SU-122

SU-122

SU-57B

YaG-10 (29-K)

SU-122

SU-57B

YaG-10 (29-K)

USSR

II Rank

Battle rating:

AB	RB	SB
2.7	2.7	2.7

Class:

Tank destroyer

Research:9 200

Purchase:16 000

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Description

The SU-122 is a rank II Soviet tank destroyer with a battle rating of 2.7 (AB/RB/SB). It was introduced during the Closed Beta Test for Ground Forces before Update 1.41. This vehicle was created on T-34 chassis. It carries a fearsome 122 mm M-30 howitzer.

The main feature of this SPG is a powerful gun, but make good use of the first shot. It is very hard to hit targets from over 500 m in realistic and simulator battles. One good tactic would be to rush an enemy tank and shoot him at point-blank range but this only works if there is no other enemy tank because with an untrained crew it can take up to 33 seconds before the SU-122 has reloaded.

General info

Survivability and armour

Armour type:

• Rolled homogeneous armour
• Cast homogeneous armour (Gun mantlet, Driver's hatch)

Armour	Front	Sides	Rear	Roof
Hull	45 mm (49-50°) Front glacis 45-100 mm (21-69°) Lower glacis	45 mm (17-41°) Top 45 mm Bottom	45 mm (47-48°) Top 45 mm (48°) Bottom	20 mm
Superstructure	45 mm (49-50°)	45 mm (17-18°)	45 mm (12°)	20 mm
Armour	Sides	Roof
Cupola	45 mm	20 mm

Notes:

• Suspension wheels and tracks are 20 mm thick.

Mobility

Game Mode	Max Speed (km/h)		Weight (tons)	Engine power (horsepower)		Power-to-weight ratio (hp/ton)
	Forward	Reverse		Stock	Upgraded	Stock	Upgraded
Arcade	60	10	30.9	710	954	22.98	30.87
Realistic	55	9		442	500	14.3	16.18

Armaments

122 M-30					Turret rotation speed (°/s)					Reloading rate (seconds)
Mode	Capacity	Vertical	Horizontal	Stabilizer	Stock	Upgraded	Full	Expert	Aced	Stock	Full	Expert	Aced
Arcade	40	-3°/+25°	±10°	N/A	13.21	18.28	22.25	24.55	26.12	23.66	20.93	19.29	18.20
Realistic					8.93	10.50	12.75	14.10	15.00

Ammunition

Penetration statistics
Ammunition	Type of warhead	Penetration @ 0° Angle of Attack (mm)
		10 m	100 m	500 m	1,000 m	1,500 m	2,000 m
OF-462	HE	37	37	37	37	37	37
BP-460A	HEAT	160	160	160	160	160	160

Shell details
Ammunition	Type of warhead	Velocity (m/s)	Projectile Mass (kg)	Fuse delay (m)	Fuse sensitivity (mm)	Explosive Mass (TNT equivalent) (g)	Ricochet
							0%	50%	100%
OF-462	HE	515	21.76	0.1	0.1	3670	79°	80°	81°
BP-460A	HEAT	335	13.4	0.0	0.1	3360	62°	69°	73°

Smoke shell characteristics
Ammunition	Velocity (m/s)	Projectile Mass (kg)	Screen radius (m)	Screen deploy time (s)	Screen hold time (s)	Explosive Mass (TNT equivalent) (g)
D-462A	515	23.3	20	5	25	50

Ammo racks

Ammo racks of the SU-122.

Full ammo	Ammo Part	1st rack empty	2nd rack empty	3rd rack empty	4th rack empty	Visual discrepancy
40	Projectiles Propellants	29 (+11) 29 (+11)	17 (+23) 17 (+23)	8 (+32) 8 (+32)	1 (+39) 1 (+39)	no

Usage in the battles

The main feature of this SPG is a powerful gun, but make good use of the first shot. It is very hard to hit targets from over 500 m in realistic and simulator battles since shell velocity is slow and shell drop is significant. The cannon's HEAT shell has excellent destructive power and higher penetration than its HE shell (and in fact can penetrate almost anything it will face), but it also has a slower shell velocity than the HE shell. Practice makes aiming at long distances easier, but it is still recommended to stay at close to medium range when possible. One good tactic would be to rush an enemy tank and shoot him at point-blank range, but this only works if there is no other enemy tank nearby because with an untrained crew it can take up to 33 seconds before the SU-122 has reloaded.

This slow reload rate also means that the SU-122 cannot effectively deal with multiple enemies at the same time. Therefore, team play is almost a necessity. This is especially important since, of course, the SU-122 is a case-mate tank destroyer without a traversable turret. The vehicle's flanks are incredibly vulnerable to enemy flankers, and although the side armour can stop small-calibre rounds, they will not usually stop shells from enemy tanks. It is very important to keep a constant lookout for enemy flankers, especially when fighting at closer ranges where the enemy can sneak up without your noticing.

When the loader(s) is wounded or knocked out, the long reload time will become even longer, and playing effectively with the SU-122 then becomes very difficult. So, avoid exposing the loader to enemy fire when possible. Thankfully, the SU-122 has a decent armour layout. Its front armour, while not anything amazing, can still protect against some low-rank guns, and the gun mantlet is very strong. The tank also has fairly small silhouette. Nevetherless, the armour is not sufficient against high-rank guns, and due to the crew layout within the tank, a shot to the left side can knock out three of the five crew members--including the driver and the gunner. This is a debilitating hit and will often result in the SU-122's outright destruction. If possible, position your tank so that it is difficult for the enemy to hit this left side of your vehicle.

The SU-122 plays well has a hull-down tank destroyer: this is where its powerful gun shines and where the issues caused by its long reload are minimized. If choosing this playstyle, the player should remember that the SU-122 suffers at long ranges due to its slow shell velocity. Therefore, choose hull-down positions so that the enemy will appear at close or medium ranges. Also be aware that the SU-122 has bad gun depression, which can make shooting over ridgelines very difficult.

Another possible playstyle is close/medium range brawling. In this playstyle, it is important to work with teammates, since the lack of a turret means that the SU-122 has very little side protection; it can only deal with enemies from the front. It it aided by good mobility and great acceleration, which are both useful qualities to have in close-range fighting.

Modules

Tier	Mobility		Protection	Firepower
I	Tracks		Parts	Horizontal Drive	BP-460A
II	Suspension	Brake System	FPE	Adjustment of Fire
III	Filters		Crew Replenishment	Elevation Mechanism
IV	Transmission	Engine		D-462A

Pros and cons

Pros:

• Great firepower, capable of destroying tanks with a single shot when used with HEAT rounds
• Front Armor - while not outstanding, can still bounce some low-rank guns
• Mantlet is very strong and can bounce off it
• Great acceleration
• Good mobility
• Somewhat low silhouette
• Two re-spawns in SB mode

Cons:

• long reload time, the wounded loader will increase it
• Weak armour against higher rank guns
• Limited gun arc
• Bad gun depression
• Gun takes time to get used to
• Gun mantlet can limit the view when in sniper mode only when in SB Mode

History

Development

The success of the Germans StuG III and other self-propelled assault gun took the Soviet High Command's interest on the concept. Self-propelled guns were generally considered cheaper and more easily produced compared to regular tanks due to the lack of turret, plus it could be made with a large fighting compartment and bigger guns than those that could be mounted on turrets, the only drawbacks to the designs were limited traverse of the gun so it would do poorly in close-quarters situations.

On the 15th April, 1942, the Soviets asked design bureaus to begin development of assault guns using a wide selection of armament ranging from their 76.2 mm ZiS-3 field guns, 122 mm M-30, and 152 mm ML-20 howitzers. The prototype assault gun was armed with the 122 mm and was quite similar to the StuG III's design, designated the SG-122, of which only 10 were made due to reliability issues. The next step was to take the standard issued Soviet tank, the T-34, and convert that into the assault gun. The prototype, U-34, was created in summer of 1942 in the Uralsky Machine Building factory by N. W. Kurin and G. F. Ksjunin. It initially had the same armament of 76.2 mm, but it was 70 cm lower than the regular T-34 and had more armour at a lighter weight, this did not enter production. Another work was done to combine the U-34 features with the SG-122, this was completed in around late summer of 1942 and featured the U-34 chassis with the 122 mm armament placed on with the least modifications possible to keep the design affordable and easy to produce. This new design, now the U-35, was created on November 25, 1942, and was sent for evaluations. There were faults discovered in the elevation mechanism, loading system, and ventilation for the crew. Despite these flaws, the vehicle was accepted into service first as the SU-35 but then renamed the SU-122. Several modifications were made to the vehicle during production, such as simplifications to the design, modified interior layout, removed vision slots, and added a commander's periscope. The production began in December 1942 and continue on until summer of 1944 with 1,150 total unit produced.

Design

The vehicle was based off the T-34 chassis, so it uses the same running gear, engine, suspension, and tracks as the T-34. This is consistent with the concept of utilizing the chassis of proven vehicles and converting them into other uses. The design mounted the 122 mm M-30 howitzer, which was made for infantry support in a role similar to the StuG III in German usage. The M-30S howitzer could be elevated or depressed between −3° and +26° and had 10° of the traverse. The design had no armour advantage over the standard T-34 with 45 mm thick frontal armour to keep production simple. The design had a crew of five, the driver, gunner, commander, and two loaders to load the 122 mm shells.

Combat usage

The first few SU-122s created were sent to training centres and to two combat units, the 1433rd and 1434th self-propelled artillery regiments. Each regiment was intended to have two batteries of four SU-122s and four batteries of four SU-76s. Thirty of such self-propelled artillery regiments were planned to be raised in the armour and mechanized corps. In January 1943, the 1433 and 1434 regiments were sent to Leningrad near the Volkhov Front to support the 54th Army. These regiments and their self-propelled guns first saw action on January 14 in the Smierdny region. Combat experience showed that the best deployment of the SU-122s was about 400 to 600 meters behind advancing tank units, to which it was sometimes reduced to just 200 meters minimum distance. The mixed deployment of the SU-76 and the SU-122 was a failure and the organization was changed. The new system had two batteries of SU-76 and three batteries of SU-122s for 20 vehicles, this was changed again in April for separate regiments for SU-76s and SU-122s (called "light" and "medium" respectively). The medium self-propelled artillery regiments had four batteries of four SU-122s each for 16 vehicles. An additional SU-122 or T-34 was added as a commander for the regiment, along with a BA-64 armoured car for reconnaissance duties. This organization of the self-propelled artillery regiments stayed until the beginning of 1944 as newer and better self-propelled guns such as the SU-85, ISU-122, and ISU-152 were being produced, when the SU-122 was beginning to be phased out as well.

The SU-122 in combat proved very effective in its role as direct fire support on strongholds. The high-power high-explosive rounds create a massive concussion blast on impact and may be powerful enough to even knock the turret off a Tiger I tank. Until May 1943, only the HE rounds were available for the 122 mm gun, but the BP-460A HEAT rounds were introduced on that month that could theoretically penetrate any armour the German have on their tanks, but the HEAT round's primitive design and fuse, adding the gun's inaccuracy, caused the SU-122 to not be an effective tank destroyer.

The SU-122 was never mass-produced in multiple variants, however, some were converted into prototypes. The SU-122M had a larger compartment and newer D-11 gun, and the SU-122-III had an even lighter gun than the D-11, but was unsuccessful due to unreliability. Both of these were cancelled when production priorities went to the SU-85 design.

Survivors

Only a small number of SU-122s survive the war, with only one known example on display at the Kubinka Tank Museum.

In-game description

"This SPG armed with a 122 mm М-30 Mod. 1938 howitzer was developed in October-November 1942 to support and escort tanks. In December of the same year, it entered production and was put into service.

The SPG was built on a T-34 chassis with an armoured cabin containing the driving compartment and the fighting compartment. To protect the howitzer's recoil mechanism, a large forward-extending armoured mantlet was used which swung with the weapon. The gunnery equipment could be used to fire both directly and from cover. The howitzer's ammunition load of 40 shots included high-explosive fragmentation shells and hollow-charge projectiles. The vehicle's undercarriage differed from the T-34 in the strengthened head assembly of its suspension. A 9R radio set was mounted on the SPG, along with the TPU-3-BisF intercom.

The vehicle was produced throughout 1942-1943, with 638 manufactured in total. Throughout its production, a large number of modifications were implemented with the aim of improving the vehicle's quality and simplifying its manufacturing. Work performed on perfecting the manufacturing and assembly technologies involved reduced the labour costs of its production by 15%.

The SU-122 was put into service in SPG regiments in quantities of up to 16 vehicles per regiment.

The SPG's flaws were: its small horizontal firing angle and complex aiming; long barrel length complicating manoeuvring on rough terrain and in urban areas; low rate of fire in combat; relatively small on-board ammunition capacity; and lack of a machine gun for self-defence. In spite of these flaws, the SU-122's high firepower, manoeuvrability and defensive capabilities made it a dangerous opponent in battle."

Media

Camouflages and skins for the SU-122 from live.warthunder.com

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