Mortar NORINCO SM-4: “Cornflower” in Chinese
At the end of 2000, NORINCO, a leading Chinese manufacturer of weapons and equipment, began developing a promising combat vehicle carrying an automatic mortar with a 81,2 caliber. This type of equipment was intended for some structures from the People’s Liberation Army of China. First of all, it was considered as a new technique for the airborne troops, and therefore should have been distinguished by its small size and weight, while at the same time obtaining high combat qualities. The task was successfully solved, and in a very curious way. The project was based on Chinese products, which are modified versions of foreign weapons and equipment.

Self-propelled mortars SM-4 on exercises in Tibet. Photo Defence-blog.com
The Dongfeng EQ2050 all-wheel-drive army vehicle was chosen as the base for the self-propelled airborne combat vehicle. This car is actually a redesigned version of the American civilian car Hummer H1, which, in turn, is a slightly modified version of the army HMMWV. According to known data, most of the design features and units were copied unchanged or ordered to foreign suppliers. At the same time, there were some minor improvements aimed at both improving the performance and reducing the similarity with the foreign prototype.
With the help of a set of new development equipment on the chassis EQ2050, the 81,2-mm automatic mortar “Type 99” or W99 is installed. This model, in principle, can be considered a creation of Chinese engineers, but it is based on foreign developments. The basis for the Chinese "Type 99" was the rather old Soviet mortar 2B9 "Cornflower". In the past, Chinese specialists managed to get their hands on a foreign sample, and soon an exact copy of it appeared. However, in the late nineties, China redesigned these weapons in order to improve the basic characteristics. The mortar has received a new barrel of greater length, and in addition, in the manufacture of weapons and gun carriage it was proposed to use new materials and technologies.
At the turn of the last decades, two copies of foreign products “met” in the new project and were supplemented with some new aggregates. As a result, a promising self-propelled mortar for the PLA Airborne Forces appeared. A new sample of technology received the designation SM-4. In addition, another name is used in its relation PCP-001.
As already mentioned, the base for the SM-4 was the army SUV EQ2050. This car has retained both the characteristic appearance and the non-standard layout of the basic foreign model. The machine is equipped with a Cummins EQB150-20 diesel engine with an 150 hp power produced in China under license. The engine and all the main transmission units are located in the central part of the chassis, in a separate casing right inside the passenger cabin. The radiator is placed under the hood and is located there with a significant slope. Mechanical transmission provides torque distribution to all four driving wheels. The chassis has retained an independent suspension based on vertical springs.
In the composition of the self-propelled mortar used chassis with an open body. The composition of the latter includes a radiator hood, sides of limited height and feed parts. In front of the driver and passenger seats is the windshield, which can be put on the hood. The rear part of the chassis is given for the installation of weapons and styling ammunition. Over their own side of the machine, Chinese designers installed a low box that bounds a similar fighting compartment. The machine does not have a roof, and therefore the main armament is placed openly.
On the stern of the landing gear, there is a top machine from the standard carriage for the mortar "Type 99". It is attached directly to the power elements of the machine and, apparently, cannot be removed for firing from the ground. The machine design provides guidance of weapons in any direction horizontally. The swinging part with the mortar's body can change its position from horizontal to + 85 °. Mortar installation retains the standard guidance tools with manual drives.
At the heart of the mortar "Type 99" is the design of the Soviet product 2B9. In this case, the Chinese designers have refined it in order to improve the main fire characteristics. The most noticeable change is the increase in the length of the trunk. According to the available data, a longer barrel allowed to increase the maximum firing range from the original 4,3 km to 6-8 km, depending on the type of mine and charge. In addition, increasing the initial velocity of a mine can be useful when shooting direct fire, provided by the Chinese project.
"Type 99", like its Soviet prototype, is a smooth-bore breech-loading weapon with automatic reloading. Weapon automatics is based on the principle of rolling out moving parts under the action of reciprocating springs compressed by recoil energy. Mortar gets ammunition from cassettes for four mines. Apparently, W99 due to the large length of the trunk lost the ability to boot from the barrel.
The barrel with the mechanisms of automation is connected with recoil devices. Together they are mounted on the upper machine tool carriage and can be moved in a vertical plane using guidance systems. It is curious that recoil devices and automation absorb almost the entire recoil impulse. Due to this, the base chassis does not need jacks, coulters or base plate to redistribute the load on the ground. Shooting is carried out directly from the wheels.
Preparation for the first shot is carried out manually. At the moment of firing, the moving parts of the gun under the action of recoil begin to move backward, compressing the return spring. When they are reversed, the next mine is removed from the cassette and then fed into the barrel chamber. Such automation allows you to get a technical rate of fire at the level of 110-120 shots per minute. The practical rate of fire depends on the calculation skills and the rate of replacement of empty cartridges, as a result of which it does not exceed 40 rounds per minute.
Like its Soviet predecessor, the Chinese Mortar Type 99 is intended for firing at a wide range of elevation angles. He is able to send ammunition to the target at high trajectories or shoot direct fire. For both modes of fire there are separate sights. In the case of direct fire shooting, an optical sight located at the gunner’s workplace is used.
An important innovation of the Chinese project is the availability of advanced firing controls. The gunner has a satellite navigation system coupled with devices for receiving and processing data. With the help of such equipment is the calculation of data for the shooting. Declared a sharp increase in the accuracy of fire and the probability of hitting the target by the first mine.
The ammunition self-propelled mortar NORINCO SM-4 / PCP-001 includes ammunition for different purposes. All existing Chinese mines of caliber 81,2 mm are compatible with it. You can use fragmentation, smoke, incendiary, lighting and other min. To combat armored vehicles it is proposed to use a special ammunition with a shaped charge. Mines are transported in packs in rectangular metal cassettes, four each. The presence of cassettes facilitates work with the tool, and in addition, simplifies the overload of ammunition from the transport vehicle or the supply of mines from the ground.
The calculation of the Chinese war machine consists of three people. They are assigned the duties of the driver, commander, gunner and loader. On the march, two crew members are located on the seats in front of the habitable compartment, one of them is the driver. The third mortar should be in its place, in the stern of the machine next to the gun. After arriving at the firing position, the calculation takes other places.
The SM-4 combat vehicle in its dimensions and weight roughly corresponds to the base car EQ2050 in the cargo-and-passenger configuration. The total length does not exceed 4,7 m, width - 2,1 m. The height, taking into account the mortar in the transport position - is about 1,8 m. The combat weight with the calculation and ammunition - not more than 3-3,5 t. The machine is capable of speeds up to 120 km / h and overcome various small obstacles. Power reserve - up to 500 km.
Together with the SM-4 self-propelled mortar, troops are encouraged to use the VPY-001A ammunition conveyor. He is a car Dongfeng EQ2050 with a full body. Dimensions of the cargo area allow you to place up to several hundred minutes in cassettes. Depending on the assigned tasks, the conveyor can transfer ammunition in the parking lot or ensure the delivery of mines directly to the firing position. In terms of dimensions and running characteristics, the VPY-001A conveyor is almost the same as a self-propelled mortar.
The NORINCO SM-4 project was created at the end of the last decade, and soon a new type of experimental equipment confirmed its capabilities at the test site. Several years ago, the mass production of such combat vehicles in the interests of the PLA was launched. To date, the army managed to get significant quantities of self-propelled mortars, but their exact number has not yet been specified. Serial vehicles are transferred to different parts of the landing forces and other structures.
The Chinese self-propelled mortar NORINCO SM-4 has a number of positive features that give it quite ample opportunities. A light wheeled vehicle can use roads and quickly reach a given firing position. The equipment is not afraid of off-road and, if necessary, can go to the position or leave it over rough terrain. There is also the possibility of dropping technology parachute or landing method.
Used automatic mortar W99 / "Type 99" provides an acceptable combination of mobility and firepower, allowing you to attack manpower, buildings and equipment of the enemy at a distance of several kilometers. A very wide range of ammunition allows to solve various combat missions. Having preserved the possibility of direct-fire shooting, the “Type 99” is capable of performing the functions of a light field gun.
However, the Chinese development is not without significant flaws. The most noticeable is the absence of any reservation and even weather protection. The firing range of the used mortar does not exceed several kilometers, and therefore he is forced to work at the forefront. Naturally, he runs the risk of being hit, and the lack of armor makes it an easy target. Small arms or enemy artillery can easily disable the combat vehicle or its crew.
Insufficient survivability in an understandable way limits the combat effectiveness of the mortar. Tasks for such equipment will have to be set taking into account the current situation and risks. Otherwise, there is a possibility of death of people or vehicles, including before the start of the shooting. This feature of combat use is unlikely to fully realize all the advantages of the weapons used.
Despite the obvious shortcomings of the new technology, the Chinese command considered it suitable for adoption and operation. A few years ago, NORINCO Corporation launched mass production of SM-4 / PCP-001 self-propelled mortars and now supplies them to the troops. A sufficiently large grouping of such machines has already been created, and it is likely that in the future it will be replenished regularly. Current events suggest that - for all its minuses - the original Chinese self-propelled mortar meets the requirements of the customer. As for the characteristic flaws, they were not considered critical.
The SM-4 Chinese self-propelled mortar primarily demonstrates a curious approach to the development of military equipment for solving certain combat missions. The new combat vehicle for the airborne troops was made the easiest way: by installing an existing gun on the serial chassis. At the same time, the NORINCO project showed an interesting variant of this approach. Both main components of the combat vehicle, produced in China, are of foreign origin. Such results of copying foreign developments cannot but attract attention.
On the materials of the sites:
https://armyrecognition.com/
http://military-today.com/
https://defence-blog.com/
http://defense-aerospace.com/
http://eng.chinamil.com.cn/
http://baijiahao.baidu.com/
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