The wide range of emergency services, which came into operation in the early days of the war or were in various stages of growth in 1939 and 1940, had behind them a long history of ministerial and departmental planning and discussion. The process of thinking out the kind of services that would be necessary for the care and protection of the civilian population depended upon the kind of war in which these services would have to function. At all levels of planning—in specialist sections within departments, in interdepartmental conferences and sub-committees of the Committee of Imperial Defence—the same set of question continually recurred, in one guise or another, during the leisurely stages of drafting schemes in the nineteen-twenties and early nineteen-thirties, and the more hurried planning of 1938 and 1939. If and when the next war came, what would be its character and how would it affect the civilian population?

Attention was concentrated upon the newest and therefore the most uncertain factor in modern warfare—the damage likely to be inflicted upon civilian society by attack from the air. Those who were charged with the drafting of plans for the relief of distress, the dispersal of mothers and children, the provision of health services and other forms of assistance, were moved by two strong influences. First, there wee the estimates of the possible weight of enemy attack provided by the Air Ministry and passed through the machinery of the Committee of Imperial Defence to the Government departments concerned; secondly, there was the general tone of public though, which was strongly affected by publications of self-styled strategists in military matters, by the prevailing political climate, and by the current of world events. It must not be assumed that these two influences worked contrariwise; departmental officials, since they were also citizens, were by no means immune from the mood and vague anticipations of the general public.

Even rough estimates were difficult to frame in answer to such questions as how much distress would occur, what groups of people should be evacuated, and how many hospital beds would be needed for civilian casualties. Little could be learnt from previous war. There had to be hypothetical calculations of the unknown or the partly known. It was the duty of official calculators to envisage the most sombre possibilities. If statements of possibility came sometimes to be accepted as statements of fact, this was understandable. It will be readily understood that the experts who produced estimates of the


bombs that might be dropped on British cities and of the casualties they would cause were well aware of their speculative character; but there was no escape from them; some quantitative measures had to be given. And, however much they may have been qualified in the minds and in the reports of those who made them, these estimates tended to acquire a natural authority—indeed, almost an inviolability—in the minds of those who had to use them. The Ministry of Health, for instance, could not dispute these estimates with the Air Staff.1 It had to accept the figures given and attempt to work out their consequences in terms of social damage and the measures appropriate for mitigating or repairing the damage.

It was in this way that a general picture of a possible future war was formed in the minds of administrators in the social service departments. And it was this picture, blurred in places but growing in precision with the passage of time, that became the most important single factor in deciding the character of the emergency social services.

The first shadowy outlines began to emerge in the early nineteen-twenties. In the background was the experience gained from the eighteen German air raids on London during 1917–18, when a total of about 128 aeroplanes reached the metropolitan area. During the whole war, about 300 tons of bombs were dropped by the Germans on the British Isles. These raids caused 4,820 casualties including 1,413 killed. The casualty ratio for the whole country thus worked out at sixteen per ton of bombs. For London, with its concentrated population, the ratio was much higher. It was estimated that for the two day raids the ration was 121 and for the sixteen night raids fifty-two per ton of bombs. On the basis of these figures the Air Staff considered that it would be 'fair to assume that, in densely populated areas such as London, there will be fifty casualties per ton of bombs dropped. Of these casualties, one-third will be killed and two-thirds wounded'.

Sixteen years were to pass before the estimated number of casualties per ton of bombs fell below fifty. Meanwhile, estimates of the total tonnage an enemy air force might drop on British cities grew with the years. '… We must not suppose', Lord Balfour wrote in 1922,2 'that the possibilities of an aerial attack in 1922 stand where they did in 1918'. After recalling that in the worst German raid only three tons


were dropped on London, Lord Balfour pointed out that a continental enemy could 'drop on London a continuous torrent of high explosives at the rate of seventy-five tons a day for an indefinite period'. 'Day after day, and night after night, the capital of the Empire would be subjected to unremitting bombardment of a kind which no city effectively acting at the military, naval and administrative centre of a country engaged in life and death struggle, has ever had to endure …'

This view of what a future war might be like may not have been held by everyone; but it was representative of many statements which appeared, year after year, in many documents and reports issuing from the Committee of Imperial Defence and its sub-committees, and from departmental bodies concerned with civil defence and emergency services

As has been seen, the starting point was the experience of 1918: three tons of bombs dropped in a single raid. The estimate3 made for the Air Raid Precautions Committee in 1924 increased the quantity that might be dropped on London to 100 tons in the first twenty-four hours, seventy-five in the second twenty-four hours, and fifty tons thereafter. Three-quarters of these quantities (including both high explosive and incendiary bombs) were allocated to day raids.

In June 1934, a year after Hitler seized power in Germany, the Chief of the Air Staff furnished a new estimate. This was framed on the air expansion programme which the German Government was at that time known to be contemplating. It was calculated that, by 1924, the maximum daily weight of bombs which might be dropped during the first few weeks of war would be 150 tons, on the assumption of aircraft operating from bases in Germany.

But this estimate was soon out of date. The evidence which Germany had given of 'her ability to create a comparatively powerful air force "de novo" within a remarkably short space of time' led the Air Staff, in 1937, to scale up its appreciation in a drastic fashion. It pushed up to 644 tons its estimate of the weight of bombs which might be dropped in a twenty-four hour period,4 and it put forward to April 1939 its estimate of the date when the Germans would be ready to launch an attack on this scale. Moreover, it made some special


allowance for the Germans' love of the 'Kolossal'; they might endeavour to drop as much as 3,500 tons in the first twenty-four hours.

Two years later, in March 1939, the Ministry of Health, in making estimates of the number of hospital beds that might be required for casualties, was informed by the Air Ministry that the possible weight of attack might now average 700 tons each day for the first fortnight.

This was part, but not all of the background to the planning of care and protection for civilians in time of war. It was not merely a matter of so many tons a day; there were also such questions as the explosive and penetrative power of bombs, the use of incendiary and delayed action bombs, and the problem of gas and bacteriological warfare. The geographical distribution of different forms of attack, and whether they would come by night or day, were other factors which had to be considered.

In these approaches to the problem of civilian protection there was a pronounced emphasis on anti-gas measures. During the five years preceding the war it was believed in the Home Office that Great Britain was ahead of other European countries in expectation of, and preparation against, gas warfare. No doubt this was also known to the enemy. The first circular on civil defence issued to local authorities in 19355 and out on sale to the public by the new Air Raid Precautions Department of the Home Office (established in April 1935) had much to say on anti-gas equipment, gas masks and the setting up of a gas school to train instructors.6 By as early as 31st December 1937, 19,500,000 containers and 1,500,000 faces pieces for masks had been manufactured and stored, and assembly of the complete mask was, by January 1937, running at the rate of 150,000 a week.7

Anti-gas defence had,by 1936, been the subject of continuous investigation by the Chemical Defence Research Department for a number of years. The amount of information available was therefore much in advance of that for incendiary and high explosive bombs. Little, in fact, was known at this time about the effects of these types of bombs. Researches had not been undertaken, primarily because the Government had not been willing to sanction the necessary expenditure. In these circumstances, it would have been poor tactics to arouse in the public mind a vivid apprehension of dangers against which the Government was able as yet to offer little protection. But this is not the whole explanation of the early emphasis on gas attack. The influence of the psychological factor during the nineteen-thirties cannot be lightly dismissed. In the public mind—for reasons which


need not be discussed here—gas warfare and air raids were vividly linked. Gas seemed that the great unknown factor in a war against civilians. It was sound judgement which prompted the Air Raid Precautions Department to spread among the people the conviction that they could do a great deal to protect themselves against gas. Nor was it unreasonable to hope that a similar spirit of self-help would be called forth when the time should come to warn them of other dangers.

By 1939, the emphasis on anti-gas measures had somewhat receded. The setting up by the Home Office of two committees8 in 1935 and 1936 to consider the problems of high explosive and incendiary bombs no doubt helped towards a more balance appreciation. In addition, voices had been raised, both inside and outside the Government, to stress the danger of the fire bomb, used singly or in combination with other forms of attack. One of the earliest of these warnings was uttered by Mr. Churchill who, in November 1934, told the House of Commons: 'The most dangerous form of air attack is the attack by incendiary bombs'.9

In 1938 the Air Raid Precautions Department was basing its plans for civil defence on the assumption that the tonnage to be dropped would comprise fifty percent high explosive, twenty-five percent incendiary and twenty-five percent gas; '… but the use of gas,' the Department believed, 'remains problematical. If it were not used it is probable that its place would be taken by high explosive, and for the calculations for services other than special anti-gas services it seems best to assume that seventy-five percent of the load is high explosive'.

In this very bare summary of the efforts which were made before 1930 to estimate the scale and character of air attack, mention has still to be made of two other matters—first, the precision of bombing, and secondly, the use of delayed action fuses.  The estimates of probabilities made under these two heads were bound to have important effects upon plans for evacuation and for the care of homeless persons.

The Air Ministry made generous allowance in its calculations for the increasing precision of bomb aiming. When, for instance, the first evacuation report was being written in 1931 by a special sub-committee of the Committee of Imperial Defence an attempt was made to plot the fall of bombs on London. The report assumed a scale of attack in which 300 aircraft (250 by day, 50 by night) would drop 100 tons of bombs in the first twenty-four hours. Thereafter, the weight of attack would decline. It was considered that this attack might paralyse London's public services, putting out of action all the


main line railway termini and a considerable part of the gas, telephone and water services, closing the underground railways, and destroying or damaging half the important electric power stations.

By 1939 a still higher degree of accuracy was being accorded to the bomb aimer. The view then held by the Air Ministry was that the largest formation of aircraft likely to release its bombs simultaneously was a squadron of twenty-seven. These aircraft might drop as much as forty tons over any one place at any one moment. The pattern on the ground formed by these bombs, when dropped from a height of 20,000 feet, would be in the nature of a square with quarter mile sides. This was the basis on which the Air Raid Precautions Department was estimating the requirements of different branches of the civil defence services.

The requirements of various emergency services were likely to be determined in large measure not only by the pattern of bombing but also by the enemy's use of delayed-action bombs. To mention one problem, which was not clearly foreseen: considerable numbers of people would have to leave their homes and be accommodated temporarily elsewhere if the enemy were to employ these bombs in quantity. In 1934 the Air Staff suggested that he might employ them up to fifty percent of the tonnage of high explosive bombs he dropped. Would they be difficult to cope with? Reports which came from Spain in 1938 declared that they 'presented no problems'. This was too optimistic. But, since the enemy's intentions could not be surely known, the problems were hard to foresee. Perhaps too little study was given to the different social consequences that would follow from different kinds of air attack. The problem of the unexploded bomb is a case in point.

Here it is convenient to record the main phases in the organisation of official study and planning. First, from 1924 to 1935 there was central coordination by the Air Raid Precautions Sub-Committee of the Committee of Imperial Defence, while each of the interested departments retained responsibility for planning the measures which it would itself have to carry out if air attacks were launched against the country. Secondly, from 1935 to 1938 there was a phase in which responsibility for planning and executive preparations was concentrated in the air Raid Precautions Department of the Home Office. Thirdly, after Munich, when preparations entered into an advanced executive stage, a process already begun during the preceding nine months of redistributing functions among the departments which would have to exercise the functions in war was completed—Sir John Anderson, as Lord Privy Seal, retaining a coordinating responsibility over the whole field. This was the method which Sir John Anderson himself had emphatically recommended in 1929. However, since the other departments were deeply immersed in peacetime problems,


the Government hoped that a centralised organisation within the Home Office might for the time being make more rapid progress in preparations for the wartime job. But the Government did not provide the finance that was requisite if the job were to be tackled in all sector. The Air Raid Precautions Department was pitifully under-staffed. Nor was it effectively linked with all the specialist branches of the local authorities, whose full participation would be essential both in civil defence and in many emergency social services.

Finance was one barrier to rapid process; secrecy was another. It was not only the local authorities that would have to participate, but the civilian population at large. Nevertheless, for reasons of international and domestic politics, the Government thought it necessary, until the late nineteen-thirties, to keep within Whitehall most of the information about its plans. A Cabinet ban on a full disclosure of information concerning wartime measures, which would of course have involved naming the enemy, was not lifted—and then only partially—until after the Munich crisis.

In Britain, as in other countries of Western Europe, the public painted its own picture of the future. As the threat of war developed, with preliminary outbreaks in China, Abyssinia and Spain, the design of things to come was foreshadowed in a constant flow of books and articles in the press of Europe and America, while the cinema, the wireless and the theatre all played a part in shaping public opinion. To the speculations of the layman, Mr. Baldwin had added the weight of his authority when he warned the House of Commons '… the bomber will always get through … I think it is well also for the man in the street to realise that there is no power on earth that can protect him from being bombed'.10 Two years later, another public statement, which also made a lasting impression, came from Mr. Churchill.

Not less formidable, he said, than these material effects are the reactions which will be produced upon the mind of the civil population. We must expect that, under the pressure of continuous air attack upon London, at least 3,000,000 or 4,000,000 people would be driven out into the open country around the metropolis. This vast mass of human beings, numerically far larger than any armies which have been fed and moved in war, without shelter and without food, without sanitation and without special provision for the maintenance of order, would confront the Government of the day with an administrative problem of the first magnitude, and would certainly absorb the energies of our small Army and our Territorial Force. Problems of this kind have never been faced before, and although there is no need to exaggerate them, neither, on the other hand, is there any need to exaggerate them, neither, on the other hand, is there any need to shrink from facing the immense, unprecedented difficulties which they involve.11


There were, of course, a great many forces, social, political and scientific, which contributed to the acceptance of this concept of what the next war would be like. Among these psychological factors played an important role. What ordinary people feared—the loss of home, of relations, of security; what statesmen and service chiefs feared—national defences broken and public morale weakened; all these fears tended to magnify the threat.

During these years there was not, in essential outline, any substantial different between the views held by the man in the street and by the officials in the social service departments as to the character of a future war.12 Perhaps the latter were more deeply conscious of the possibilities because they had the task of devising schemes to meet the social consequences of such a war. And they, after all, had been something of what the Air Staff had written.

The general view which had emerged by 1938, and then became the most important single factor in determining the form of the wartime emergency services, contained the following basic features. At the outset (and perhaps without any declaration of war) London would be subjected to concentrated and intensive air attack by bombers operating from Germany. In the first twenty-four hours the Germans might attempt to drop as much as 3,500 tons. Subsequently, and for a period of weeks, the daily weight of attack might average 700 tons. A high degree of accuracy might be achieved by the enemy in bombing specific targets and areas. It was thought that high explosive would be employed to a great extent than incendiary bombs, while the use of gas was considered possible. The introduction by the enemy of bacteria directed against human life, animals and crops was believed to be unlikely—but 'we must expect,' said the Government's Bacteriological Warfare Sub-Committee, 'a serious dislocation of our sanitary system and the resultant increase of disease'.13

The enemy was expected to launch attacks on the chief provincial centres of industry and on the ports (particularly on the east coast).14


The most vulnerable areas were considered to be those lying south-west, south and south-east of a line drawn from the Humber to the Bristol Channel. In preparing schemes for civil defence the Air Raid Precautions Department, with the advice of the Air Ministry, accordingly classified provincial cities and towns in Britain by order of vulnerability, while the Health Departments, for purposes of civil evacuation, zoned the country into evacuation, neutral and reception areas. But overwhelming all else, during the period of active planning, was the problem of London. This concentration in 750 square miles of about 9,000,000 people, or one-fifth of the population of Britain, was expected to the target of massed assault by the enemy's bombers. The theory of a 'knock-out.blow' which the enemy would aim at the country's nerve centre influenced many of the early plans, and explained much of the birth and development of wartime emergency services.


Contents  *  Previous Chapter (Preface)  *  Next Chapter (II)


1 Estimates of four kinds had to be made:

  1. Of casualties per ton of bombs. These were made in 1924 by the Air Staff and, later, by the Home Office.
  2. Of the operational strength of the probable enemy. This was a matter for the Air Staff.
  3. Of the strength of British defences. This was a matter for the Air Staff.
  4. Of the rate of enemy output. In the nineteen-thirties, this was estimated by the Industrial Intelligence Centre.

2 Lord Balfour was presiding over the Committee of Imperial Defence in 1922.

3 This estimate, like all subsequent ones, was subject to various qualifications which cannot be discussed here—size of the enemy air force, location of its bases, the type of bombs employed, strength of the defences, whether or no the country had allies, etc., etc.

4 This was based on an estimated German first-line strength by April 1030 of 2,520 aircraft, of which 1,710 would be bombers. The total weight which these bombers could drop would be 2,250 tons a day. This, it was said, was a conservative estimate since no allowance was made for technical improvements. The figure of 2,250 tons was reduced by one-third as it was assumed that this proportion of bombers would be directed to France. Other deductions were made for the effects of counteroffensives, fighters, ground, defences, weather conditions, forced landings and other forms of wastage, thus bringing the daily tonnage down to 644.

5 Home Office circular 700216/14, 9th July 1935.

6 Five of the eight handbooks and memoranda issued by the Department in 1935–36 were concerned with some aspect of gas defence.

7 A detailed account of these matters is the concern of Civil Defence, O'Brien, T. H. (1955)

8 The Structural Precautions Committee and the Incendiary Bombs Committee.

9 H. of C. Deb., 28th November 1934, Vol. 295, Col. 858.

10 H. of C. Deb., 10th November 1932, Vol. 270, Col. 632.

11 H. of C. Deb., 28th November 1934, Vol. 295, Col. 859.

12 A pamphlet The Nature of the Air Threat (June 1939), published by the Air Raid Defence League and quoted in the Report of the Royal Commission on the Distribution of the Industrial Population (1940, Cmd. 6153), estimated that '200 bombers per day, each carrying 1½ tons of bombs, would drop 3,000 tons of bombs in 10 days. In congested districts such raiding might cause at least 200,000 casualties …'

13 First Report of the Bacteriological Warfare Sub-Committee of the Committee of Imperial Defence (March 1937). This Committee was set up in November 1936 by the Minister for Coordination of Defence. In addition to recommending the purchase of, for instance, gas gangrene and tetanus anti-toxins and anthrax vaccine, it was responsible for the establishment of the Emergency Bacteriological Service (afterwards renamed, as 'less disturbing to the public mind', the Emergency Public Health Laboratory Service).

14 A Government committee on the distribution of imports in wartime made the assumption in 1935 that seventy-five percent of the capacity of the ports between the Tees and Southampton might be put out of action.

Transcribed and formatted for HTML by David Newton, HyperWar Foundation