The draft of the GMM-120 mortar system was first introduced last year. 26 May in Tbilisi hosted an exhibition dedicated to Independence Day, during which defense companies demonstrated their new developments. One of the most interesting exhibits at the exhibition was the GMM-120 mortar system, which includes the artillery unit itself, a carriage and automated guidance systems with digital fire control equipment. It was argued that the new product can be used with various self-propelled platforms that have the appropriate characteristics.
A year later, the state scientific and technical center "Delta" presented the further development of the already known system. At the end of May, 2016 was shown to specialists and the general public for the first time a prototype of a self-propelled combat vehicle equipped with a GMM-120 gun. In the foreseeable future, a self-propelled mortar must pass all the necessary tests, the results of which will determine its further fate. The real prospects of the complex, however, at the moment may be the subject of controversy for one reason or another.
As a platform for the placement of weapons and auxiliary systems, the designers of Delta have chosen the commercial commercial chassis of a MAN truck. Used car bonnet layout with a three-axle chassis. The exact model of the used truck has not yet been announced. During the construction of a self-propelled mortar complex, an armored corps, an artillery system, space for the crew, etc. are mounted on the cargo chassis. The GMM-120 self-propelled mortar in the stowed position has a length of 8,4 m, a width of 2,8 m and a height of 2,8 m. The combat weight is 15 t.
Characteristics of mobility are not called, but the available information about modern truck chassis suggests that the GMM-120 combat vehicle has a fairly high mobility and is able to quickly arrive in a given area, as well as leave it after shooting. In some cases, the patency of the wheeled chassis will be sufficient even when driving on rugged power.
An interesting feature of the self-propelled mortar chassis is the lack of any means to stabilize during firing. The machine does not have jacks outriggers or other similar equipment. The absence of traditional stabilization systems is associated with the characteristics of the mortar system underlying the project. It is equipped with advanced recoil devices, which, according to the calculations of the authors of the project, should reduce the recoil impulse to the minimum values, which allow to do without additional supports.
The automobile chassis receives the original armored body, which protects the crew and internal units from small-arms bullets. weapons and light fragments. The body is divided into several main parts for different purposes. In front of the hull there is a driver’s and commander’s cabin, equipped with large bulletproof glass windows and its own side doors. Directly behind the cabin there is a small compartment with seats to accommodate the calculation of the mortar. This compartment also has its own doors, and is also connected by an opening with a fighting compartment. Above the cockpit and gunnery compartment in the hull roof there are two hatches.
The cargo platform of the chassis is given under the fighting compartment. It is made in the form of a large box-like structure with an opening roof. Most of the roof is made in the form of a hinged double hatch, the doors of which are equipped with hydraulic opening drives. The hull's stern leaf has a side opening door, under which is a small ladder that facilitates landing. In the sides of the fighting compartment there are several small windows with bulletproof glass.
The central part of the combat compartment is occupied by the GMM-120 mortar module, which was previously presented and modified for installation on a self-propelled chassis. Outwardly and in its design, this system strongly resembles some foreign developments, which may be the reason for assumptions about joint mortar design. However, officially the cooperation of Georgian designers with foreign experts is not reported.
Directly on the floor of the fighting compartment, on the cargo platform of the chassis, a round base plate of the mortar with pointing devices is installed. The plate is equipped with drives to rotate the equipment mounted on it around the vertical axis, which are responsible for the horizontal guidance of the weapon. On the swivel base there is a U-shaped support for the rocking part of the artillery system. To change the angles of vertical guidance, it is proposed to use hydraulic cylinders located near the support legs. This design means the installation of tools allows the guidance using automated electric and hydraulic systems on commands from the remote. This simplifies the work of the calculation, and also, to a certain extent, improves the accuracy of pointing.
The swinging block of the mortar system is an assembly of the barrel with the necessary equipment and recoil devices. All elements of the artillery unit are installed in an elongated body of rectangular cross section, hinged on a support and connected to the guidance hydraulics. In the housing-casing placed recoil devices, the type of which is not specified. Probably a hydraulic or hydropneumatic system is used. The task of recoil devices is to absorb the recoil momentum when firing in order to reduce the forces acting on the base chassis. Two cylinders of recoil devices are placed on the sides of the barrel.
Mortar GMM-120 has a smooth barrel caliber 120 mm. Used muzzle loading, to facilitate which the barrel is equipped with a socket. Barrel life is declared at the level of 4 thousand shots. When developing the project, it was decided to abandon any automatic loader systems. This led to a reduction in the size and weight of the structure, as well as cheaper production and operation. The authors of the project found that the calculation of the mortar, even on their own and without the help of mechanisms, will be able to provide the required rate of fire.
Mortar system GMM-120 separately from the carrier
Self-propelled mortar received automated guidance system. To the left of the gun is a rack with control devices. The gunner's console has a display and a set of various controls. The existing equipment, reportedly, allows the combat vehicle to determine its own coordinates and carry out the calculations necessary for firing. Also, with the help of automated control systems, the gunner can perform the guidance of a mortar with the required angles. It is alleged that the fire control system and communications equipment allows the commander of the GMM-120 to control the operation of his own mortar, as well as control the operation of the battery or division.
To the right of the mortar on a rotating platform is a small stowage for storing part of the ammunition used in the first place. This device is made in the form of ten vertically arranged holders-glasses in which it is proposed to place 120-mm mines. During shooting, the loaders must extract shots from this piling and send them to the barrel. Next to the piling, there is a box-like structure, which probably should perform the functions of a step when loading the trunk, raised at maximum elevation angles.
The artillery piece in the form of a carriage with automated guidance drives, control systems and mortar with recoil devices in total weighs 2 tons. In this case, some recoil devices are designed to reduce the recoil impulse acting on a commercial chassis with limited characteristics.
In the stern of the fighting compartment, in the rear corners of the hull, the GMM-120 prototype carries two ammunition racks. They are made in the form of a frame with a set of tubular restraints in which mines are placed. Such holders-glasses are located with an inclination back and are placed in five rows of five. Two such racks, as well as laying on a carriage mortar allow you to transport ammunition in 60 min. Other regular means of transporting ammunition are not provided.
As mentioned, the GMM-120 mortar is not equipped with any loading systems, because of which the crew must supply ammunition to the gun. Trained loaders should provide a firing rate of up to 15 shots per minute. This allows the combat vehicle to spend the entire ammunition load in a matter of minutes, inflicting the greatest possible damage to the enemy, then leaving the position without waiting for a retaliatory strike.
Due to the change in the charge of mines and the angle of elevation of the barrel, the firing range can vary within fairly wide limits. The minimum firing range of the 120-mm mine is 480 m, the maximum is declared at the level of 7100 m.
To manage the work of all systems of the new self-propelled mortar must crew of six people. One of them is the driver, the rest are responsible for the operation of the mortar system. For the guidance of weapons responsible commander, also operating the communication system. Other crew members must perform various tasks, primarily to load weapons.
The GMM-120 self-propelled mortar armor is able to protect the crew, weapons and various units from enemy small arms or debris. In addition, the project provides for the use of other means of self-defense. On the roof of the cab, in front of the upper hatch, is a turret with a large-caliber machine gun. Using this weapon, the crew can attack targets in the front hemisphere and effectively counteract manpower or unprotected enemy equipment. On the prototype, shown at the end of May at the exhibition in Tbilisi, the turret was equipped with a 12,7-mm NSVT machine gun.
View from the gunner's workplace
In the proposed form, the GMM-120 self-propelled mortar project looks quite interesting. Scientific and Technical Center "Delta" managed to create a curious and modern look of self-propelled artillery on a wheeled chassis. The main features of the project allow us to expect to achieve a sufficiently high combat performance. However, for obvious reasons, the project may face serious difficulties of one kind or another.
In case of successful completion of the project, a successful combat vehicle may appear, able to quickly reach the firing position, quickly determine its location and calculate the guidance angles, and then begin to fire the target from a distance of several kilometers. After completing the fire mission, the crew can quickly collapse the complex and leave the position. One of the main factors affecting both the combat qualities and the mobility of equipment are anti-recoil devices, which have made it possible to do without additional supports. In the case of using other, traditional ideas and solutions, the tactical and technical characteristics of the machine could look different.
Of particular interest is the maximum automation of all major processes. With the help of control systems and mechanical drives, it is proposed to perform various operations, first of all, the guidance of an instrument. However, it should be noted that on the GMM-120 prototype, manual guidance systems are not visible, and this may indicate a lack of duplication of fixed assets with negative operational consequences. In the event of problems with hydraulics or electric equipment, the crew may lose the possibility of further pointing weapons, which will thwart the performance of a combat mission.
The study of available materials shows that the prototype of a self-propelled mortar presented at a recent exhibition is not of high build quality and sophisticated design. The individual elements of the GMM-120 look show that the authors of the project are only working on them and have not finally decided on the design. However, such features of the prototype can not be considered the shortcomings of the project as a whole. Rather, they may be the reason for claims to the developers or to the leadership of the industry, who have decided to send a “raw” sample to the exhibition, which has not yet passed the entire cycle of tests and refinement.
There are questions about the prospects of the original Georgian project. GMM-120 self-propelled mortar may be of interest to various customers, both for the Georgian army and for the armed forces of third countries. However, the state of the Georgian industry and some other factors may exclude the possibility of the emergence of contracts for the supply of new equipment. Since the beginning of this decade, several variants of military equipment for various purposes have been created by the efforts of the Georgian industry, but these developments are not in particular demand from their own army or other states. Some samples have already entered mass production, while others have remained in the form of several prototypes.
The project GMM-120 self-propelled mortar, developed by the Delta Scientific-Technical Center, proposed several interesting and promising ideas. Their successful implementation will allow to present a promising model of self-propelled artillery with rather high characteristics. Nevertheless, the project has so far managed to reach only the stage of construction of a prototype, which, apparently, only recently came to the test and has not yet passed all the necessary checks. Only the successful completion of the tests and the necessary improvement of the project will allow to draw full conclusions about the new development. Whether the project's authors succeed in fully implementing all the proposals and solving the tasks posed, time will tell.
On the materials of the sites:
Detailed photo review of the prototype: