An Encyclopedia of the History of Technology part 103 potx

PART FIVE: TECHNOLOGY AND SOCIETY 1002 Gauss, who introduced the gauss as the unit of measurement of magnetic fields. Acoustic mines and pressure mines, designed to detonate as a result of the change in water pressure created by a vessel as it passed through it, were also developed. A cross between the mine and the torpedo was the human torpedo, which was pioneered by the Italians and successfully used by them to sink the British battleship Queen Elizabeth in Alexandria harbour on Christmas Eve 1941. Called ‘chariots’ by the British, they were shaped like torpedoes and ‘ridden’ to the target by two frogmen who, on arrival, merely disconnected the explosive warhead, clamped it to the ship’s keel and set a time fuse. The war at sea also saw the rise of the aircraft carrier over the battleship. Air power proved a key factor in defeating the U-boat, and it also provided a serious threat to the surface warship, as was dramatically brought home by the sinking of the British Prince of Wales and Repulse by Japanese aircraft off the coast of Malaya on 10 December 1941. It was in the Pacific, however, that this phenomenon was most marked: all the major naval battles between the Americans and Japanese were largely conducted by carrier-based aircraft, with the opposing fleets often not seeing one another. Land warfare The dominant feature of land warfare during 1939–45 was the Blitzkrieg, or lightning war, concept first put into practice by the Germans and the key to their dramatic early victories. The ingredients of this strategy were mechanized forces and tactical airpower and the object dislocation of the enemy’s command and control processes. This meant the ability to think and act faster and was much helped by the development of robust and reliable battlefield radio communications. Aircraft were used as aerial artillery, armed with rockets, bombs and machine guns and controlled by air-ground radio links. Typical of the types of aircraft used in this role were the Soviet Stormovik series, the British Typhoon and, perhaps the most well known of all, the German Ju87 Stuka dive-bomber. During the years 1919–39 there had been great progress in tank development. Different countries had divergent views on their form and role. The Germans began the war with light tanks, armed only with machine guns, and medium with 50mm (2in) and 75mm (3in) guns. The Americans had much the same categories, but the British had three types—light, infantry and cruiser. Light tanks, together with armoured cars, were for reconnaissance. Infantry tanks were relatively slow moving, thickly armoured and had either a machine gun or 2-pdr (40mm). They were used, as their name suggests, to support infantry on their feet in the attack. Cruiser tanks, although also armed with the 2-pdr, were lightly armoured and fast moving, and employed in the old cavalry role of shock action. The French and the WEAPONS AND ARMOUR 1003 Russians, on the other hand, had light, medium and heavy tanks, the last- named being designed to break through the enemy’s defences. Most tank ammunition was solid shot, using the tungsten carbide core developed by the Germans in 1917. By 1942 the Americans, Germans and Russians had fixed on the 75– 76.2mm (3in) calibre as the main tank gun, while the British lagged behind with the 6-pdr (57 mm), but increasing armour thicknesses meant that existing muzzle velocities were no longer sufficient to impart the required kinetic energy to the armour piercing round. The initial German answer was to increase the barrel length of the 50mm (2in) and 75mm (3in) guns. They also introduced a refinement to the standard shot by surrounding the tungsten carbide core with a soft metal jacket. This Armour Piercing Composite Rigid (APCR) round was lighter than the normal shot and hence had a greater muzzle velocity and better penetration, although its performance did fall off as the range increased. In 1944 the British improved on this with the Armour Piercing Discarding Sabot (APDS) round, which remains today one of the main types of armour defeating ammunition. Here the tungsten carbide slug was encased in a pot, or sabot, which broke up as the round left the muzzle. In this way APDS did not suffer the same performance degradation as APCR. Another solution was the tapered bore, used on light anti-tank guns and armoured cars, in which the soft casing surrounding the slug was squeezed as the round travelled up the barrel. The main drawback was that the barrel became quickly worn. By the end of 1942 the Germans had begun to introduce a new breed of heavy tank based on the highly successful dual purpose anti-aircraft/anti-tank 88mm (3.5in) gun. Tanks like the Tiger and Panther (this retained the long barrelled 75mm (3in)) were heavily armoured as well, and more than a match for the lighter Allied types; the later Jagdtiger even had a massive 128mm (5in) gun. Lighter Allied tanks, like the American Sherman, British Cromwell and Russian T-34, acclaimed by many as perhaps the best all-round tank of the war, were more manoeuvrable. This competition represented the perennial problem for the tank designer, how to reconcile firepower, mobility and protection; overemphasis on one must be at the expense of the other two. It was the British who produced what was to become the standard concept of the tank of the future, the Centurion, which made its first appearance in 1945, just too late to see action. The Centurion was designed to undertake all the roles of the tank —infantry support, anti-tank and shock action—and this concept remains as today’s main battle tank. Nevertheless, led by the British, a large number of tanks were developed for specialized roles—mine clearing, bridging, flame-throwers, swimming tanks, air portable tanks. The Germans, Russians and Americans also produced armoured fighting vehicles whose sole role was anti-tank. The German and Russian models were turretless, and thus cheaper to produce than a normal tank, while the Americans went for types with open- PART FIVE: TECHNOLOGY AND SOCIETY 1004 topped turrets, which, while having excellent mobility and firepower, paid the penalty of being too thinly armoured. Besides tank guns themselves, a wide range of other anti-tank weapons was produced during the war. Anti-tank guns, often using tank guns mounted on wheeled artillery carriages and relying on kinetic energy developed through high muzzle velocities, abounded. For the infantryman, his ability to counter tanks was greatly enhanced by the development of hollow charge ammunition. An American engineer called Monroe had discovered in the 1880s that if a slab of explosive was hollowed out, placed in contact with a piece of steel and detonated, the shape of the hollow would be reproduced in the steel, but serious efforts made to apply the Monroe effect to weapons were not made until 1940. Taking a cylindrical- shaped charge, one end was given a conical hollow which was lined with metal. On detonation, the metal liner collapses and is transformed into gas and molten metal which is then projected at the target as a high-speed jet with great penetrative power. For it to be effective detonation has to take place at an optimum stand-off distance from the target to allow the jet to form, and this is normally achieved by a false nose or a rod projecting from the nose. Hollow charge was first used in demolition charges, but then the British introduced the No 68 anti-tank rifle grenade. It was also used to give field artillery an improved anti-tank capability. Then, during the latter half of the war, came a family of hand-held recoilless hollow charge round projectors, the German Panzerfaust, American Bazooka and British FIAT. The principle was also used in anti-tank mines, which became a major threat to tanks. The emphasis on mechanized warfare meant that infantry and artillery had to be able to keep up with the tanks. The result was a wide range of close support self-propelled artillery, often mounted on existing tank chassis, although some chassis were purpose built. For infantry there were both half and fully tracked armoured personnel carriers. However, while the Allies always emphasized the need for wheeled mechanical transport and were, apart from the Russians, fully motorized, the Germans relied heavily on horse-drawn transport throughout the war. The infantryman’s weapons were generally much lighter and had a faster rate of fire than during 1914–18. This was especially so with mortars and light machine guns. One new category of weapon was the sub-machine gun. This works on the ‘blow-back’ principle. On firing, the propellant gases both drive the projectile forward down the barrel and the breechblock to the rear, where it comes up against the return spring. When firing single rounds it is retained by a sear and released by pressure on the trigger, while on automatic the spring automatically drives the breechblock forward. It normally uses pistol ammunition. The two pioneers of the sub-machine gun were the German Hugo Schmeisser and American General John WEAPONS AND ARMOUR 1005 T.Thompson, both of whom began to produce a series of models in the years after 1918. While the Germans with their Nebelwerfer and the Russians with the Katyusha brought back the concept of the multiple-barrelled rocket launcher, the rockets themselves being filled with high explosive, more dramatic was the German development of free flight rockets. In great secrecy they began work on these in the late 1930s, and they later became known as Vergeltungswaffen (Vengeance- or V-weapons). By 1944 there were two types in existence. The first, the V-1, was in essence a flying bomb, fitted with wings, tailplane and a ramjet motor driven by low grade aviation spirit; when close to the target, the engine shut off. It carried 850kg (1874lb) of explosive in its warhead and had a range of 250 miles, and was launched either from a ground ramp or from a specially modified Heinkel 111 bomber. The V-2 was a rocket bomb, fin stabilized, carrying a one-tonne warhead and 9 tonnes of liquid fuel (see p. 649). It was launched vertically and climbed to a height of 80–100km (50–60 miles), when preprogrammed controls would shut off the fuel supply and it would complete its flight along a ballistic trajectory. The V-weapons appeared in service too late to alter the course of the war, but the German experience in this field was to be the foundation of today’s ballistic missiles (see p. 1007). Most awesome by far of all the weapons to appear during the Second World War was the atomic bomb. Its origins lie in the discovery of radioactivity by the Frenchman Henri Becquerel in 1896 when experimenting with uranium. Three years later the New Zealand physicist Ernest Rutherford established that uranium emitted two types of radiation, a-particles and ß-particles. While the ß-particle was an electron, the a-particle was much heavier and released an intense energy. Later he established that this was a helium nucleus containing two positive particles, protons, and two neutral particles, neutrons. In 1920 the Danish scientist Niels Bohr completed the theory of the atom by establishing that the electrons revolved around the nucleus. Then, in 1930, the Germans Bothe and Becker showed that when beryllium is bombarded with a-particles a very penetrating neutral particle was emitted: the basis for deriving energy from the nucleus was established. The work on this next step was begun by a Hungarian, Leo Szilard, who settled in the USA in the late 1930s and, separately, by two Germans, Hahn and Strassman. From now on it became a race between the Germans and the Western democracies, whose efforts were centred on the Committee on Uranium set up in the United States in 1939. In 1942 the name was changed to the Manhattan Project, and it was based at Los Alamos in New Mexico where a large team of scientists set about trying to design a bomb which would fit into an aircraft, and which would explode when required to but was otherwise safe. To create it, they initially used uranium 235 but, finding that it was a lengthy and expensive business to isolate it from the more abundant and infinitely more stable uranium 238, they turned to plutonium. Much less plutonium was needed for it to be critical, that PART FIVE: TECHNOLOGY AND SOCIETY 1006 is, to be of sufficient size for the splitting of the nucleus, fission, to become a chain reaction, in that the resultant neutrons would have more than 350 per cent probability of hitting another nucleus and thus continuing the fission process in order to release a significant amount of energy. However, the plutonium 239 isotope being used created plutonium 240 if it absorbed a neutron without fissioning, and the latter isotope was prone to spontaneous fission. This meant that it could produce enough energy to destroy the bomb casing before sufficient destructive energy had been created, since the chain reaction would then cease. They therefore conceived the idea of making a sphere of plutonium 239 of such density as to be sub-critical and then to compress it—what was called implosion—so that there would be explosive fission. In the meantime, the German programme fell behind, especially as a result of the Allied destruction of the heavy water plants in Norway (heavy water containing the heavy hydrogen isotope, vital in the manufacture of fissile material). Not until 16 July 1945 was the first nuclear weapon detonation carried out, at Los Alamos. On 6 August came the dropping of the atomic bomb on Hiroshima, followed three days later, on 9 August, by that on Nagasaki. For peaceful uses of nuclear energy see pp. 212–16. WEAPONS TODAY Ever since 1945 the world has lain under the shadow of the nuclear weapon, which has grown ever more powerful and efficient. At the end of the Second World War the USA, being the sole possessor of the nuclear bomb, appeared all-powerful, but in 1949 the Soviet Union successfully exploded an atomic device, and the nuclear weapons race was on, complicated by the fact that Britain, France and, latterly, China, also developed a nuclear capability. In the meantime came the development of the hydrogen bomb. During the course of the Manhattan Project, theoretical calculations had suggested that the intense energies created by the atomic bomb could be used to trigger far more violent reactions in two isotopes of hydrogen, deuterium and tritium, by converting them into helium. This made use of a concept called fusion, in which, under conditions of extreme temperature and pressure, two atomic nuclei can combine to form larger elements. In the case of very light elements, energy is given off in the process, since the new nucleus has less mass than its two parent nuclei. The implication is that in a fusion, or, as it is more commonly called, thermonuclear device, much more energy is released than in an atomic weapon of equivalent weight. It was, however, not until the Soviet Union exploded its first atomic bomb that the Americans began seriously to develop the hydrogen bomb. The main obstacle was how to create fusion before the explosion destroyed the device. This was overcome by making use of photons, particles of light containing energy but lacking mass, WEAPONS AND ARMOUR 1007 which constitute electromagnetic radiation. They travel several times faster than the expanding nuclear explosion caused by the fission trigger and hence are able to create fusion in the core before it is engulfed and destroyed. The Americans successfully exploded their first thermonuclear device towards the end of 1952, but it was not long before the Russians matched this. By the end of the 1950s what was known as the ‘nuclear triad’ for delivering strategic nuclear weapons had come into existence. While the nuclear bomber aircraft was and still is retained as one leg of the triad, both the Americans and Russians made use of German wartime expertise to develop ballistic missiles. The first to be brought into service was the US Corporal in 1952. This was a tactical or battlefield weapon of limited range, little more than an improved V-2, adopting a ballistic trajectory after the fuel had been shut off by radio command. It was, however, the first to be armed with a nuclear warhead. Within a few years inter-continental ballistic missiles (ICBM) had been developed, like the US Titan and Soviet SS–9. These work on the same principle as the V-2, but have booster rockets to propel the missile into space, after which they fall away. Both liquid and, now more usually, solid fuels are used; once the missile has reached the desired height the engine is shut off, and a computer is used to trigger alterations in the trajectory in order to ensure that the missile hits the target. That part carrying the warhead is known as a re-entry vehicle, and modern ICBMs have multiple warheads, enabling them to attack several targets simultaneously. These are known as multiple re-entry vehicles (MIRVs). ICBMs can be land-based, launched from hardened silos, or mounted in submarines, which are known as SSBNs (Surface-to-Surface Ballistic Nuclear), and these are the other two legs of the triad. The main effects of a nuclear explosion are blast, heat, and immediate and residual radiation. Protection against these is generally called ‘nuclear hardening’. Immediate radiation is that generated in the first minute of a nuclear explosion, while residual is spread through neutron-induced activity, or fall-out. The general effect on human beings is to destroy body cells, especially bone marrow, brain and muscle, and to attack tissue. Protection against radiation is best achieved through shielding by dense materials, although respirators and nuclear, chemical and biological (NEC) clothing does help. Many armoured fighting vehicles also have collective protection in that they can be sealed and pure air drawn in through filters. A further effect is electromagnetic pulse (EMP) which damages electronic equipment. Two other categories of nuclear weapon exist today. The first is the theatre nuclear weapon, of which a typical example is the US Pershing 2 missile, which can carry a 200 kiloton (1 kiloton=the destructive force of 1000 tons of TNT) warhead (the atomic bombs dropped on Japan were 12 kiloton) a distance of 1600km (1000 miles). A new type is the cruise missile, designed to fly low enough to pass under radar coverage, and which can be air-, ground- PART FIVE: TECHNOLOGY AND SOCIETY 1008 and sea-launched. Tactical nuclear weapons continue to exist in the form of missiles and artillery shells, and there are also nuclear mines, both land and sea, as well as nuclear depth charges. Both the USSR and the USA have been trying to perfect active defence against nuclear missiles, the latest attempt being the US Strategic Defense Initiative (SDI), which is intended to intercept missiles at three stages—launch, mid-flight and re-entry. There are fears that this course could be destabilizing. A major disadvantage of battlefield nuclear weapons is the amount of collateral damage caused by heat and blast, which can hinder friendly as well as enemy forces. Consequently, in 1958 the USA began to develop a weapon which minimized these two effects in favour of increased radiation. The enhanced radiation/reduced blast (ERRB) or neutron bomb relies on the effect of highly lethal penetrative neutrons produced in the fusion process. It has low yield and is a ‘clean’ weapon, with minimum fall-out, which would contain radiation casualties to the immediate target area. In 1981 the USA announced that it intended to stockpile the bomb, but Soviet protests that it too was destabilizing, in that it too might make nuclear war more likely, resulted in this plan not being carried out. Missiles are also used in a large variety of conventional roles—air-to-air, surface-to-air, anti-tank, air-to-surface. Guidance on to the target is all- important. Surface-to-air missiles generally use infra-red homing, detecting and locking on to the infra-red given out by the aircraft’s engine exhausts. The counter to this is for the aircraft to drop flares to deflect the missile, but the most modern type of missile is now designed to operate in the ultra-violet spectrum, which makes such countermeasures less effective. At the lower levels, multiple cannon, usually mounted on a tracked chassis and radar- controlled, with a very high rate of fire are used. Crucial to all air defence systems is the incorporation of an Identification Friend-or-Foe (IFF) device, which interrogates the aircraft, usually through the form of a radio signal to which the aircraft’s built-in responder will reply if it is friendly. Anti-tank guided missiles, whether launched from the ground, vehicle or helicopter, are wire-guided, a wire connecting the missile to the sighting and control unit. Earlier models were manually guided, which meant that the operator had to line up the missile with the target and steer it along this line, but now by means of an infra-red detector in the sight, the operator merely has to keep this on the target and the detector, using the flare in the missile’s tail, will sense if the missile is off course and corrective signals will automatically be sent down the wire. A variation on the guided missile is the precision guided munition (PGM) or ‘smart’ munition. This is being increasingly used for air delivered munitions, as well as for artillery, mortars and multiple launch rocket systems. The munitions themselves are radar controlled, heat seeking or can be guided on to the target by means of laser. The munition or sub-munition has a laser WEAPONS AND ARMOUR 1009 sensor which locks on to the reflections of a laser beam projected on to the target by an observer equipped with a laser designator. In spite of the continued ban on chemical weapons, many nations still possess them and they have been used in war since 1945, the Iran-Iraq conflict being one example. Decapacitating agents, like the drug LSD and the CS and VN gas used to control riots, which are not fatal, have now joined the choking, blood, nerve and blister types. There is also a biological threat. Biological agents are micro-organisms which cause disease or deterioration in material, and take the form of fungi, protozoa, bacteria, rickettsiae and viruses. Formerly they could be distinguished from chemical agents in that they exist naturally, but now they can be artificially produced in laboratories and the boundary is becoming blurred. The main means of protection against both chemical and biological agents are the wearing of NEC clothing and the use of chemical antidotes. Helmets continue to be worn by all armies, but a more recent innovation is the flak jacket designed to protect the body against shell splinters. It was first worn by US air gunners during the Second World War, but is now standard combat wear in a number of armies. Early models used plates of ballistic plastic, but this made them relatively heavy and cumbersome, and the most recent types incorporate an American-developed fibre material called Kevlar, which is much lighter. Modern main battle tanks, like the American M-1 Abrams, Soviet T-80, British Challenger and German Leopard 2, weigh 45–60 tonnes and have a 120mm (4.7in) gun. Some are still rifled, but an increasing number are smoothbore. The main advantage of this is that barrel wear is less and hotter charges can be used, resulting in higher muzzle velocities, thus increasing effective range against other tanks, which is now 3000m (9840ft). In order to maintain accuracy, fin-stabilized ammunition is used, the fins being folded and automatically positioning themselves as the projectile leaves the muzzle. Sophisticated fire control systems, incorporating ballistic computers, further enhance accuracy. New types of ceramic armour, specifically designed to increase protection against hollow charge projectiles without increasing the weight, are also being introduced. Mines, too, are ever more sophisticated. Most have anti-handling devices, and in order to make their detection more difficult many are made of plastic. A new type of anti-tank mine is the off-route mine. This is positioned at the side of a road or track and is detonated by the vehicle passing over a pressure tape or by acoustic sensor. Minelaying is very much faster than the old manual methods. Machines resembling agricultural ploughs are used, and remotely delivered mines, using rocket systems or artillery, are coming into service. As far as infantry weapons are concerned, the most dramatic change during recent years has been an overall reduction in small arms calibre, from 7.62mm (0.3in) to 5.56mm (0.22in). While this has reduced effective ranges, it has PART FIVE: TECHNOLOGY AND SOCIETY 1010 resulted in smaller and lighter weapons, and means that the infantryman can carry more ammunition, since it is also lighter than in the past. Surveillance devices have undergone notable improvements during the past forty years, especially in the shape of infra-red image intensification, which concentrates the ambient light, and low level television systems used to see at night and in other conditions of poor visibility. Radar is becoming ever more effective and one new development is that of sideways-looking airborne radar, which enables an aircraft to survey enemy territory from the safety of its own lines. High-flying ‘spy planes’ like the US Lockheed SR-71 Blackbird carry long-focus cameras which can cover an area of 325km 2 (125 square miles) in one exposure from a height of 40km (15 miles), with sufficient resolution for targets as small as artillery guns to be accurately identified. At a lower level, another class of surveillance device is the remotely piloted vehicle (RPV), which can be directed on photographic flight missions with pictures being instantaneously reproduced on a television screen at the ground control station. The computer, too, is playing an ever increasing part in war. Apart from being used in fire control systems, it is a highly effective means of recording and collating the increasing mass of information available to a commander and assisting him in problem solving and decision making. A new role for the computer which is being explored in the USA is in robotic weapons and surveillance systems. However, while many aspects of warfare are becoming automated to a high degree, the computer will not, at least in the foreseeable future, replace the human brain, which will remain ultimately responsible for the conduct of war. Attention is turning to the threat of war in space. Already a comprehensive network of military intelligence and communications satellites exists and, in spite of constant efforts to ensure that space has peaceful uses only, it is very likely that anti-satellites (ASATs) will soon make an appearance. War in space is likely to use a new breed of weapon, directed energy, which is now under active development. Directed energy weapons comprise lasers, which use photons of electro-magnetic radiation, particle beams, made up of sub-atomic particles which have mass and destroy a target through nuclear reaction, sonic and radio frequency weapons, which use sonic waves and electrical fields only to focus and accelerate particles. The pace of military technological development is ever quicker, and the only two brakes that can be applied to it are economic and humanitarian. Nevertheless, and perhaps increasingly, besides influencing the art of war, military technology is applied to many other fields of human endeavour. WEAPONS AND ARMOUR 1011 FURTHER READING Beckett, B. Weapons of tomorrow (Orbis, London, 1982) Dupuy, T.N. The evolution of weapons and warfare (Janes, London, 1982) Fuller, J.F.C. A military history of the western world (Minerva, New York, 1967) Montgomery, B.L. A history of warfare (Collins, London, 1968) Reid, W. The lore of arms: a concise history of weaponry (Arrow, London, 1984) Tarassuk, L. and Blair, C. (Eds.) The complete encyclopaedia of arms and weapons (Batsford, London, 1982) . the Germans and the key to their dramatic early victories. The ingredients of this strategy were mechanized forces and tactical airpower and the object dislocation of the enemy’s command and control. worn. By the end of 1942 the Germans had begun to introduce a new breed of heavy tank based on the highly successful dual purpose anti-aircraft/anti-tank 88mm (3.5in) gun. Tanks like the Tiger and Panther. swimming tanks, air portable tanks. The Germans, Russians and Americans also produced armoured fighting vehicles whose sole role was anti-tank. The German and Russian models were turretless, and thus