85 mm air defense gun M1939 (52-K)

85 mm air defense gun M1939 (52-К)
52-K in Nizhny Novgorod Kremlin.
Type	Air defense gun
Place of origin	Soviet Union
Production history
Produced	1939-1945
Specifications
Weight	combat: 4,500 kg (9,921 lbs) travel: 4,500 kg (9,921 lbs)
Length	7.05 m (23 ft 2 in)
Barrel length	55 Calibers
Width	2.15 m (7 ft 1 in)
Height	2.25 m (7 ft 5 in)
Crew	7
Shell	85×629 mm. R
Caliber	85 mm (3.34 in)
Breech	vertical sliding wedge
Recoil	hydraulic buffer
Carriage	2-axle and 4-wheeled
Elevation	-3° to 82°
Traverse	360°
Rate of fire	10-12 rounds per minute
Muzzle velocity	792 m/s (2,598 ft/s)
Effective firing range	10,500 m (34,448 ft) (vertical range)
Maximum firing range	15.65 km (9.72 mi)

The 85 mm air defense gun M1939 (52-K) (Russian: 85-мм зенитная пушка обр. 1939 г. (52-К)) was an 85-mm Soviet air defense gun, developed under guidance of leading Soviet designers M. N. Loginov and G. D. Dorokhin. This gun was successfully used throughout the German-Soviet War against level bombers and other high- and medium-altitude targets. In emergencies they were utilized as powerful anti-tank weapons. The barrel of the 52-K was the basis for the family of 85-mm Soviet tank guns. Crews of 85-mm AD guns have claimed to have shot down 4,047 Axis aircraft (likely over-reported by factor of 3 to 10). The claimed quantity of 85-mm ammunition required to shoot down one enemy plane was 598 rounds, although actual number may be in range 2000-7000 rounds per kill.^[1] After the war some 52-Ks were refitted for peaceful purposes as anti-avalanche guns in mountainous terrain.

Virtually every country behind the Iron Curtain received this gun after World War II for their air defense. In the Soviet Union itself, these guns were largely superseded by the 100 and 130 mm guns.

Description

Adopted in 1939, the 85-mm M1939, like its counterpart the 88-mm gun, was meant for air defense. Like many anti-aircraft (AA) guns of the era it was provided with antitank ammunition in the event a tank should appear.

Organization

85-mm M1939 guns were organized into heavy anti-aircraft regiments of 16 guns. The regiments were organized into divisions of the field anti-aircraft forces.

Tank guns

By 1942, the 76.2mm F-34 tank gun of the T-34 medium tank was found to be lacking in range and penetration compared to the German 75 mm Pak 40 anti-tank gun, now mounted on the Stug III and Panzer IV, and markedly inferior to the 88-mm gun of the Tiger I. Military planners directed the design bureaus of both Gen. Vasiliy Grabin and Gen. Fyodor Petrov to modify the 85mm anti-aircraft gun for use as an anti-tank weapon.

Petrov's bureau developed the D-5 85mm gun. Though much too large for the T-34 turret, it could be mounted in the chassis of the SU-122 self-propelled gun to create a tank destroyer. This was done, and the SU-85 tank destroyer went into production. Meanwhile, efforts were underway to redesign the T-34 turret to make it large enough to accommodate the newly developed gun.

Grabin, who had been working on a second 85mm gun, the ZiS-53, at Joseph Stalin Factory No. 92 in Gorky near Moscow, was reassigned to the Central Artillery Design Bureau (TsAKB) in Moscow. His project was turned over to 23-year-old A. Savin. A third team led by K. Siderenko was assigned to yet another 85mm gun project, and developed the S-18, to be used in the modified T-34 turret.

The resulting guns were tested at Gorokhoviesky Proving Grounds near Gorky, with Grabin's ZiS-53 winning the competition. However, the new T-34/85's turret had been designed to accommodate the already-available D-5 gun, and did not mate properly with Grabin's gun. The T-34/85 tank went into production making use of the D-5 gun (designated D-5T, for "tank").

Savin was put to work modifying Grabin's gun to fit the new turret and incorporate other improvements. His initial was added to his gun's designation in recognition of his contribution: the ZiS-S-53. From T-34/85 Model 1944 onwards, all T-34/85s used Savin's ZiS-S-53. It went into production in the spring of 1944. Later tests against captured German tanks found that the tank gun developed from the 85-mm AA gun, though an improvement over the 76 mm gun, still lacked the firepower of its German competitors. A new antitank gun was then developed, the 100 mm field gun M1944 (BS-3).

Penetration comparison

Penetration figures (90 degrees) uses American and British 50% success criteria,
and allowing direct comparison to foreign gun performance.^[2]

Gun type	Ammunition type	Muzzle velocity (m/s)	Penetration (mm)
			100 m	250 m	500 m	750 m	1000 m	1250 m	1500 m	2000 m	2500 m	3000 m
85mm/L52 (D-5T)	AP	792 m/s (2,600 ft/s)	142	135	125	116	107	99	92	78	67	57
85mm/L52 (D-5T)	APBC	792 m/s (2,600 ft/s)	139	133	123	114	105	98	91	81	73	65
85mm/L52 (D-5T)	APCR	1,050 m/s (3,400 ft/s)	175	159	136	117	100	85	73	54	39	29

See also

• Designations of Russian towed artillery

Weapons of comparable role, performance and era

• QF 3.7-inch AA gun : contemporary British anti-aircraft gun, firing a heavier (28 pounds (13 kg)) shell
• 8.8 cm Flak 18/36/37/41 : contemporary German anti-aircraft gun
• Cannone da 90/53 : contemporary Italian anti-aircraft gun
• 90 mm Gun M1 : contemporary US anti-aircraft gun

References

1. http://www.bergstrombooks.elknet.pl/bc-rs/raid.html
2. Bird, Lorrin Rexford; Livingston, Robert D. (2001). WWII Ballistics: Armor and Gunnery. Overmatch Press. p. 59.

• Hogg, Ian (2000). Twentieth-Century Artillery. Friedman/Fairfax Publishers. ISBN 1-58663-299-X.
• Jane's Armour and Artillery (1982). Jane's Publishing Company, Ltd. ISBN 0-7106-0727-X.
• Shunkov V. N. - The Weapons of the Red Army, Mn. Harvest, 1999 (Шунков В. Н. - Оружие Красной Армии. — Мн.: Харвест, 1999.) ISBN 985-433-469-4.
• Zaloga, Steven J., James Grandsen (1984). Soviet Tanks and Combat Vehicles of World War Two, London: Arms and Armour Press. ISBN 0-85368-606-8.

External links

• Soviet 85mm tank guns penetration table