After the end of World War II, the American armed forces had a significant number of medium and large-caliber anti-aircraft guns, small-caliber anti-aircraft guns and 12, 7-mm machine gun mounts. By 1947, about half of the anti-aircraft positions of 90 and 120 mm guns in the United States had been eliminated. The towed guns went to the storage bases, and the stationary anti-aircraft guns were mothballed. Large-caliber anti-aircraft guns were preserved mainly on the coast, in the areas of large ports and naval bases. However, reductions also affected the Air Force, a significant part of the piston-engine fighters built during the war years was scrapped or handed over to the allies. This was due to the fact that in the USSR until the mid-50s there were no bombers capable of performing a combat mission in the continental part of North America and returning back. However, after the end of the American monopoly on the atomic bomb in 1949, it could not be ruled out that in the event of a conflict between the United States and the USSR, Soviet Tu-4 piston bombers would make combat missions in one direction.
The flywheel of the nuclear race was spinning, on November 1, 1952, the first stationary thermonuclear explosive device was tested in the United States. After 8 months, the RDS-6s thermonuclear bomb was tested in the USSR. Unlike the American experimental device the height of a two-story house, it was a thermonuclear ammunition quite suitable for combat use.
In the mid-1950s, despite the multiple superiority of the Americans in the number of carriers and the number of nuclear bombs, the likelihood that Soviet long-range bombers would reach the continental United States increased. At the beginning of 1955, the combat units of Long-Range Aviation began to receive M-4 bombers (chief designer V. M. Myasishchev), followed by the improved 3M and Tu-95 (A. N. Tupolev Design Bureau). These machines could already reach the North American continent with a guarantee and, having inflicted nuclear strikes, return back. Of course, the American leadership could not ignore the threat. As you know, the shortest route for aircraft flying from Eurasia to North America lies through the North Pole, and several defense lines were created along this route.
Radar post of the DEW line on the Shemiya island of the Aleutian archipelago
In Alaska, Greenland and northeastern Canada, on the most probable routes for the breakthrough of Soviet bombers, the so-called DEW-line was built - a network of stationary radar posts interconnected by cable communication lines and air defense command posts and radio relay stations. At several posts, in addition to the radar for detecting air targets, missile attack warning radars were subsequently built.
Layout of DEW-line radar posts
To counter Soviet bombers in the mid-50s, the United States formed the so-called "Barrier Force" to control the air situation along the western and eastern coasts of the United States. Coastal radars, radar patrol ships, as well as ZPG-2W and ZPG-3W balloons were tied into a single centralized warning network. The main purpose of the "Barrier Force", located on the Atlantic and Pacific coasts of the United States, was to control the airspace for the purpose of early warning of approaching Soviet bombers. The Barrier Force complements the DEW line's radar stations in Alaska, Canada and Greenland.
Aircraft AWACS EC-121 flies over the destroyer of the radar patrol
Radar patrol ships appeared during the Second World War and were used by the US Navy mainly in the Pacific Ocean as part of large naval squadrons, in order to timely detect Japanese aircraft. In the late 1940s and early 1950s, Liberty-class transports and Giring-class destroyers of military construction were mainly used for conversion into radar patrol ships. The following radars were installed on the ships: AN / SPS-17, AN / SPS-26, AN / SPS-39, AN / SPS-42 with a detection range of 170-350 km. As a rule, these ships alone were on duty at a distance of up to several hundred kilometers from their coast and, in the opinion of the admirals, were very vulnerable to surprise attacks by combat aircraft and submarines. Wanting to reduce the vulnerability of maritime long-range radar control, in the 50s, the United States adopted the Migraine program. As part of this program, radars were installed on diesel submarines. It was believed that submarines, having detected the enemy on the radar screens, after issuing a warning, would be able to hide from the enemy under water.
In addition to the conversion of boats built during wartime, the US Navy received two specially built diesel-electric submarines: USS Sailfish (SSR-572) and USS Salmon (SSR-573). However, diesel-electric submarines for long-term duty did not have the necessary autonomy and, due to their low speed, could not operate as part of high-speed operational groups, and their operation was too expensive compared to surface vessels. In this regard, the construction of several special nuclear submarines was envisaged. The first nuclear submarine with a powerful air surveillance radar was the USS Triton (SSRN-586).
A tablet of the air situation and radar consoles in the information and command center of the nuclear submarine "Triton"
The AN / SPS-26 radar installed on the Triton nuclear submarine was capable of detecting a bomber-type target at a distance of 170 km. However, after the appearance of quite advanced AWACS aircraft, they decided to abandon the use of radar patrol submarines.
In 1958, the operation of AWACS E-1 Tracer aircraft began. This vehicle was built on the basis of the C-1 Trader carrier-based supply transport aircraft. The Tracer's crew consisted of only two radar operators and two pilots. The functions of a combat control officer had to be performed by the co-pilot. In addition, the plane did not have enough space for automated data transmission equipment.
Aircraft AWACS E-1V Tracer
The detection range of air targets reached 180 km, which was not bad by the standards of the late 50s. However, during operation it turned out that the Tracer did not meet expectations, and the number of built was limited to 88 units. Information about the target from the Tracer was transmitted to the interceptor pilot by voice over the radio, and not centralized through the flight control point and the air defense command post. For the most part, "Tracers" were operated in carrier-based aviation; for a land-based AWACS aircraft, the detection range and patrol time were unsatisfactory.
The radar patrol aircraft of the EC-121 Warning Star family had much better capabilities. The base for heavy AWACS aircraft with four piston engines was the C-121C military transport aircraft, which in turn was created on the basis of the L-1049 Super Constellation passenger airliner.
The large internal volumes of the aircraft made it possible to accommodate onboard radar stations for viewing the lower and upper hemisphere, as well as data transmission equipment and workplaces for a crew of 18 to 26 people. Depending on the modification, the following radars were installed on the Warning Star: APS-20, APS-45, AN / APS-95, AN / APS-103. Later versions with improved avionics received automatic data transmission to ground control points of the air defense system and the AN / ALQ-124 electronic reconnaissance and jamming station. The characteristics of the radar equipment were also consistently improved, for example, the AN / APS-103 radar installed on the EC-121Q modification could steadily see targets against the background of the earth's surface. The detection range of a high-flying target of the Tu-4 (V-29) type in the absence of organized interference for the AN / APS-95 radar reached 400 km.
Change of operators of the EU-121D
Even at the design stage, the designers paid great attention to the convenience and habitability of the crew and operators of electronic systems, as well as ensuring the protection of personnel from microwave radiation. The patrol time was usually 12 hours at an altitude of 4000 to 7000 meters, but sometimes the duration of the flight reached 20 hours. The aircraft were used by both the Air Force and the Navy. The EC-121 was serially built from 1953 to 1958. According to American data, 232 aircraft were transferred to the Air Force and Navy during this time, their service continued until the end of the 70s.
In addition to the "Barrier Force" and stations of the DEW-line, ground-based radar posts were actively built in the USA and Canada in the 50s. Initially, it was supposed to be limited to the construction of 24 stationary high-power radars to protect approaches to five strategic areas: in the northeast, in the Chicago-Detroit area, and on the west coast in the Seattle-San Francisco areas.
However, after it became known about the nuclear test in the USSR, the command of the US armed forces authorized the construction of 374 radar stations and 14 regional air defense command centers throughout the continental United States. All ground-based radars, most of the AWACS aircraft and radar patrol ships were tied into an automated network of interceptor SAGE (Semi Automatic Ground Environment) - a system for semi-automatic coordination of interceptor actions by programming their autopilots by radio with computers on the ground. According to the scheme for building the American air defense system, information from radar stations about invading enemy aircraft was transmitted to the regional control center, which, in turn, controlled the actions of the interceptors. After the interceptors took off, they were guided by signals from the SAGE system. The guidance system, which worked according to the data of the centralized radar network, provided the interceptor to the target area without the participation of the pilot. In turn, the central command post of the North American air defense was supposed to coordinate the actions of the regional centers and exercise overall leadership.
The first American radars deployed in the United States were the AN / CPS-5 and AN / TPS-1B / 1D stations during World War II. Subsequently, the basis of the American-Canadian radar network was the AN / FPS-3, AN / FPS-8 and AN / FPS-20 radars. These stations could detect air targets at a distance of more than 200 km.
Radar AN / FPS-20
To provide detailed information about the air situation of the regional air defense command centers, radar systems were built, a key part of which were stationary high-power AN / FPS-24 and AN / FPS-26 radars with a peak power of more than 5 MW. Initially, the rotating antennas of the stations were mounted openly on reinforced concrete capital foundations; later, to protect them from the effects of meteorological factors, they began to be covered with radio-transparent domes. When located at dominant heights, the AN / FPS-24 and AN / FPS-26 stations could see high-altitude air targets at a distance of 300-400 km.
Radar complex at Fort Lawton airbase
AN / FPS-14 and AN / FPS-18 radars were deployed in areas where there was a high probability of a low-altitude penetration by bombers. To accurately determine the range and altitude of air targets as part of radar and anti-aircraft missile systems, radio altimeters were used: AN / FPS-6, AN / MPS-14 and AN / FPS-90.
Stationary radio altimeter AN / FPS-6
In the first half of the 50s, jet interceptors formed the basis of the air defense of the continental United States and Canada. For the air defense of the entire vast territory of North America in 1951, there were about 900 fighters designed to intercept Soviet strategic bombers. In addition to highly specialized interceptors, numerous air force and navy fighters could be involved in the implementation of air defense missions. But tactical and carrier-based aircraft did not have automated target guidance systems. Therefore, in addition to fighter aircraft, it was decided to develop and deploy anti-aircraft missile systems.
The first American fighter-interceptors specifically designed to combat strategic bombers were the F-86D Saber, F-89D Scorpion, and F-94 Starfire.
NAR launch from the F-94 interceptor
For self-detection of bombers from the very beginning, American interceptors were equipped with airborne radars. Attacking enemy aircraft was originally supposed to be 70-mm unguided air-to-air missiles Mk 4 FFAR. At the end of the 40s, it was believed that a massive NAR salvo would destroy a bomber without entering the zone of action of its defensive artillery installations. The views of the US military regarding the role of the NAR in the fight against heavy bombers were greatly influenced by the successful use of Me-262 jet fighters by the Luftwaffe, armed with 55-mm NAR R4M. Unguided rockets Mk 4 FFAR were also part of the armament of the supersonic interceptors F-102 and Canadian CF-100.
However, against bombers with turbojet and turboprop engines, which have a much higher flight speed compared to piston "Fortresses", unguided missiles were not the most effective weapon. Although hitting a 70-mm NAR bomber was fatal for him, the spread of a salvo of 24 unguided missiles at the maximum range of fire of the 23-mm AM-23 cannons was equal to the area of a football field.
In this regard, the US Air Force was actively searching for alternative types of aircraft weapons. At the end of the 50s, the AIR-2A Genie unguided air-to-air missile with a nuclear warhead with a capacity of 1.25 kt and a launch range of up to 10 km was adopted. Despite the relatively short launch range of the Gene, the advantage of this missile was its high reliability and immunity to interference.
Suspension of AIR-2A Genie missiles on a fighter-interceptor
In 1956, the rocket was first launched from the Northrop F-89 Scorpion interceptor, and at the beginning of 1957 it was put into service. The warhead was detonated by a remote fuse, which was triggered immediately after the rocket engine had finished working. The explosion of the warhead is guaranteed to destroy any aircraft within a radius of 500 meters. But even so, the defeat of high-speed, high-flying bombers with its help required an accurate calculation of the launch from the fighter-interceptor pilot.
F-89H fighter-interceptor armed with AIM-4 Falcon guided missiles
In addition to the NAR, the AIM-4 Falcon air combat missile with a launch range of 9-11 km entered service with air defense fighters in 1956. Depending on the modification, the rocket had a semi-active radar or infrared guidance system. In total, about 40,000 missiles of the Falcon family were produced. Officially, this missile launcher was removed from service with the US Air Force in 1988, along with the F-106 interceptor.
The variant with a nuclear warhead was designated AIM-26 Falcon. The development and adoption of this missile system is associated with the fact that the US Air Force wanted a semi-active radar-guided missile capable of effectively hitting supersonic bombers when attacking on a head-on course. The design of the AIM-26 was almost identical to the AIM-4. The missile with the nuclear submarine was slightly longer, much heavier and had almost twice the diameter of the body. It used a more powerful engine capable of providing an effective launch range of up to 16 km. As a warhead, one of the most compact nuclear warheads was used: the W-54 with a capacity of 0.25 kt, weighing only 23 kg.
In Canada, in the late 40s - early 50s, work was also carried out to create its own fighter-interceptors. The CF-100 Canuck interceptor was brought to the stage of mass production and adoption. The aircraft entered service in 1953, and the Royal Canadian Air Force received over 600 interceptors of this type. Like the American interceptors developed at that time, the APG-40 radar was used to detect air targets and aim at the CF-100. The destruction of enemy bombers was to be carried out by two batteries located at the wingtips, in which there were 58 70-mm NAR.
NAR launch from a Canadian fighter-interceptor CF-100
In the 60s, in parts of the first line of the Canadian Air Force, the CF-100 was replaced by the American-made supersonic F-101B Voodoo, but the operation of the CF-100 as a patrolling interceptor continued until the mid-70s.
Training launch of the NAR AIR-2A Genie with a conventional warhead from the Canadian fighter-interceptor F-101B
As part of the armament of the Canadian "Voodoo" there were missiles with a nuclear warhead AIR-2A, which was at odds with Canada's nuclear-free status. Under an intergovernmental agreement between the United States and Canada, nuclear missiles were controlled by the US military. However, it is not clear how it was possible to control the pilot of an interceptor fighter in flight, with a missile with a nuclear warhead suspended under his plane.
In addition to fighter-interceptors and their weapons, significant funds in the United States were spent on the development of anti-aircraft missiles. In 1953, the first MIM-3 Nike-Ajax air defense systems began to be deployed around important American administrative and industrial centers and defense facilities. Sometimes the air defense systems were located at the positions of 90 and 120-mm anti-aircraft guns.
The complex "Nike-Ajax" used "liquid" missiles with a solid-propellant accelerator. Targeting was done using radio commands. A unique feature of the Nike-Ajax anti-aircraft missile was the presence of three high-explosive fragmentation warheads. The first, weighing 5.44 kg, was located in the bow section, the second - 81.2 kg - in the middle, and the third - 55.3 kg - in the tail section. It was assumed that this would increase the likelihood of hitting a target, due to a more extended cloud of debris. The oblique range of defeat "Nike-Ajax" was about 48 kilometers. The rocket could hit a target at an altitude of a little over 21,000 meters, while moving at a speed of 2, 3M.
Radar aids SAM MIM-3 Nike-Ajax
Each Nike-Ajax battery consisted of two parts: a central control center, where bunkers for personnel were located, radar for detection and guidance, computing-decisive equipment, and a technical launch position, which housed launchers, missile depots, fuel tanks, and an oxidizing agent. The technical position, as a rule, had 2-3 missile storage facilities and 4-6 launchers. However, positions from 16 to 24 launchers were sometimes built near major cities, naval bases and strategic aviation airfields.
The starting position of the SAM MIM-3 Nike-Ajax
At the first stage of deployment, the position of Nike-Ajax was not strengthened in engineering terms. Subsequently, with the emergence of the need to protect the complexes from the damaging factors of a nuclear explosion, underground missile storage facilities were developed. Each buried bunker held 12 rockets that were hydraulically fed horizontally through the drop-down roof. The rocket raised to the surface on a rail cart was transported to a horizontally lying launcher. After loading the rocket, the launcher was installed at an angle of 85 degrees.
Despite the huge scale of deployment (more than 100 anti-aircraft batteries were deployed in the United States from 1953 to 1958), the MIM-3 Nike-Ajax air defense system had a number of significant drawbacks. The complex was stationary and could not be relocated within a reasonable time. Initially, there was no data exchange between individual anti-aircraft missile batteries, as a result of which several batteries could fire at the same target, but ignore others. This flaw was subsequently corrected by the introduction of the Martin AN / FSG-1 Missile Master system, which allowed information to be exchanged between individual battery controllers and to coordinate the allocation of targets between multiple batteries.
Operation and maintenance of "liquid-propellant" rockets caused major problems due to the use of explosive and toxic components of the fuel and oxidizer. This led to the acceleration of work on a solid fuel rocket and became one of the reasons for the decommissioning of the Nike-Ajax air defense system in the second half of the 60s. Despite a short service life, Bell Telephone Laboratories and Douglas Aircraft managed to deliver more than 13,000 anti-aircraft missiles from 1952 to 1958.
The MIM-3 Nike-Ajaх air defense system was replaced in 1958 by the MIM-14 Nike-Hercules complex. In the second half of the 50s, American chemists managed to create a solid fuel formulation suitable for use in long-range anti-aircraft missiles. At that time, this was a very great achievement, in the USSR it was possible to repeat this only in the 70s in the S-300P anti-aircraft missile system.
Compared with the Nike-Ajax, the new anti-aircraft complex had almost three times the range of destruction of air targets (130 instead of 48 km) and height (30 instead of 21 km), which was achieved through the use of a new, larger and heavier missile defense system and powerful radar stations … However, the schematic diagram of the construction and combat operation of the complex remained the same. Unlike the first Soviet stationary air defense system S-25 of the Moscow air defense system, the American air defense systems "Nike-Ajax" and "Nike-Hercules" were single-channel, which significantly limited their capabilities when repelling a massive raid. At the same time, the single-channel Soviet S-75 air defense system had the ability to change positions, which increased survival. But it was possible to surpass the Nike-Hercules in range only in the actually stationary S-200 air defense missile system with a liquid-propellant missile.
The starting position of the SAM MIM-14 Nike-Hercules
Initially, the system for detecting and targeting the Nike-Hercules air defense missile system, operating in continuous radiation mode, was practically similar to the Nike-Ajax air defense missile system. The stationary system had a means of identifying the nationality of aviation and target designation means.
Stationary version of the radar detection and guidance SAM MIM-14 Nike-Hercules
In the stationary version, anti-aircraft complexes were combined into batteries and battalions. The battery included all the radar facilities and two launch sites with four launchers each. Each division includes six batteries. Anti-aircraft batteries were usually placed around the protected object at a distance of 50-60 km.
However, the military soon ceased to be satisfied with the purely stationary option of placing the Nike-Hercules complex. In 1960, the Improved Hercules modification appeared - "Improved Hercules". Albeit with certain limitations, this option could already be deployed in a new position within a reasonable time frame. In addition to mobility, the upgraded version received a new detection radar and modernized target tracking radars, with increased immunity to interference and the ability to track high-speed targets. Additionally, a radio range finder was introduced into the complex, which carried out a constant determination of the distance to the target and issued additional corrections for the calculating device.
Upgraded mobile radar system SAM MIM-14 Nike-Hercules
Progress in the miniaturization of atomic charges made it possible to equip the missile with a nuclear warhead. On the MIM-14 Nike-Hercules SAMs, YABCHs with a capacity of 2 to 40 kt were installed. An aerial explosion of a nuclear warhead could destroy an aircraft within a radius of several hundred meters from the epicenter, which made it possible to effectively hit even complex, small-sized targets like supersonic cruise missiles. Most of the Nike-Hercules anti-aircraft missiles deployed in the United States were equipped with nuclear warheads.
Nike-Hercules became the first anti-aircraft system with anti-missile capabilities, it could potentially intercept single warheads of ballistic missiles. In 1960, the MIM-14 Nike-Hercules missile defense system with a nuclear warhead managed to carry out the first successful interception of a ballistic missile - the MGM-5 Corporal. However, the anti-missile capabilities of the Nike-Hercules air defense system were rated low. According to calculations, to destroy one ICBM warhead, at least 10 missiles with nuclear warheads were required. Immediately after the adoption of the Nike-Hercules anti-aircraft system, the development of its Nike-Zeus anti-aircraft missile system began (more details here: US missile defense system). Also, the MIM-14 Nike-Hercules air defense system had the ability to deliver nuclear strikes against ground targets, with previously known coordinates.
The deployment map of the Nike air defense system in the United States
A total of 145 Nike-Hercules batteries were deployed in the United States by the mid-1960s (35 rebuilt and 110 converted from Nike-Ajax batteries). This made it possible to provide a fairly effective defense of the main industrial areas. But, as Soviet ICBMs began to pose the main threat to US facilities, the number of Nike-Hercules missiles deployed in US territory began to decline. By 1974, all Nike-Hercules air defense systems, with the exception of batteries in Florida and Alaska, were removed from combat duty. The stationary complexes of the early release were for the most part scrapped, and the mobile versions, after refurbishment, were transferred to overseas American bases or transferred to the allies.
Unlike the Soviet Union, surrounded by numerous US and NATO bases, North American territory was not threatened by thousands of tactical and strategic aircraft based on forward airfields in the immediate vicinity of the borders. The appearance in the USSR in significant quantities of intercontinental ballistic missiles made the deployment of numerous radar posts, anti-aircraft systems and the construction of thousands of interceptors pointless. In this case, it can be stated that billions of dollars spent on protection from Soviet long-range bombers were eventually wasted.
