Due to the simplicity of design and combat qualities, mortars have long and firmly taken their place in the structure of the artillery of modern ground forces. Soon after its appearance, this type of weapon began to be installed on various self-propelled chassis, which significantly improved their mobility and survivability. The idea of a self-propelled mortar has survived to this day and is unlikely to be abandoned in the near future. An armored wheeled or tracked chassis gives a combat vehicle the ability to quickly enter and leave a position, and new, more advanced mortars are capable of effectively hitting targets in a minimum of time and with a minimum consumption of ammunition.
General trends
In the field of self-propelled mortars in recent years, there have been several trends aimed at improving the combat qualities. First of all, it is necessary to note the gradual transition from systems of caliber 81 or 82 mm to more serious weapons. Over the past decades, almost all leading countries have begun to actively develop the direction of 120-mm self-propelled mortars. In fact, such a weapon represents a compromise between weight and size and firepower. With acceptable dimensions, it is mortars of 120 mm caliber that make it possible to send relatively large ammunition to the target over a fairly long distance.
One of the most modern howitzers in the world is the German Panzerhaubitze 2000 (in an abbreviated form - PzH 2000, where the digital index indicates the new millennium). Experts unanimously classify it as the perfect model of field artillery in the world, which has a serial production.
Another interesting trend observed in this area concerns the architecture of combat vehicles. New self-propelled mortars appear regularly, the armament of which is not located inside the armored hull, but in a rotating turret. This "hybrid" of the classic self-propelled guns and mortars has the advantages of both classes of equipment and, thanks to this, is able to solve a wide range of tasks. Recently self-propelled mortars are almost always equipped with an advanced automated fire control system and a number of other electronic equipment. In addition, mortars are also mastering those methods of firing that were previously characteristic only of howitzers - for example, the MRSI or "flurry of fire", when the gun fires several shots at the maximum rate and different elevation of the barrel, due to which several mines fly up to the target almost simultaneously.
In the field of ammunition for self-propelled mortars, exactly the same trends are observed as in other areas of weapons. Along with high-explosive fragmentation mines, new types of corrected mines are being created. In addition, attempts are being made to create cluster munitions. Weaponsmiths seek to increase the accuracy and power of new mines, and also try to increase their flight range. The latter is achieved mainly by creating active-jet mines with their own jet engine. Currently, the US is running the PERM (Precision Extended Range Munition) program, which aims to create an adjustable mine with a flight range of up to 16-17 kilometers, which is about double that of conventional ammunition.
Consider some foreign self-propelled mortars created in recent years.
Germany
In the late nineties, the German company Rheinmetall proactively modernized the Wiesel 1 tracked chassis. The resulting Wiesel 2 with improved characteristics attracted the attention of the military and, as a result, became the basis for several developments, including the self-propelled mortar. In 2004, tests began on two 120-mm mortars based on the Wiesel-2. The new Advanced Mortar System complex includes three vehicles: the mortar itself, a command post with communication and control systems, and a reconnaissance vehicle.
Due to the small dimensions of the Wiesel-2 base vehicle, a 120-mm mortar in a combat position is placed outside its armored hull. When transferred to a stowed position, it is placed on special holding devices by turning forward and fixed. The mortar is mounted on recoil devices, which, in turn, are mounted on a rotary carriage. Horizontal guidance is carried out within 30 ° from the vehicle axis to the right and left, vertical - in the sector from + 35 ° to + 85 °. The combat vehicle is equipped with an automated digital fire control system. For guidance, manual mechanisms or drives controlled by the OMS are used. The maximum firing range when using the new ammunition created by Rheinmetall exceeds 8 kilometers. The ammunition stowage of an armored vehicle can hold up to 30 minutes. The crew of the combat vehicle consists of only three people, one of whom is a driver mechanic. After the modernization of the armored chassis, the Wiesel-2 has a combat weight of about 4.2 tons, which makes it suitable for air transport and landing.
In 2009, the German Ministry of Defense and Rheinmetall signed a contract, according to which, in the coming years, the army will receive 38 Wiesel-2 self-propelled mortars, as well as 17 reconnaissance and command vehicles. The first batches have already been delivered. There is information about the continuation of the supply of such self-propelled mortars after the fulfillment of the existing contract.
Israel
At the beginning of the 2000s, Soltam Systems created the CARDOM system (Computerized Autonomous Recoil Rapid Deployed Outrange Mortar - "Autonomous computerized rapid-fire mortar with an increased range of fire and recoil devices"), designed to be installed on various chassis. The CARDOM system is a set of technical means that allow you to mount the required mortar of the appropriate caliber on an existing chassis. A turntable with a horizontal and vertical guidance system is installed on the base vehicle or armored personnel carrier. To expand the list of usable chassis, Soltam Systems engineers have provided recoil devices that are unusual for mortars.
In addition to the weapon platform, the CARDOM includes navigation systems, a ballistic computer and other equipment. The main type of weapon suitable for use in the CARDOM system is the Soltam K6 120mm mortar with a semi-automatic loading system. When using it, guidance devices allow you to fire in any direction at a distance of up to 7.2 km (when using conventional mines). An experienced calculation can provide a rate of fire of up to 15-16 rounds per minute.
CARDOM systems are already in service with the Israeli army. The version for Israel is mounted on a modified chassis of the M113 armored personnel carrier and is named Keshet ("Bow"). In the middle of 2012, Soltam Systems delivered to Spain the first batch of CARDOM systems with 81mm mortars mounted on the chassis of four-wheeled vehicles in accordance with the contract. A contract is expected to be signed for the supply of CARDON systems to the United States, where they will be mounted on the Stryker chassis.
China
Approximately in the middle of the 2000s, a new self-propelled mortar PLL-05, created by NORINCO and combining all the advantages of a mortar and a cannon, entered service with the People's Liberation Army of China. A new combat module with a universal weapon suitable for firing in a wide range of guidance angles is mounted on the WZ551 six-wheeled chassis. It is worth noting that the first mentions of the PLL-05 appeared at the beginning of the last decade, but then this combat vehicle was offered only for export. Obviously, a few years later, due to lack of demand, the self-propelled mortar was reworked in accordance with the requirements of the Chinese army and its mass production began.
In its concept, the PLL-05 strongly resembles the Soviet / Russian project 2S9 "Nona-S": a tower with a universal gun is installed on the base chassis, which combines the best qualities of a mortar and a cannon. The PLL-05 combat module rotates in a horizontal plane by 360 °, and the mortar installation system allows you to fire with an elevation from -4 ° to + 80 °. The 120mm mortar is capable of using a wide range of ammunition. When using standard high-explosive fragmentation mines, the maximum firing range does not exceed 8.5 kilometers. When firing active-rocket mines, this figure increases to 13-13.5 km. There is also information about the existence of a cluster mine carrying 30 armor-piercing sub-elements. The declared penetration is up to 90 mm. Also, a cumulative ammunition has been created for the PLL-05 mortar, which allows it to hit armored targets at ranges up to 1100-1200 meters. The maximum rate of fire, regardless of the type of ammunition, is 7-8 rounds per minute.
The PLL-05 combat module with a 120 mm universal mortar can also be installed on other chassis. In particular, a variant based on the Type 07P eight-wheeled armored personnel carrier was demonstrated at exhibitions of weapons and military equipment. Nevertheless, the equipment for the army is made on the basis of a six-wheeled armored vehicle. Probably, this was influenced by the weight indicators of both options: the PLL-05 available in the PLA are about five tons lighter than a self-propelled mortar based on the Type 07P. Thus, combat vehicles weighing about 16.5 tons can be transported by Shaanxi Y-8 transport aircraft.
United Arab Emirates
An original approach to the design of self-propelled mortars was used by IGG (International Golden Group) when creating the Agrab ("Scorpion") combat vehicle. This self-propelled mortar, unlike similar machines of foreign production, was made on the basis of an army off-road vehicle. As a chassis for a promising combat vehicle, IGG engineers chose the South African-made RG31 Mk 6 MPV armored car. This choice was justified by the peculiarities of the landscape of the Emirates and surrounding regions. The authors of the Agrab project considered that the cross-country ability of a four-wheeled armored car would be sufficient to fulfill the assigned tasks, and the protection complex, made in accordance with the MRAP concept, would ensure the safety of the crew and weapons.
A combat module with high armored sides was placed in the rear of the armored car. Before firing, the tailgate is folded back and, with the help of a special truss, brings into a firing position a Singapore-made 120-mm mortar SRAMS (Super Rapid Advanced Mortar System). The exact angles of aiming the weapon are unknown, but based on the available data, it can be concluded that a horizontal sector is about 50-60 degrees wide and an elevation of up to 75-80. Inside the combat module there are stowages for 58 minutes. The Arachnida fire control system is responsible for firing in the SRAMS combat module. Electronics allows you to calculate data for firing and transfer them to guidance mechanisms. If necessary, the calculation of the mortar can use manual mechanisms. When using standard high-explosive fragmentation mines, the Agrab combat vehicle is capable of firing at targets at distances of up to 8-8.5 kilometers. The maximum firing range of lighting mines does not exceed 7-7.5 km. The existence of other ammunition has not yet been said, but the caliber and characteristics of the mortar probably make it possible to expand the range of mines used.
The Agrab self-propelled mortar was created by IGG on an initiative basis. In 2007, testing of the first prototype began. Further tests and fine-tuning of the promising combat vehicle continued until 2010, after which the armed forces of the United Arab Emirates expressed a desire to purchase a batch of new equipment. In 2011, the UAE Ministry of Defense ordered 72 self-propelled mortars from IGG with a total value of about $ 215 million.
Poland
In 2008, Poland presented its project of a self-propelled mortar. Then the company Huta Stalowa Wola (HSW) began construction of the first prototype of the new RAK combat module. Like some foreign developments, the new Polish tower with weapons was supposed to combine the capabilities of a mortar and a cannon.
The first prototype of the RAK combat vehicle was assembled on the basis of the Soviet self-propelled gun 2S1 "Gvozdika", which allowed saving time for modifying the chassis for a new combat module. Inside the armored volume of the RAK turret is a 120-mm breech-loading mortar and all the necessary units. The declared rate of fire of the system is up to 10-12 rounds per minute, which is achieved using an automated loading system. The vertical angles of the mortar guidance - from -3 ° to + 85 °; horizontal - no restrictions. A system manufactured by WB Electronics is used for fire control. The maximum range of hitting a target with a standard mine, like other self-propelled mortars of 120 mm caliber, does not exceed 8-8.5 kilometers. When mines are used with an additional jet engine, this figure increases to 12 kilometers.
The first prototypes of the PAK self-propelled mortar were made on the basis of the Gvozdika self-propelled artillery chassis, but later HSW chose a different base chassis. It was the Rosomak armored vehicle, which is a licensed version of the Finnish Patria AMV armored personnel carrier. According to reports, small-scale production of RAK self-propelled mortars is currently underway, but there is no information on the number of vehicles assembled.
Singapore
The SRAMS mortar mentioned above, used in the Agrab complex, was created by the Singapore company STK (Singapore Technologies Kinetics) in the late nineties and was soon adopted. The SRAMS combat module was designed taking into account the requirements of the Singaporean military, which significantly influenced its appearance.
So, the combat vehicle, which entered service with the Singapore army, is made on the basis of the STK Bronco articulated tracked carrier. All units of the mortar are located on the rear link of the vehicle, which made it possible to competently smash weapons and equipment. The mortar is equipped with an original loading system: the units located next to the barrel raise the mine to the muzzle level and lower it into the barrel. The supply of mines to the loading mechanism is carried out manually. In such an original and at the same time complex way, the problem of high-speed loading of a muzzle-loading mortar was solved: it can fire up to ten rounds per minute. The SRAMS mortar itself is installed on recoil devices, and is also equipped with an original muzzle brake. As a result of these measures, the recoil is significantly reduced, which makes it possible to install the combat module on a relatively light chassis like cars, as is done in the Agrab complex. Horizontal guidance of the SRAMS mortar is possible only within a sector with a width of 90 °. Vertical - from +40 to +80 degrees. In this case, shooting is carried out "through the roof" of the front conveyor module. The automated fire control system AFCS is located in the cockpit of a tracked vehicle and allows you to hit targets with a standard mine at ranges up to 6, 5-6, 7 kilometers.
The SRAMS self-propelled mortar based on the STK Bronco tracked chassis was adopted in the first half of the 2000s and still remains the main such weapon in the Singapore army. For possible export supplies, STK carried out some modifications to the design of the combat module. In particular, there is a prototype based on the American HMMWV car, equipped with a SRAMS mortar and a lowering base plate.
Finland and Sweden
In the late nineties, the Finnish company Patria, in cooperation with the Swedish BAE Systems Hagglunds, created an original combat module for self-propelled mortars called AMOS (Advanced Mortar System - "Advanced mortar system"). He had a characteristic difference from foreign developments of a similar purpose, namely, two guns. After several years of design, testing and development, the new system entered service with the armies of Finland and Sweden.
The towers of the serial Finnish and Swedish self-propelled mortars AMOS are installed on the CV90 tracked chassis. The tower itself houses two 120-mm guns, automatic loaders and auxiliary equipment. In the advertisement for the AMOS complex, it was specifically noted that it is capable of firing ten shots in four seconds. However, the practical rate of fire of two mortars is limited to 26 rounds per minute. The rotating tower leaves no dead zones, and the inclination of the barrel block from -5 to +85 degrees allows you to shoot standard mines at a distance of up to ten kilometers. It is worth noting that at a certain stage of testing it was possible to throw ammunition at 13 kilometers, but the more powerful recoil had a bad effect on the units of the entire combat vehicle. In this regard, the maximum firing range was also limited. The fire control system allows you to calculate the guidance angles of guns, taking into account external conditions. If necessary, it provides firing in motion at a speed of no more than 25-30 km / h, but in this case, the effective range of fire is halved. If you need to hit the target in motion at a distance close to the maximum possible, there is another algorithm for calculators. When using it, all calculations are made on the move, followed by a short stop and a volley. Further, a self-propelled mortar can leave the position and continue calculations for an attack from another place.
The Finnish and Swedish armed forces have ordered several dozen AMOS self-propelled mortars and are actively using them in exercises. For export supplies, it was necessary to create a special modification of the combat module with one mortar. This tower was named NEMO (NEw MOrtar - "New mortar"). NEMO differs from the basic design only in a few details directly related to the number of weapons. It is worth noting that the single-barreled version of the Finnish-Swedish mortar, in contrast to the original system, interested foreign buyers. Orders from Saudi Arabia, the United Arab Emirates and Slovenia are already being carried out. Poland has also expressed a desire to purchase NEMO combat modules, but the contract has not yet been signed.
Switzerland
In the late nineties, the Swiss company RUAG Land Systems presented its new development called Bighorn. This combat module is a turntable with a mortar and a set of electronic equipment, designed to be installed on various types of armored vehicles. The Bighorn mortar was primarily proposed for installation on MOWAG Piranha armored personnel carriers, which determines its size, weight and recoil force.
The 120mm mortar is mounted on a turntable with a lifting mechanism and anti-rollback devices. The latter, according to official data, can reduce recoil by 50-70% compared to mortars that do not use such mechanisms. The Bighorn module is designed to be mounted in the troop compartment of any suitable armored vehicle. In this case, shooting is carried out through an open sunroof. Because of this, horizontal guidance of the mortar is possible only within a sector with a width of 90 °. The elevation angles are from +40 to +85 degrees. Loading is carried out by a semi-automatic system: the calculation feeds mines to a special tray and further loading of the ammunition into the barrel is carried out by a mechanical device. The declared maximum rate of fire is up to four rounds in 20 seconds. The maximum range when using the most powerful powder charge does not exceed 10 kilometers. The location of the fire control devices is interesting. All electronics are arranged in a small console located next to the mortar. Guidance control is performed either with a joystick or manually, using the appropriate mechanisms.
The Bighorn combat module could become the basis for several types of self-propelled mortars based on different chassis. Variants were tested based on MOWAG Piranha (Switzerland), FNSS Pars (Turkey), etc. In all cases, the advantages and disadvantages of the mortar and related systems were identified, but things did not go further than fine-tuning. In the fifteen years since the development of the Bighorn system, no country has taken an interest in it or even initiated contract negotiations. The development company continues to improve the mortar complex, but its prospects remain vague.
***
It is easy to see that in recent years, the development of self-propelled mortars has been going in accordance with two main ideas. The first of them involves the installation of platforms with weapons and electronics inside the body of existing vehicles (primarily armored personnel carriers). The result is a simple and easy-to-use mortar complex, suitable for performing all the tasks assigned to it. The second concept is much more complicated, although it implies a tangible increase in combat qualities. The capabilities of such a self-propelled mortar are growing due to the use of a full-fledged gun turret with large vertical guidance angles. Despite the obvious advantages, self-propelled mortars of the second type are unlikely to be able to completely replace combat vehicles made in accordance with the first idea. Having great firepower, "tower" mortars are seriously inferior in cost and design complexity. Therefore, over the next years, even in the most powerful and developed armies, self-propelled mortars of both types will be encountered.
