View source for ASU-57

{{more footnotes needed|date=April 2014}}
{{Infobox weapon
| name = ASU-57
| image = ASU-57 US Army Armor and Cavalry Collection.jpg
| image_size = 300
| caption = ASU-57 on display at the [[U.S. Army Armor and Cavalry Collection]]
| origin = [[Soviet Union]]
| type = Airborne [[assault gun]]/[[tankette]]
| is_vehicle = yes
| service = 1951 – late 1960s (USSR)
| used_by = [[USSR]]<br>[[Egypt]]<br>[[Vietnam]]<br>[[Yugoslavia]]<br>[[Ethiopia]]
| wars = [[Six-Day War]]<br>[[Warsaw Pact invasion of Czechoslovakia]]<br>[[Ogaden War]]
| designer = Astrov Design Bureau
| design_date = 
| manufacturer = [[Mytishchi Machine-Building Plant|MMZ]]
| unit_cost = 
| production_date = 1950-1962
| number = 
| variants = 
| crew = 3+6
| length = {{convert|3.48|m|ftin|abbr=on}}<br>(hull)
| width = {{convert|2.08|m|ftin|abbr=on}}
| height = {{convert|1.18|m|ftin|abbr=on}}<br>(shield up)
| weight = {{convert|3.4|to|4|t||abbr=on}}
| armour = {{convert|6|mm|abbr=on}}
| primary_armament = 1x Ch-51 or Ch-51M L/73 57mm Gun
| secondary_armament = 1x 7.62mm anti-aircraft machine gun
| engine = one M-20E4 water cooled [[gasoline]] engine
| engine_power = 50hp (37.29 kW) (55hp with later engine)
| transmission = 37,000/75,000 now
| fuel_capacity = 140 liters (37 gallons)
| suspension = torsion bar
| speed = {{convert|45|km/h|mi/h|abbr=on}}
| pw_ratio = 
| vehicle_range = {{convert|250|km|mi|abbr=on}}
| is_ranged = 30 to 300 m highest effectiveness
}}

The '''ASU-57''' was a small, lightly constructed [[Soviet Union|Soviet]] [[assault gun]] specifically designed for use by [[Soviet Airborne Forces|Soviet airborne]] divisions. From 1960 onwards, it was gradually phased out in favour of the [[ASU-85]].

==Development history==
[[File:ASU-76.jpg|thumb|left|ASU-76]]
The task to develop a lightweight assault gun for the airborne troops (with either a 57&nbsp;mm gun or a 76&nbsp;mm gun) was given to two design bureaus, Astrov (OKB-40) in Mytishchi and Kravtsev in Moscow. Nikolaj Astrov's OKB-40 designed the '''ASU-76''', based on components of the [[T-70]] light tank and the [[SU-76]] assault gun, and armed with the new 76&nbsp;mm gun D-56T. The ASU-76 turned out to be too heavy, even though the armour was only 3&nbsp;mm thick, and the project was cancelled. Anatoly Kravtsev's team came up with the similar, amphibious '''K-73'''. This vehicle was armed with Charnko's 57&nbsp;mm anti-tank gun Ch-51 and was even more thinly armoured than the ASU-76. This project too was shelved.

In 1949, Astrov was instructed to continue with his project, but with reduced weight and with the Ch-51 gun as the main armament instead of the D-56T, since it offered better anti-tank performance. The redesigned '''Ob.572''' was developed simultaneously with the [[AT-P|Ob.561 (AT-P)]] light artillery tractor. After successfully passing the various test phases in 1949, it was accepted for series production from 1951 as the '''ASU-57'''.

==Design==
[[File:ASU-57 paradrop sequence.png|thumb|upright|left|ASU-57's paradropping sequence from [[An-12]] transport plane.]]

===Armament===
The ASU-57 was designed to be a lightweight assault gun that could be air-dropped out of the [[An-12]] transport plane which was the standard cargo aircraft of the Soviet military at the time and deployed by rocket-assisted [[parachute]] (PP-128-500 or P-7) along with the troops. It was lightly armored and armed with a 57&nbsp;mm gun Ch-51, a development of the World War II [[ZIS-2]] but with some similarities to the Ch-26. From 1954, an improved 57&nbsp;mm gun Ch-51M with a much shorter double-baffle muzzle brake was fitted. The gun fired the standard caliber 57x480R ammunition of the ZIS-2 anti-tank gun, such as the BR-271 series and the O-271U, of which it had 30 on board, stored in various ammunition racks located at the rear of the vehicle and in easy reach of the loader, who sat facing backwards. The ASU-57 was also able to be fitted with an optional 7.62&nbsp;mm DTM with 2500 rounds or 12.7&nbsp;mm [[DShK]] machine gun.

===Propulsion===
The ASU-57's M-20E4 engine was taken from the [[GAZ-M20 Pobeda|GAZ-M-20 "Pobeda"]] civilian car and featured {{cvt|50|hp|kW}} of power. The engine was located on the left side of the transmission, which was located at the front of the vehicle and connected to frontal sprocket wheels driving tracks with four rubberised roadwheels on each side, with the last one acting as an idler wheel. The ASU-57 could reach a maximum speed of 45&nbsp;km/h and had a 250&nbsp;km range.<ref>{{cite web|title=ASU-57|url=http://www.tanks-encyclopedia.com/coldwar/USSR/soviet_ASU-57.php|website=Tank Encyclopedia|access-date=2018-11-11}}</ref>

===Protection===
Designed to be as light as possible, the ASU-57 featured very limited armour in the form of steel plates that were a maximum of 6&nbsp;mm thick at the front of the vehicle that was either bolted or welded on. The armour was only intended to resist rifle-calibre bullets fired by infantry and could be defeated easily by heavy machine guns such as the 12.7&nbsp;mm [[M2 Browning]]. The top of the vehicle was completely open and thus exposed the crew to both the elements and enemy fire, especially in the form of grenades. If a crew stood up completely in the vehicle, their heads would be in view. Rather, the ASU-57 was intended to use its small size and mobility to avoid enemy fire. The open topped-nature of the vehicle also facilitated good vision and situational awareness for the crew, as well as easy access into and out of the vehicle.

==Operational history==

[[File:Асу-57 1.jpg|thumb|ASU-57. Packed parachute system in the foreground]]
The ASU-57 was a successful design that saw service with Soviet airborne divisions for around 20 years before being replaced by the [[ASU-85]]. During its years of operation, 54 vehicles would have been assigned to each airborne [[division (military)|division]]. One main drawback was the vehicle's [[welded]] [[aluminium]] hull, which offered little protection for the crew. However the vehicle gave lightly armed [[airborne troops]] mobile [[artillery]] support on the battlefield. Every vehicle was equipped with a 10RT-12 radio and a TPU-47 intercom system. Late-production models (from 1961) replaced these with the R-113 and R-120 respectively, and also had a TVN-2 night vision device for the driver.

The ASU-57 became the first successful Soviet airborne tank, overcoming failings in previous Soviet concepts that had stemmed from the 1930s. When the ASU-57 was introduced, every airborne division acquired 54 vehicles each, however by the turn of the 1960s, the ASU-57s only numbered 245 in service. It was realised that the armament of the main gun, a WWII-derived design, was vastly obsolete, especially when compared to NATO-equivalents such as the [[M40 recoilless rifle]]. The ASU-57 saw its first major deployment during Dniepr, a 1967 military exercise performed by the 76th VDD. In the following year, in 1968, ASU-57s saw its first combat-action during the Warsaw Pact-invasion of Czechoslovakia, with several vehicles used by the USSR. The ASU-57 was gradually supplanted and replaced by the heavier [[ASU-85]], which featured a fully enclosed casemate design with a vastly superior 85&nbsp;mm main gun. According to Isby, some apparently were kept for training as late as 1988, while unarmed command versions remained in service until they were replaced by command versions of the [[BMD-1]].{{sfn|Isby|1988|page=404}}  

In foreign military service, 20 ASU-57s saw service with the East German military, while 200 were given to North Korea. ASU-57s were also supplied to Egyptian forces, being used in the [[Six-Day War]] against Israel in 1967. Several dozen ASU-57s were sent to Ethiopia as well, where they took part in the [[Ogaden War]] with Somalia in November 1977, where ASU-57s were used in battles around Areva and Jijiga, assisting friendly forces during the battle, where notably, [[Mil Mi-6|Mi-6]] helicopters dropped at least several ASU-57s behind the Somali frontlines.
{{clear left}}

==Variants==
[[File:K-73 in Patriot Park.jpg|thumb|ASU-57P, also known as K-73, in [[Patriot Park]]]]
* '''ASU-57KShM''' – An unknown number of ASU-57s were converted into command and staff vehicles ({{langx|ru|командно-штабная машина}}). These had the gun removed and were fitted with additional signals equipment and an extendable canvas tent mounted at the rear.{{sfn|Isby|1988|page=404}} 
* '''BSU-11-57F''' or '''2T2''' – Recoilless gun carrier for the [[B-11 recoilless rifle|B-11]] of 107mm. Prototype only.
* '''ASU-57P''' or '''Ob.574''' or '''K-73''' – From 1951, work on an amphibious ({{langx|ru|плавающая}}) variant of the ASU-57 started. This version had a re-designed front hull and was armed with a Ch-51P gun with 30 rounds. Even though the five  prototypes passed the evaluation with success, series production was never started.

{{clear left}}

==Operators==
[[File:ASU-57 operators.png|thumb|400px|Map of former ASU-57 operators in red]]

===Former operators===
;{{flag|Egypt|1958}}{{sfn|Isby|1988|pages=405,407}}
* [[Egyptian Army]] received a small number of ASU-57s in early 1960s; they were used during [[Six-Day War]] in 1967.
;{{flag|Ethiopia|1975}}{{sfn|Isby|1988|pages=405,407}}
* [[Ethiopian Army]] received a few dozen SPGs during the [[Ogaden War]] in 1977.
;{{GDR}}
* ''[[National People's Army|Nationale Volksarmee]]'' received 20 former Soviet Army vehicles in 1961–62.
;{{PRK}}
* [[Korean People's Army Ground Force]] ordered 200 vehicles in 1966. All were previously used by the Soviet Army and were delivered in 1967 and 1968
;{{flag|Sahrawi Republic}}
* [[Polisario Front]] received an unknown number of vehicles from Libya.
;{{USSR}}
* [[Soviet Army]] operated ASU-57s in the airborne divisions of the [[Soviet Airborne Forces]]. Reportedly remained in limited use for training as late as 1988.{{sfn|Isby|1988|page=404}}
;{{VNM}}
* [[Vietnamese People's Army]]{{sfn|Isby|1988|pages=405,407}}
;{{YUG}}
* [[Yugoslav People's Army]]{{sfn|Isby|1988|page=407}}

==References==
<references />
* {{cite book
  | last = Koll
  | first = Christian
  | title = Soviet Cannon: A Comprehensive Study of Soviet Arms and Ammunition in Calibres 12.7mm to 57mm
  | publisher = Koll
  | year = 2009
  | location = Austria
  | url = http://www.russianammo.org
  | doi =
  | isbn = 978-3-200-01445-9
  | page = 491 }}
*{{cite book |last1=Isby |first1=David C. |title=Weapons and Tactics of the Soviet Army |date=1988 |publisher=Jane's Publishing Company Limited |location=London |isbn=978-0-7106-0352-4 |url=https://archive.org/details/weaponstacticsof0000isby |url-access=registration |edition=Revised}}
* {{cite book
  |author1=Zaloga Steven J. |author2=Hull Andrew J. |author3=Markov David R. | title = Soviet/Russian Armor and Artillery Design Practices: 1945 to Present
  | publisher = Darlington Productions
  | year = 1999
  | location =
  | url =
  | doi =
  | isbn = 1-892848-01-5
  | pages = 288–291 }}
* {{cite book
  |author1=Solyankin, A.G. |author2=Zheltov, I.G. |author3=Kudryashov, K.N. | title = Otechestvenniye Bronirovanniye Mashiny - XX Vek, Tom 3: 1946-1965
  | publisher = OOO "Tsejkhgauz"
  | year = 2010
  | location =
  | url =
  | doi =
  | isbn = 978-5-9771-0106-6
  | pages = 530–533 }}

==External links==
{{Commons category}}
* [http://www.russianwarrior.com/STMMain.htm?1947vec_ASU57.htm&1 Sword of the Motherland Foundation]
* [http://dishmodels.com/wshow.htm?p=854 Walkaround of ASU-57 presented in the Central Museum of Armed Forces (Moscow)]
* [http://www.dishmodels.ru/wshow.htm?p=1843 Walkaround of 2T2 presented in Il'inskoye (Moscow)]
* [http://www.dishmodels.ru/wshow.htm?p=1845 Walkaround of APNP-1 presented in Il'inskoye (Moscow)]
* [http://www.tipolog.totalh.com/img_tanks_1950_2000/asu_ussr_asu57.jpg Poster]
* [https://web.archive.org/web/20110813223045/http://modelingmadness.com/reviews/misc/vehicles/stewartasu57.htm Maquette 1/35 ASU-57 SPG, by Blair Stewart]
* [https://archive.today/20120904023043/http://www.museum-tank.ru/IIIwar/pages3/asu57.html K-73 in Kubinka]
* [http://vitalykuzmin.net/?q=node/84 ASU-57P prototype during IDELF-2008]

{{PostWWIISovietAFVS}}
{{SovArtyColdWar}}

[[Category:Cold War armoured fighting vehicles of the Soviet Union]]
[[Category:Airborne fighting vehicles]]
[[Category:57 mm artillery]]
[[Category:Assault guns of the Soviet Union]]
[[Category:Assault guns of the Cold War]]
[[Category:Mytishchi Machine-Building Plant products]]
[[Category:Military vehicles introduced in the 1950s]]