The main parameter affecting the accuracy of firing is the accuracy of measuring the range to the target. On all Soviet and foreign tanks of the post-war generation, there were no rangefinders in the sights, the range was measured using a rangefinder scale using the "base on target" method at a target height of 2, 7 m. This method led to large errors in measuring the range and, accordingly, to low determination accuracy aiming angles and lateral lead.
Laser rangefinders did not yet exist and technically it was only possible to create optical base rangefinders, which provided for two exit windows for optics on the tank turret, spaced as far apart as possible. The use of such rangefinders led to a significant decrease in the protection of the tower, but this had to be reconciled.
For the T-64 tank (1966), a TPD-2-49 optical rangefinder sight was developed with a stereoscopic range measurement method based on combining two halves of the image. The sight had an optical base of 1200mm (1500mm), a pancratic (smooth) change in magnification up to 8x, the base tube was connected to the sight by a parallelogram mechanism. The optical rangefinder made it possible to measure the range to the target in the range (1000-4000) m with an accuracy of (3-5)% of the measured range, which was higher than when measuring the range by the "base on target" method, but insufficient for accurate determination of angles aiming and anticipation.
Rangefinder sight TPD-2-49
A three-degree gyroscope was installed in the sight, providing independent stabilization of the vertical field of view. The connection of the sight gyroscope with the gun was provided through the gyroscope position angle sensor and the parallelogram mechanism. On the horizon, the sight's field of view was with dependent stabilization from the turret stabilizer.
Two-plane stabilizer 2E18 (2E23) "Lilac" provided vertical stabilization of the gun according to the mismatch signal from the gyroscope angle sensor of the TPD-2-49 sight relative to the direction set by the gunner and stabilization of the tower using a three-degree gyroscope installed in the tower. The gun was guided vertically and horizontally from the gunner's console.
The cannon and the turret were controlled using electro-hydraulic drives, as actuating elements in the gun drive there was a hydraulic booster and a hydraulic power cylinder, and in the tower drive a high-torque gyro motor installed in the tank hull.
The use of a sight with independent vertical field of view stabilization made it possible to calculate the aiming angle from the measured range and automatically enter it into the vertical gun drive, taking into account the tank's own stroke, determined using a tank speed sensor and a cosine potentiometer, which fixes the position of the turret in relation to the tank hull. The sight was provided for blocking the shot in case of an unacceptable vertical misalignment of the aiming line and the axis of the cannon bore.
The angle of lateral lead when firing at a moving target along the measured range was determined by sighting scales and entered by the gunner before firing.
The system allowed the commander to give the gunner target designation along the horizon with a transfer speed from the button on the handle of the TKN-3 commander's observation device and block the rotation of the turret with the driver's hatch open, as well as to make an emergency turn of the tower from the driver's button.
The TPD-2-49 sight and the Lilac stabilizer became the basis of the gunner's sighting system on the T-64A, T-72 and T-80 tanks and ensured effective firing when firing on the spot.
It should be noted that if the sights and observation devices of the gunner on Soviet tanks went through a certain path of evolutionary development, then the improvement of the commander's devices slowed down for a long time and did not go far from the level of the devices of the Great Patriotic War.
The unsatisfactory results of the use of the panoramic PTK device by the gunner-commander of the T-34-76 tank due to its poor placement and rather mediocre characteristics slowed down the creation of effective instruments for the tank commander for a long time. The development of commander's instruments followed the path of improving the MK-4 observation device; the commander's panorama was forgotten for many years.
In the early 50s, a daytime periscopic binocular observation device for the commander TPKU-2B with a magnification of 5x was developed, intended for observing the terrain, searching for targets and targeting the gunner. The device was pumped vertically from -5 deg. up to +10 deg. and rotated along the horizon 360 degrees. together with the commander's hatch.
To operate at night, the TPKU-2B device is replaced with a monocular device for the commander TKN-1 with an image converter, which provides in an "active" mode with an 0U-3G IR illuminator with a night vision range of up to 400 m. These devices were equipped with T- tanks. 54, T-55, T-10.
To replace the TKN-1 in 1956, a combined day-night binocular observation device for the commander TKN-3 was created, providing an increase in the day channel with a magnification of 5x and the night channel 3x. The night channel worked only in the "active" mode with the same range of up to 400 m, guidance along the horizon was carried out manually by turning the commander's hatch, and horizontally manually by tilting the body of the device. The TKN-3 device was used for the T-55, T-62, T-72, T-64, T-80 tanks.
In the 1980s, with the advent of 3rd generation image intensifier tubes, the TKN-3M device was developed, which provides a range of 400 m in passive mode and 500 m in active mode.
On the T-64A tank in 1972, following the results of the Arab-Israeli wars, the Utes anti-aircraft gun was introduced, providing the commander with firing at ground and air targets from a 12.7 mm remote-controlled machine gun with the commander's hatch closed through the PZU-5 periscope sight field of view 50 deg.
In the early 60s, a panoramic sight 9Sh19 "Sapphire" with two-plane independent stabilization of the field of view was developed for a missile tank with the Typhoon complex (object 287). Prototypes were made and tested as part of the tank. A tank with such weapons was not accepted for service, unfortunately, work on a panoramic sight was discontinued and the groundwork was not used in any way to develop a panorama of the commander for the main tanks.
In the mid-70s, an attempt was made to create a commander's panoramic sight with two-plane stabilization of the field of view to modernize the sighting complex of the T-64B tank commander as part of work to improve the 1A33 MSA, but the Central Design Bureau KMZ, the lead developer of sights, mainly for organizational reasons, did not develop a panorama completed. The obtained technical groundwork for the commander's sighting complex was used to create the FCS of the T-80U tank.
In this regard, a decent panoramic sight of the commander did not appear on Soviet tanks; the commander's primitive observation devices remained on all Soviet tanks and are still installed on certain modifications of Russian tanks.
Also, no steps were taken to integrate the gunner's sights and commander's observation devices into a single fire control system, they existed as if by themselves. The commander on Soviet tanks could not provide duplicate fire control instead of the gunner, and this was only provided when creating the FCS of the T-80U tank.
At the first stage, tank sights solved the problem of firing only during the day, and with the advent of a new element base in the form of electro-optical converters (EOC) in the infrared range, it became possible to create sights that ensure the crew's work at night. The basis for the creation of the first generation night vision scopes was based on the principle of target illumination with an IR illuminator, and a visible image was formed from the signal reflected from the target. Such sights worked only in the "active" mode and naturally unmasked the tank.
In 1956, the first TPN-1 gunner's tank night sight was created, which was installed on all Soviet tanks of this generation. The TPN-1 sight was a monocular periscope device with an electro-optical converter, with a magnification factor of 5, 5x and a field of view of 6 degrees, providing a range of vision at night up to 600 m when illuminated by an L2G searchlight. Various modifications of the sight were installed on T-54 tanks, T-55, T-10.
With the development of a new generation of highly sensitive image intensifier tubes, it became possible to create a sight for work in a "passive" mode. In 1975, the TPN-3 "Crystal PA" night sight was adopted, operating in passive-active mode and providing a range in passive mode of 550 m and in active mode of 1300 m. These sights were equipped with T-64, T-72 and T-80.
The development of the LMS elements on German and American tanks of this generation proceeded in approximately the same direction as on Soviet ones. Unstabilized sights, optical rangefinders, and weapon stabilizers appeared later on the tanks. On the American M-60 tank, the rangefinder sight was installed not by the gunner, but by the commander, in connection with which the commander was overloaded with the process of measuring the range to the target and was distracted from performing his main duties. On the first modifications of the M60 (1959-1962), the commander installed a periscope monocular sight-rangefinder M17S with an optical base of 2000 mm and a 10x magnification in the tower of the commander, which ensures the measurement of the range to the target (500 - 4000) m.
In the commander's cupola, a periscopic binocular sight XM34 was installed (could be replaced with a night sight) with a magnification of 7x with a field of view of 10 °, which was intended to monitor the battlefield, detect targets and fire from a machine gun at ground and air targets.
For firing, the gunner had two sights, the main M31 periscope sight and the M105S auxiliary telescopic articulated sight. The sights had a pancratic (smooth) magnification up to 8x.
For firing from a coaxial machine gun, the M44S sight was used, the reticle of which was projected into the field of view of the M31 gunner's main sight. In one case with the main sight, a night sight was combined, operating in an "active" mode.
The loader had a prismatic observation device of circular rotation M27.
The tank had a mechanical ballistic calculator (adding machine) M13A1D, similar to the calculator on the M48A2 tank, connected by an M10 ballistic drive with the commander's rangefinder sight and the gunner's periscope sight. The calculator automatically set the gunner's sight reticle and rangefinder sight to the position corresponding to the measured range. Due to the complexity of its use and unreliability, the crew practically did not use it.
On the modification of the M60A1 tank since 1965, the M13A1D mechanical ballistic computer was replaced by the M16 electronic ballistic computer, taking into account the data of the rangefinder sight.
On the first modifications of the tank, the gun was not stabilized, it was controlled by manual drives or from the gunner's and commander's consoles with the help of electrohydraulic drives, which ensure a smooth pointing speed of the gun in the vertical and horizon and transfer speed along the horizon. A two-plane weapon stabilizer with dependent stabilization of the field of view was introduced with the M60A2 modification (1968).
On the German Leopard tank, produced since 1965, the approach to the commander and gunner's sighting complexes was completely different. The optical sight-rangefinder was installed by the gunner, and the commander had a panoramic periscope sight with an unstabilized 360-degree rotating periscope for visibility and search for targets. sight head.
As the main sight for firing from a cannon and a coaxial machine gun, the gunner had a TEM-1A optical rangefinder sight with two magnifications of 8x and 16x, providing range measurements using a stereoscopic method with a base optical tube 1720 mm long. In addition to the main sight, the gunner had a reserve sight TZF-1A with a magnification of 8x, installed in the mask to the right of the gun. On the modification of the Leopard A4 tank, the TZF-1A sight was replaced with the FERO-Z12 telescopic articulated sight.
The commander had an unstabilized panoramic sight TRP-1A with a horizontally rotating head and pancratic (smooth) magnification (6x - 20x). On the modification of the Leopard A3 (1973), an improved panoramic monocular sight of the commander TRP-2A was installed, the pancratic magnification range became (4x - 20x). The TRP-2A sight could be replaced with a night sight, operating in an "active" mode and providing a night vision range of up to 1200 m.
The gun on the Leopard tank was not stabilized and was controlled from the gunner's and commander's consoles using electro-hydraulic drives along the vertical and horizon, similar to the M60 tank. Since 1971, a two-plane weapon stabilization system with dependent stabilization of the sight field of view began to be installed on the Leopard A1 modification.
The development of the elements of the fire control system of Soviet and foreign tanks of this generation took place in the same direction. Improved observation devices and sights were introduced, an optical rangefinder was installed, sights with independent vertical field of view stabilization and weapon stabilizers began to be introduced. The first sights with independent field of view stabilization were introduced on the Soviet T-10 and T-64 tanks, the first weapon stabilizers were also introduced on the Soviet T-54, T-55, T-10, T-64 tanks.
They were introduced on German and American tanks somewhat later. On foreign tanks, serious attention was paid to creating a set of perfect optical sights with the possibility of duplicating them and providing the tank commander with conditions for a circular view and search for targets. Of the tanks of this generation, the Leopard tank, with the use of the commander's panorama, had the most optimal set of sights and observation devices for the crew members, which ensured them effective work in finding targets and firing, and which subsequently made it possible to create the most advanced FCS of the tank.
It should be noted that foreign tanks of this generation had more advanced night vision devices, providing a greater range of vision at night. In addition, they were immediately developed in the same design as daytime appliances. On Soviet tanks, the gunner's night sights were developed and installed in the tank as independent devices, which complicated the layout of the tank's fighting compartment and led to the inconvenience of the gunner with two sights.
None of the Soviet and foreign tanks of this generation had an integrated fire control system, there was only a set of sights, instruments and systems that solved certain tasks. The next stage in the development of the FCS elements was characterized by the introduction on main battle tanks of sights with independent stabilization of the vertical and horizontal field of view, laser rangefinders and tank ballistic computers.
