All artillery guns of traditional schemes, including mortars, make a certain noise when firing, and also "demonstrate" a large muzzle flash. Loud gunshots and flames can unmask the position of the weapon and make it easier to retaliate. For this reason, troops may be interested in special samples of weapons, characterized by a reduced shot volume and the absence of a flash. In the early eighties, one of the Soviet research institutions proposed an original project for a light mortar with similar capabilities.
According to known data, at the turn of the seventies and eighties, Soviet scientists and designers from several organizations of the defense industry were working on the issues of reducing the noise of artillery, including light portable systems. Together with other institutions, this topic was studied by the State Research Artillery Range (GNIAP). In the early eighties, his employees proposed an original solution to the problem, and soon a ready-made sample of a silent mortar appeared.
An experimental mortar with unusual capabilities was created and submitted for testing in 1981. It was created by a group of designers from GNIAP under the leadership of V. I. Koroleva, N. I. Ivanov and S. V. Zueva. Due to its specific role, the project did not receive any designation or index of its own. It is known by its simplest name - "60-mm silent firing mortar". It should be noted that this name fully revealed the essence of the project.
The problem of noise reduction and flash elimination turned out to be quite complex, which affected the ways of its solution. In the new project, it was necessary to create new mortar designs and mines for it, seriously different from the existing ones. So, it was proposed to get rid of the flash and shock wave at the expense of the so-called. locking powder gases inside the ammunition. To work properly with such a mine, the weapon had to combine the main features of the barrel and column mortars. At the same time, it was planned to use solutions uncharacteristic for domestic weapons in the design of the mortar.
GNIAP specialists proposed an original design of the weapon, even outwardly different from other domestic models of its class. First of all, the "unitary barrel" scheme was used, which was rarely used in Soviet practice. It was proposed to mount the barrel only on the appropriate attachments of the base plate, while there was no biped for additional support on the ground. There were also internal differences due to the need to use a special mine.
The main part of the new mortar was the barrel of a special design. Used a 60 mm smooth barrel with a length of 365 mm. The new mine did not create high pressure inside the barrel, which allowed a reasonable reduction in its length, strength and, consequently, weight. The breech was made in the form of a separate part, including a glass for installing the barrel and a ball bearing for fastening to the "gun carriage". On the front of the breech was a relatively strong rod with a diameter of 20 mm. The breech also contained the details of a simple firing mechanism.
The absence of the bipod affected the design of the base plate and related parts. The barrel and the plate were connected using the so-called. attachment and guidance unit - in fact, a compact upper machine, similar to those used on artillery carriages. This design provided horizontal and vertical guidance of the barrel. The elevation angle varied from + 45 ° to + 80 °. In the horizontal plane, the "gun carriage" with the barrel moved within a sector 10 ° wide. If it was necessary to transfer the fire to a greater angle, the entire mortar would have to be moved.
The base plate of the silent mortar was made in the form of a disk with a diameter of 340 mm with a set of protrusions and various devices on the upper and lower surfaces. There was a side ledge on top of the plate, and a hinge was provided in the center for installing the attachment point. Below on the plate were several rounded protrusions, under which there were small openers in the form of vertical metal discs of small diameter. Such a slab design could provide sufficient penetration into the ground and effective transfer of the recoil momentum.
On the central part of the slab there was a rotary attachment and guidance unit. The axle was in direct contact with the plate, above which there was a holder for the ball bearing of the barrel. A rack was provided at the back above the clip for mounting some aiming mechanisms. Also, the attachment point had a pair of side parts of a complex shape that protected other devices from external influences.
Horizontal guidance should be performed by turning the barrel and the attachment point around the vertical axis. Separate drives or mechanisms were not used for this. For vertical guidance, the designers used a simple screw mechanism. It consisted of a stationary tube with an internal thread, fixed at the rear on the support of the attachment unit, and an internal screw. The latter was pivotally connected to a collar on the breech of the barrel. Turning the screw around the longitudinal axis led to its translational movement, and at the same time to the inclination of the barrel.
The 60-mm silent-firing mortar was an exclusively experimental model and was intended for conducting experiments, which affected the composition of its equipment. So, the mortar did not have any sighting devices. Moreover, the project did not even provide for the use of mounts for the sight. The designers of GNIAP were interested in noise issues, and therefore there were no special requirements for shooting accuracy.
According to known data, the mortar was made collapsible. For transportation, it could be divided into three parts: the barrel, the attachment and aiming unit, and the base plate. However, even without this, the experienced weapon had acceptable ergonomics, which provided a certain ease of portability and operation. The possibility of disassembly could come in handy in the further development of the project with the subsequent receipt of the mortar into service.
The experimental mortar was distinguished by its small dimensions and weight. The maximum height of the product, at an elevation angle of 85 °, did not exceed 400 mm. The length and width in this case were determined by the diameter of the base plate - 340 mm. The mass in the firing position is only 15.4 kg. At the same time, a significant part of the mass fell on a large and heavy base plate. A crew of two could service the weapon.
A special ammunition was developed for the new mortar. In the design of this mine, the principles of a stick ammunition and locking of powder gases were used. These decisions led to the fact that the new mine externally significantly differed from the "traditional" ammunition. At the same time, despite all the innovations, the product had a fairly simple design with acceptable characteristics.
The mine received a head with a cylindrical body with a diameter of 60 mm, complemented by a conical fairing. This body was supposed to contain an explosive charge weighing hundreds of grams. At the back, a tubular tail with a tail was attached to the body. The shank was made hollow: a propelling charge was placed in its front part, immediately behind which was a special movable piston. The shank channel was made in such a way that the mortar rod could enter into it, and the piston could move freely, but was decelerated in the rear position.
A mine for a 60-mm silent-firing mortar had a total length of about 660 mm and was noticeably longer than the barrel. As a result, when loading, a significant part of the body protruded in front of the muzzle. This design feature gave the charged mortar a characteristic appearance. At the same time, the weapon did not need a separate indicator of the presence of a mine in the barrel - these functions were performed by the ammunition itself.
The combination of the units of the barrel and mortar mortars, as well as the use of locking the powder gases, led to the obtaining of a specific principle of operation of the weapon. Preparing a mortar for a shot was not difficult. The mine should have been placed in a mortar from the muzzle. At the same time, the stabilizer on the shank provided centering and allowed the shank to be put on the stem inside the barrel. After shifting the mine to the rearmost position with the stabilizer resting on the breech, the weapon was ready to fire.
The use of the trigger led to the displacement of the striker and the ignition of the propellant charge inside the mine. The expanding powder gases were supposed to press on the movable piston inside the shank, and through it interact with the mortar rod. The piston remained stationary relative to the weapon, while the mine accelerated and left the barrel. The movable part inside the shank was inhibited in the extreme rear position, as a result of which the gases were trapped inside the mine. Thanks to this, the formation of a muzzle flash and a shock wave responsible for the noise of a shot was excluded.
According to known data, in 1981, GNIAP specialists assembled an experienced silent mortar and sent it to the shooting range for verification. Unfortunately, there is no information about the fire characteristics of this product. Apparently, a 60-mm mine of a special design could fly at a distance of at least several hundred meters, and the limited volumes of its warhead did not allow a high explosive or fragmentation effect to be obtained. However, the goals of the project were different - the designers planned to determine the real prospects for the unusual architecture of weapons and ammunition.
Some sources mention that the 60-mm mortar from GNIAP actually showed a sharp reduction in the loudness of the noise of the shot. The presence of moving metal parts did not exclude some clanging, but the absence of a muzzle shock wave significantly reduced the overall noise during firing. In the conditions of the landfill, it was possible in practice to confirm the correctness of the applied ideas.
An experimental 60mm silent firing mortar proved its capabilities and demonstrated the potential of the new weapon architecture. If there was a corresponding order from the army, the proposed concept could be developed and lead to the appearance of a full-fledged mortar. However, the potential customer was not interested in the proposed ideas, and work on all topics stopped for a long time.
Fortunately, the original principles of the silent mortar have not been forgotten. In the middle of the last decade, the Nizhny Novgorod Central Research Institute "Burevestnik" took up this topic. As part of the development work with the Supermodel code, this organization has developed a new lightweight 50 mm mortar designed for the use of special mines with locking gases. The finished mortar 2B25 "Gall" was presented at the end of the 2000s, and then, after some refinement, it was offered to future customers.
The 2B25 mortar has a lightweight barrel with an internal rod for interaction with the mine shank. The shot for "Gall" also uses the basic ideas and solutions of the 1981 project. At the same time, the modern silent mortar received other guidance means and a base plate, more similar to the "traditional" units from other domestic projects.
For the solution of special tasks, troops may need special weapons - for example, silent mortars. At the same time, such weapons are highly specialized and have serious limitations of various kinds. Probably, it is for this reason that the 60-mm silent-firing mortar from the Main Research Artillery Range remained an experimental model and did not receive further development. However, the original ideas were not forgotten and still applied in a new project, even after a quarter of a century.
