| D-20 | |
|---|---|
 | |
| Type | Towed howitzer |
| Place of origin | Soviet Union |
| Service history | |
| Used by | Soviet Union, many others |
| Wars | |
| Production history | |
| Designer | Petrov Artillery Design Bureau |
| Designed | 1947 |
| Manufacturer | Artillery Plant Number 9,Yekaterinburg |
| Specifications | |
| Mass | 5.7 t (5.6 long tons; 6.3 short tons) |
| Length | 8.69 m (28 ft 6 in) |
| Barrel length | 5.195 m (20 ft) L/34 (withmuzzle brake) |
| Width | 2.35 m (7 ft 9 in) |
| Height | 1.93 m (6 ft 4 in) |
| Crew | 8 |
| Shell | 152.4 x 547.5 mm R Separate loading charge and projectile[1] |
| Caliber | 152.4 mm (6.00 in) |
| Breech | Vertical semi-automaticsliding-wedge |
| Recoil | Hydraulic buffer andhydro-pneumatic recuperator |
| Carriage | Split trail |
| Elevation | -5° to 45° |
| Traverse | 58° |
| Rate of fire | Burst: 5–6 rpm Sustained: 1 rpm |
| Muzzle velocity | 650 m/s (2,100 ft/s) |
| Effective firing range | 17.4 km (10.8 mi) |
| Maximum firing range | 24 km (15 mi) (rocket-assisted projectile) |
| Sights | PG1M indirect sight and OP4M direct fire sight |
The152 mm gun-howitzer M1955, also known as theD-20, (Russian:152-мм пушка-гаубица Д-20 обр. 1955 г.) is a manually loaded, towed 152 mmgun-howitzerartillery piece, manufactured in theSoviet Union during the 1950s. It was first observed by the West in 1955, at which time it was designated the M1955. ItsGRAU index is52-P-546.[2]
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152 mm has been a Russian caliber since World War I, when Britain supplied6-inch howitzers and Russia purchased 152 mm guns fromSchneider (probably derived from the 155 mm Gun Mle 1877/16) for the Imperial Army. The new gun-howitzer, was a replacement of the pre-warML-20 gun-howitzer (the152 mm howitzer M1937) and various World War II era 152 mm field howitzers,Model 09/30,Model 1910/30,Model 1938 (M10) andModel 1943 (D-1).
By Soviet definition, a 152 mm howitzer is "medium"-caliber artillery. It was designated a "gun-howitzer" because its muzzle velocity exceeded 600 m/s, and its barrel length exceeded 30 calibers. It equipped battalions in the motor rifle division artillery regiment and army level artillery brigades.
The design, which was probably initiated in the late 1940s, was first seen in public in 1955. It was designed by the well-established design bureau at Artillery Plant No. 9 inSverdlovsk, nowMotovilikha Plants in Yekaterinburg, led by the eminent artillery designerFyodor Fyodorovich Petrov, who was responsible for several World War II pieces. The gun'sfactory designation was "D-20".
The carriage is the same one used for theD-74 122 mm field gun. The barrel assembly is the basis for theD-22 (GRAU index:2A33), which is used for the self-propelled2S3 Akatsiya ("Acacia").
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The D-20 has a 26 caliber (3.962 m) barrel, with a double bafflemuzzle brake and a semi-automatic verticalsliding-block breech, with a tied jaw and the block moving down to open. The barrel is mounted in a long ring cradle with the trunnions just forward of the breech. The recoil system (buffer and recuperator) is mounted on the cradle above the barrel. Compression balancing gear is attached behind the saddle support, passing through the complex shaped saddle to connect to the cradle just forward of the trunnions. This can be manually repressured by a pump below the breech. The breech has a projectile retaining catch to prevent the shell sliding out at higher elevations before it is rammed with a manual rammer.
Top traverse totals 58° and the vertical elevation range is −5° to 45°.
Box girder sectionsplit trail legs are hinged to the cradle support, with bolts to lock them into either the open or closed position. The cradle support has a bolt for locking the barrel in the centre for traverse before towing the gun. Large spades are permanently fixed close to the end of each trail. These are hinged and it appears that the gun can be fired with them up or down depending on the terrain. They are always up when the gun is towed.
To assist with all-round carriage traverse, there is a pivot jack mounted at the front of the cradle support. The pivot jack is not a sole plate and the gun fires with its foam filled rubber tyred wheels supporting the gun on the ground. When the gun is brought into action, the pivot jack is folded down and adjusted to be on the ground. If a large traverse is required, small jacks on each trail leg are rotated downwards, and the trails jacked up until the main wheels are lifted clear of the ground and the bogey wheels mounted on each trail leg swung downwards and the trail jacks raised. The carriage is then traversed, and the trail jacks reused to lift the bogey wheels and then place the piece back on its main wheels.
The pivot jack is used to secure the barrel against vertical movement when the gun is being towed. The barrel is locked in the centre for traverse with a bolt on the cradle support. The jack is folded upwards, lugs on the ring cradle engage the jack base and two tensioners fixed to the saddle support are hooked to the cradle. These are tightened to lock the cradle onto the jack base.
As was normal for the period, the gunhas a shield, including a folding piece below the cradle support. The centre section of the upper shield slides both up and down, and folds to accommodate the barrel at higher elevation angles of fire. The shield may offer some protection against muzzle blast to the sights and layer, although it is usually shown being fired with a long lanyard, but is probably mostly for defence against machine gun fire.
The non-reciprocating sights are standard Soviet pattern, designed for one-man laying. Included are a direct fire anti-tank telescope (OP4M), a panoramic periscopic indirect-fire sight, a dial sight, (PG1M) in a mounting, an angle of sight scale, and a range drum for each charge engraved with the range (distance) scale, coupled to an elevation leveling bubble mounted on dial sight mount. The range drum enables the standard Soviet technique of semi-direct fire when the piece is laid visually on the target, and the range set on the range drum.
Like most Soviet artillery, the gun fires separate ammunition using metal cartridge cases that also provideobturation. The ammunition is interchangeable with that used with other 152 mm guns, although the more modern ones have a third, much larger cartridge. The D-20 uses two types of cartridge. One has a base charge and up to five increments, the other is a single 'super' charge cartridge.
The standard shell weight is 44 kg with a muzzle velocity of 655 m/s, but some projectiles are more or less than this. The basic shell ishigh explosive (HE) andfragmentation (HE-frag). Other projectiles include smoke,illuminating,chemical and probablyincendiary.
Later projectiles include bomblet,anti-personnelland mine,flechette,Krasnopolprecision-guided munition (PGM), communicationjammer, and extended range HE using rocket assistance (RAP). The normal maximum range is 17.4 km, RAP being farther. Two direct-fire anti-tank projectiles have been used,high-explosive anti-tank (HEAT) andarmour-piercing ammunition (APHE), the latter being 5.2 kg heavier and with a lower muzzle velocity.
The maximum rate of fire is usually stated as five rounds per minute, and 65 rounds per hour sustained. In Soviet service, the unit of fire was 60 rounds.
The detachment was either 8 or 10 men, probably differing between armies and the time period. In Soviet service, the 5,700 kg gun was usually towed by a URAL-375 6×6 truck or, in some regions, an AT-S or AT-L medium tractor.
During the2022 invasion of Ukraine both sides have relied on the D-20.[3][4] Russian forces have started deploying the weapons from storage.[3] There are reports of at least one Russian D-20 being destroyed due to poor ammunition. This weapon was in the service of theLuhansk People’s Republic.[5]
The USDefense Intelligence Agency has reported the existence of several self-propelled artillery systems, mating existing cannon systems with a locally designed chassis. TheSPH 152 mm M1974 appears to be a D-20 or Type 66 mounted on a tracked chassisTokchon.[8]
An unnamed self-propelled version of D-20 placed on 8×8 chassis developed by Viettel.
Source:[12]
Angola – 4 as of 2016[update][14]
Armenia – 34 as of 2016[update][15]
Azerbaijan – 24 as of 2016[update][16]
Belarus[17]
Bulgaria – 44 as of 2016[update][18]
Cuba – 100, supplied between 1972–1974[17]
Democratic Republic of the Congo – 6[19]
Ethiopia – 20
Georgia – 12 received from Bulgaria in 2009[17]
People's Republic of China – Type 66[20]
Republic of the Congo[21]
Hungary – 18 as of 2016[update][22]
Iran – 30 as of 2016[update][23]
Iraq – All destroyed in2003 invasion of Iraq, new models bought from Bulgaria in 2015[24]
Iraqi Kurdistan[25] – 6 captured fromIraqi Army in 1991, 4 captured in 2003, 10 in total used byKurdistan Democratic Party (KDP) Peshmerga
Laos – in service as of January 2019[update][26]
Moldova – as of 2016[update][27]
Myanmar – 150+ delivered in 2009 from North Korea and Ukraine[28]
Nicaragua – 12 serving, 30 stored as of 2016[update][29]
Nigeria – 4 M81/M85 from Romanian Army stocks[citation needed]
North Korea – 200 possibly supplied by China in 1972–1975[17]
Russia – 1,075 as of 2016[update][30] - 575 as of 2025[update]
Romania –Romanian Army has 247 M1981 howitzers, 103 M1985 gun-howitzers[31]
Sri Lanka – 46 Type 66 as of 2016[update][32]
Syria[33]
Turkmenistan – 72 as of 2016[update][34]
Ukraine – 130+ as of 2016[update][35]
Vietnam[36]
Yemen[37]
Albania – 90 type 66 supplied from 1968–1973[17]
Artsakh − Seized by Azerbaijan after the2023 Azerbaijani offensive in Nagorno-Karabakh[38]
Bolivia − 18 Type 66 delivered by China in 1992[39]
East Germany – 137 supplied in 1974–1975,[17] passed to Germany afterGerman unification
Egypt – 300 supplied between 1964–1970[17]
Finland – 126 bought from ex-DDR in 1991; phased out 2017; known as152 H 55[17]
Germany – Phased out
Kazakhstan[citation needed]
Soviet Union – passed to successor states
Uzbekistan[citation needed]
Yugoslavia – 36 supplied in 1971[17]
