The Overstretched Superpower
Does America Have More Rivals Than It Can Handle?
THIRTY-FIVE years ago the English Channel had not yet been crossed by air. Now the crossing of the Atlantic by airplanes is a commonplace. One of this war's sensations was the cross-Channel bombardment of England by flying bombs and rockets. If there is another world war, will the transatlantic flight of bomb and rockets become a commonplace also? There is every reason to believe so. The technical problems involved are not so great as those which had to be overcome by the men who invented and perfected the airplane. A few years from now it probably will have become technically possible to bombard the United States from European bases, and vice versa. And the nature of the bombs so carried may be, as we now have had confirmed to us, terrible beyond any previous imagining.
Both British and Americans have a tendency to hide their concern over some unexpected move on the part of an enemy by scoffing at it. The flying bomb, or VI, was at first greeted in Britain as a great joke. Flight, one of the leading British aeronautical journals, commented on June 29, 1944, 16 days after the attack had begun: "One would have to search diligently through the records of warfare to find a more telling case of substituting futility and propaganda for true military measures than the recent employment of the air torpedo." That scoffing attitude was dangerous then. We should be putting ourselves in extreme peril if we persisted in taking the same sort of attitude toward the future development of these and other new weapons.
The fact is that V1 gave the Nazis real and substantial military gains. At a time when the Allies were engaged in the mightiest military undertaking the world had ever known -- the invasion of the Continent -- the British, aided generously and indispensably by the Americans, had to deploy large forces for the direct and indirect protection of London. Several squadrons of fighters had to be drawn away from the operations on the Continent in order to cope with VI. In the period of greatest activity, at least 30 fighters were constantly in the air, around the clock. A belt of heavy and light antiaircraft guns 20 miles deep was set up; and, as a final obstacle, as many as 2,000 balloons were put to use. To provide communications for this force, 5,000 miles of telephone cables had to be laid and a fleet of 3,000 vehicles was employed continuously. This tremendous defensive expenditure was made at a time when our full force should have been concentrated on the offensive.
Moreover, for nine months before the V1 attack began, and during all the time it lasted, the Allied Air Forces were engaged in reconnoitering and bombing German experimental stations as far east as Peenemünde, as well as the hundred and more launching sites which the Germans were constructing on the Continent. This involved a tremendous diversion of photo reconnaissance and photo interpretation effort, besides imposing a heavy strain on our intelligence services. Hitler's most substantial gain, however, lay in the extent to which the Allies were forced to divert their bombing efforts from German homeland targets in order to concentrate on the cleverly camouflaged launching sites set up in the French countryside. More than 100,000 tons of bombs were dropped in the effort to knock out these sites, and in these operations 450 British and American aircraft were lost.
Thus even if the flying bomb offensive had failed to register hits on important objectives, Germany would have found it militarily worth while. And, in fact, it did inflict substantial damage on London and throughout southern England. In a period of 80 days and nights, the V1 damaged nearly a million houses and caused thousands of casualties. In the last 12 months of the war, three million Londoners had their homes destroyed or damaged (an estimate which presupposes only three people to each home).
There is reason to believe, however, that the Germans expected a very much greater proportion of their missiles to get through the defenses than actually did so. During the early summer they had staged an experimental operation before high officers of the German Air Staff (Milch was reputed to have been present) at Vicenza, in northern Italy, in the course of which 20 fighters, including one captured Spitfire, endeavored to shoot down flying bombs. The results led the German Air Staff to believe that we could bring down only 10 percent of their bombs in actual operations. And, indeed, there were good grounds for this conclusion. The V1 travelled at 350 miles an hour and it generally flew at a height of 2,000 to 3,000 feet. This height was far below the rated altitude of fighters, and the flying bomb was difficult to see from above. With its 1,870-pound warhead, moreover, it was an extremely dangerous target for a pilot to shoot at. In addition, since it flew so low and so fast, it presented great problems to the AA predicators as developed at the time.
Fortunately, the estimate of the Germans proved over-optimistic. Although they increased the difficulties of the defense by sending the bombs over when weather conditions were favorable, i.e. when there were low clouds, 33 percent of the missiles were destroyed in the first week. By dint of great efforts, the defenders increased this figure until on August 28 they brought down no less than 97 out of 101 flying bombs. Much credit for this was due to the magical development in AA fire during the period, and to the invaluable practical and technical assistance given by American AA units. In the first week that the AA batteries were deployed, they shot down 17 percent of the bombs; in the last week this figure had risen to 74 percent. The American gunners brought with them a new technique which the British were not slow to admit was better than their own.
Londoners are particularly grateful for the aid given by American flying and ground units in what was, from one point of view, a "domestic" operation. The author may perhaps be permitted to record that during the summer he was on occasion engaged in photographing the flying bomb sites from high altitude. Being a Londoner, he felt a most acute interest in his work. He never failed to be moved by the sight of American comrades setting out on the same task with no other motive than duty willingly undertaken in furtherance of the common cause.
The V1 carried 1,870 pounds of explosive a distance of 150 miles at a speed of 350 miles an hour. There was nothing startlingly unexpected about this. Even during the First World War the idea of a crewless airplane carrying explosives had appealed to the imagination of strategists, and for years subsequently inventors had been trying to produce one. They had been unable, however, to solve the fundamental problem of designing a craft simple enough to be put into comparatively large-scale production.
After the defeat of the Luftwaffe in 1940, Germany's need for a long-range weapon to bombard London became so acute that great pressure was put on German scientists and manufacturers; and in the end they succeeded in producing the desired simplification of the power unit. They discarded the orthodox reciprocating gasoline engine containing a large number of precision-made parts and in its place devised an entirely new form of simple reaction-propulsion unit, developing some 600 horsepower. The unit consists of a welded steel tube 11 feet, 3 inches, long, mounted above the rear of the fuselage. Fuel is fed to the engine from a tank in the fuselage, by means of air from compressed air bottles, through a pipe in the forward supporting strut of the propulsion unit. This article does not pretend to go into mechanical detail. Suffice it to say that this engine has about one quarter of the weight of an equivalent gasoline reciprocating motor; but its fuel consumption is eight times greater.
The overall length of the flying bomb is slightly more than 24 feet and the wing span 17 feet, 6 inches. Its loaded weight (with 130 gallons of gasoline) is 4,700 pounds. Once in flight, it is controlled by four gyroscopes which govern direction and pitch, while an aneroid barometer operating to a pre-set figure governs height. Only some 3 percent of the bombs launched were fitted with radio transmitters. The course of these could be plotted by means of direction-finding receivers. Forecasts which had been made as to the velocity and direction of the wind could then be checked, and bombs launched subsequently could be more accurately directed. The range was controlled by an air-log driven by a small air-screw which was revolved by an air stream. When the set distance was reached, the air-log, by means of an electrical impulse, automatically exploded the detonators attached to the tailplane; two tabs were forced into a down position and the flying bomb was thrown suddenly into an almost vertical dive. The engine would then cut out.
By destroying a hundred or more launching sites, the Allied bombing operations delayed for many months the beginning of the V1 offensive against London. These sites were being built on fairly solid lines. As a result of the bombing, the Germans evolved a launching ramp that could be erected in a little more than a week and which lent itself to camouflage. It was from these modified sites that the flying bombs were finally launched against England and also against our lines of communication behind the western front. The ramp is nothing more than a catapult driven by compressed air. The bomb is assembled in nearby sheds, and is hoisted onto the catapult by a derrick. The controls are then pre-set and the propulsion unit started up. The catapult carrier, on which the bomb rests, is then carried up the ramp at a fierce rate of acceleration. The minimum powered flying speed of a missile is 170 miles an hour, so that the launching speed is extremely high. At the end of the ramp the flying bomb instantly detaches itself and climbs at a gentle rate to its operating height of from 2,000 to 3,000 feet.
Hardly had the Londoner recovered his breath from intensive bombardment by flying bombs than the threatened long-range rockets, the V2, started to arrive. There also continued to be a bombardment by flying bombs launched from airplanes, but it proceeded on such a reduced scale that, everything being judged comparatively in this world, Londoners barely noticed them. V2 was something new, something with added devilment. It betrayed no sign of its approach, but simply arrived from nowhere and exploded with even worse results than VI.
Although rockets in various elementary forms have been used spasmodically in warfare for hundreds of years, they did not come into favor on any considerable scale until the present war, when the Russians began to fire them from aircraft against ground targets. They have since been used extensively by aircraft in all theaters and they have yielded large dividends in tactical operations. But rockets fired from aircraft have little in common with the giant V2 rockets which the Germans so skillfully developed. V2 is the outcome of at least 20 years of extensive German experimentation with all forms of rocket propulsion. It is not clear at the time of writing when the Germans concentrated on the production of this long-range weapon, but it would seem to have been about 1942.
The V2 rocket is a streamlined projectile 46 feet long, 5 feet, 6 inches, in diameter, with a sharply pointed nose. It carries at the rear four large external stabilizing fins at right angles to each other. It has an explosive warhead of 2,000 pounds in the nose; and when it is filled with fuel the whole rocket weighs about 12 tons. The fuel is carried in two large aluminum tanks, one holding 7,500 pounds of alcohol, the other 11,000 pounds of liquid oxygen. Since, therefore, the rocket does not depend upon external air for combustion, it can operate equally well at low or extremely high altitudes. In actual fact, its flight carries it to a height of 60 miles above the earth's surface.
V2 is considerably more complicated in design and manufacture than the flying bomb. Its radius of destruction is comparable, but it is apt to cause more casualties, since it gives not even a half second of warning before the actual explosion. This is because it falls at a speed greater than sound travels; one hears the tremendous rumbling roar of its headlong rush through the air only after the explosion has occurred.
The launching and operation of V2 are simple. The rocket is placed in a vertical position on a concrete platform or hard surface. A flat road is suitable. Within the rocket is a turbine, driven by superheated steam produced by mixing very concentrated hydrogen peroxide with calcium permanganate solution. This mixture is ignited electrically from a distance, whereupon the rocket takes off. Throughout the flight the turbine drives the pumps which force the liquid oxygen and alcohol into the combustion chamber. The products of combustion are forced out at a high speed through the orifice in the rear end of the venturi as a jet of very high gases. One set of control vanes is in the path of this jet stream. The other is fitted externally on the edges of the stabilizing fins. The rocket starts climbing vertically, but a gyroscope control within the projectile comes into play to operate the control vanes, and this causes the rocket to curve away from the vertical toward the target. The combustion of the gases and their ejection through the venturi creates a thrust of about 26 tons. It is this which propels the rocket forward.
When the fuel is exhausted, V2 is pointing upward at about 45 degrees and is travelling at a speed of about 3,000 miles per hour. It continues upward, following the same path that would be taken by a shell fired at this angle. The maximum range at present is 220 miles. If the target is within that range, the fuel is automatically cut off at the appropriate moment. Descending through the atmosphere from a height of 60 miles, the projectile is slowed down by the resistance of the air to about 1,600 miles per hour; and at the same time it becomes heated by friction to such an extent that it has been observed glowing a dull red. Sometimes the overheating results in a premature explosion in the air.
No one can deny that V2 is a most remarkable technical achievement. In its development the Germans had to find a solution to two hitherto insurmountable problems. The weapon would have been of little value if its construction had involved the use of rare metals; and considering the high temperatures and pressures involved, this might well have been the case. Since the jet is the part which has to bear the highest temperature, the Germans contained in it a liquid-cooled jacket of mild steel. The second big problem was to provide adequate directional control. The stabilizing surfaces are gyro-controlled and, as previously mentioned, one of the two sets of surfaces is placed in the jet stream itself. In this way the rocket can be controlled immediately the jet stream is ejected. It is this device which enables the rocket to take off from the simplest of bases. A half dozen lorries can hold all the equipment necessary for launching.
The only possible form of defensive action against the rockets was for fighter bombers to attack their bases, storage depots and lines of supply. A V2 base is such a mobile affair that it was extremely difficult to spot. When intelligence provided information on the storage depots nearby, however, attacks on these could interrupt the flow of supplies. A number of ways were developed by which a V2 base could be plotted and placed within a comparatively small area. Attacks on bridges, railroads and transport would then help to isolate that area and disrupt the supply line from the factory to the operating base. In the end, the sites near The Hague were completely cut off from the supply area; but this was possible only because of the close proximity of our armies to the firing area in the final stages.
London was only just within range of the robot bombs fired from the nearest enemy territory. This meant that the V2 bases operating against London were close to the front line, which simplified the task of our fighter bombers. In addition, the invasion towns in France and Belgium in the rear of our front line were subject to rocket and flying bomb bombardment. In these cases, the enemy was able to choose whether to put his bases near his front line and thus, by firing at short range, improve the accuracy of his weapons, or whether to reduce our attacks on his bases by withdrawing them well into his own territory, out of easy reach of our attacking aircraft. He chose a compromise, and arranged his bases in depth. London was not intensively bombarded by V2; but the rockets prolonged the strain and anxiety of life in the capital after the buzz-bomb no longer menaced it acutely with death from the skies.
The flying bomb and rocket have come into military plans and strategy to stay. Londoners have had only a grim preview of what the future can hold for the population of every city in the world -- unless, that is, the destructive possibilities of these weapons are brought under control by the agreement of all the nations. In view of this, a brief recapitulation of London's experiences may be relevant at this time.
Bombardment by rocket is generally agreed to be not so trying to the nerves as bom bardment by flying bomb. The rocket arrives unheralded; there is a vast explosion; and there is a wide area of devastation. If one is still alive, one knows that another rocket is hardly likely to land in exactly the same spot, at any rate for some time. But though the rocket does not have the psychological impact of the flying bomb -- which one listens for and gauges the course of, and which comes over in sufficient quantities to make second and third explosions at nearly the same spot possible and indeed likely -- it is potentially more accurate. From a strictly military point of view, therefore, it is a more important weapon.
As a flying bomb approaches a great city it brings a warning of death to the ears of millions. When all was quiet in London at night you could hear a flying bomb approaching for three minutes before it came overhead -- three minutes of mounting anxiety. You heard it for probably two minutes before you could say safely that it was not going to pass within three miles of you. The sound of its engine is indescribable -- a vulgar, roaring noise, rather like the rapid, flapping vibration of giant obscene lips. No one can listen to it without alarm.
After some experience, you could decide with some certainty whether an approaching bomb necessitated taking shelter. Normally, there were a few final seconds of warning of imminent danger between the time you heard the engine cut off overhead, which happened when the flying bomb was thrown into its vertical dive, and the moment of impact. According to some authorities, this warning silence was not expected by the Germans. It occurred because the sudden movement from the horizontal to the vertical threw the gasoline in the tank away from the feed-line and caused the engine to cut, thus preventing the bomb from diving with engine still running. This cutting out of the engine must have saved hundreds of lives by giving people a split-second opportunity to get clear of glass.
Unfortunately, the German missiles had irregular tricks. Enough of them did manage to strike the ground with their engines still running for it to be unsafe to await the dying away of the motor before taking shelter. Furthermore, you could not relax with complete assurance after the wave of anxiety -- mounting as the bomb approached, reaching a peak as it came overhead, and normally diminishing as it passed on -- for some bombs turned round in a circle before crashing to earth. Others cut out at 3,000 feet and, instead of diving, came down in a gentle glide, striking the ground eventually some four miles away. In such cases, people on the spot had no prior warning. If the flying bomb fell in a built-up area, probably 20 houses were totally destroyed and several hundred more were damaged. Human life vanished in a flash which shook the ground and rent the heavens.
The author may in part have owed the invitation to write this article to the fact that the editor, who was in London the latter part of last year, was given particular reason to reflect on the potentialities of V2. One evening as he was preparing to go to bed, the mansion in which he was staying suddenly bounced violently up and down and from side to side, and he was left prone and dazed, his ears ringing with the grotesque noise of a dozen express trains roaring past and away into the night. A rocket bomb had exploded a couple of hundred yards away. It was not surprising that he thereafter displayed an enlarged interest in the future of this weapon. That particular explosion, which wrecked several blocks on Oxford Street, took, it is reported, 64 lives, among them the lives of a number of American soldiers, serving their country thousands of miles from home. Their compatriots will (or at any rate should) demand to know precisely what are the potential future uses of these flying bombs and rockets.
The flying bomb is likely to be used in future against the shorter-range targets. Its range will be increased, but it will not be as accurate as the rocket, since it has to fly in the lower altitudes and its speed and direction are, therefore, subject to the action of the wind. The airplane has to have a wing area sufficiently large to enable it to land safely; the flying bomb, however, requires only a large enough wing area to permit it to stay in the air at high speeds. The wing area can be considerably reduced simply by increasing the speed of the bomb at the moment it reaches the end of the launching ramp. We may therefore expect to see the lifting surfaces become smaller and smaller and the bomb become more of a conventional artillery weapon -- a self-propelled shell rather than a flying bomb.
The range of the rocket can be increased up to some 2,500 miles without employing any new principles beyond those already introduced by the Germans. This range would be obtained by a two-stage rocket, i.e. two rockets in one. The first would drive the second a certain distance and then disintegrate, leaving the second to start up automatically at that point. Some years will elapse before such projectiles are perfected, but there is nothing Wellsian in the prediction that they will be perfected. Existing scientific knowledge makes them practicable. We should remember, moreover, that the power of explosives is likewise increasing enormously and will perhaps reach a point where destruction from a single charge spreads over such a vast area that it could not be dropped from aircraft operated directly by men if the men were to live. Robot-bombs will be the only means by which a charge of that nature could be poured upon an enemy.
Such are some of the facts about flying bombs and rockets, as we know them to be and as we can expect them to become. The Germans will certainly continue to be interested in the new weapons they developed and will wish to carry their achievements further at some later date. Are we going to keep up our interest also, both in the weapons as such and in what the Germans may wish to do with them? The idea of discharging destructive rockets to a distant portion of the world by merely pressing a button may still sound in some ears fantastic. But it is in the realm of fact. Is it too much to hope that there can be one law and one controlling authority in a world any part of which can be laid waste by the pressure of a single finger?