Land and Marine Excalibur
The military conflicts of recent decades have shown the need for high-precision weapons systems capable of delivering dagger strikes at point targets. This is especially becoming relevant in connection with the widespread use of communication means. In the 20th century, for the sake of destroying a group of militants, it was possible to wipe out an entire settlement from the face with several massive blows, as was done, for example, in Vietnam. Now such a trick is unlikely to pass: the saturation of video and photographic recordings is so high that in a couple of hours the whole world will know about such facts. Therefore, precision weapons are becoming one of the ways not to lose face in front of the world community.
In addition, guided projectiles allow you to very quickly respond to sudden threats: GPS guidance allows you to abandon the spotter of fire, as well as quickly transfer fire even without changing the gun pointing angles.
Unfortunately, in Russia, despite the presence of the "Centimeter", "Kitolov" and "Krasnopol" shells, there is a significant lag in the development of long-range high-precision large-caliber artillery shells. The main limiting factor is the lack of domestic onboard vibration-resistant satellite navigation equipment.
One of the most famous examples of foreign small dispersion guided artillery projectiles is the American Excalibur (and its many modifications). About him the first deputy managing director of the Tula instrument-making design bureau named after V. I. Academician A. G. Shipunov N. I. Khokhlov, answering a question from journalists about respectable foreign analogues, said:
"The most advanced projectile is probably the Excalibur."
For the first time, the Americans used the most successfully guided projectiles in 2007 in Iraq during Operation Arrowhead, when they fired 70 rounds of ammunition at the enemy at once. The circular probable deviation in 92% of cases did not exceed 4 meters. In 2012, in Afghanistan, Marines from Forward Operating Base Zeebrugge in the village of Kajaki hit a group of Taliban militants from a record 36 km away from an M777 howitzer. Actually, these successes prompted the Pentagon to increase purchases of "smart" shells - in total, the Americans have fired such Excalibur more than 1400 times. At first, the Ministry of Defense bought each projectile for an incredible 100-150 thousand dollars at a cost price of only 40 thousand. There is no corruption component here, just the developers from Ratheon and Bofors spent about a billion on the creation of the projectile and wanted to quickly recapture the money. One of the Excalibur variants, index 1b, is the basic variant for the creation of a 127-mm Excalibur N5 (Naval 5-inch) guided projectile for naval 5-inch artillery guns of the armies of NATO countries.
70% of all filling of "Marine Excalibur" is standardized with option 1b. The Excalibur N5 can be fired from both BAE Systems 5-inch cannons and OTO Melara's 127-mm systems. For the first time, the 127-mm Excalibur projectile was demonstrated at the Euronaval-2014 exhibition in Paris. Excalibur N5 has three modes of detonation: non-contact (air), contact, contact with delayed detonation for penetration beyond obstacles, including bunkers.
Paul Daniels, senior business development manager for the Excalibur project, explained the situation with the aiming of ammunition at moving targets:
“Modern systems for controlling the artillery fire of naval vessels have the ability to take into account the speed and direction of movement of the target vessel determined with the help of radars and calculate the expected point of meeting of the projectile with it. Thus, a projectile, guided by a GPS system, has the basic ability to intercept moving vessels, especially large ones, which cannot quickly change course and maneuver."
In addition, the MQ-8B Fire Scout drone-helicopter, which is now used by the US Navy, can act as a laser designator for the 127-mm Excalibur on a moving target.
However, the high cost of each shot with this type of projectile forces us to look for new options to improve the accuracy of artillery fire - it is not always possible to find a worthy target for a projectile at the cost of an elite car.
Calculated - wept
One of the methods for increasing accuracy was ammunition with a flight trajectory correction system. For example, it is possible to increase the aerodynamic resistance of a projectile or mine at the right time, thereby "correcting" its flight in the desired direction. One of the most budgetary options was a device with brake flaps from the French Nexter for 155-mm SPACIDO projectiles. Flight correction is carried out with the help of an artillery radio ballistic station and makes it possible to reduce the circular probable deviation several times at a distance of 15-18 km. The operation of such correction devices is as follows: the projectile flies along a ballistic trajectory with a predicted flight relative to the target, the artillery radio ballistic station measures the initial velocity of the projectile and its change along the trajectory during the projectile's flight; then the information is processed by a ballistic computer, which translates the required time for opening the braking devices to the projectile. The system has been tested and is ready for serial production.
According to the manufacturer's estimates, the cost of one shot with the SPACIDO corrector rises to 7, 8 thousand dollars. A similar development (so far in the prototype stage) is the ECF system for 155-mm projectiles from the British BAE Systems and the Swedish VCSM, which differs from the French idea in the principle of GPS guidance. The cost of such a shot is 9 thousand dollars, and the circular deviation is about 25 meters.
The second technique for increasing the accuracy of standard artillery ammunition was the trajectory correction system with rigid rudders that receive commands from the GPS. The principle is implemented, in particular, in the XM1156 device from ATK for 155-mm M107, M549A1 and M795 projectiles. The circular probable deviation of such corrected high-explosive fragmentation projectiles does not exceed 50 meters at any range. Before launch, target coordinates and flight path are programmed and transmitted to onboard systems using a portable programmer. After the projectile leaves the barrel, the power supply battery is activated and the GPS receiver immediately begins to receive satellite signals. During the first second of the flight, the projectile rolls along the roll, as well as the determination of its coordinates. Further, if the projectile deviates from the calculated trajectory, on the basis of constantly updated navigation data, the electronic equipment of the bow guidance unit calculates trajectory correction corrections for the rudder unit.
Under the influence of the incoming air flow in flight, the ring with rigidly fixed control surfaces rotates freely in the direction opposite to the rotation of the projectile. The rotation frequency of the ring is less than the rotation frequency of the projectile. The rudders installed at different angles during the rotation of the ring for a full revolution create the same disturbing effects in all directions perpendicular to the longitudinal axis of the projectile, and do not affect the ballistic flight trajectory. At the design moment, the locking device stops the rotation of the ring when the rudders are at a certain angle along the roll, which ensures the correction of the trajectory in the desired direction. Further, after unlocking the ring, its free rotation begins again, opposite to the rotation of the projectile, until the next moment when it will be necessary to correct the trajectory. Naturally, this option, although it is less accurate, allows, in comparison with the Excalibur, to save about 85 thousand dollars per shot. But that's not all. Israel and South Africa believe that the systems mentioned above do not satisfactorily cope with the frenzied rotation of the projectile of the order of 250-300 rpm, which negatively affects the correction accuracy. Indeed, the Excalibur does not rotate at all for normal flight operation, although it is used in rifled weapons. The design provides an obturator in the form of a sliding bearing, which, when moving along the rifling of the barrel, practically does not transfer the moment of rotation to the projectile. That is why the Israeli firm BAE Systems Rokar International Ltd has created a complex flight correction unit based on four aerodynamic rudders. The unit is quite tricky: two rudders are responsible for the rotation of the correction unit in the direction opposite to the rotation of the projectile, and two adjust the direction of flight. This "autonomy" in rotation is possible due to the junction with the main part of the projectile. The GPS-based system was given the name Silver Bullet, and it can reduce the circular deviation at a distance of 20 km to 5-7 meters, however, the cost of each shot is a considerable $ 20 thousand. These are truly "silver shells". The South African firm Denel has created a similar "smart" attachment for a 155-mm projectile, but the final cost of a shot is even higher - $ 25,000.
Now let's get acquainted with the calculations of the costs of the above 155-mm ammunition for the destruction of a hypothetical MLRS installation. Materials on this topic are given in one of the issues of the Izvestiya TulGU. Technical Sciences "for 2019. So, if the MLRS is located at a distance of 8 km, then for its guaranteed destruction of projectiles with SPACIDO brake flaps, about 45 pieces are required, while only 8 pieces are needed for the controlled Excalibur Block 1b. Now in development is a promising Excalibur Block S with a semi-active laser homing head, which is expected to be able to hit such a target with an average of 1, 2 projectiles. It is noteworthy that the key advantages of the XM1156 and Silver Bullet systems is the independence of the ammunition consumption from the target range. If the MLRS is located at a distance of 8 to 25 km, then the XM1156 will need 65-67 shells, and the Silver Bullet - 8-9. At the same time, the "Silver Bullets" are actually on par with the Excalibur Block 1b in terms of efficiency (despite the fact that it is 5 times cheaper): Israeli shells have a similar consumption at the indicated ranges to the target. The advantage of all Excaliburs is the firing range increased to 48 km due to the bottom gas generator. By the way, SPACIDO brake flaps on 155-mm shells are not particularly effective at ranges of 15-25 km - in this case, 65 to 173 shells are required to destroy MLRS. That is, theoretically, the elimination of a multiple launch rocket system may require a million dollars or more. This, of course, if you do not take into account that artillery positions conducting such an intense fire will be detected by counter-battery systems and destroyed.
