The Bomark air defense system was designed to provide air defense for large areas of the United States and Canada. This is a stationary anti-aircraft complex.
A feature of the structure of the complex's subunits is that the detection and target designation system, as well as missile control facilities, serve several launchers located at a considerable distance from each other.
The contract for the development of the US Air Force complex was signed with Boeing and the Michigan Aeronautical Research Center subcontractor in 1951.
The development of the air defense system was accompanied by disputes between American specialists about the optimal structure of the air defense of the territories of the United States and Canada. Air Force specialists believed that this defense should be built on the basis of complexes with an interception range of about 400 km or more, thereby providing cover for significant areas and zones. Army specialists defended the concept of "point", object air defense, which provides for the use of medium-range air defense systems located around individual defended objects.
SAM "Bomark" at the starting position, 1956
Military-economic studies carried out in the United States have shown the advantage of the point of view of Air Force specialists: the cost of such complexes is approximately two times lower; they require almost seven times less maintenance personnel; occupy an area of military equipment almost 2, 5 times less. However, for reasons of "defense in depth", the US military command approved both concepts.
A distinctive feature of the Bomark air defense missile system is that it does not include a detection and target designation system, as well as a significant part of the SAM control facilities. The functions of these means and systems are performed by the Sage, a unified semi-automatic air defense control system for the territories of the United States and Canada, which simultaneously controls the combat actions of fighter-interceptors and other air defense systems.
With such a construction of the Bomark air defense system, it was practically required only to develop a missile interacting with the Sage system and a launcher for it.
Flight tests of SAM "Bomark", August 1958
Initially, the complex received the designation XF-99, then IM-99 and only then CIM-10A.
Tests of the propulsion system for the Bomark missile defense system began back in 1951. Flight tests began at the end of June 1952, but due to a lack of equipment, tests were postponed until September 10, 1952. The second tests took place on January 23, 1953 at the Cape Canaveral range, and the third on June 10, 1953. In 1954, 3 launches were carried out. At the end of the tests, in 1958, 25 missiles were fired and the program was submitted for testing at the Santa Rosa Island test site. During the tests 1952-1958. at the Cape Canaveral test site, approx. 70 rockets. By December 1, 1957, "Air Proving Ground Command" and "Air Force Armament Center" were combined into a single air defense test center "Air Proving Ground Center", where the "Bomark" was tested later.
There are two known modifications of the Bomark missile defense system - A and B, which were adopted by the air defense of the territories of the United States and Canada in 1960 and 1961, respectively. They differ in maximum combat range and flight altitude (which is achieved mainly due to the power of the main engine), the type of starting accelerator and the type of radiation of the active radar homing head. Combat maximum ranges of their flight are 420 and 700 km, respectively. The transition to the GOS from pulsed radiation (option A) to continuous (modification B) increased the capabilities of the missile defense system to intercept low-flying targets.
SAM "Bomark" in the US Air Force Museum
Commands for the guidance of the Bomark missile defense system are generated by the digital computer of the guidance center of the Sage air defense sector and are transmitted via underground cables to the radio command transmission station, from where the missiles are sent on board. This computer enters data on targets received from numerous radars for detection and identification of the Sage system.
The launcher for missiles of both modifications is the same. It is stationary, designed for one rocket and provides its vertical launch. Built by a number of 30-60 launchers make up the SAM base, the launch pad. Each such base is connected by underground cables to the corresponding center of the Sage system, located at a distance of 80 to 480 km from it.
There are several types of launch hangars for Bomark missiles: with a movable roof, with sliding walls, etc. In the first version, the block reinforced concrete shelter (length 18, 3, width 12, 8, height 3, 9 m) for the launcher consists of two parts: a launch compartment, in which the launcher itself is mounted, and a compartment with a number of rooms, where control devices and control equipment for the launch of missiles are located. To bring the launcher into a firing position with hydraulic drives operating from the compressor station, the roof flaps are moved apart (two shields 0.56 m thick and weighing 15 tons each). The rocket is lifted by an arrow from a horizontal to a vertical position. For these operations, as well as for turning on the on-board missile defense equipment, it takes up to 2 minutes.
The SAM base consists of an assembly and repair shop, launchers proper and a compressor station.
The assembly and repair shop assembles missiles that arrive at the base disassembled in separate transport containers. In the same workshop, the necessary repairs of missiles are carried out.
The layout diagram of the Bomark A (a) and Bomark B (b) missiles:
1 - homing head; 2 - electronic equipment; 3 - combat compartment; 4 - combat compartment, electronic equipment, electric battery; 5 - ramjet
The Bomark anti-aircraft guided missile of modifications A and B is supersonic (maximum flight speeds of 850 and 1300 m / s, respectively) and has an aircraft configuration (similar to the Soviet Tu-131 projectile aircraft). It flies to maximum range and altitude with two cruise ramjet engines operating on liquid fuel (active flight stage). A rocket engine is used as a starting accelerator in rocket A, and solid propellant rocket in rocket B.
In appearance, the modifications of missiles A and B differ little from each other. Their starting weight is 6860 and 7272 kg; length 14, 3 and 13, 7 m, respectively. They have the same hull diameters - 0, 89 m, wingspan - 5, 54 m and stabilizers - 3, 2 m.
The head radio-transparent fairing of the SAM body, made of fiberglass, covers the homing head. The cylindrical part of the body is mainly occupied by a steel carrier tank for liquid fuel ramjet.
Swivel wings have a sweep of the leading edge of 50 degrees. They do not turn entirely, but have triangular ailerons at the ends - each console is about 1 m, which provide flight control along the course, pitch and roll.
Launch SAM "Bomark"
As an active radar homing head for missiles, modernized aircraft intercept and aiming radars are used. Rocket A has a pulsed seeker, operating in the three-centimeter range of radio waves. Rocket B has a continuous emission head that uses the principle of Doppler velocity selection of a moving target. This makes it possible to direct the missile defense system at low-flying targets, the targets are active jammers. The range of the seeker is 20 km.
A warhead weighing about 150 kg can be conventional or nuclear. The TNT equivalent of a nuclear warhead is 0, 1 - 0.5 Mt, which, it is believed, ensures the destruction of the aircraft if it misses up to 800 m.
Silver-zinc batteries are used to power the on-board SAM equipment.
The starting booster for rocket A is a liquid-propellant rocket engine operating on kerosene with the addition of asymmetric dimethylhydrazine and nitric acid. This engine runs for 45 seconds, accelerating the rocket to the speed at which the ramjet is activated at an altitude of about 10 km.
In rocket B, the starting booster is a solid propellant rocket, the body of which is separated after the fuel is burned out. The use of solid propellants instead of liquid-propellant rocket engines made it possible to reduce the acceleration time of missiles, simplified operation and increased the reliability of the rocket.
In both versions of missiles, two liquid-fueled ramjets, mounted on a pylon under the rocket body, are used as propulsion engines. The diameter of each of these engines is 0.75, and the length is 4.4 m. The fuel is gasoline with an octane rating of 80.
Ramjet missiles are most effective at cruising altitudes. For rocket A it is 18.3 km, and for rocket B it is 20 km.
The scheme of action of the Bomark air defense system according to the commands of the Sage system:
1 - launchers (hangars); 2 - starting section of the trajectory; 3 - marching section of the trajectory; 4 - the final section of the trajectory; 5 - command post of the interceptor battalion; 6 - data transmission lines; 7 - reports on the state of combat assets; 8 - pre-launch data; 9 - operational center of the Sage system; 10 - station for transmitting commands on board the missile defense system; 11 - early warning radar of the air defense sector; 12 - radar information about the target and missiles; 13 - guidance commands.
The controlled flight path of the Bomark missile defense system to the target is divided into three sections.
The first, vertical, is the climb section. In rocket A, before reaching supersonic speed, programmed gas-dynamic control is performed due to turns on the gimbal of the starting liquid-propellant engine, and upon reaching this speed - aerodynamic control of the ailerons. For rocket B, due to the more intensive acceleration by the starting solid propellant rocket, effective aerodynamic control becomes possible much earlier. The missile launcher flies vertically to the cruising altitude, then turns to the target. By this time, the tracking radar detects it and switches to auto-tracking using the on-board radio responder.
The second, horizontal, is a section of a cruising flight at a cruising altitude to the target area. Television commands in this area come from the Sage radio command transmission station. Depending on the maneuvers of the target being fired, the type of the SAM flight path in this area may change.
The third section is the section of the direct attack of the target, when the active radar seeker of the missile defense system searches for the target by radio commands from the ground. After "capture" by the target head, communication with ground-based tele-guidance equipment is terminated, and the missile flies, aiming autonomously.
Modernization
In 1961, an improved modification of the Bomark missile defense system, the Super-Bomark IM-99V, was put into service.
Conclusion
SAM "Bomark" in the Museum of weapons of the US Air Force
The missiles of this complex protected 6 strategic objects in the United States and two in Canada.
Both types of missiles were decommissioned in 1972.
