# Aircraft in Warfare (1916)/Chapter 19

CHAPTER XIX.
UNSOLVED QUESTIONS OF NATIONAL DEFENCE. RADIUS OF ACTION AND POWER OF AGGRESSION. INTER-DEPENDENCE OF NAVAL AND AIR DEFENCE. AERONAUTICAL DEVELOPMENT A NATIONAL RESPONSIBILITY. IMMEDIATE MEASURES ADVOCATED.
§ 120. National Defence. Air Raids. In considering the more far-reaching effects of Aircraft in Warfare, it is more than ever necessary that we should substitute in our minds for what we may see to-day, a picture of what may reasonably be expected in the not very distant future. Thus from the military standpoint and even from the standpoint of the Nation, the effect of the raids by German aircraft has been a negligible quantity; it has moreover cost the enemy no small expenditure of energy (which he can ill afford to squander) to effect this relatively microscopic injury. Tersely put, air-raids on Great Britain by Zeppelin do not pay. We have no reason, however, to assume that this condition of affairs will last; on the contrary, we must make provision against future possibilities, when air-raids will be conducted in so effective a manner that, if not successfully opposed and beaten back, they will pay.
§ 121. The Defence of London. A broad question at once arises: will it be possible in the future to entirely and effectively defend from aerial attack a city of the size of London situated within so short a distance of the enemy's frontiers? For the purposes of the proposition we must assume the whole of the continental coastline as hostile territory; on this basis the distance is no more than one hour's flight.
​There is uo doubt that so long as the weather conditions are favourable to defence, anything in the nature of a daylight attack on London could be rendered impossible by a sufficient defending force of aeroplanes, but here even, in the event of an attack in great force, it is by no means certain that some measure of success might not be achieved; it would at least require an immense preponderance of power, if every hostile aeroplane is to be beaten back or otherwise accounted for.
When, however, the weather conditions are favourable to attack, also in the case of attack by night, there is no means of defence at present known to the author which would prevent the enemy from inflicting enormous damage if he attack in sufficient numerical force and is prepared to act with determination in spite of any losses he may sustain; no reasonable superiority in the defending aircraft, either individually or numerically, can be entirely effective. Neither can we pin our faith to counter-aircraft artillery; under the conditions in question it may prove to be useless.
We have so far not witnessed an attack by aircraft on an important city on a grand scale, such as, without doubt, the future has in store. The " raids " which have hitherto been carried out are quite trivial and ineffective affairs compared with what in due course will become possible. The critical point, and the point to be aimed at as an act of war, is that at which the fire-extinguishing appliances of the community are beaten or overcome. Up to this point the damage done may be taken as roughly proportional to the means and cost of its accomplishment; beyond that point the damage is disproportionately great: the city may be destroyed in toto.
There will always be the sentimentalist who has implicit faith (in spite of experience) in the omnipotence of peace conferences and the like and the unalienable ​rights of humanity, who will decline to believe that after the present war Nation will need to defend itself against Nation by brute force. To these the destruction of a city of 5,000,000 peaceable inhabitants by fire with the scenes of horror that would inevitably ensue, will be looked upon as the figment of a diseased imagination, to these the author does not address himself; he regards the possibility as one which it behoves us to consider and meet as a matter of ordinary military precaution, not regarding it as any more improbable or unexpected than any other hostile act of which an enemy might be capable.
§ 122. Justification for Attack upon Capital City. It is futile to attempt to disguise the self-evident fact that a serious attack on the capital city of an enemy, containing in its heart the administrative centre both of his Army and Navy, in addition to the headquarters of his Government, cannot be regarded other than as a legitimate act of warfare. No international agreement or convention can make it otherwise. Once war is declared the successful waging of war becomes the first duty of a belligerent Government, it obviously cannot do or countenance any act, or the neglect of any act, which could by any possibility compromise the issue, without thereby proving false to its trust. There is really no escape from this. Unquestionably, the destruction of a capital city such as London, with the administrative centres aforesaid, would be a military achievement of the first order of magnitude; it would be, from an enemy standpoint, an achievement of far greater potential value than any ordinary success or victory in the field of battle.
We may then disabuse our minds of the popular notion that the raiding or attacking of London by aircraft is to be regarded as something contrary to the ​established ethics of warfare; we recognise that we are, in the protection of our capital, face to face with a necessary problem of national defence of the first magnitude. Let us admit that, given a determined enemy in the possession of the French and Belgian littoral, the problem in future will be increasingly difficult. Let us go further, and, for the purpose of argument, assume that it may become impossible. We have no assurance in all the circumstances that this is not the truth. What then will be the measures by which the new situation can be met? It is wholesome to consider the position on this basis.
§ 123. The Incentive to Attack. The Real Source of Weakness. It is evident that if the administrative headquarters of the Army and Navy were removed to some less accessible position, and in fact if London were to cease to be the centre of Government, the main incentive to attack, as a military operation, would be destroyed, and the danger in question disposed of. Obviously London as a city would be no less vulnerable than before, and it would be open to be wantonly raided unless adequate means of defence were provided. Measures of defence, however, to be effective have always to be proportioned to the incentive to attack, and to reduce the incentive to a minimum is to make the most of such means of protection as are available. Putting this in other words, we have it that the enemy would not be prepared to pay so high a price or take the same risks for the privilege of destroying private property and murdering civilians, as he would if he were able at the same stroke to disorganize the whole administrative machinery of the State. Also, so long as any act of aggression has admittedly no military value, it may be answered by appropriate reprisal.
​The possible need for abandoning the present capital as the centre of administration in wartime carries with it as a corollary its abandonment equally in time of peace, at least so far as the control of the Army and Navy is concerned; since, on the declaration of war, or even without a formal declaration, the aircraft of the enemy may already be mobilised for an attack. Of course our premises are hypothetical, we have no proof yet that the adequate defence of London from hostile aircraft will actually become impossible, but equally it is clear that the contingency may have to be faced, and therefore it is one that must be taken seriously.
§ 124. The Question of Fire Risk. Apart from the active defence provided by a numerically strong and vigilant air fleet, the most important factor in the protection of a city from hostile aircraft is to be sought in the prevention of fire. Thus a city in which fire-proof or fire-resisting construction is extensively employed, and in which a town-planning scheme has been adopted with a view to the localisation of any conflagration that may get out of hand, will be far safer and more easily defended than one in which these precautions are not taken. It goes without saying that all the usual appliances for dealing with the outbreak of fire should be liberally provided in any case. The greater and more thorough the precautions, the less probability will there be of the enemy attack being successful, and the larger the scale on which it will have to be conducted to have any hope of success; conversely the easier will be rendered the effective defence. It is to be understood that the word success as here used is measured by whether or no the extent of
​direct injury is sufficient to cause a general conflagration, as already laid down.
§ 125. The Question of Radius of Action. A point of great importance in the present connection is the radius of action of the aircraft by which attacks such as under discussion will be carried out. Evidently it is the aeroplane or flying machine which chiefly concerns us, and due allowance for possible improvement over existing performance must be admitted.
When we are discussing the range or radius of action of a battleship or cruiser we are dealing with something definite, such vessel can either reach a given destination with its power of aggression unimpaired, or it cannot get there at all; not so with the aeroplane. In the aeroplane the power of aggression and the range •r radius of action are alternative quantities, which, measured by the weight of bombs and the weight of fuel (i.e., petrol) respectively, represent a definite amount in sum. Thus if one-third of the maximum gross weight of the machine be taken to represent its combined petrol and bomb capacity, the maximum distance which can be flown by an aeroplane is about 1,200 miles, or 600 out and home, if the whole of the said capacity be devoted to petrol. When part of the capacity is devoted to the carrying of bombs the range of flight is proportionately lowered, so that the position of affairs may be represented as in Fig. 20, in which it will be seen that as the range of flight is increased the value of the machine for the purposes of attack is diminished till at a maximum out-and-home radius of 600 miles it falls to zero: the machine has ceased to be capable of offence.
It is not only in its power of offence that the longdistance aeroplane is at a military disadvantage; it is so in respect of all other attributes which are involved in the problem of weight. For example, any machine built ​expressly for long distance raiding, will be essentially a relatively slow machine, since speed means engine weight; it must be, comparatively speaking, a relatively poor climber for the same reason. Again, it cannot afford to carry shield or armour, neither can weight be spared for a defensive gun armament. All these facts mean that as the distance to be raided becomes greater, defence will become more and more easy, and point to the conclusion that in actual warfare the maximum distance which can be effectively raided by aeroplane will be far less than the theoretical maximum aforesaid. Beyond this the opportunities for defensive counter
Fig. 20
measures become greater, and the possibility of taking advantage of favourable weather conditions less, the greater the distance involved in the raid. Taking everything into account, the author thinks it improbable that raids over territory held by an enemy exceeding 300 or 400 miles will be found practicable, and in the face of opposition it would be rare for an attempt of this magnitude to succeed unless conducted by a force of overwhelming numerical strength.
§ 126. The Danger to Aircraft Factories and Production. There is a further point in respect of which the position of aircraft is without exact parallel in the other arms of the Services; in a war of any magnitude or duration the manufacture during the period of ​hostilities is vital to the maintenance of the Arm at its initial strength, and the manufacture is itself threatened if the enemy once obtain, aeronautically, the upper hand. Thus the life of an aeroplane in active service is a matter of only some three or four months, and the manufacturing resources of the country must thus be capable of replacing the whole active force of aeroplanes three or four times over in every year. On the other hand, our sources of supply, or those situated within raiding distance of hostile territory, would be seriously imperilled were the enemy to obtain, even for a short time, a sufficient preponderance of air power. The intention of thus making use of aeronautical ascendency to extinguish the enemy's sources of supply has been clearly manifested in the present war, as witness the raids executed against Friedrichshaven and other Zeppelin bases; the reason that such tactics have not been pushed to the extreme and followed to their logical conclusion is clearly that the raiding aeroplane, in respect of type, numerical strength, and organisation, is yet in its infancy.
For the above reason it is the author's opinion that the main aeronautical manufacturing resources of any country will eventually be established out of effective reach of hostile territory; in the case of Great Britain this indicates the selection of a position some three or four hundred miles from the continental littoral. The circumstances point ultimately to the industrial districts of Belfast and the Clyde, as appropriate centres for the production of both aeroplanes and so-called "seaplanes" in the quantities the future will demand. Such a position is out of range of existing hostile aircraft, and will probably remain so for many years to come. Looking beyond this it is a position giving such great possibilities of defence, that so long as we assume the motive power engine subject ​to its known restrictions as a form of heat engine, it may be regarded as safe for all time. The position of Belfast is such that, even if we assume the whole Netherlands. Belgium and the French littoral to be in the hands of an enemy, the distance to be flown is approximately 400 miles, during almost the whole of which distance enemy aircraft will have to run the gauntlet of our air defence, both aeroplane and counter aircraft artillery.
§ 127. Comparison with Navy. It is true that the Aeronautical Arm is not alone in requiring manufacturing facilities during the period of hostilities, and in being liable to the dislocation of these facilities by its own kind. The same is true, but in far less degree, of the Navy; in the latter these facilities (in the form of our Naval building yards and dockyards) are quite essential to the proper upkeep of the Fleet, although the amount of new construction (in comparison with aircraft) is relatively small. It is nevertheless regarded by the Naval authorities as essential that our dockyards, etc., shall be so placed as to be capable of effective defence against naval raids, and any situation which cannot be made to comply with this condition has sooner or later to be abandoned, or at least new bases have to be created to take over its more important functions. The position of the Aeronautical Arm, however, is unique in the relatively great importance of the daily output of new machines, and in the relative ease with which this may be interfered with by enemy enterprise if due precautions are not taken. Thus the present recommendation may be regarded as the extension of a principle, admitted in the selection for the site of a ship-building yard or dockyard, to the choice of a headquarters for aeronautical construction.
It is extremely doubtful whether we shall witness ​during the present war raids extending to anything approaching 300 or 400 miles out and home over enemy territory, so that the recommendation suggested above is probably more drastic than necessitated by present conditions; however, all depends upon the duration of the war, the technical difficulties in the way of the production of suitable machines can be surmounted at any time without great difficulty. Beyond this there is no reason to suppose that during the present war the French littoral will be in other than friendly hands, whereas in the foregoing discussion the broader basis has been assumed, namely, that all territory not actually British must be considered as potentially hostile.
§ 128. Air Raids and the Naval Outlook. The possibility of air raids on a large scale on the Naval outlook will certainly be far-reaching in its effects. All dep6ts, dockyards, etc., within easy range of alien territory, such as those situated on our southern coast, can no longer be regarded as secure from bombardment; the defence of such places as Portsmouth and Devonport from attack by air may prove an almost if not quite impossible proposition; the weather conditions may be such as to let the enemy through even in face of a numerically superior defensive force. Thus it may be confidently anticipated that these southern depôts will become points of subsidiary importance, useful enough in times of European peace, but forming no really essential part of the scheme of National defence in the event of a great European war. The "centre of gravity" of the bases on which the Navy will rely for its support is bound to move northward and still further north as the power of the aeronautical Arm is uncoiled, and eventually the strategic centre of our defences, both Naval and Aeronautical, will perforce be located in the region of the Irish Sea and North Channel; it will then be in the neighbourhood of Belfast on the one ​hand and the Clyde on the other, that our main Naval building yards, dockyards and important depots will be established, and our largest and most important aircraft factories will be installed.
If the above conclusions are sound it may be found necessary, for reasons of Naval strategy, to cut a ship canal through from the Clyde to the river Forth. This would be an engineering feat of considerable magnitude, involving, besides the actual cutting itself, the deepening of the Clyde for a distance of some 12 or more miles between Clydebank and Greenock, in addition to extensive dredging of the River Forth. The existing Forth and Clyde Canal is an ordinary inland navigation, with numerous locks, fit only for lighters or barges of length not exceeding 68 feet. The height of the "divide" is about 160 feet.
A real ship canal for the purpose intended—to be navigable by the largest of our battleships—would be an undertaking of the same order of magnitude as the Kaiser Wilhelm or Kiel Canal, and we may assume would involve an expenditure probably not less than forty millions sterling. Such a canal would bring the Naval base at Rosyth within a few hours steaming of the Clyde, or roughly within twelve hours of Belfast Lough.
§ 129. Aeronautical and Naval Defence indissolubly associated. It is evident that the whole scheme for aeronautical defence must and will be closely related to the distribution of our Naval bases. In fact it is our Navy and defensive aircraft which henceforward will jointly constitute Britain's first line of defence. It is for this reason that the control of our defending air forces falls naturally to the Admiralty rather than the War Office. The most important objectives of an enemy air-raid, apart from attack on our centre of government, will be without doubt our Battle Squadrons, our Naval bases and ​dockyards, and our aircraft and shipping centres, for it is here that, apart from any question of invasion. Great Britain is most vulnerable. The problem of giving adequate protection to these is manifestly a work which only the Admiralty is competent to undertake. As already pointed out there are geographic positions which in no way lend themselves to aeronautical defence, it will be incumbent upon the Naval Authorities to determine when and under what conditions these will need to be abandoned. Generally speaking, a point can only be defended from hostile aircraft when its approach necessitates a considerable length of flight over British territory. Alternatively a point may also be considered defendable if the total distance from hostile territory is sufficient, provided that the intervening sea is effectively patrolled; thus again the intimate relation of aeronautical to naval defence becomes manifest.
§ 130. The Future of the Aeronautical Arm a National Question. It is more than probable that before the termination of the present war we may witness and experience aerial raids on a scale immeasurably greater than anything so far attempted, either by the enemy or by our own airmen; it is also probable that the strategic employment of the aeronautical Arm on the lines laid down in the preceding chapter (§ 119) will become a fait accompli. The extent of realisation depends upon the duration of the war and the numerical strength of the air-fleets which will become available before the conclusion of hostilities.
In the author's opinion it is vitally necessary, both with a view to ensuring speedy victory and to our future as a nation, that our manufacturing resources in the production of aircraft should be developed to the utmost; aeroplanes and still more aeroplanes will be needed, aeroplanes in the maximum possible quantities of every useful ​type, whether reconnaissance, bmb-dropping, or fighting machines; our total present capacity for production is petty in comparison with what we have evidence the future will demand.
The question of the future of the Aeronautical Arm is not purely the concern of the Army and Navy, it cuts deeper; it is essentially an affair of the Nation. It is national because it concerns both Services. It is national because it is of wider and more far-reaching moment than comprised by its relation to either. It is national because it depends upon our national industrial resources, and may tax these to the uttermost; national because it is the Arm of greatest potential development in the present war, and in future warfare may decide the fate of Nations. Finally, it is national because it is the Arm which will have to be ever ready, ever mobilised, both in time of peace and war: it is the Arm which in the warfare of the future may act with decisive effect within a few hours of the outbreak of hostilities.
§131. In Conclusion. That we have temporarily the upper hand in military aeronautics there is no doubt, but this is due more to our technical prescience than to the scale or magnitude of our national preparedness. In other words, our present lead is only in part due to our own effort, it is largely due to the mistake made by the enemy prior to the war in devoting altogether disproportionate attention to the large dirigibles: Germany backed the wrong horse. The Zeppelin, from the military standpoint, has proved a complete failure. If the resources thus diverted into a useless channel had been devoted to the development of the aeroplane and strengthening of the enemy flying corps, the position from our point of view might have been nowise so satisfactory. Having been thus favoured with the advantage by what may almost be regarded as a ​"chance of war," we must make up our minds to maintain it by any and every means in our power.
Let us not delude ourselves by supposing that the enemy will be content to allow us to retain our advantage without a keenly contested struggle; he is probably ere this fully alive to his past mistake, and will strain every nerve to rectify matters; there is already evidence of strenuous effort in that direction. The chief factor in the coming contest in aeronautical armament will undoubtedly prove to be the relative manufacturing resources available respectively to the two belligerent groups; here Great Britain and her Allies have an undoubted advantage.
In concluding the present work, the author claims that a clear case has been made out for an immediate and thoroughgoing overhaul of our programme and administration as touching the future of, the Aeronautical Arm, and to this end urges for immediate consideration the following:—
(1) That in view of the potentialities of the Aeronautical Arm, a comprehensive scheme of construction should be forthwith prepared, in which provision shall be made for organizing, utilizing, and developing every available source of manufacture and supply.
(2) That if possible certain of our present types of aeroplane be virtually adopted "for the duration of the war," and existing manufacturing facilities should be utilised for their uninterrupted production to the utmost of their capacity.
(3) That where it is decided that new types are required, new sources of production should so far as possible be tapped or new works equipped, in order that ​output should not be made to suffer. In other words, the policy should tend in the direction of establishing each new type with the factory for its production as a complete proposition.
(4) That more adequate provision be made for the development of improved models and new types, both as regards initial manufacturing facilities and finance.
(5) That a Board of Aeronautical Construction be formed on the lines adumbrated in the present work, to deal with the needs of the Services and to settle specifications and approve the designs for new types, and generally to assume control and responsibility for our National Aeronautical Programme, both as to sufficiency and otherwise.
* ↑ A certain cynic once defined a fool as a man who could only learn by experience. The author prefers the more benevolent definition that a fool is one to whom the teaching of experience is of no avail.
* ↑ A reprisal to be effective must be delivered with promptitude like the riposte of a skilled fencer. A reprisal which is too long delayed possesses no moral weight and has every appearance of an independent act of aggression; it may even plausibly be given as an excuse for a subsequent repetition of the original offence. It is thus detrimental to the cause of humanity to tie the hands of a belligerent by international convention. Such conventions result in delays whilst law officers are consulted and whilst committees are called and decisions are reached; also they result in no preparations being made for counter measures such as comprehended by the word reprisal. The power of reprisal and the knowledge that the means of reprisal exists will ever be a far greater deterrent than any pseudo-legal document.
* ↑ Compare Appendix 11. In the present war the position is far more favourable; the Midlands and West of England are reasonably safe from attack.
* ↑ A given type of aeroplane may not be the best we know how to make, but the same may be said of our small arms, or our field pieces; it does its work, however, and is understood by the men who handle it in the field: these are points worth a great deal. It is not realised by those who are not intimately connected with manufacture the extent to which alterations or improvements during quantity manufacture are detrimental to output; especially is this the case when working at high pressure. Fixity of design should be looked upon as a sine qua non once manufacture has been embarked upon.
* ↑ Under the Presidency of a responsible Minister.