In the USSR, after the Second World War, work intensified on the development and creation of new models of military equipment and weapons, landing equipment and transport aircraft for the Airborne Forces. The development of combat vehicles for the airborne assault also acquired a new direction. Prior to that, the focus was on light or small airborne tanks. The British, however, developed a 57-mm semi-closed self-propelled gun "Alekto" II based on the light tank "Harry Hopkins", but this project was soon abandoned. In the Soviet Union, in the first years after the war, efforts were concentrated on an anti-tank self-propelled artillery unit: mechanized and tank units were considered the most dangerous enemy of the landing after its landing. Although the idea of creating a light airborne tank was not abandoned, light self-propelled artillery mounts became the "armor of the winged infantry" for two decades, significantly increasing the mobility of the landing force, performing transport tasks.
In October 1946 in Gorky at the plant No. 92 named after I. V. Stalin began to create a 76-millimeter cannon, and at plant number 40 (Mytishchi) - a chassis for a light airborne self-propelled artillery unit (ACS). The development of the chassis was led by one of the best designers of the USSR N. A. Astrova, who had extensive experience in the development of light armored vehicles. In March 1947, a preliminary design of the "object 570" was completed, and already in June of the same year, those. project. Plant # 92 in November 1947 produced two prototypes of the LB-76S cannon, which were transferred to plant # 40. The first experimental self-propelled gun was assembled at the plant in December. Factory tests began in 1948. In the middle of the year, the prototype was tested in Kubinka at the NIIBT test site and near Leningrad at the GNIAP. By the end of the year, the LB-76S gun was brought to a series. She received the designation D-56S.
From July to September 1949, in the 38th Airborne Corps (Tula Region), four prototypes of self-propelled guns underwent military trials. On December 17, 1949, the Council of Ministers signed a decree, according to which the installation was put into service under the designation ASU-76 ("airborne self-propelled gun, 76-mm"). ASU-76 became the first domestic armored vehicle that entered service, designed specifically for the Airborne Forces.
Airborne self-propelled gun ASU-76
A D-56S cannon was installed in an open-top fixed wheelhouse (an analogue of the D-56T cannon, installed on a PT-76 tank). It was equipped with a jet-type muzzle slot brake. The fire was conducted from closed positions or direct fire. For guidance, the OPT-2-9 sight was used. The ammunition load included armor-piercing and sub-caliber armor-piercing shells. The maximum firing range was 11, 8 thousand m, with direct fire - 4 thousand m. In the front of the hull, a folding support was mounted on which the gun was attached. The gun was removed from the stopper without leaving the crew.
The machine body is welded. 13mm armor provided protection from shell fragments and small arms bullets. The crew got into the car through the sides of the wheelhouse and the aft door.
The layout of the ASU-76 was not quite usual. The power unit was located on the right, in the rear of the hull. The GAZ-51E carburetor engine, main clutch and four-speed gearbox were mounted in a single block. The exhaust pipe and air intake were located on the right in the rear of the wheelhouse. The rest of the transmission units were in the front of the hull. To make it easier to start the engine at low temperatures, an air heater with a blowtorch was built into the cooling system.
ASU-57 on the march. In the foreground is a car with a Ch-51 cannon, in the background - with a Ch-51M cannon.
To increase the cross-country ability and stability of the self-propelled gun when firing, the rear guide wheels were lowered to the ground. Stability was also achieved by the introduction of brakes in the road wheels and self-braking idler wheels. The car was equipped with a 10RT-12 radio station and a tank intercom.
Despite the fact that ASU-76 was adopted, it did not go into mass production. In the absence of aircraft of the necessary carrying capacity, it was supposed to drop it with an Il-32 glider developed by the SV Design Bureau. Ilyushin. The glider was built in 1949 (with a carrying capacity of up to 7 thousand kg, it was able to transfer one ASU-76 or a pair of ASU-57). However, the Il-18 was never finalized. Two head ASU-76s did not pass field tests within the scope of the warranty period. In August 1953, work on this machine was curtailed, especially since the serial production of the 57-millimeter airborne self-propelled artillery unit began.
ASU-57
Work on the 57-millimeter self-propelled gun, which had greater mobility compared to the 76-millimeter one, proceeded in parallel. In addition to the Astrov Design Bureau, work was carried out by other design teams.
Back in 1948, a variant of the ASU-57 was developed, which was equipped with a 57 mm 113P automatic cannon. This gun was developed as an aircraft gun, but the Yak-9-57 fighter with 113P cannons developed by the Yakovlev Design Bureau did not pass factory tests. With the start of work on airborne self-propelled guns, the Astrov Design Bureau took an active part in them. The designers proposed a vehicle weighing 3, 2 thousand kg with a crew of two. At the same time, a transport-assault glider was created in the Yakovlev Design Bureau for an airborne self-propelled gun. However, the installation of the gun did not make it possible to conduct aimed fire according to the requirements.
Diagram of the ASU-57 device (with the Ch-51M cannon):
1 - case; 2, 15 - stowage of ammunition; 3, 13 - gas tanks; 4 - optical sight; 5 - muzzle brake; 6 - gun barrel (Ch-51M); 7 - power unit; 8 - M-20E engine; 9 - driving wheel; 10 - supporting roller; 11 - support roller; 12 - muffler; 14 - air cleaner; 16 - balancer of the rear support roller with a mechanism for adjusting the tension of the caterpillar; 17 - rear support roller (steering wheel).
In 1949, at VRZ No. 2, a compact amphibious self-propelled gun K-73 was built, developed by the Design Bureau under the leadership of A. F. Kravtseva. The mass of the vehicle was 3.4 tons, the height was 1.4 m. The vehicle was armed with a 57 mm Ch-51 cannon with an OP2-50 sight, and paired with it 7, 62 mm SG-43 machine guns. The ammunition consisted of 30 rounds for the cannon, as well as 400 rounds for machine guns. Armor thickness - 6 millimeters. Armor resistance was increased by the inclination of the frontal sheets of the cabin and the hull. In the front part of the hull, transmission units and a GAZ-51 carburetor engine (power 70 hp) were installed. The propeller was a propeller located on a folding shaft. In the stowed position, it was attached to the stern leaf of the cabin. The maximum speed on land is 54 km / h, while overcoming water obstacles - 8 km / h. The Kravtsev self-propelled gun could not stand the competition with the Astrov car, since it did not have sufficient maneuverability.
Experienced airborne self-propelled gun K-73
The first experimental ASU-57 ("object 572") with a 57-millimeter gun Ch-51, which was created in OKB-40 under the leadership of D. I. Sazonov and N. A. Astrov, manufactured in 1948 at the plant number 40 (now CJSC "Metrovagonmash"). In April 1948, field tests were carried out, and in June 1949 - military ones. On September 19, 1951, by a decree of the Council of Ministers of the USSR, ASU-57 was put into service. MMZ began mass production of the machine in 1951. The production of armored hulls was carried out by the crushing and grinding equipment plant ("Drobmash", Vyksa, Gorkovskaya oblast). ASU-57 was first presented to the general public on May 1, 1957 in Moscow during a parade on Red Square.
ASU-57 was a semi-closed tracked installation. The engine compartment was in front. The combined fighting compartment and control compartment were located in the aft part of the hull. Ahead, to the right of the gun, was the driver, behind him was the loader, and to the left of the gun was the commander (he was also the radio operator and gunner).
The Ch-51 cannon was designed in 1948-1950. in the design bureau of plant number 106 under the leadership of E. V. Charnko under the ammunition of the ZIS-2 anti-tank gun. The gun had a monoblock barrel with a cross-slit reactive muzzle brake, a vertical wedge gate with semiautomatic copying type, a hydropneumatic knurler and a hydraulic recoil brake. Manual loading. The gun was installed in the wheelhouse on a frame, which was attached to the bottom of the hull and the frontal plate. The cannon's mask was covered by a cover. Pointing angles from -5 to + 12 ° vertically and ± 8 ° horizontally. Ch-51 had screw guidance mechanisms. During direct fire (range 3.4 km), an optical sight OP2-50 was used, and a panorama was used from closed positions (range 6 km).
The ammunition included fragmentation (shot weight - 6, 79 kg, projectile - 3, 75 kg), armor-piercing tracer (6, 61 kg and 3, 14 kg, respectively) and subcaliber armor-piercing tracer (5, 94 and 2.4 kg) shells. An armor-piercing projectile pierced armor 85 mm thick at a distance of 1 km, a sub-caliber (initial speed 1158 m / s) - 100 mm armor at a distance of 1 km and 72 mm armor at a distance of 2 km. The direct firing range of this projectile was 1060 meters. In the stowage in the wheelhouse for actions outside the vehicle, an SGM or SG-43 machine gun was transported (on the ASU-76 company machine gun RP-46). Later, AK or AKM were carried in packing.
To reduce the mass of the ACS, aluminum alloys were used, and the armor protection was left minimal. The hull was assembled from steel armor plates (in the most critical places) and aluminum sheets (aft hull plates and bottom), connected by welding and riveting. To reduce the height of the self-propelled gun, the side and upper frontal sheets of the wheelhouse were folded back on hinges. In the niches of the fighting compartment, located on the fenders, compartments for part of the ammunition were located on the starboard side of the wheelhouse, and on the left side for spare parts and batteries. The fighting compartment, as in other machines of this class, was covered from above with a canvas awning with a rear viewing window.
In this car, the time-tested principle of using automobile units has been preserved. The four-cylinder compact M-20E engine was a direct descendant of the motor of the passenger car "Victory". It developed a power of 50 horsepower at a frequency of 3600 rpm (this engine was also installed on the GAZ-69 all-wheel drive car). The engine was installed across the body of the machine in a single block with a dry friction clutch, a mechanical four-speed gearbox and clutches. The power unit was mounted in a housing on four spring-loaded mounts, and the fastening with only four bolts made replacement faster. The final drives are simple gearboxes. The location of the engine was shifted to the starboard side. It was closed by a folding armored cover with shutters. The exhaust pipe with a silencer was displayed in the front of the hull from the starboard side. In the front left part of the case there were oil and water radiators and a fan with a drive. They were also closed by a hinged cover with an air intake louver. The gearbox cover was located in the middle of the upper frontal armor plate of the hull. Combined air cleaner. ASU-57 also had a pre-heater.
The chassis of the self-propelled gun as a whole repeated the chassis of the ASU-76. It included four single rubberized road wheels and two supporting rollers on each side. Each roller has an individual torsion bar suspension. The front units are equipped with hydraulic shock absorbers connected to the roller balancers by rods. The torsion bars of the first three road wheels on the starboard side are displaced by 70 mm relative to the torsion bars on the left side. The drive wheel is located at the front. The idler wheel is lowered to the ground. It is the fourth track roller. The balancer of this roller is equipped with a screw mechanism for adjusting the track tension. Metal caterpillar chain fine-link, pinned engagement, with two ridges, consists of 80 204 mm tracks. By reducing the mass, the ASU-57 self-propelled gun compared to the ASU-76 received better cross-country ability even with a smaller track width: ground pressure of 0.35 kgf / cm2 ensured high cross-country ability on snow cover and swampy terrain. A removable wing was installed to protect the tracks.
Observation blocks B-2, located in the frontal leaf of the cabin, as well as observation windows, equipped with armored shields, in the side armor plates, served for observation. ASU-57 was equipped with radio stations YURT-12 and TPU-47 (tank intercom) for three subscribers. The radio station was in front of the commander's seat. She worked on a whip antenna 1 - 4 meters high, located at the port side in front of the wheelhouse. Starting from 1961, the car was equipped with the R-113 radio station and the TPU R-120 intercom. The maximum radio communication range is 20 km. The voltage of the on-board network is 12 V.
The self-propelled artillery mount ASU-57 combined small dimensions, good mobility and sufficient firepower. We can say that Astrov finally managed to solve the problem that many designers have been fighting over since the 1930s - to combine a tankette and an anti-tank gun.
The low silhouette of the ASU-57 contributed not only to its transportation, but also to camouflage on the ground. The anti-tank company of the parachute regiment read nine such installations. The stealth and 57-millimeter cannon, which had APCR shells in the ammunition load, made it possible to fight medium tanks, which at that time formed the basis of the tank fleet of potential opponents. The armor of a self-propelled artillery mount could accommodate four paratroopers. In addition, it was used as a light tractor.
ASU-57 in 1954 was rearmed with a modified Ch-51M cannon. The upgraded gun received an ejector and a two-chamber active muzzle brake. The total length of the installation was reduced by 75 cm. In addition, the extraction of the sleeves and the opening of the bolt were carried out at the end of the reel (for the Ch-51 - at the end of the recoil). The swivel mechanism was equipped with a braking device. The latest series of ASU-57 were equipped with illuminated night vision devices for the driver (a headlamp with an IR filter was attached above the right fenders). In addition, an additional fuel tank was installed.
Floating option
Since September 1951, the Astrov Design Bureau has been developing a floating modification of the ASU-57 (in 1949 an experimental floating ASU-76 was created). The first prototype ASU-57P (object 574) was built in November 1952. In 1953-1954, four more prototypes were assembled and tested. ASU-57P (weighing 3.35 tons) differed from the prototype in its elongated body (4.25 m), streamlined. The buoyancy of the vehicle was provided by the hull displacement. On the upper frontal sheet there was a folding wave breaker. The engines of the ASU-57 were a forced engine (60 hp) and a water-propeller. The self-propelled artillery cannon has also been redesigned. The Ch-51P differed from the Ch-51M in its technological muzzle brake, the design of the lifting mechanism, the semi-automatic mechanism and the breech. The cradle pins were moved forward by 22 mm. The rate of fire reached 11-12 rounds per minute.
Experienced self-propelled amphibious unit ASU-57P
At first, two propellers located in the stern were used as water propellers. They were driven by the rotation of the guide wheels, but when such a machine went ashore, there was not enough traction on the tracks. In this regard, the choice was made in favor of a scheme with power take-off from the gearbox to the propeller. The screw in this case was located in a special niche in the bottom of the case. The steering wheel was placed in a single tunnel with a propeller - by analogy with the T-40, developed on the eve of the war by N. A. Astrov. A heat exchanger was added to the cooling system, which, while driving on water surfaces, provided heat removal to the seawater.
In 1955, the car could be put into service, but it was never transferred to mass production. Only four copies were produced. This limited release was due to the fact that the power of the 57mm cannon was insufficient, however, as well as the extremely lightweight booking. At the same time, the serial production of the ASU-57 was curtailed. It was clear that the increased role of airborne assault forces and the development of armored vehicles of a potential enemy require the creation of a new vehicle with more powerful weapons.
In the OKB-40 on the ASU-57, a 107-mm recoilless gun B-11, developed by the Shavyrin Design Bureau, was installed in an experimental order instead of a 57-mm cannon. The ammunition load of the BSU-11-57F experimental installation (weight 3.3 tons) included shots with cumulative and high-explosive fragmentation projectiles. Shooting was carried out using an optical or mechanical (backup) sight. The maximum firing range is 4.5 thousand meters. And although in those years recoilless guns aroused wide interest as the amphibious assault rifle, the development of airborne self-propelled artillery installations quite reasonably followed the path of "classical" artillery systems.
The self-propelled guns ASU-57, after being replaced by more powerful ones, were not forgotten: some were used as training, some were converted into tractors (the chassis units were used even earlier in the AT-P tractor).
ASU-57 landing methods
After World War II, the main methods of airborne assault were considered: glider, parachute and landing. The landing of self-propelled artillery installations ASU-57 was carried out by landing method on a platform with a multi-dome parachute system or Yak-14 gliders.
The Yak-14 heavy transport glider was developed in 1948 at the Yakovlev Design Bureau. The glider could transfer the ASU-57 and two members of its crew (the mass of the ASU-57 with a fully equipped ammunition load and crew was about 3, 6 thousand kg). ASU-57 entered the glider through the bow hatch along the ladders. In this case, the nose of the fuselage was tilted to the side (to facilitate loading, air was vented from the landing gear of the airframe, thus, the fuselage was lowered). Inside, the installation was fastened with cables. To prevent swaying during transportation in an airplane or glider, the extreme suspension units of the self-propelled gun were locked onto the hull. An Il-12D aircraft was used to tow the Yak-14 glider. In addition, an experienced Tu-4T was considered as a towing vehicle.
The lack or absence of amphibious assault vehicles with an average carrying capacity forced to severely limit the weight of airborne self-propelled guns. This determines the small size of the hull (the height of the frontal plate and the sides of the cabin was small) and the thickness of the armor.
In 1956, a P-98M suspended cockpit was developed for the Tu-4D transport aircraft, which was used for landing the ASU-57, but soon this cockpit was redesigned for the 85-mm SD-44 cannon. But the "landing" modifications of bombers and passenger aircraft were already replaced by transport aircraft, designed specifically for these purposes.
After the adoption of the Antonov transport An-12, developed in GSOKB-473, into service in 1959, the situation changed. The new aircraft significantly expanded the capabilities of the assault forces, providing parachute or landing landing for equipment, including the ASU-57, and personnel. The An-12B aircraft was equipped with a TG-12 roller conveyor for dropping amphibious cargo systems. ASU-57 were landed using a parachute platform developed at the design bureau of plant No. 468 (Moscow aggregate plant "Universal") under the leadership of Privalov, with multi-dome systems MKS-5-128R or MKS-4-127. The self-propelled gun was fastened with ropes with mooring devices on the PP-128-500 (when landing from the An-12B), and later on the P-7 (from the Il-76, An-22 and An-12B). To prevent deformation and damage, the self-propelled gun under the bottom was fixed with supports. The total flight weight of the PP-128-5000 platform with the ASU-57 installed on it in full ammunition was 5160 kilograms. An-12B was able to take on board a pair of ASU-57 placed on platforms.
The release took place in several stages. At the first stage, a platform with a load was removed from the aircraft with an exhaust parachute. At the same stage, the stabilizing parachute began to work. The platform descended on reefed main canopies and a stabilizing parachute. At the next stage, the main domes were deflated and filled with air. At the last stage - the descent with the main parachutes and landing. At the moment the platform touched the ground, depreciation was triggered. At the same time, the main parachutes were disconnected by automatic uncoupling. The release from ISS-5-128R took place at an altitude of 500 to 8 thousand meters. The rate of descent was about 7 m / s. The platform was equipped with a marker radio transmitter P-128, which made it possible to detect it after landing.
The transfer of self-propelled guns was also carried out by the heavy Mi-6 helicopter, which appeared in 1959, developed at the Mil Design Bureau.
ASU-57 took part in all major exercises of the airborne troops. In the "Rossiyskaya Gazeta" there was a mention that the ASU-57 was used in military exercises with the use of nuclear weapons, which were held at the Semipalatinsk test site on September 10, 1956. ASU-57 was also exported to Egypt.
ASU-57 has become a kind of "test bench" for the development of airborne armored vehicles. For example, in 1953-1954 at Research Institute No. 22 PBTT (now the 38th Research Institute), they carried out pile tests of the ASU-57: using the KT-12 crane, the self-propelled gun was dropped several times to determine the maximum permissible overloads for different variants of its landing. During those tests, it was found that the ultimate overload is 20g. Later, this indicator was included in the GOST for landing systems.
It should be noted that in 1951, when the ASU-57 was put into service, the Airborne Test Flight Unit was transformed into the Technical Committee of the Command. One of its departments dealt with ground engineering, automotive, artillery and armored vehicles. This fact in itself testified to the increased attention to the technical equipment of this type of troops. In 1954, General Margelov became the commander of the airborne forces. 25 years, during which he held this post, became the time of the development of the Airborne Forces, the qualitative improvement of their military equipment and weapons. In 1962, the Technical Committee was transformed into the Department of Experienced Equipment of the Office of the Commander of the Airborne Forces. In 1964, the Department was transformed into the Scientific and Technical Committee of the Airborne Forces.
SU-85
The light 85-mm self-propelled gun was developed to solve the tasks of escorting and anti-tank equipment of tank and motorized rifle units (later a 90-mm self-propelled gun "Jagdpanzer" of a similar purpose was in the Bundeswehr of Germany), and as an anti-tank self-propelled artillery installation of airborne units. However, it was the airborne assault that became the main role for her. Work on the machine, named Object 573, began in 1953. The self-propelled gun was created at the Mytishchi machine-building plant on the original base, developed under the leadership of Astrov. In 1956, it was accepted into service under the designation SU-85 (the designation ASU-85 was also used).
This time, the layout was chosen with the rear placement of the MTO and the front placement of the fighting compartment (as before, it was combined with the control compartment) in a fixed wheelhouse. To the right of the cannon, in its front part, there was a driver-mechanic, behind him - the loader and the commander, to the left - the gunner.
The 85-mm D-70 cannon was mounted in the frontal leaf of the wheelhouse in a frame with a spherical mask covered with a cover. It was slightly shifted to the left of the longitudinal axis of the self-propelled gun. The cannon was created in the design bureau of plant number 9 under the leadership of Petrov. Serial production was carried out by plant No. 75 in the city of Yurga. The D-70 gun had a monoblock barrel, an active two-chamber muzzle brake, an ejector for purging, a vertical wedge breech with a semiautomatic copy type. The recoil device included a hydraulic recoil brake, as well as a hydropneumatic knurler with a valve for additional braking. The gun was loaded manually. Aiming angles: ± 15 ° horizontally, -4.5 to + 15 ° vertically. Sector-type vertical guidance mechanism, helical horizontally. The flywheel of the lifting mechanism was located under the gunner's right hand, and the swing mechanism under the left. On the handle of the flywheel of the lifting mechanism there was an electric release lever, which was duplicated by a manual release. The articulated telescopic sight TShK2-79-11 was used during direct fire. For shooting from closed positions, a mechanical sight S-71-79 with a gun panorama PG-1 is used. For different types of shots, both sights had scales. When firing direct fire, the range was 6 thousand m, at the maximum elevation angle, the aiming range was 10 thousand m, the maximum firing range when using high-explosive fragmentation projectiles was 13, 4 thousand m. In addition, an active night tank was installed on the vehicle. sight TPN1 -79-11 equipped with IR illuminator L-2.
The ammunition load included various types of unitary shots, similar to the D-48 ammunition load. However, the barrel of the D-70 was shorter than the D-48 by 6 calibers, which affected ballistics. UBR-372 carried 9, 3 kg armor-piercing tracer projectile BR-372, the initial speed of which was 1005 m / s. This projectile could penetrate armor up to 200 millimeters thick at a distance of 1000 meters at an angle of 60 °. The 3UBK5 carried a 7, 22 kilogram 3BK7 cumulative projectile, which penetrated 150 mm armor. This made it possible to fight the tanks "Centurion" Mk III or M48A2 "Paton III". UOF-372 carried a 9.6 kilogram HE-372 high-explosive fragmentation projectile, which was intended to destroy fortifications and destroy enemy manpower, UOF-72U with an OF-372 projectile, but with a significantly reduced propellant charge, UOF-372VU carried an OF- 372V, as well as a reduced charge. In addition, there were shots with practical and smoke shells. The mass of the shot was no more than 21.9 kilograms. The shots were placed in the fighting compartment: at the MTO bulkhead in the niche - 14 pieces, along the bulkhead - 8 pieces, at the left side of the hull - 7 pieces, in the right side niche - 6 pieces, in the left side niche and in front of the gunner - 5 pcs.
It should be noted that the SU-85 was practically not inferior to medium tanks in terms of firepower, and the vehicle's lower protection was compensated for by its small dimensions. 7, 62-mm machine gun SGMT was paired with a cannon. Machine gun belts (250 rounds each) were in eight box magazines. The machine was packed with an AKM assault rifle and 300 rounds of ammunition, an SPSh signal pistol, 15 F-1 grenades.
The welded hull had rational angles of inclination of the side and frontal armor plates. The hull provided protection against medium and small caliber armor-piercing shells. Additional rigidity of the body was given by a corrugated bottom, which has a trough-shaped cross-section. The bottom had a hatch designed for emergency evacuation of the crew. A board was installed on the brackets of the upper frontal sheet, which served as a mud flap.
The power unit was quick-changeable. The remaining stringent requirements for the use of units of the automotive industry forced the designers to use the YAZ-206V automobile diesel two-stroke engine, which developed 210 hp. at 1800 rpm. The engine was mounted across the hull and was shifted to the starboard side. The cannon and the engine counterbalanced each other. To reduce power losses, an overall, but not requiring power take-off, liquid cooling system with ejection ventilation was used. There was a nozzle pre-heater and three Multicyclone air filters. The engine was started by an electric starter. Access to the engine was provided by hinged top MTO covers.
The mechanical transmission consisted of a main clutch, a gearbox, a propeller shaft, a five-speed gearbox, planetary swing mechanisms and final drives (single-stage gearboxes). At first, a single-disk main clutch was used, but in the process of operation, multi-plate clutches were installed on some of the machines, which were more reliable. An automobile transmission was used, but it was so modified that the percentage of the use of automobile units in self-propelled guns turned out to be not significant as a result. The gearbox had five forward speeds and one reverse. Planetary steering mechanisms (PMP) were two-stage, and had brakes and locking clutches. With the left PMP, the gearbox was connected with a cogwheel with a clutch, with the right one - with a semi-axle. The driver-mechanic used the PMP control levers, gear levers, oil pump and engine stop, brake pedals, fuel supply and main clutch to control the self-propelled artillery installation. The chassis consisted of six single rubberized road wheels on board (similar to the PT-76 tank) with an individual torsion bar suspension and double-acting hydraulic shock absorbers on the sixth and first suspension nodes. The drive wheels were located at the back. Torsion shafts went from side to side. The caterpillar is fine-link, metal, with two ridges, pinned engagement. The track belt consisted of 93 stamped steel tracks.
The SU-85 was equipped with B-1 observation units for observation (one for the gunner and the loader, two for the driver). The commander also had an active night vision device TKN-1T, and the driver had a TVN-2. IR illuminators were fixed above the driver's seat, as well as above the gun mask. Internal communication was carried out by TPU R-120, external - by radio station R-113. When working on a whip antenna with a height of 1 - 4 meters, it provided communication at a distance of 20 km. The antenna was mounted on the starboard side. The on-board network - 24 V. The setting of the smoke screens was carried out by two smoke bombs BDSH-5 mounted on the aft sheet of the hull. Dropping took place without leaving the crew. In the stern, two additional fuel tanks were also attached to provide an increase in the range. Spare parts and tools were stored on the sides of the hull and in the fighting compartment. The OU-5V fire extinguisher was also housed in the fighting compartment.
The SU-85 self-propelled guns were mass-produced until 1966. Each airborne division had a self-propelled artillery division, which included 31 SU-85s.
Initially, the self-propelled gunnery was open on top. This made it possible to reduce the height and lighten its weight. But in 1960, for better protection (including protection against weapons of mass destruction - this requirement became mandatory), a roof with four hatches, as well as a filter ventilation unit, were installed. The cap of the supply fan was located above the embrasure of the gun, behind it was the air intake housing. In the roof for the commander, a TNPK-240A periscope was mounted with an 8-fold optical zoom system. Since the SU-85 was created as a semi-closed one, the addition of a cover to it somewhat constrained the fighting compartment. Nevertheless, the troops liked the airborne SU-85 due to its reliability and good mobility. In addition to the fight against armored vehicles and tanks, the SU-85 was used to solve the tasks of direct fire support, and also to carry out the transportation of troops "on armor". The paratroopers willingly used this transport before the appearance of their own transport and combat vehicles.
When the SU-85 self-propelled artillery unit began to enter service, the An-12 transport aircraft, which was capable of transporting such a machine, was being prepared for the first flight. During loading on the plane, the torsion bar suspension was turned off using a device included in the spare parts machine. It took from 1 to 1.5 minutes to transfer the SU-85 from traveling to combat. The SU-85 was primarily designed for landing landing. This significantly limited the possibilities of the combat use of this vehicle. Ammunition for the landing could be dropped by An-12B aircraft. For this, PP-128-5000 platforms equipped with MKS-5-128M multi-dome systems were used. For example, a GAZ-66 car was parachuted, carrying 85-mm shots in the back, packed in boxes.
In the 1960s, airborne assault (including into the operational depth of the enemy's formation) was a constant element in the formation of armies. The landing depth has increased, the requirements for the landing speed have increased, as well as the time for independent actions.
In this regard, the dropping of armored vehicles was carried out as part of the landing. In 1961, work began on expanding the transportation capabilities of military equipment and landing equipment. After the appearance of the P-16 platforms (maximum flight weight - 21 thousand kg), it became possible to drop the SU-85 from the An-2 not only by landing, but also on a platform with a multi-dome system. However, a new generation of combat vehicles was already replacing self-propelled artillery mounts.
Self-propelled artillery mounts SU-85 were exported to Poland. In 1967, self-propelled guns participated in the Arab-Israeli "Six Day War" on the Arab side. The experience of combat use has shown the need for self-defense means from army aviation helicopters and attack aircraft. In the 1970s, anti-aircraft 12, 7-mm DShKM machine guns with a collimator sight were installed on the roof of the SU-85 self-propelled gun. SU-85s took part in other military conflicts, including the entry of troops in 1968 into Czechoslovakia (admittedly, the Soviet airborne forces in that operation demonstrated excellent training, as well as the ability to act quickly and competently), and the war in Afghanistan. The SU-85 was removed from service in 1993.
The development of anti-tank self-propelled artillery installations stopped, as the effectiveness of the ATGM (anti-tank missile system) increased, and the paratroopers for fire support of the units received a completely different machine.
Among foreign self-propelled artillery installations, mention should be made of the American open 90-mm self-propelled gun M56 "Scorpion", which was produced in 1953-1959 almost simultaneously with the ASU-57 and SU-85. The American self-propelled gun demonstrates a different approach to the creation of such vehicles: a powerful anti-tank gun mounted on a light chassis and having armor protection, limited only by a shield. It should be noted that the M551 Sheridan airborne tank that appeared later and equipped with a 152-mm gun-launcher had the character of an “anti-tank gun
