The tank's fire control system is one of the main systems that determine its firepower. LMS have gone through an evolutionary path of development from the simplest optical-mechanical sighting devices to the most complex devices and systems with widespread use of electronic, computing, television, thermal imaging and radar technology, which led to the creation of integrated tank information and control systems.
The OMS of the tank should provide:
- visibility and orientation on the ground for crew members;
- all-day and all-weather search and target detection;
- precise determination of meteorological ballistic data and their accounting when firing;
- the minimum time for preparing a shot and effective firing from the spot and on the move;
- well-coordinated and duplicated work of the crew members to search for and defeat targets.
The LMS consists of many constituent elements that solve a certain range of tasks. These include optical-mechanical, optical-electronic, electronic, radar means of searching and detecting targets, systems for stabilizing the field of view of sights and weapons, equipment for collecting and recording weather ballistic data for shooting, computers for calculating the angles of aiming and lead, means of displaying information to members crew.
Naturally, not all of this immediately appeared on the tanks, they were gradually introduced as they were needed and the level of technology development. In reality, the LMS on Soviet and foreign tanks appeared only in the 70s, before that they had gone a long way of their development and improvement.
First generation observation and aiming devices
On foreign and Soviet tanks of the period of the Great Patriotic War and the first post-war generation of tanks, there was no control system, there was only a set of simple observation devices and sights, which ensured firing from the tank only during the day and only from the spot.
Almost all observation devices and sights of this generation were developed by the Central Design Bureau of the Krasnogorsk Mechanical Plant (Central Design Bureau KMZ).
The composition and comparative characteristics of the sighting devices of Soviet and German tanks of this period are detailed in Malyshev's article (Courage 2004 website).
What were the sighting devices of Soviet tanks? Until 1943, three types of the simplest optical-mechanical sighting devices were installed.
A telescopic sight TOP and its modifications TMPP, TMPP-1, TMPD-7, T-5, TOD-6, TOD-7, TOD-9, YuT-15 with optical characteristics - magnification 2, was attached to the gun parallel to the axis of the cannon barrel bore. 5x with a field of view of 15 degrees. It allowed direct fire during the day only from a place or from short stops. Searching for targets and shooting on the move was almost impossible. Determination of aiming angles and lateral lead was carried out on sighting scales.
Telescopic sight TOP
Due to the fact that the sight was rigidly connected to the gun, during its movement in the vertical plane, the gunner had to track the movement of the gun with his head.
The PT-1 panoramic periscope sight and its modifications PT4-7, PT4-15 were installed in the turret of the tank and provided direct fire. The optics of the sight had the ability to magnify by 2, 5x with a field of view of 26 degrees, and the sight head rotating horizontally provided a circular view. In this case, the position of the gunner's body did not change. With a fixed position of the sight head parallel to the cannon, the gunner could use this sight to fire from the cannon.
On the basis of the PT-1 sight, the PTK command panorama was developed, which outwardly practically does not differ from the sight, providing an all-round view and target designation to the gunner when the sight head rotates along the horizon.
Periscopic sight PT-1
Modifications of these sights were installed on T-26, T-34-76, KV-1 tanks. On the T-34-76 tank, a TOD-7 (TMFD-7) telescopic sight was mounted on the gun and a PTK panorama was mounted on the roof of the tower. The set of sights fully corresponded to the requirements of that time, but the crew was not able to use them correctly.
The T-34-76 tank suffered from poor visibility for the commander and the complexity of using instruments. This was explained by several reasons, the main one being the absence of a gunner in the crew and the combination of his functions by the commander. This was one of the most unfortunate decisions in the concept of this tank. In addition, the commander did not have a commander's cupola with viewing slots and a set of observation devices for a circular view, and there was an unsuccessful layout of the commander's workplace. The PTK panorama was placed on the back right and the commander had to turn to work with it.
With a 360-degree rotating head, there was a large dead zone due to poor placement on the tower. The rotation of the head along the horizon was slow due to the mechanical drive, which the commander controlled using the handles on the body of the device. All this did not make it possible to fully use the PTK panoramic device and it was replaced with a PT4-7 panoramic sight.
German tanks on telescopic sights associated with the gun had an optical hinge, the eyepiece of the sight was attached to the tank turret, the gunner did not have to twitch after the gun. This experience was taken into account, and in 1943 the telescopic articulated sight TSh with a magnification of 4x with a field of view of 16 degrees was developed and introduced. Subsequently, a number of modifications of this sight were developed, which began to be installed on all Soviet tanks T-34-85, KV-85, IS-2, IS-3.
TSh articulated sights have eliminated the disadvantages of the TOP series telescopic sights. The head part of the TSh sight was rigidly connected to the gun, which eliminated errors in the transfer of angles from the gun to the sight, and the eyepiece of the sight was attached to the tower and the gunner no longer needed to track the movement of the gun with his head.
Telescopic articulated sight TSh
Also, a technical solution was used, applied on the English Mk. IV. On this basis, a rotating observation device MK-4 was created, with a turn angle in the horizontal plane of 360 degrees. and pumping vertically upwards 18 degrees. and down 12 degrees.
On the T-34-85 tank, many shortcomings were eliminated, a fifth gunner was introduced, a commander's cupola was introduced, a TSh-16 telescopic sight, a PT4-7 (PTK-5) periscope sight and three MK-4 all-round periscopes were installed. The telescopic sight PPU-8T was used for firing from a course machine gun.
The sights of the TSh series still had a drawback, when the gun was brought to the loading angle, the gunner lost his field of view. This drawback was eliminated by the introduction of weapon stabilizers on the tanks. In the sights of the TSh series, "stabilization" of the field of view was introduced due to an additional optical attachment, the mirror of which was controlled by a signal from the gyro unit of the gun stabilizer. In this mode, the field of view of the gunner's sight retained its position when the gun went to the loading angle.
On the post-war generation of the T-54, T-10, T-55, T-62 tanks, the sights of the TShS series (TShS14, TShS32, TShS41) were used as the gunner's sights, providing a "stabilization" mode.
Telescopic articulated sight TShS
Weapon stabilizers
With the increase in the caliber of the guns and the mass of the turret of the tank, it became problematic to control the armament manually, and the adjustable electric drives of the gun and turret were required. In addition, it became necessary to provide fire from a tank on the move, which was impossible on any tank. To do this, it was necessary to ensure both the stabilization of the field of view of the sights and the stabilization of weapons.
The time has come for the introduction of the next element of the FCS on the tanks - stabilizers, which ensure the retention of the field of view of the sight and weapons in the direction specified by the gunner.
To this end, in 1954, the Central Research Institute of Automation and Hydraulics (Moscow) was appointed the head of the development of tank stabilizers, and the production of stabilizers was organized at the Kovrov Electromechanical Plant (Kovrov).
At TsNIIAG, the theory of tank stabilizers was developed and all Soviet stabilizers for tank armament were created. Subsequently, this series of stabilizers was improved by VNII Signal (Kovrov). With the increased requirements for the effectiveness of firing from a tank and the complication of the tasks being solved, TsNIIAG was appointed head of the development of tank fire control systems. TsNIIAG specialists developed and implemented the first Soviet full-format MSA 1A33 for the T-64B tank.
Considering the stabilization systems for tank armament, it should be borne in mind that there are one-plane and two-plane (vertical and horizontal) stabilization systems with dependent and independent stabilization of the sight field of view from the gun and the turret. With independent stabilization of the field of view, the sight has its own gyro unit; with dependent stabilization, the field of view is stabilized together with the gun and the turret from the gyro unit of the weapon stabilizer. With dependent stabilization of the field of view, it is impossible to automatically enter the aiming and lateral lead angles and keep the aiming mark on the target, the aiming process becomes more complicated, and the accuracy decreases.
Initially, automated electric drive systems for tank turrets were created, and then guns with smooth speed control in a wide range, which ensured accurate gun guidance and target tracking.
On the T-54 and IS-4 tanks, the EPB turret electric drives began to be installed, which were controlled using the KB-3A controller handle, while providing both smooth aiming and transfer speeds.
The further development of the turret and gun electric drives was the more advanced automated electric drives TAEN-1, TAEN-2, TAEN-3 with electric machine amplifiers. The weapon aiming speeds in the horizontal plane were (0.05 - 14.8) deg / s, along the vertical (0.05 - 4.0) deg / s.
The commander's target designation system allowed the tank commander, when the gunner's drive was turned off, to direct the gun at the target horizontally and vertically.
Telescopic sights of the TShS family were installed on tanks of the post-war generation, the head part of which was rigidly attached to the gun and no gyroscopic units were installed in them to stabilize the field of view. For independent stabilization of the field of view, it was necessary to create new periscopic sights with gyro assemblies, such sights did not exist then, therefore the first Soviet stabilizers were with dependent stabilization of the field of view.
For this generation of tanks, weapon stabilizers with dependent stabilization of the field of view were developed: single-plane - "Horizon" (T-54A) and two-plane - "Cyclone" (T-54B, T-55), "Meteor" (T-62) and " Zarya "(PT-76B).
A three-degree gyroscope was used as the main element holding the direction in space, and the cannon and the tower, using a drive system, were brought to a position coordinated with the gyroscope in the direction specified by the gunner.
The single-plane stabilizer STP-1 "Horizon" of the T-54A tank provided vertical stabilization of the gun and telescopic sight using a gyro unit located on the gun and an electro-hydraulic gun drive, including a hydraulic booster and an executive hydraulic cylinder.
Unstable control of the turret was carried out by an automated electric guidance drive TAEN-3 "Voskhod" with an electric machine amplifier, providing a smooth guidance speed and a transfer speed of 10 deg / s.
The gun was guided vertically and horizontally from the gunner's console.
The use of the "Horizon" stabilizer made it possible, when firing on the move, to ensure the defeat of a standard target 12a with a probability of 0.25 at a distance of 1000-1500 m, which was significantly higher than without the stabilizer.
The two-plane weapon stabilizer STP-2 "Cyclone" for the T-54B and T-55 tanks provided vertical stabilization of the gun and the tower horizontally using two three-degree gyroscopes mounted on the gun and the turret. An electro-hydraulic stabilizer of the gun from the stabilizer "Horizon" was used vertically, the stabilizer of the tower was made on the basis of an electric machine amplifier used in the TAEN-1 electric drive.
The use of a two-plane stabilizer "Cyclone" made it possible, when firing on the move, to ensure the defeat of a standard target 12a with a probability of 0.6 at a distance of 1000-1500 m.
The obtained firing accuracy on the move was still insufficient, since the power stabilizers of the gun and turret did not provide the required accuracy of stabilization of the sight field of view due to the large moments of inertia, imbalance and resistance of the gun and turret. It was necessary to create sights with their own (independent) stabilization of the field of view.
Such sights were created and on the T-10A, T-10B and T-10M tanks were installed periscopic sights with independent stabilization of the sight field of view, and a new generation of weapon stabilizers was introduced: the single-plane "Uragan" (T-10A) with independent stabilization of the field of view by vertical and two-plane "Thunder" (T-10B) and "Rain" (T-10M) with independent stabilization of the field of view along the vertical and horizon.
For the T-10A tank, the TPS-1 periscope sight was first developed with independent vertical stabilization of the field of view. For these purposes, a three-degree gyroscope was installed in the sight. The connection of the sight gyroscope with the gun was provided through the gyroscope position angle sensor and the parallelogram mechanism. The optics of the sight provided two magnifications: 3, 1x with a field of view of 22 degrees. and 8x with a field of view of 8, 5 degrees.
Periscopic sight TPS-1
The single-plane electro-hydraulic stabilizer of the Uragan cannon ensured the stabilization of the gun according to the mismatch signal from the gyroscope angle sensor of the TPS-1 sight relative to the direction set by the gunner. Semi-automatic guidance of the tower along the horizon was provided by the TAEN-2 electric drive with an electric machine amplifier.
For the T-10M tank, a T2S periscope sight was developed with an independent two-plane stabilization of the field of view with optical characteristics similar to the TPS-1 sight. The sight was equipped with two three-degree gyroscopes, which ensure the stabilization of the sight's field of view vertically and horizontally. The connection between the sight and the gun was also provided by a parallelogram mechanism.
Periscopic sight Т2С
The two-plane stabilizer "Liven" provided stabilization of the gun and the turret according to the mismatch signal from the sight gyroscope angle sensors relative to the direction set by the gunner with the help of servo drives, an electro-hydraulic gun and an electric machine turret.
The T2S sight had automatic aiming angles and lateral lead. The aiming angles were entered according to the measured range to the target and taking into account its movement, and the automatic pre-emption, when firing at a moving target, automatically set a constant lead, and before firing the gun was automatically adjusted to the aiming line at the same speed, as a result of which the shot took place with one and the same lead
The introduction of a sight with independent stabilization of the field of view vertically and horizontally and a two-plane stabilizer of weapons made it possible to improve the conditions for searching for targets, observing the battlefield while the tank was moving, ensured the detection of targets at a distance of up to 2500 m and effective firing, since the gunner had only to keep the aiming mark on the target, and the system automatically entered the aiming and lead angles.
Tanks T-10A and T-10M were produced in small series and sights with independent stabilization of the field of view on other tanks, for various reasons, were not widely used. They returned to such a sight only in the mid-70s when creating the LMS 1A33.
The introduction of scopes with independent stabilization of the field of view and weapon stabilizers, however, did not provide the required efficiency of firing from a tank on the move due to the lack of a range finder to accurately measure the range to the target, the main parameter for the precise development of aiming and lead angles. The base-on-target range was too rough.
An attempt to create a radar tank rangefinder was unsuccessful, since on rough terrain using this method it was difficult to isolate the observed target and determine the range to it. The next stage in the development of the LMS was the creation of optical base rangefinders.
