The Type 74 Fighting Vehicle (BM) is designed to remotely mine the ground in front of advancing enemy units. It was developed and produced by the Chinese military industrial corporation NORINCO.
The Type 74 BM was adopted and is probably still in service with the People's Liberation Army of China. Production was completed in the early 90s. The total production volume was 197 vehicles. In the Forecast International source, August 2011 the Type 74 combat vehicle and its ammunition are not mentioned.
By its design the Type 74 fighting machine (see photo) is similar to the Soviet Guards mortar of the Great Patriotic War - M-13 machine.
The guide package consists of five I-beams with the length of four meters. Each girder on the top and bottom has a groove. This groove includes the guide pins of the projectile. There are two projectile pins on each guide: one at the top and one at the bottom.
The artillery part is mounted on the modified chassis of ZIL-157 6×6 series truck. Chinese designation of SA-30A chassis 6×6. For the stability of the vehicle when firing, the hull is supported by the jacks mounted at the rear of the chassis. To protect the windows of the cabin at firing, special steel plates are used.
Unguided rockets (NURS) of 284 mm caliber are used for firing, and their heads are equipped with ten Type 69, Type 70 or Type 72 anti-tank mines. The bodies of the mines are made of plastic.
The latest version of the NURS from the BM ammunition set, designated Type 85 (see diagram), is fitted with 10 anti-tank mines and has a maximum range of 3,000 metres. The full salvo of the combat vehicle is mine-sized 700 × 500 meters.
The calculation of the fighting vehicle consists of six numbers. On the march, four numbers are located at the back of the cockpit on an open bench, facing in the course of movement. Four numbers of calculation are required to charge one projectile.
Organizationally, the units that were in service with the Type 74 BM and the projectiles to it were brought together in batteries of four installations each.
Composition:
The combat module of the complex includes:
- two bags of six Sosna-R missiles in transport and launch containers,
- optical-electronic control system,
- digital computer system,
- guidance mechanisms,
- the power supply system.
Pine Rocket - two-stage rocket with a detachable engine. After leaving the container, the missile is controlled by a radio command system, which brings it to the line of sight, then the starting engine is separated and the interference-proof laser guidance system is activated.
Battle unit: shrapnel rod to engage on the span, armour-piercing rod to engage in direct hits. Exploder: Non-contact laser with a continuous circular radiation pattern and adaptive blast time.
The missile does not require additional checks or tests during its lifetime. The small weight of the rocket allowed to exclude the transport and charging machine from the complex.
Initially, the complex used an anti-aircraft two-stage guided missile 9M337 (see photo_1, photo_2, photo_3), now the Sosna SAM system is equipped with SAM 9M340 (9M340E) (see photo_1, photo_2, photo_3, photo_4, photo_5).
The 9M337 missile is capable of engaging targets flying at altitudes up to 3500 meters. Its range is between 1.3 and 8 km, with a maximum flight time of 11 seconds. The combat unit weighs 5 kg. The weight of the missile in the transport and launch container is 36 kg, without the container - 25 ... 26 kg.
Opto-electronic control system of the complex has high accuracy characteristics of target coordinates determination, interference and stealth and provides automated combat operation of the complex from the moment of target detection to their firing.
It includes: optoelectronic module (OEM), digital computer system, drives for horizontal and vertical guidance of weapons, control and display panel, power supply unit, automatic systems for acquisition and tracking of SAM and target.
OEM is placed on a gyrostabilized platform and serves for autonomous or according to external target designation (radar, superior control) target detection, automatic or semi-automatic tracking, high-precision determination of its coordinates (angles of sighting the target and range) and their issuance to a digital computer system for shooting.
The OEM consists of:
- the television system,
- thermal imaging channel,
- laser rangefinder with beam deflection device,
- laser beam channel control equipment for the missile,
- the missile's direction finder's thermal imaging channel,
- climate control device.
Autonomous target detection is carried out by a television channel with a wide field of view, and the distance to it is determined by a laser rangefinder, working in automatic mode.
Rockets and the anti-aircraft system itself are protected from interference by several methods implemented at the construction level. Thus, the location of the laser receiver in the rear of the missile does not allow to distort or jam the control signal. Interference immunity of the ground part of the complex is provided by a narrow field of view of TV and thermal imaging channels, as well as the use of special computing algorithms that allow to identify the target by its characteristics. The complex is practically insensitive to radar and optical suppression means used by the enemy.
The combination of the high level of missile characteristics and the control system makes it possible to obtain large kill zones (see diagram). Sosna" SAM system can be used as part of a battery, including mixed composition, receiving target designation from the battery control station or commander's vehicle, as well as autonomously. The Sosna SAM system battery, using sector search, can do without external target designation, providing all-around visibility and target detection in passive mode, which makes it impossible to attack the PRR.
Characteristics:
| BM Specifications | |
| Length in hiking position, mm | 6440 |
| Width in hiking position, mm | 2270 |
| Height in hiking position, mm | 2930 |
| Weight of loaded combat vehicle, kg | 8780 |
| Weight of unloaded combat vehicle, kg | 6954 |
| Maximum movement speed of the fighting vehicle, km/h. | 40 |
| Salvo time, s | 15 |
| Calculation, man. | 6 |
| Number of rails, pcs. | 5 (2 NURSE on guide) |
| The length of the guideway, m | 4000 |
| Angle of elevation, deg: | |
| minimum | +7 |
| maximum | +48 |
| Angle of horizontal fire, deg: | |
| to the right of the chassis axle | 45 |
| to the left of the driving axle | 90 |
| Technical specifications of NURS (standard) | |
| Caliber, mm | 284 |
| The length of the projectile, mm | 2470 |
| Weight of projectile, kg | 127 |
| Off-rail speed, m/s. | 34,6 |
| Maximum projectile flight speed, m/s | 120 |
| Maximum projectile range, m | 1500 |
| NURSE Specifications Type 85 | |
| Caliber, mm | 284 |
| The length of the projectile, mm | 2600 |
| Start weight, kg | 156 |
| Maximum projectile range, m | 3000 (3500) |
Testing:
From September 1 to November 28, 1945, the Nb.W.42 trophy mortar was tested at the Red Army State Automobile and Space Administration. The tests were carried out on the basis of the order of the Deputy Chief of SAKP, Major-General of the Engineering and Artillery Service of Serebryakov under the program of the range - SAKP task №4410.
In the report No 0116 dated 19.1.46 the description of the device and operation of the Wgr.42 mine, L.J.gr.Z23nA fuse and the mortar were given. Data on the heap and range, as well as theoretical calculations of internal and external ballistics are given. In addition, the report contains the results of analysis of the hull materials and equipment. The test manager was Captain Lerner.
The purpose of the tests was to determine:
- basic characteristics of the mortar and the mine Wgr.42 /description of the device, operation and purpose/.
- Intraballistic characteristics Wgr.42 /powder gas pressure and charge burn time/.
- aerodynamic characteristics Wgr.42 (wind tunnel blowing).
- The impact and maximum mine speed and the nature of mine buildup in the active area.
- Maximum range at 10°, 20°, 30° and 45° elevation angles.
- The mine's blast and fragmentation effect on the target.
- the system's strength, stability and rate of fire.
When measuring five minutes on centering belts, the projectile caliber was 214 mm, so the report suggested "counting the caliber not 210 mm as usual, but 214 mm".
The conclusions of report No. 0116 were as follows:
- The 210 mm Wgr.42 rocket projectile with the M-13UK missile was characterized by simplicity, cheapness and availability of materials that were used for its production. It was noted that the Germans considered it possible for missile chambers to allow deformation at maximum pressure beyond the elastic limits, i.e. the chambers were calculated not on the elastic limit, but on the temporary resistance to rupture with a margin of strength of the order n=1.5.
- Manufacturing of dinitroglycol powders for rocket charges had advantage in comparison with manufacturing of nitroglycerine powders. As glycol was based on cheap raw material base (vegetable oils), and glycerin was mainly produced from animal fats.
During the study of the mine, it was disassembled into structural elements. See their photos: photo 1, photo 2, photo 3, photo 4, photo 5, photo 6, photo 7.
From August 8th till August 13th 1945 at the State Mine Stockpile of Ukraine there were conducted shooting to determine experimental data for drawing up tables of shooting. Shots were fired at an elevation angle of 10°, 20°, 30° and 45° (maximum possible elevation angle).
The mortar was simultaneously loaded with 5 shells. The mortar was fired in single shots. The charge was corrected after each shot, and the shoot down rate was insignificant. Due to lack of German mortar sight, side aiming was made with MP-41 sight.
As a result of tests it was received:
- The puchiness and range of the 210 mm Wgr.42 missile did not differ from the characteristics of the domestic M-13UK projectile. When the angle of Ө decreases (elevation angle) the heap drops sharply especially in range: gri Ө=10° the range of 2650m and the WDX = 1/17 was obtained; WDX = 1/58, at Ө=45° the range of 8000 m and the WDX = 1/88; WDX = 1/76.
- The effect of the Wgr.42 mine on the target was undoubtedly more powerful than that of the M-13UK, as the 210mm projectile carried 9.27 kg of explosives, while the M-13UK carried 4.55 kg. However, the Wgr.42 has a smaller fill factor /WB to passive weight ratio than the M-13UK. The M-13UK had a filling ratio of 13% and Wgr.42 had a filling ratio of 10%.
- The design of the Wgr.42 mine was characterized by the simplicity, affordability and accessibility of the materials used in its manufacture.
- Calculation of internal ballistics showed the following results: at charge temperature - 40°C the pressure in the chamber was equal to 106 kg/cm2, at charge temperature +40°C the pressure was equal to 325 kg/cm2. This gave grounds to suppose that the rocket charge will work at low temperatures and will not break the chamber at high ones.
- The chemical composition and physical characteristics of the gunpowder rocket charge did not differ from glycol powders, which were adopted in German artillery. Powder strength and caloric value were of the same order as M-13UK rocket charges, but the use of glycol undoubtedly extended the raw material base of the powder production.
- The design of the 210-mm 5-barrel Nb.W.42 mortar carriage did not differ from that of the 150-mm 6-barrel Nb.W.41 mortar carriage.
- The maneuverability and ease of operation are satisfactory, but the power of the 210 mm mortar salvo is about 1.5 times smaller than that of the BM-13. For one salvo of 5-barrel mortar ejected 46 kg ВВ, and installation BM-13 - 73 kg ВВ.
It was concluded that the design of the 210 mm Nb.W.42 rocket launcher and its projectile was found to be successful, both in combat and operational terms.
The mortar was disassembled into its structural elements during its study. See their photographs: photo 1, photo 2, photo 3, photo 4, photo 5, photo 6, photo 7, photo 8.
Sources:
- Bob Furlong. China’s New Arms Export Policy. // International defense review. – 1984. – Vol. 17. – № 12. – P. 1795.
- Forecast International. – August 2001.
- Forecast International. – August 2011.
- http://www.bemil.chosun.com.
- Jane’s Ammunition Handbook 2000-2001. – P. 632.
- Jane’s Armour and Artillery 1986-1987. – London: Jane’s Publishing Limited, 1988. – P. 739-740.
- Jane’s Armour and Artillery 2000-2001. – P. 761.
