Grad-P lightweight portable jet system

The 9P132 Portable Unit (see photo) is a tubular guide with a U-slot for initial rotation of the projectile and a light tripod machine with guidance mechanisms and sighting devices. The design of the tubular guide rail is similar to that of the BM-21 combat vehicle of the M-21 Field Rocket System, but its length is 0.5 meters shorter and is 2500 mm.

The cradle guide is mounted on a tripod machine with a constant line of fire. Each of the three supports of the machine is made folding. The front one is equipped with a coulter for increased stability when firing. Guidance mechanisms allow for vertical alignment in the range of angles from +10° to 40°. The horizontal firing angle range (without changing the installation position) is ±7°. The launcher weighs 55 kg in combat position and can be disassembled into two packs: with the barrel (25 kg) and with the machine (28 kg). The time to move the launcher from the camping position to the combat position shall be 2.5 minutes and back 2 minutes. The launcher is guided by the PBO-2 sight and a booster.

Shots are fired by the 9M22M unmanned 122mm unguided rocket projectile, which is dismantled into two sealed parts (see diagram). It has a single-chamber rocket engine and a fragmentation fuse combat unit. The combat unit was completely, without any changes, borrowed from the M-21OF shell. The engine housing was developed on the basis of the M-21OF projectile engine housing. A hermetically sealed remote control equipped with a generator and connected to the launcher by an electric cable 20 m long is used to ensure the launch. The short current pulse generated by the remote control ensures ignition of the projectile pyrophatron. The flame enters the central channel of the rocket motor gunpowder and ignites it. When the propulsion force reaches a certain value, the contact cover of the projectile is broken and the propeller groove starts to rotate. When the projectile descends from the tube, the stabilizer blades are opened and installed under the action of a spring mechanism at a small angle to the longitudinal axis of the projectile.

In general, the Grad-P rocket was 98% unified with the M-21OF for the BM-21 combat vehicle. According to other data, in the 9M22M design 87% of parts were unified with Grad parts. The engines of projectile 9M22M were 75% unified with those of projectile 9M22U. The combat units of 9M22M were fully aligned with the combat unit of 9M22U.

Since 1974, the 9M22M was equipped with a new MRV-U fuse, which had the same installations as the 9E231. The MRV-U fuse had a non-removable safety cap. The 9M22M projectiles with this type of fuse were fired with the safety cap only. When firing 9M22M projectiles without a brake ring with MRV-U fuse, it was necessary to use the tables of firing of 9M22M fragmentation and blast rockets with 9E231 fuse without a brake ring (TS-78), introducing additional correction of minus 120 m for all ranges of firing (with MRV-U fuse the projectile flies further). When firing 9M22M shells with MRV-U brake ring fuse, one should have used the TS-78K firing tables without introducing additional corrections for a new fuse.

Calculation - 5 persons (see calculation with pack).

During the operation of the first serial launchers 9P132, released in 1965, a number of shortcomings were identified. In accordance with the action plan approved by the Deputy Minister of Defense Industry and the commander of the 64176, the following improvements were made to eliminate these shortcomings:

• dead maneuver of the lifting mechanism flywheel is made no more than 1/10 turn;
• a transverse risk is applied at the rear quadrant under the quadrant, ensuring a certain position of the quadrant on the site;
• the handle of the lifting gear flywheel has been extended;
• elongated carbines on the belts for carrying the machine;
• the weight of the belt wrench for the projectile has been reduced;
• introduced annealing of the cotter pins to reduce their brittleness.

At the meeting held on August 29, 1967, "at the State Hydroelectric Power Plant's Inspectorate, a number of wishes were expressed by the representatives of the General Staff of the Ministry of Defense of the Democratic Republic of Vietnam (DRV) on the modernization of the "Grad-P" jet system, in particular:

• increase the range of the Grad P launcher (over 10 km), without increasing the total weight of the unit;
• find a way to shorten the barrel length, make the launcher lighter;
• mount 3-4 detachable barrels on one launcher, so that 3-4 projectiles could be fired in 5 minutes, this will avoid the enemy's return fire (now it takes 10-15 minutes to launch and shells);
• Consider using the Grad-P launcher against the helicopter when landing from the helicopter, when the helicopters are still at 200-300 m altitude;
• provide an electric cable and increase the reliability of the control panel (there was a failure and the control panel, the reason is unknown)".

In accordance with Decree No. 722-rs of 08 April 1968 of the Council of Ministers of the USSR and Order No. 70 of 20 April 1968 of the Minister of Mechanical Engineering, work was carried out to modernize the projectile and launch unit "Grad-P" according to the schedule of the Ministry of Mechanical Engineering and Ministry of Defense. Taking into account the wishes of the Vietnamese side, the schedule provided for the following major improvements:

• to increase the range of fire;
• increase the length of the barrels of the launcher;
• reduce the height of the tripod of the launcher;
• to work out the possibility of creating a launcher with two barrels;
• create an airtight capping on the projectile;
• to determine the possibility of firing M-21OF shells from the 9P132 launcher;
• to carry out range tests of the projectile with the incendiary combat unit (equipped with a firearm) 9M22MS and some others.

The work on modernization of "Grad-P" system was carried out by the following enterprises:

• The G4575 company is the leading organization in the system, a projectile developer and supplier of projectile samples;
• X-5498 enterprise - developer of powder charge and ignition system;
• Firm G-4406, developer of the launcher system
• enterprise of the p/o V-8916 - detonating device;

Tests of the modernized system "Grad-P" were carried out at an hour 33491 under the program №232 of the Ministry of Defense agreed with the VP, out. №04244 of 31.5.68, the enterprise p/o G-4575 in the period June-September 1968 in the amount of 292 shots. Of these, 292 were fired:

• 228 rounds of modernized projectiles (9M22MD);
• 54 rounds of Grad-P system shells. (9M22M);
• 10 rounds of M-21OF shells.

Tests were conducted from the 9P132 launcher and pilot launchers with one and two shafts (the tripod is 220 mm lower in height and the shafts are 500 mm shorter than from the 9P132). The projectiles were assembled and prepared for firing in the military unit 33491.

The 9M22MD projectile with extended range was created as a result of development, experimental checks and firing tests. The main differences between 9M22MD and 9M22M are as follows:

• instead of a 9.52 kg powder charge, a charge of 11.9 kg of VIC-2D powder was used from PSI-12M;
• nozzle diameter dk = 35.5 mm, da = 17.5 mm, instead of "k = 13 mm and da = 23.5 mm for projectile 9M22M.
• The tail diaphragm design has been changed.

Key points of conclusions in/h 33491:

• The extended range projectile with the 9P132 launcher and the experimental single-barrel and double-barrel projectile functions normally: the trajectory is correct, there were no projectile failures on the trajectory.
• The extended range projectile when fired from the 9P132 launcher provides the following characteristics:
• the experimental range is 15 km, i.e. approximately 4 km more than the 9M22M projectile;
• heavier range when firing at the maximum range:
  • in WD/Hop range = 1/108
  • by range WB/Hop = 1/129
• The 9M22M projectile's range of fire and heap of combat at the maximum range are almost the same for the 9P132 and pilot launchers with one and two barrels.
• The single barrel pilot launcher is more compact and convenient than the 9P132:
• the barrel of the 9P132 prototype PU is 500 mm shorter and 2.8 kg lighter than the 9P132;
• the bag with tripod prototype PU is 100 mm shorter and does not rest on a soldier's legs when moving;
• prototype launchers with one and two barrels and 9P132 installation are unstable (tilted) when firing long range projectiles at elevation angles up to 20°-25°.
• to prevent the PU from tipping over when firing on the front support, it is necessary to place the load weighing about 50 kg. Two loads from the rocket parts of the projectile filled with soil can be used as cargo.
• Due to the high hit rate of fire, the direction of fire of the launchers must be taken after each shot.
• The rate of fire of pilot launchers with two barrels is slightly higher than that of PU with one barrel. However, in a dual barrel machine, the sector of the aiming angle selection is limited (the upper barrel on the right is overlapped) and the number of calculations must be increased to carry the second barrel.
• Special covers ensure the tightness of the projectiles when placed in water, but the strength of the covers is insufficient.
• Firing of 9M22MS projectile, MSO and SCS fire hydrants showed unsatisfactory firing and ignition effect both when shooting on the ground and on targets.
• The firing of the 9M22M projectile with the 9M22S incendiary ordnance showed the fundamental capability of the 9M22S projectile warhead when fired from the Grad-P system.

	Developer	Manufacturer
Cartridge 9M22M	NII-147	Tula, plant 176 (assembly - Selzo, s-d 121).
Powder charge 9X111M	NII-6	Perm, plant №98
Ignition 9X227M	NII-6	Perm, plant №98
Fuse 9E231	NITI-11	Kazan, plant №144