The mortar differs unfavorably from barrel artillery in the large amount of dispersion of ammunition, which makes it necessary to increase the consumption of mines to hit the target. Most artillery design bureaus around the world have come to the conclusion that the introduction of mine control systems in flight is inevitable.
The minimum caliber for the development of guided mines was 81 millimeters. Despite the compact size of the ammunition, the engineers managed to place control and guidance equipment in the hull, as well as a cumulative warhead. In accordance with this concept, British Aerospace (Great Britain) has been developing the Merlin anti-tank mine based on the standard fragmentation mine for the 81-mm L-16 mortar since the early 80s. Each mortar crew equipped with such “smart” ammunition must have a special ballistic firing table and a portable computer. Equipped with an all-weather millimeter-wave radar homing head, the Merlin at the end of the trajectory begins scanning the terrain in the 0.3x0.3 km square in search of a moving target.
Guided artillery mine "Merlin": a - typical trajectory of a mine flight; b - general view of the mine; 1 - disclosure of plumage; 2 - cocking the fuse of the warhead; 3 - turning on the seeker; 4 - transitional area; 5 - opening the bow rudders; 6 - target search; 7 - aiming at the target; 8 - target search area; 9 - propelling charges; 10 - GOS; 11 - bow rudders; 12 - shaped charge; 13 - stabilizing tail; 14 - onboard electronic control equipment and power supply; 15 - fuse protection and cocking mechanism
In the absence of movement of equipment on the battlefield, the radar head switches to stationary objects (usually command posts and bunkers) in the 0, 1x0, 1 km square. The bow rudders of the mine adjust the position of the ammunition so that it hits the target strictly vertically - the armor penetration in this case is 360 mm, which leaves no chance for any tank roof. The effective range of the Merlin is about 1, 5-4, 5 kilometers and, as the developers assure, only two or three mines are required for one enemy tank. On average, a defending battalion equipped with such equipment can increase its combat capabilities by 15% at once.
Guided 81-mm mine of the ACERM project
In 2014, in the United States, the Naval Surface Warfare Center (NSWC) of the Navy initiated the development of an 81-mm guided mine as part of the Advanced Capability Extended Range Mortars (ACERM) program. Like all guided mines, American development can be launched from conventional light mortars, which have served in the army for many decades and are worth mere pennies. True, a mine of the ACERM project, even in the most successful scenario, will cost almost $ 1000 per copy. The developers declare the outstanding characteristics of the ammunition - a range of up to 22.6 km, an accuracy of up to 1 meter, while guidance can be carried out by an operator from a tablet computer or using laser target illumination from a drone.
Much more promising for the creation of "smart" mines has become a caliber of 120 millimeters, which allows more freedom to place flight correction equipment and leave enough space for explosives. One of the first were the Germans from the Diehl company, when in 1975 they began to develop a guided 120-mm mine, which later received the name XM395 PGMM Bussard (later development was carried out in conjunction with Lockheed Martin). The mass of the mine is an impressive 17 kilograms with a length of about a meter. Immediately after departure from the barrel of the mortar, the tail of the ammunition opens up, serving to stabilize the flight, and after passing the highest point, four wings are extended, intended for gliding to the target. Aiming at a target Bussard is capable of both laser illumination and using an infrared homing head. The launch of the mine is provided from standard M120 mortars in a towed version, M121 on an M1064A3 tracked vehicle and an IAV-MS armored personnel carrier.
120-mm guided mine "Strix"
In 1993, the Swedes adopted the Bofors Strix guided mine, in which they implemented a slightly different principle of control in flight. The mine is equipped with 12 impulse correction engines located perpendicular to the axis of the hull in the area of the center of mass of the ammunition. It should be noted that the concept of impulse correction or RCIC-technology, according to many experts, is an exclusively domestic "know-how", so in the first in the series it was implemented in the famous product "Centimeter" 2K24. The American concept of aerodynamic control is called ACAG technology and was first used in the M712 Copperhead projectile. In a Swedish mine, flight stabilization is carried out by rotating at a speed of 10 revolutions per second and by the tail, opening immediately after leaving the mortar. Strix is equipped with a dual-band infrared (thermal) homing head, which, according to the developers, in the final phase of the flight, is able to distinguish a burning previously destroyed target from a working tank engine. The mass of the mine is more than 18 kilograms, of which eight are accounted for by the cumulative warhead, capable of penetrating almost 700 millimeters of armor. It is believed that the Swedish mine corresponds to high-precision weapons of the second generation and implements the famous principle of "fire-forget-hit", since it does not require laser illumination of the target at the final stage of flight. But, according to Academician of the Russian Academy of Missile and Artillery Sciences V. I. Babichev, there are a number of reservations:
- to launch Strix, you need to know the exact coordinates of the target, which, as a rule, cannot be observed from a closed mortar position;
- it is necessary to reliably know the meteorological conditions in the target area, and this is additional trouble in a combat situation;
- since the fire is fired from a closed position, it is necessary to assess the results of the shooting.
All this forces the use of an observer at the forefront, who does a lot of work - from establishing the coordinates of the target to assessing the hit of the Strix with the enemy's equipment. Despite this, the Strix mine was very warmly received in the US military.
Guided artillery mine "Griffin": 1 - main engine; 2 and 3 - shaped charge of tandem type; 4 - folding plumage; 5 - corrective jet engines; 6 - a safety cap; 7 - GOS; 8 - onboard electronic equipment; 9 - propelling charges
An international collaboration between Great Britain, Italy, France and Switzerland developed the 120-mm Griffin anti-tank mine in the late 90s. The ammunition weighing 20 kilograms is equipped with a tandem cumulative warhead and is capable of flying 8 kilometers. The homing head is similar to that of the Merlin mine, which allows it to work, regardless of weather conditions, starting from an altitude of 900 meters. The aiming of mines at the target is carried out by impulse jet engines - the designers adopted the successful experience of the Swedish Strix ammunition. New players are gradually being added to the number of countries developing their own guided mine weapons - work is underway in Bulgaria on the 120-mm Konkurent mine, it also became the base for the joint Polish-Ukrainian project Polish IR THSM, and in India they are working on the Indian SFM mine equipped with a combined homing system - radar and infrared.
One of the disadvantages of thermal homing heads is the impossibility of measuring the distance to the target by them, similar to how it is done in radar. As a result, targets lying in the same direction create mutual interference for guidance. Another disadvantage of infrared heads is their low noise immunity to thermal background radiation, for example, clouds illuminated by the sun, atmospheric smoke, the action of smoke and aerosol shields, as well as to the action of heat traps. That is why the future is obvious for the combined homing systems.
At the forefront of progress is the technology of the third generation, used for guidance and correction of the flight trajectory data from space radio navigation systems, and in the final segment - passive or semi-passive laser homing. Such ammunition was the Israeli 120-mm mine LGMB Fireball with a firing range of 15 kilometers and equipped with a multifunctional warhead. Depending on the nature of the target, the fuse is set for shock action (for armored objects) or high-explosive fragmentation (for weakly protected targets). The developments of the Israeli company Israeli Military Industries were used in the development of the American GPS-controlled mine PERM (Precision Extended Range Munition) from Raytheon.
120-mm guided high-explosive fragmentation mine "Gran"
Caliber - 120 mm
Mine length - 1200 mm
Mine weight - 27 kg
BCH / VV - 11, 2/5, 3kg
Warhead - high-explosive fragmentation
Loading mines "Edge"
The use of a guided mine "Gran" in combat conditions
The domestic military-industrial complex can, within the framework of this 120-millimeter theme, offer only one guided mine KM-8 "Gran", developed by the Tula Instrument Design Bureau. The complex includes an M120 high-explosive fragmentation mine and a portable complex of automated fire control equipment for artillery units "Malakhit" with a laser designator, range finder and thermal imaging guidance channel. You can use the "Edge" with any domestic 120-mm rifled and smooth-bore mortars. It remains only to state that at the moment there are no standard guided mines in the arsenal of the Russian army that can correct the trajectory according to the signal of the satellite navigation system and do not require a laser target unmasking operator.
Used photographs: Precision ammunition: textbook. allowance / V. A. Chubasov; Precision ammunition. Fundamentals of the device and design: textbook. allowance / V. I. Zaporozhets; kbptula.ru; janes.com.
