German sources the bomb-load for December was distributed as follows:

Target Major Attacks Other large Attacks Tons of H.E. Incendiary Canisters
London 3 625 4,129
Liverpool-Birkenhead 2 485 1,701
Manchester 2 467 1,925
Sheffield 1 1 435 1,057
Birmingham 1 2 409 1,317
Bristol 1 1 198 773
Southampton 1 147 586
Portsmouth 1 88 148

‘Major attacks’ are those in which 100 tons or more of high-explosive were aimed; ‘other large attacks’ those involving a load of 50 to 99 tons. Smaller attacks are ignored throughout the table. For further details, see Appendix 30.

Plate 21

Plate 21. The City of London on the morrow of 29th December 1940.

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hundred incendiary-canisters dropped throughout the raid fell east of the displaced beam, largely within a circle of about two-and-a-half miles in diameter centred near St. Paul’s Cathedral. High-explosive bombs were thickest in the riverside boroughs from Poplar to Westminster, but many fell further south in Lewisham and Camberwell. In commercial quarters of the City, crowded with warehouses and dotted with fine churches, and also in Bermondsey and Southwark, fearful harm was done by fires which quickly became uncontrollable. Of nearly fifteen hundred fires reported from various parts of London, fifty-two were afterwards classed as ‘serious’, twenty-eight as ‘major’, and six as ‘conflagrations’. The two largest covered areas of about a half and a quarter of a square mile respectively. By an evil chance, the raid reached its peak when the Thames was at its lowest ebb and therefore of least use to firemen. Outside the City heavy damage was done at many places; but the devastation wrought there, the scars inflicted on treasures of architecture cherished in the imagination of thousands throughout the English-speaking world, were by far the most impressive features of a night which Londoners will long remember. Apart from churches, well-known buildings damaged on that night of terror included the Guildhall and the County Hall, the Tower of London and nine hospitals.

As in several earlier raids on London, Birmingham and Sheffield, damage done by fire was far heavier than that done by high explosive.41 The moral was clear. In many cases incendiary bombs and minor fires could be quickly rendered harmless if tackled at once by someone on the spot. Firemen, whether professional or auxiliary, could not be on the spot for the simple reason that they could not be everywhere at once. Their business was with fires of some size which had already gained a hold. As the Air Staff urged, what was wanted was a person in every building—and especially every building otherwise left unoccupied at night—to keep watch for incendiary bombs and scotch them and their immediate consequences without delay. Accordingly the Government instituted a system of ‘fire-watching’ whereby members of the public were made responsible for dealing with incendiary bombs which fell on their dwellings or places of work. Though introduced too late to offset the consequences of some of the worst raids, the system saved much damage to property in the later stages of the night offensive.42

Meanwhile the air defences continued to struggle with tasks beyond their strength. On many occasions anti-aircraft fire was sufficiently well-placed to draw tributes from German bomber-crews, but not quite accurate enough to hit their aircraft.43 In December the guns claimed ten victims, fighters four—an almost negligible fraction of the German effort.

On the 11th an oddly-conceived experiment was tried, when

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twenty-four Hampden bombers patrolled Birmingham in layers separated by intervals of five hundred feet while the city was being raided. Crews report seeing aircraft—supposedly German bombers—on twenty-six occasions, but the Hampdens were too slow and unwieldy to catch them. As a rehearsal for a ‘fighter night’ the test was inconclusive, for lone pilots of faster single-seater aircraft might not have seen anything.

The first trial of the balloon-borne aerial minefield on the 27th was still more disappointing. Communications were so unsatisfactory that the order for release was followed by a delay of more than half an hour before the first balloons went up.44 About a third of the nine-hundred-odd balloons inflated proved defective; others exploded early in their flight or descended prematurely in unexpected places.45 Observation of two special test-balloons suggested/that those which continued on their course were flying much too high.46 About two hours after the first release an apparent scarcity of German bombers led to the suspension of the operation; but again some forty minutes elapsed before the last release was made.47 The German report of the night’s events refers to numerous ‘parachute-grenades’ (Fallschirmgranaten), but there is no evidence that the barrage achieved anything of value.48 The project was not, however, to be condemned on the strength of a single experiment, and arrangements were made for a further trial in due course.

December saw another new departure in the shape of the first ‘intruder’ patrols flown by British fighters.49 For some time past aircraft of a German long-range night-fighter unit had been visiting British aerodromes at night for the purpose of hampering our bomber effort.* With a similar end in view, aircraft of Bomber and Coastal Commands had made many attacks on aerodromes in France and the Low Countries since the summer. Quite often their crews had seen German aircraft apparently awaiting their turn to land. The inference was that British long-range fighters armed with guns, flares and light bombs would find good opportunities of damaging or destroying German bombers returning from raids on the United Kingdom. Accordingly, when the Air Ministry suggested that Fighter Command should relieve the bomber force of at least part of its responsibility for patrolling aerodromes in German hands, the way seemed open for a valuable extension of the defensive to the enemy’s camp. Good intelligence and a flexible system of control would, however, be needed to ensure that fighters went to the right aerodromes and reached them at the proper moment. As a first step No. 23 Squadron, one of the original twin-engined night-fighter squadrons, parted with

* Between 1st October 1940, and 31st March 1941, some fifty attacks were made on aircraft of Bomber Command over the United Kingdom. Seven bombers were destroyed and twenty damaged.

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its airborne radar—which could not be risked on the far side of the Channel—and went through a short period of special training at a Bomber Command station. On the night of 21st December six of the squadron’s Blenheims made the first ‘intruder’ sorties over France. Crews saw four aircraft, presumably all German, but were unable to engage them. Bombs aimed,, at six aerodromes in Normandy and Artois did negligible damage.50 Further patrols were made on the next night and that of the 29th, with much the same results.


At the beginning of the New Year the long-range bomber strength of Luftflotten 2 and 3 stood at 1,214 aircraft, as compared with 1,291 in September.51 The strain imposed by recent operations was, however, reflected in the large number of aircraft undergoing or awaiting minor repair or overhaul. On 4th January the two Luftflotten mustered only 551 serviceable bombers—about 250 fewer than the corresponding figure for September.52 Thus in four months the ratio of serviceable bombers to total bomber strength had fallen from 61 to 45 per cent.

Throughout the first two months of 1941 bad weather continued to limit the scale of attack. In January, major raids were confined to two on London and one each on Avonmouth, Bristol, Portsmouth, Cardiff and Manchester. London and Avonmouth, with Swansea, Derby and Southampton, also drew substantial raids of smaller scope. In addition, Plymouth and Devonport suffered a sharp attack, mainly with incendiary-canisters.* The majority of these places are in the western half of England and nearly all of them are ports. As early as January events thus foreshadowed changes in German strategy to which full effect was to be given later.†

In February no major raids were made, but London and Swansea

* According to German sources the bomb-load for January was distributed as follows:

Target Major Attacks Other large Attacks Tons of H.E. Incendiary Canisters
London 2 3 490 1,987
Avonmouth 1 1 206 2,232
Bristol 1 154 1,488
Portsmouth 1 148 1,409
Cardiff 1 115 392
Manchester 1 111 735
Swansea 1 89 901
Derby 1 59 41
Southampton 1 57 325

For definitions of ‘major attacks’ and ‘other large attacks’, see p. 272. The foregoing figures ignore raids in which less than 50 tons of high-explosive were aimed at a single area. Further details are given in Appendix 30.

† See Chapter 18.

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suffered fairly heavily in attacks of lesser weight. Between them the two places attracted roughly one-third of a bomb-load totalling about a thousand tons. Among many places which drew minor raids were Chatham, Cardiff and Great Yarmouth.

Major bombing was resumed in March with the return of better weather. During the moonlit period in the second and third weeks of the month twelve major attacks were made on ports and centres of industry. London was again the favourite target, suffering three major raids which totalled seven hundred tons; but Glasgow with its outskirts, drawing about five hundred tons in two raids on successive nights, was close behind. Other sufferers were Plymouth, Hull and Liverpool-Birkenhead, each with more than three hundred tons; Portsmouth with about two hundred; and Bristol-Avonmouth and Birmingham with about a hundred and seventy and a hundred and twenty tons respectively. In several cases major raids were preceded or followed by smaller raids on the same target so as to produce a cumulative effort.

February and March were also notable for several attempts by small numbers of bombers to score precise hits on aircraft factories and the like with the help of Y-Gerät. Although technical difficulties hindered counter-measures, the usual result was a spectacular ‘near-miss’ which left the factory untouched.53

The first three months of 1941 saw modest but appreciable progress by the night defences. ‘Fighter nights’ brought claims to the destruction of three bombers—admittedly an almost negligible number. New trials of the airborne minefield in January and March went more smoothly than the first, but yielded no material return.* On the other hand, twin-engined fighters gave convincing evidence that G.C.I. control could yield practical results. On ninety-five occasions in March (as compared with forty-four in January and twenty-five in February) crews detected aircraft with their airborne radar; on another twenty they saw aircraft which they had not previously detected.† Combats followed on only thirty-one of these occasions; but the main point was that the ability of G.C.I. control to bring twin-engined fighters near enough to the enemy for crews to detect him or even see him was conclusively established. There was thus a good chance that before long growing experience, additional equipment and possibly better weather might enable the night defences to declare a handsome dividend on the work and skill invested in them.

At the same time a great deal was being done in other fields to rob

* Thereafter trials were confined to an experiment at Liverpool in May and a few tentative releases from ordinary balloon-sites in the London area. The scheme was finally abandoned towards the end of 1942.

† For further details, see Appendix 34.

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the night offensive of its sting. Balloons and anti-aircraft fire, always valuable deterrents to low-level bombing, sometimes scored more tangible successes. In February and March at least seven German aircraft crashed after striking balloon-cables in various parts of the United Kingdom. Anti-aircraft gunners claimed the destruction of thirty-seven night-bombers in January-March (and a share in the destruction of a thirty-eighth), as compared with twenty-nine claimed by fighters. Altogether the Luftwaffe lost ninety bombers during the three months in raids by day and night on the United Kingdom and on shipping. Other methods of defence included radio counter-measures cunningly reinforced by decoy-fires designed to simulate the effects of incendiary-bombs dropped as markers. In February such fires twice drew bombs intended for delivery elsewhere, though only four were lit; next month, out of seventeen kindled, sixteen scored some success, two at Cardiff and Bristol in particular drawing upwards of a hundred and seventy high-explosive bombs between them.54 Finally the new fire-watching system, backed by the growing experience of Civil Defence workers, tended to make even well-directed bombing less destructive than heretofore. As spring drew on much, therefore, fostered the impression that, while the menace of the night-offensive had not yet been overcome, at least its measure had been taken.


In April the German bomber force confronting the United Kingdom was reduced by the withdrawal of about a hundred and fifty bombers, with other units, to support the campaign in the Balkans. In May still further withdrawals were made in preparation for the offensive against Russia. Steps were taken to conceal them by means of dummy signals traffic; perhaps to the same end, units which remained behind were exceptionally active.

Accordingly the last weeks of the night-offensive against British industry and communications saw an undiminished effort by diminished forces. In April some very heavy raids were made on London; in the same month familiar targets on the coast and in the Midlands were revisited, and major attacks were extended to some places hitherto little troubled by night bombing. The next month opened with big raids on Liverpool-Birkenhead, Clydeside and Belfast. The last phase of the night offensive culminated on 10th May in a big attack on London, and six nights later closed with a raid on Birmingham. During the raid on London Rudolf Hess, Deputy Fuhrer of the Third Reich, landed by parachute near Glasgow from an aircraft in which he had flown alone from Germany. Announcing that he had

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come on a private peace mission, he asked to see the Duke of Hamilton and Lord Simon.

The last three major raids on London were the heaviest yet suffered by any British city.55 To swell the effort some crews made double and even triple sorties. Inevitably, great damage was done, especially to riverside boroughs. Belfast, too, was sorely tried by two raids in which some four hundred tons of high explosive and many thousands of incendiaries were dropped on a city that had hitherto seen little of the enemy. Heavy loss of life and damage to property in the first raid caused many inhabitants to seek a roof elsewhere, and convinced others of the wisdom of taking shelter at once when the sirens sounded. The result was that, though the consequent demand for accommodation outside Belfast cut across the official plan of dispersal, casualties in the second raid were only about a quarter of those suffered in the first. Damage to Harland and Wolff’s shipyard was, however, so great that production was cut by nine-tenths for about ten days and did not fully recover until more than six months later.

Meanwhile the strength of the defences was increasing, though much less rapidly than the defenders could have wished. By May, General Pile had 1,691 heavy and 940 light anti-aircraft guns.56 These figures compared with pre-war approved scales of 2,232 heavy and 1,860 light guns, increased in August 1940, to 3,744 and 4,410 respectively.57 Under the new scheme he was entitled also to some 8,000 rocket-projectors, and in fact well over 7,000 were available.58 Unhappily, output of the rockets themselves had fallen so far short of expectations that only a few of the projectors could be used. By the end of March 18,600 rockets had been delivered, of which Pile’s share was 8,400.59 This allotment enabled him to deploy only 840 projectors with ten rounds apiece. At the same time future supplies were threatened by a decision to give preference to the Admiralty, who sorely needed weapons for the defence of merchant shipping.* Demands from the Admiralty contributed likewise to his other shortcomings, for in recent months he had not only been compelled to hasten the return of over a hundred 3-inch guns lent to him in 1939, but had also been asked to find for the defence of shipping three hundred Bofors guns from his existing resources and from new production on which he had previously counted.60 His allotment of searchlights had risen earlier in the year to the substantial total of 4,532, but shortage of men had since obliged him to reduce the number in commission. As a remedy for his chronic shortage of manpower in other spheres he proposed in April that women of the Auxiliary Territorial Service should serve with men on gun sites. The

* See Chapter 18.

Map 28: The German Night 
Offensive, September 1940–May 1941

Map 28: The German Night Offensive, September 1940–May 1941

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suggestion was adopted, but the first Mixed Battery was not ready until four months later. It was then deployed in Richmond Park, south-west of London. Ultimately the employment of women in Mixed Batteries manned in the proportion of two women to one man freed some 28,000 soldiers for other duties and was thus a valuable contribution to home defence.

Air Marshal Douglas was better off than General Pile, with some fifteen night-fighter squadrons by mid-May towards the twenty he required.* Of seven twin-engined squadrons designed for pure defence by orthodox means, one had Havocs, while re-equipment of all the rest with Beaufighters was next door to completion. His eight single-engined squadrons were equipped with Hurricanes and Defiants in varying proportions. In addition, No. 23 Squadron was still engaged on its ‘intruder’ duties, the aerial minelaying unit had now achieved the status of a full squadron, and elements of the Fighter Interception Unit remained at his disposal for occasional active operations. Eleven G.C.I, stations were in position by the end of April and in May two more were added.61

Thus equipped, and favoured by more frequent opportunities, the fighter force began to find its feet. April, with its big raids on a variety of targets, brought fifty-five engagements by twin-engined fighters, all but five of them resulting from the use of airborne radar.† In the same month pilots and gunners of single-engined fighters saw their quarry on forty-five occasions and had thirty-nine engagements. These combats were not all successful—in the whole of April the Germans lost seventy-five bombers over or near the United Kingdom as compared with nearly ninety claimed at night by guns and fighters62—but at least the trend was upward. In May the same tendency continued; and during the last big raid on London single-engined fighters seemed at last to come into their own. In bright moonlight sixty Hurricanes and Defiants patrolling over London, with another twenty over Beachy Head and smaller numbers elsewhere, met many bombers and claimed excellent results. When claims were reckoned up next morning, nineteen victories were credited to single-engined fighters, four each to twin-engined fighters and anti-aircraft gunners (the latter hampered by ‘fighter night’ restrictions) and one to an ‘intruder’ aircraft. In fact, the Germans lost only eight aircraft destroyed (including one which crashed on take-off) and three damaged,63 but at least there was some foundation for the belief that the tide was turning.

In a sense the subsequent falling-off of the night offensive came, therefore, as a disappointment to Douglas and his subordinates, who saw their adversary elude their grasp at the very moment when they

* For details, see Appendix 29.

† For further details, see Appendix 34.

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seemed on the point of overthrowing him. ‘We were confident’, wrote Douglas later, ‘that if the enemy had not chosen that moment to pull out, we should soon have been inflicting such casualties on his night-bombers that the continuance of his night-offensive on a similar scale would have been impossible’.64 On the other hand, the general run of results achieved so far had admittedly been disappointing. In retrospect, at least, the struggle between the night-bomber and the air defences appears at best as a drawn battle, at worst as a victory for the enemy, who must be admitted to have come off very lightly. But in another sense the night-offensive had clearly failed. Eight months’ bombing had caused much hardship and raised many problems, but British industry and communications had survived to feed the long war so inimical to German interests. Aircraft factories and aero-engine works had suffered setbacks but escaped disaster; heavy industry had sustained wounds which appeared of small importance when viewed on the national scale.65 Stocks of oil were virtually unaffected by losses trifling in proportion to their total bulk, while tankage written off could be replaced without much difficulty from reserves.66 Reserves of food, especially animal feeding-stuffs and sugar, had been rather heavily depleted by certain raids on London and Liverpool, but such losses were not disastrous while external communications remained open. Traffic on the railways had suffered many interruptions, but none had been sufficiently prolonged or widespread to hold up war production to any serious extent.67 And troubles arising from damage to public utility undertakings and their distribution systems, though they caused much inconvenience and some loss of output, had come well short of calamity. Despite a lengthy catalogue of ‘incidents’, each with its overtones of pathos, humour, miraculous escape or domestic tragedy, the night-offensive had failed to halt the machinery of production and distribution in these islands or to break the national will to fight.

To sum up the effects of the night-offensive more precisely is difficult without prolixity on the one hand or misleading brevity on the other. Statistical comparisons are tempting but lead readily to false conclusions. German documents record the weight and number of bombs supposedly dropped on various objectives night by night throughout the whole course of the offensive, but necessarily ignore the effects of unsuspected errors in aim or navigation. On the night of 8th May, for example, crews instructed to bomb Derby believed that they had done so when in fact they had bombed Nottingham, with the result that other crews who were instructed to bomb Nottingham dropped their load unprofitably in open country as far east of their objective as Nottingham lies east of Derby.68 And British records of the bombing, while remarkably informative in some respects, are incomplete, particularly with respect to the first few

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months of the offensive.69 But even with all the data a comparative assessment of the bombing would be hard to make. Besides area, population, weight and frequency of big and small attacks, number of killed and seriously injured and of buildings damaged past repair, a recalcitrant array of imponderable factors would claim consideration.

By rough-and-ready standards first place goes unquestionably to London, most heavily and frequently attacked of British cities. Admittedly its big bomb-tonnage—according to German reports amounting to some 18,000 tons in major raids alone during the eight months of the whole offensive—was distributed over nearly a hundred boroughs and districts, ranging in size from about four hundred to more than twenty thousand acres.70 Among them Holborn, the City and Westminster reported the largest numbers of hits in proportion to their size, the first apparently receiving many bombs intended for its neighbours. Shoreditch, Southwark and Stepney, all dockland areas, also suffered heavily, as did Finsbury, Chelsea and Bethnal Green, with the riverside boroughs of Lambeth, Bermondsey and Deptford. Outside London, Liverpool (with Birkenhead) was probably the biggest sufferer, especially if earlier raids in August are brought into the reckoning; but Birmingham, with eight big raids, was close behind, while Coventry and Plymouth were probably as heavily attacked in proportion to their size as any British city. And any list of claimants to the melancholy honour of having suffered most in the night offensive must mention also Glasgow, Bristol, Portsmouth, Southampton, Hull and Belfast. Manchester, with only three big raids, may be thought to have come off lightly in view of its great size and importance. Sheffield, Newcastle, Nottingham and Cardiff complete the tally of cities considered worthy by the enemy of major raids. (See Map 26.) In all sixteen of these cities, as in countless other places from the Scottish Highlands to quiet villages in rural England, bombing caused incalculable distress and hardship. Yet it can be claimed without exaggeration that, while these experiences led occasionally to passing discontents—habitually expressed in criticism of the air defences—in the long run they left the people everywhere not only with spirits undismayed, but more than ever determined to see the war through to the end.

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