WW2 Soviet Heavy Tank Prototypes

KV-220 (Object 220/T-220)

Soviet Union (1940-1941)
Heavy tank – 2 Prototypes Built

Even before the KV-1 entered mass production, there were plans to improve its characteristics, most importantly the armament and armor. One of these was the KV-220, an attempt to improve the armor of the KV-1 up to 100 mm, and increase firepower with an 85 mm F-30 gun. Designed and built at the Kirov Leningrad Plant, two prototypes were finished in late 1940 and mid-1941 after a convoluted history. They then saw combat in the Leningrad area with the start of the Great Patriotic War (Operation Barbarossa).

The KV-220 before its trials, January 1941.
Source: Tank Archives, colorized by Johannes Dorn

The KV-1

The experiences gathered during the Winter War (November 1939 – March 1940) against Finland gave the Soviets invaluable tactical and technical information regarding development and use of heavy tanks. The massive SMK (from LKZ, Leningrad Kirov Factory) and T-100 (from Plant No.185) multi-turreted tanks were attempts to create a successful breakthrough heavy tank. Nevertheless, their fundamentally troubled design, based on the hopelessly obsolete T-35, would fail them. The U-0, essentially a smaller, lighter, one-turreted SMK, would prove to be far more successful during its trial combat period on the Karelian Isthmus. Consequently, on 19 December 1939, 50 such tanks were ordered. The tanks would be known with the acronym KV, from Kliment Voroshilov, the People’s Commissar of Defense of the Soviet Union at the time, but as they were preseries production, each vehicle was documented with U-XX, with each new tank receiving a new, higher number.

The U-0, armed with a 76 mm L-11 gun and a coaxial 45 mm 20-K gun. It would see combat on the Karelian Isthmus from December 1939.
Source: Topwar

Despite the KV’s improvement over its larger predecessors, it was still far from perfect. By July, only 32 tanks had been built (including 14 KV-2s, or, as known at the time, ‘Big Turret KVs’). This was caused by the fact that the KV’s were not fully refined yet, with countless mechanical and production flaws. Each new U-series tank was unique, with different features meant to fix previous problems. This was accounted for from the beginning, as mass production was expected to begin by 1941. However, Stalin’s patience waned. In what would become “The Stalin Task” via a decree from the Council of People’s Commissars of the Soviet Union, it was required that LKZ reach a yearly production quota of 230 KV tanks of both turret variants (130 small turret and 100 big turret), essentially forcing the still unrefined tanks into service. This move would have detrimental effects on the KV-1 and KV-2 throughout their service life.

Only by August 1940 could full scale production of the KV tanks begin, with 20 built in August and 32 units in September, surpassing the expected monthly quota of 20 vehicles.

Stacking Weight

As early as May 1940, the GABTU (Main Directorate of Armored Forces) and the People’s Commissariat of Heavy Engineering considered improving the armor of the KV-1. This was a curious move, as the KV-1, with 75 mm of armor all-around, was capable of withstanding fire from most anti-tank guns used at the time. Perhaps even more bizarrely, would be that the KV-1 was struggling to function at its 44 tonnes. The wiggling room for additional armor was small.

First concrete mentions of thickening the armor of the KV came on 11 June, suggesting to up-armor the tank to 90 to 100 mm. Around a month later, on 17 July, the Council of People’s Commissars of the Soviet Union adopted decree No. 1288-495§, which stated:

  • By November 1, 1940, the Kirov Plant will produce two KV tanks with 90 mm of armor: one with a 76 mm F-32 gun, the other with an 85 mm gun. The Izhora Plant will deliver one hull at the end of October, the production of the tank is scheduled to be completed by November 5. The second hull will be made by November 5th.
  • By December 1, 1940, the Kirov Plant will produce two KV tanks with 100 m of armor: one with a 76 mm F-32 gun, the other with a 85 mm gun. One hull will be delivered by the end of October and by the end in November.

The first paragraph discusses two tanks, both integrating 90 mm of armor all-around. The variant armed with the 76 mm F-32 gun would become the T-150, while the one with the 85 mm F-30 would become the T-221.

The second paragraph mentions another two tanks, with 100 mm of armor all-around. Like previously, one was to be armed with the 76 mm F-32 and the other with the 85 mm F-30. The latter would become the T-220. What exactly happened to the variant with the 76 mm gun is unclear. It was likely either dropped in favor of the T-150 or incorporated within the T-220.

Despite the decree, work did not begin immediately. LKZ was working full-time on improving the existing KV-1 and KV-2, and preparing for their mass production. Further delays were caused by the GABTU sending the specific technical requirements late.

The new tanks were to be designed at LKZ’s SKB-2 design bureau and the prototypes would be built at the Izhora plant. The projects were handled by the head of SKB-2, J.Y. Kotin, who, in August 1940, would appoint several teams for the development of the tanks. For the T-150, Kotin appointed Military Engineer L.N. Pereverzev as head of the project, while the T-220 team was to be headed by L.E. Sychev. An experienced tank engineer, Sychev had worked on the T-28, SMK, and KV-1, having completed his bachelors at SKB-2 in 1932 and after graduating in 1934, starting work at SKB-2. At some point during the project, Sychev was replaced by B.P. Pavlov as head designer. Gun installation and mechanism were designed by P.F. Muraviev, while the transmission was designed by N.F. Shashmurin. Ultimately, the design team of the T-150 (and likely KV-220 as well) consisted of B.P. Pavlov, L.E. Sychev, V.K. Sinezersky, S.V. Kasavin, F.A. Marishkin, and N.F. Shashmurin.

Joseph Yakvolevich Kotin, at the time head of the SKB-2 design bureau of LKZ. He would be the man behind most Soviet heavy tanks.
Source: Andrei BT
Leonid Efimov Sychev, chief designer of the KV-220. He was born in 1913 and was native to Leningrad (St. Petersburg).
Source: Museum of SPbPU

When designing the T-220, Sychev’s team encountered several issues. It was clear that the hull of the KV-1 was not big enough to accommodate the larger turret or additional 25 mm of armor. Additionally, the tank would have been significantly heavier, and a much more powerful engine was required. The clear choice was to lengthen the hull by 1 roadwheel, allowing for a much larger 850 hp V-2SN engine, as well as comfortably fitting a longer turret. Ground pressure was also lowered. The tank was named T-220 and later called Object 220 and KV-220.

Fitting the 85 mm F-30 gun in the KV-1 turret was ruled out, as it was simply too large. Instead, a turret inspired from the earlier designed KV-2 was drawn. It featured long side walls, allowing the crew members to adequately operate the gun, as well as a smaller turret on top armed with a DT 7.62 mm machine gun.

By September, the technical documents and drawings were ready and were sent to the Izhora plant for prototype production. However, the Izhora plant Hall No.2 was working at full capacity with the production of KV-1 and KV-2 tanks, with four tanks on the lines at the same time. Consequently, the construction of the prototype was delayed, and the tank was sent to the factory, complete, on 7 December, six days late. This first tank was given serial number M-220-1.

The finished KV-220 tank without machine guns at LKZ. Note the KV-2 turret in the bottom left corner.
Source: TsAMO
The lighter “brother” of the KV-220, the T-150 (KV-150/Object 150). Colorization by Johannes Dorn
Source: Warspot

Second Prototype

A second KV-220 was to be built as well, with the serial number M-220-2. The exact characteristics of this prototype had been tinkered with several times, which led to a very delayed production, with various sources claiming that this was in fact the Object 221, while other data contradict this claim. It is possible that this prototype was to be the 76 mm F-32 armed KV-220, but at the start of February, the turret of the tank was at Plant No.75, awaiting installment of the same 85 mm F-30 gun as on the M-220-1. On 19 February, the tank was instead to be armed with the 107 mm ZiS-6 after a series of studies had been made. Construction of the second prototype would only begin by 7 June and the military representative of LKZ, Military Engineer 2nd Rank A. Shpitanov, would claim that the tank would be ready no earlier than 10-15 July.

Object 221/T-221

Between the T-150 and T-220, there was a third vehicle, as originally requested in July 1940. It was to have 90 mm of armor, as the T-150, but with the same 85 mm F-30 gun as on the KV-220. The result was essentially just a KV-220, but with just 90 mm of armor, as opposed to 100 mm, and named T-221 (Object 221). Thus, due to its appearance, this vehicle is often confused with the KV-220. On 19 February, its armament was changed to the 76 mm ZiS-5 gun, and the turret was to be produced by 1 March. Only a mock-up was built in March 1941, and its mock-up chassis was later used on the mock-up of the Object 223 (KV-3).

Object 212 SPG

Another project based on the KV-220 was the Object 212 SPG, also named in documents as just 212, but not to be confused with the KV-based tractor with the same index. It was meant as a genuine bunker buster vehicle, intended to replace the KV-2, as a result of the sour taste left by Finnish fortifications encountered during the Winter War. It was to be armed with the 152 mm Br-2, based on the inverted chassis of the KV-220, with a large casemate. Only some components were built until the evacuation of SKB-2 in August 1941, and the entire project was transferred to UZTM factory, where development would continue slowly until the project died out, largely due to the cancellation of the KV-220 and later the KV-3.

The Object 212 SPG. Note the KV-220 inverted chassis
Source: Warspot


The addition of 25 mm of armor all around and the larger 85 mm gun necessitated a major overhaul of both the hull and turret of the KV-1. The thickening of the armor was done outwards, which allowed for very similar interior dimensions to those on the KV-1.

Firstly, the hull was elongated to over 7.8 m, most noticeable with the addition of an extra roadwheel and return roller. The lengthened hull allowed for the mounting of a larger engine, as well as decreasing the ground pressure of the tank. As the tank was to be far heavier, a new engine was required, and the 850 hp V-2SM experimental engine from Plant No.75 was chosen.

Secondly, and most importantly, the turret was a completely new design. It was largely based on the turrets of the KV-2 and Object 222. A large curved mantlet with gun housing was mounted on the flat frontal turret face. The sides were vertically flat, but had a slight curve along their length. The rear was also flat, but featured a large square door, used for entry and exit of the crew, ammunition replenishment, and removing the armament. The sides of the turret were flat, as opposed to angled at 15°, as both Kotin and factory director I.M. Zaltsman noted that mounting the turret walls at a right angle allowed for far stronger joints and easier production, without sacrificing much in terms of protection.

Across the upper edge of the turret, five handles were added for easier climbing on the large turret for the crew. On each side, a firing port for crew weapons was added.

Side view of the KV-220.
Source: Tank Archives

Perhaps one of the most interesting features of the KV-220 was the small secondary turret, which also acted as a commander’s cupola, with full 360º traverse. It was very similar to those designed by Plant No.185 for their T-103, though there might be an element of coincidence. It had four periscopes, one facing each direction. A 7.62 mm DT machine gun was mounted within. The cupola armor was also 100 mm thick all around, making it cramped when loading and firing the machine gun. The cupola was just large enough for the commander to fit his head. No service hatches were given. Another problem with the cupola was the firing blindspots created by the periscopes in front of it, especially the rotating PTC periscopes.

Rear view of the KV-220. The joint reinforcing rods can be seen on each side of the turret rear.
Source: Warspot


The larger turret and gun now required an additional loader, bringing the total crew to 6: tank commander, gunner, two loaders, bow machine gunner/radio operator, and driver-mechanic. The latter two were seated in the hull front, much like on the standard KV, with the driver in the center and radio operator to his left. Behind the driver was an emergency exit hatch in the floor.

The other four crew members were cramped in the turret, with the gunner to the left of the main gun. The commander was placed behind him and could control the machine gun turret. The two loaders were to the right of the gun.


The hull armor was nearly identical in layout and angling to the one on the KV-1, just 25 mm thicker, reaching 100 mm. The front had an angled lower plate, 100 mm, thick meeting with the belly (30 mm) and upper frontal plate (90 mm at 20º from horizontal) meeting into the frontal shield (100 mm at 60º). The sides were completely flat, also 100 mm thick. The rear, just like on the KV-1, consisted of two plates, the lower being 100 mm and the upper portion just 50 mm, as the engine cooling system was behind it.

The turret had 100 mm of armor all around, and the joints were welded together and reinforced by rods, which would run across from one plate into the other. It is important to acknowledge that the KV-220 was one of the first tanks where the Soviet industry had to deal with such thick armor.

Internal cutout view of the Object 220, showing the internal layout and details of the new turret. The blueprint is dated 6 January 1941.
Source: Edit from Stalin’s Supertanks IS-7


The engine used was the V-2SN 850 hp diesel engine developed by Plant No.75, which was a boosted variant of the V-5 engine (with a supercharger from the AM-38 aircraft motor combined with a pressurization system), which itself was a boosted variant of the V-2K engine used on the KV-1. Naturally, the engine was bound to become problematic due to its unstable nature. The tank was able to carry 825-845 liters of fuel.

Unlike its smaller ‘brother’, the T-150, the unreliable KV-1 gearbox was not used on the KV-220, but rather a reinforced and slightly modified version designed by N.F. Shashmurin. These alterations included a more compact box, improved tolerances and better dynamics. This was a crucial step in the right direction, not just for the KV-220 but for future KV tanks, which were to be fitted with better gearboxes.

Internal cutout top view, showing the engine, gearbox, and other hull components.
Source: Edit from Stalin’s Supertanks IS-7
KV-220 gearbox designed by N.F. Shashmurin.
Source: V. Lehn


The main armament on the KV-220 was the 85 mm F-30, developed at Factory No.92 by V.G. Grabin. It was based on the F-27 75 mm gun, but chambered for the larger 85 mm round and with improved recoil systems. The gun was installed and tested on the T-28 in spring 1939, and after a series of firing trials, was deemed satisfactory. Ballistically, the gun was near identical to the 52-K anti-aircraft gun, and shared ammunition.

T-28 medium tank armed with the 85 mm F-30, used for the gun’s testing.
Source: Yuri Pasholok

Mounting of the gun on the KV-220 was conceived by P.F. Muraviev. A PT-6 sight would be used for aiming, and a PTK panoramic periscope for battlefield vision for the gunner. The tank carried 91 rounds for the 85 mm gun, with at least 15 rounds stored in the turret bustle. The rest were in the hull, stowed in two different frames.

Secondary armament consisted of three DT 7.62 machine guns, one in a ball mount in the hull bow, one coaxially (right) with the main gun and one in the cupola. For these, 64 drums were provided, for a total of 4,032 rounds.

85 mm F-30 gun specifications
Muzzle velocity (m/s) 793
Shell weight (kg) 9.2
Penetration 88 mm from 1 km @ 30º


After the KV-220’s (M-220-1) reception in early December, the tank was inspected and prepared for trials. On 14 January 1941, an order from the People’s Commissariat of Defence and People’s Commissariats of Heavy Engineering requested that the T-150 and KV-220 tanks undertake driving and chassis trials at LKZ.

A commission, headed by assistant head of testing, Military Engineer 1st Rank Glukhov, and consisting of GABTU and LKZ officials, were to analyze the tanks and establish the following goals:

  • Determining the tactical and technical characteristics of the tank
  • Identifying the shortcomings in the designs and their elimination prior to mass production
  • Judging whether it is possible to conduct military tests
  • Accumulating data for operating and repairing the tanks
T-150 towing the KV-220 after it broke down. Although it also suffered a critical engine failure, the T-150 would get much further with its trials.
Source: TiV 11 2014

From a letter dated 28 January 1941 from Glukhov, reporting on the progress of the trials, several alarming details can be found, as both tanks broke down during driving trials. For the KV-220, it broke down while driving around the factory, on 21 January, as the engine failed after its main bearings melted. A new engine would be fitted a week later.

Another issue found with both the T-150 and KV-220 was when they were weighed. Both had surpassed the initial weight threshold imposed. The KV-220 weighed 62.7 tonnes, instead of 56 tonnes.

A second report from Glukhov would reveal the true failure of the KV-220’s engine. The tank had traveled 106 km and the engine worked for 5 hours and 51 minutes, allowing the 62.7 tonne tank to reach a top road speed of 21.2 km/h (according to Yuri Pasholok, 33 km/h) and averaged 18.6 km/h. During operation, hot engine oil was squirted from the engine cooling vents on top, as well as encountering power loss due to piston ring wear. Thus, oil usage spiked uncontrollably, to 15.5 liters per hour of operation, or 0.83 liters per km.

The KV-220 driving through heavy mud.
Source: Warspot

Unlike the T-150, the KV-220 never undertook firing trials either, mostly because of the unbalanced gun and the foot trigger being poorly made, an issue discovered in December 1940, and which would be postponed. On 19 February 1941, after a letter specifying the issue from Deputy People’s Commissar of Armament Mirzakhanov, Marshall Kulik would request that the KV-220’s turret be sent to Plant No.92 for alterations of the gun mechanism, but a specific date or deadline was not given.

The failure of the engines was not a surprise. In fact, before the trials, Plant No.75, through T.P. Chupakhin, could not guarantee the operation of either the V-5 engine on the T-150 or V-2SN on the KV-220. On 28 January 1941, another V-2SN engine was brought in and trials continued, but this one failed a few days later, on 3 February. Another engine could not be provided until 15 February.

In order to fix these crucial problems, a commission was set up on fixing and refining the V-5 and V-2SN engines, consisting of Glukhov, Chuptakhin, head of tank production at LKZ A.I. Lantsberg, as well as representatives from GABTU. The commission would determine that the engine trials were done prematurely and that they required operation testing, not field trials on tanks. Plant No.75 was tasked with finishing testing and fine tuning the engines by 10 April, and by the same date, the engines and improved cooling systems were mounted and tested on said tanks.

When the news of the failed trials of both tanks reached the GABTU and People’s Commissariat of Heavy Engineering, the head of the armored department of the GABTU, Military Engineer 1st Rank Korobkov, sent a letter to LKZ director I.M. Zaltsman demanding the engines to be fixed and continuing trials.

The KV-220 and the T-150 were covered with tarpaulins during trials to protect the gun, sights, and other sensitive equipment from the elements.
Source: Tank Archives
KV-220 driving on a slope during trials.
Source: TiV No.11 2014
Removing the KV-220’s engine’s plate, likely after the engine broke down during trials.
Source: Warspot
Removal of the transmission after critical powerplant failure on the KV-220. Note the T-150 to the right.
Source: TiV 11 2014

The KV-220 was not a cheap tank project. A report dated 30 May 1941 mentions in detail the developmental costs of KV experimental tanks, which in total amounted to 5.35 million rubles. The KV-220 alone cost 4 million rubles, this sum including both the KV-220-1 and KV-220-2. For context, a KV-1 Mod.1941 would cost between 523,000 to 635,000 rubles.

Stage of KV-220 Development Price (thousands of rubles)
Draft drawings 100
Scale models 25
Technical drawings 250
Prototype construction and factory trials 1200+1200
Proving ground trials 125+125
Drawing correction after trials 75
Repair of prototypes and improvements 450+450
Total cost 4,000

Source: CAMD RF 38-11355-101

Fitting the 107 mm F-42 (ZiS-6)

Both Kotin and Grabin had juggled with the idea of installing an 107 mm gun in a tank since 11 June 1940, originally in the KV-2. By August 1940, SKB-2 engineer G.N. Moskvin was tasked with researching the fitting of a 107 mm gun inside the KV-220 turret. The gun would turn out to be the 107 mm F-42, developed by December of the same year, and which was later indexed ZiS-6.

Initial calculations revealed that fitting the F-42 gun in the KV-220 turret would have raised great challenges, especially regarding the movement of the shells within the tank, as they were simply too long. Factor in bouncing of the tank while driving, and the loader’s job was impossible. The round was 1,200 mm long and weighed 18.8 kg. Splitting it into two, like on larger 122 mm and 152 mm rounds, was impossible.

Chief designer of Plant No.92, V.G. Grabin, on a trip at LKZ, would try to convince Kotin and the tank engineers that it was possible to fit the F-42 inside the KV-220. After struggling to fit inside the turret hatch, he was unable to lift the shell from the hull floor and into the turret. He would then criticize the tank designers for their reluctance to change the design and stated that the tank was merely a gun platform.

The second KV-220 prototype, M-220-2, was to be originally armed with the 76 mm F-32, and later the 85 mm F-30, as on the first prototype. However, by 19 February, the F-42 would appear again in a letter from Marshal Kulik, stating that the second prototype of the KV-220 was to be armed with the 107 mm F-42 gun at Plant No.92, where the turret was already at. Although the KV-220 was never fitted with the gun, its immediate offspring was.

Overlay of the 107 mm ZiS-6 (F-42) on the KV-220. Also note the difference in size between the 107 mm and 85 mm shell.

Heavier Tanks

By March, the improved engines from Plant No.75 were ready to be tested, but the situation was starting to change. On 1 March, the T-150 had been replaced by the Object 222, which featured a new, improved turret on the same hull. Shortly after, on 11 March, a letter from the intelligence services to the GABTU regarding German tank developments would lead to a series of changes in tank developments.

The highlight of the report was a 90-tonne Pz.Kpfw.VIII armed with a 105 mm gun, which would become the Löwe in late 1941. As a response, on 17 March, the GABTU tasked LKZ with designing an equivalent tank, namely the Object 224 or KV-4, weighing 72 tonnes and armed with the 107 mm ZiS-6, a secondary 45 mm gun, various machine guns, and a flamethrower. Frontal armor was to be 130 mm and side armor 120 mm.

By 7 April, the GABTU had reconfigured their requests. The Object 223 was born, which was a direct evolution from the KV-220 with thicker armor, up to 120 mm on the hull, and an entirely new turret made out of stamped armor sheets, also fitted with the ZiS-6. The turret was far larger than that of the KV-220, made out of 120 mm armor. The KV-4 was also altered, with a weight of at least 75 tonnes and side armor thickness increased to 125 mm. Lastly, a 100-tonne tank was requested as well, Object 225 or KV-5, with 170 mm of frontal armor, 150 mm of side armor, and the same 107 mm gun.

Combination of several photos of the Object 223 (KV-3). The hull of the mock-up was actually borrowed from the T-221 (Object 221), which was essentially just a KV-220 with 90 mm of armor.
Source: Yuri Pasholok

As a result of these developments, the KV-220 became sidelined, but its mere physical existence made it crucial in the development of the Object 223 (KV-3). For trial purposes, the hull of the KV-220 would be used, but with a V-5 engine which was to be replaced with a V-2SN once they were available. Between 12 and 14 April, weight tests with 70 tonnes were done on the chassis, to simulate the weight of the KV-3, with several issues discovered:

  • Leak from the V-5 engine’s crankcase
  • Incredibly slow speed and low power, the tank only being able to drive in 1st and 2nd gear off-road
  • 2 idlers had to be replaced
  • 2 roadwheels were damaged
  • 1 torsion bar was damaged

With this smaller engine, the trial tank sustained a consumption of 2.9-3.2 liters per kilometer (31-34 liters per 100 km).

The Object 224 (KV-4), namely the winning design of the KV-4, by N.L. Dukhov would be an enlarged KV-220. The hull was much larger and the turret was equipped with a loading assistant mechanism for the large shells. There are at least two documents mentioning the KV-220 as the KV-4, before the Object 224 existed, which makes sense considering the T-150 was also temporarily called KV-3.

KV-4 design by N.L. Dukhov, essentially just an enlarged KV-220.
Source: ASKM

During May and June 1941, SKB-2 was busy working on the technical details of the Object 223, 224, and 225, as well as conducting firing trials of the ZiS-6 gun mounted on a KV-2. But with the Axis’ invasion of the Soviet Union, priorities changed. The heavy tank losses suffered by the Soviets required massive efforts from both repair units, but also factories to ramp up tank production and repair. Thus, progress on the massive heavy tanks slowed down. Likewise, the KV-1 proved to be catastrophically unreliable, although its excellent armor shined several times, and work had to be done to improve the tank.

It is worthy to mention that during the same period, the KV-2 was armed with the 107 mm ZiS-6 fitted via a KV-3 mantlet and firing trials were held.

KV-2 during firing trials, middle of June 1941. The man with white uniform was V.G. Grabin himself. The KV-220 was also meant to be armed with this gun, but it was simply too large.

Second Trials

Despite the development of the new heavy tanks, work on the KV-220 continued. On 31 May, a third V-2SN engine was delivered by Plant No.75. The new engine (serial number 1193-03) worked well, and by 20 June, the tank had rolled a total of 1,979 km, of which 583 km between May and June. The engine worked for 27 hours and 21 minutes. There were still several problems with the tank:

  • 3 exhaust manifolds burned over 284 km
  • 4 drive belts broken off/burned (caused by improper alignment, sides got worn out)
  • 10 of the 14 roadwheels sustained rim damage and one was cracked.
  • 5 return rollers suffered damage to the rubber.
  • Right final drive failed due to failure of 2 ball bearings, 2 roller bearings, 1 cone bearing, and the main gear was worn out and had heat damage

In response, changes were made to the tank, such as thickening the amount of rubber on the return rollers, of which half had rubber compressed at 16 tonnes and the other half at 18 tonnes. Other changes were the replacement of old filters with the experimental ‘Vortex’ oil filters , which had a mushroom shaped filter for trapping oil, as well as new exhaust manifolds and compensators.


For LKZ, the situation turned sour in August, when the German forces were knocking on the doors of Leningrad. Many SKB-2 engineers were evacuated to the ChTZ plant in Chelyabinsk, alongside some tank prototypes for further work, like the KV-3 (Object 223), which was meant to continue development. The KV-4 and KV-5 were discontinued. Interestingly, based on an order from Zaltsman on 30 June, the KV-3 was to be shipped to ChTZ with the V-2SN engine from the Object 220. This likely never happened.

The T-150 and the two KV-220 prototypes suffered a different fate. Kliment Voroshilov, member of the State Defense Committee, had a meeting with LKZ officials, including I.M. Zaltsman in Smolny, requiring prototype vehicles to be made combat ready in order to defend Leningrad. According to Military Engineer A.F. Shpitanov, 20 tanks were prepared for combat. They were placed in the Kirov district in Leningrad.

But how exactly the KV-220 tanks were to be used in combat was unclear. The M-220-1 prototype was functional, but the 85 mm F-30 was never tested and the gun was unbalanced, thus unsuitable for firing. The M-220-2 prototype had just left the production line in mid-July, but it still had no turret. The logical solution was that each of the tanks were fitted with standard KV-1 turrets, armed with the 76 mm F-32 guns.

The two KV-220 prototypes were sent to the 124th Brigade, with prototypes M-220-1 and M-220-2 being sent on 5 and 16 October respectively to defend Leningrad district. Not much is known about the fate of the first prototype, but the second one has a much more interesting story.

Documents show that the 124th Brigade, including tank M-220-2, named ‘For the Motherland!’, and likely prototype M-220-1 as well, were engaged in combat in the Ust-Tosno area, south-east of Leningrad, alongside 43rd Rifle Division.

On 11 November, at 12:00, the 124th Brigade and 147th Infantry Regiment assaulted a railway bridge in the direction of Ust-Tosno. Fighting commenced around the railway embankment and the bridge over the Tosna River. In total, 19 KV tanks were lost, of which 5 were burned. The KV-220 (serial number M-220-2) was likely one of these.

Russian historian Maxim Kolomiets interviewed with D. Osadchim, who was commander of a KV tank company belonging to the 124th Brigade in autumn 1941. Regarding the KV-220 he recalled:

“In the autumn of 1941, our brigade received several KV tanks for replenishment, one of which was called “For the Motherland!”. It was made in a single copy at the Kirov plant. It had the same capabilities as the KV tank, but had enhanced armor protection, a weight of more than 100 tonnes and a more powerful turbine engine. When driving in higher gears, the engine whistled, and this whistle was very similar to the whistle of the Junkers dive bombers. The first time after receiving the tank, when driving, the brigade even gave the signal “Air!” (raid). The tank entered my company, and at first they wanted to appoint me as its commander, but then my deputy, an experienced tanker, Lieutenant Yakhonin, became its commander. The tank was considered almost invulnerable to enemy artillery and was intended for assaulting fortified positions.
In December 1941 (I do not remember the exact date) our brigade was given the task of breaking through the German defenses in the Ust-Tosno section – the railway bridge, crossing the Tosna River and, in cooperation with units of the 43rd Rifle Division, developing an offensive on the Moscow State River. In the first echelon, I attacked as part of the 2nd Tank Battalion under the command of Major Paikin, while in the 1st Battalion was the tank “For the Motherland” from my company. In this battle, the tank was given the task of capturing the railway bridge over the Tosna River and holding the bridgehead for the approach of the main forces. The battle unfolded in an open area. The frozen top layer of peat bog could not hold the tank. When it came close to the bridge, it was met with fire from German heavy guns, and radio contact with them was lost. I was at the battalion’s command point at the time. When communication with the tank “For the Motherland” was interrupted, I tried to make my way to the scene along the railway embankment. When I managed to crawl up to the tank, I saw that the turret had been knocked down and the entire crew had been killed.”

It is important to highlight that Osdachim’s report was not entirely accurate, though it is understandable, as the interview took place at least 40 years after the fact. Nonetheless, it provides a good picture of how its users saw the machine, as well as the events of how it was lost.
In a tank write-off report from the 55th Army, the tank M-220-2 from 124th Brigade was listed as irreversibly lost via burning and it mentions that the tank had not been recovered. Its crew, tank commander Jr. Lieutenant Yakhnin, driver-mechanic Kypuladze, gunner Efremov, radio operator Matinov, loader Antipov, and radio operator Afanasyev, all succumbed to the fire. After the engagements, 17 KV tanks were recovered.

On 18 March 1942, a KV-220 tank was listed in the inventory of the 84th Heavy Tank Battalion, part of the 55th Army. The tank was also named ‘For the Motherland!’ and was commanded by Lt. Smirnov and crewed by Pugay, Prokhorov, Boykov, and Vikhorov.

In late 1942, one KV-220 was repaired at Plant No.372. A propaganda video titled Leningrad’s Struggle from 1942, shows a KV-220 with a KV-1 turret and painted white being lifted off the repair line of Plant No.372. Here, the tank was fitted with a standard V-2K engine. It is unknown which of the two tanks it was.

Frame captured from the propaganda video Leningrad’s Struggle, showing one of the KV-220s armed with a KV-1 turret, sometime during 1942.
Source: Leningrad’s Struggle

Normally, burning of the tank would mean scrapping, but the KV-220 with serial number M-220-2 would reappear once again in a report on 8 February 1943 in the tank inventory of the 12th Tank Training Regiment. The tank, still with the slogan ‘For the Motherland!’ was appointed to tank commander V.V. Strukov. The tank would be used for training until 1944.

The other KV-220, M-220-1, likely had a much shorter fate. In autumn/winter 1941, the tank was sent to defend the northern Kirov district, western Leningrad, with driver-mechanic V.I. Ignatiev. The vehicle was assigned to defend Petergofske Boulevard at the bridge over the Krasnenkaya River (a portion of which today is called Stachek Avenue), about 1 km from LKZ. The tank was likely lost here.

In 1949, before the 10th Anniversary of the start of defense of Leningrad, Kotin proposed the creation of a monument in the exact spot where the KV-220 was lost. The monument was unveiled in 1951 and still stands to this day, and displays a KV-85 tank (actually a hybrid between the KV-122 prototype hull and IS-1 prototype turret) in Leningradsky Square.

Monument with the KV-85, allegedly raised in the same spot where the KV-220 was lost, coordinates: 59°51′40″N 30°15′30″E
Source: Alex Fedorov

It was not just the hulls of the KV-220 that saw combat, but also the turret of the first prototype. After it was dismounted from the tank, it was sent to Karelia, where it was integrated into a static firing bunker (BOT) in the 22nd Karelian Fortified Area. It was indexed BOT KV with 85 mm ‘Victory’ gun. It would not see action. This would not be the only turret to suffer this fate, the T-100Z prototype turret was also moved into a Karelian firing point.

The turret of the KV-220 with the F-30 85 mm gun, Karelia.
Source: Warspot


The KV-220, much like its heavier brethren, can be today seen as a large waste of resources, at a time when the Soviets officials and LKZ were rushing the unfinished and unreliable KV-1 into service. The heavier tanks, like the KV-220 and KV-3, although having excellent characteristics on paper, would prove to be expensive, complicated, and their origination from the KV-1’s mechanical components, although improved, would have likely affected the even heavier tanks.

Regarding the KV-220, the Soviets had essentially designed, built, and tested a heavy tank on similar capability levels as the infamous German Tiger I tank. While this comparison might seem of historical irrelevance, it was made by Kotin himself after seeing the Tiger tank for the first time.

The first Tiger I tank was captured by the Soviets on 16 January 1943, the tank having been disabled by artillery fire, and a second almost intact Tiger, with technical documents, tools, and ammunition, was captured on 17 January. A rifle platoon and 4 Soviet tanks were sent in for recovery. Both tanks were sent to the Kubinka proving grounds, where both J.Y. Kotin and head of Plant No.100, A.S. Ermolaev, who also worked at SKB-2 before the war, were able to analyze the tank. It is here where they would learn that the Germans were just now fielding a tank on par to the KV-220, designed over 2 years prior. After the analysis, Kotin would write:

“The tank was impressive, it had an 88 mm cannon and two machine guns. Frontal parts of the hull and turret are protected by strong armor. Despite this data, we saw the tank’s “Achilles heel” so to speak– a vulnerability. Previously, Hitler’s machines were lighter, more maneuverable, developed greater speed – in a word, they were created for the offensive. “Tiger” weighed almost 55 tons, moved slowly, was clumsy, was more suitable for defensive combat. By the way, it was because of its poor maneuverability that it fell into our captivity.”

One can argue Kotin was describing his earlier heavy tank creations, though it is true that the Soviets were not fighting an offensive war.


The KV-220 was a powerful heavy tank based on the KV-1 and was well ahead of its time in terms of technical capabilities. However, much like its predecessor, the KV-1, it was plagued by mechanical problems, primarily in the form of the experimental V-2SN engines. Once the powerplant had been sorted, it proved to be a capable platform, which unfortunately never got to test its equally capable 85 mm F-30 gun. While it did serve as a platform for the even more powerful KV-3 and KV-4 tanks, the entire philosophy of adding extra armor and large armaments on the platform of the KV-1 was faulty. The two KV-220 prototypes would see action on the outskirts of Leningrad, but were lost in combat.

KV-220. Illustration by Pavel Alexe.
KV-220 with 107mm ZiS-6 gun. Illustration by Pavel Alexe.
KV-220 with a regular KV-1 turret. Illustration by Pavel Alexe.

KV-220 (Object 220/T-220) Specifications

Dimensions (L-W-H) 7.83 x 3.41 x 3.11 m
Total weight, battle-ready 62.7 tonnes
Crew 6 (Commander, gunner, driver, radio operator/bow gunner, 2x loaders)
Propulsion V-5SN 12-cylinder diesel, outputting 850 hp w/ AM-38 supercharger
Speed 33 km/h
Suspension Torsion bar, 7
Armament 85 mm F-30 (91 rounds) later replaced w/ 76 mm F-32
3x 7.62 mm DT machine guns (4,056 rounds)
Armor Front/sides/rear of hull and turret: 100 mm
Top/Belly: 30 to 40 mm
No. Built 2 prototypes built


Breakthrough tank KV – Maxim Kolomiets
Supertanki Stalina IS-7 – Maxim Kolomiets
Victory Tank KV Vol.1 & 2 – Maxim Kolomiets
Tanks in the Winter War 1939-1940 – Maxim Kolomiets
Constructors of Combat Vehicles – N.S. Popov
Bronevoy Schit Stalina. Istoriya Sovetskogo Tanka (1937-1943) – M. Svirin
TiV No.11 2014 (p.22-24) – I.V. Pavlov & M.V. Pavlov
TiV No.10 2013 (p.10-15) – I.V. Bach
Domestic Armored Vehicles 1941-1945 – A.G. Solyakin
About the forgotten creators of Soviet armored power. ( – S.I. Pudovkin
Малая модернизация КВ | – Yuri Pasholok
КВ-3: набор танковой массы | – Yuri Pasholok
Опытный танк с боевой биографией | – Yuri Pasholok
Tank Archives: KV’s Replacements – Peter Samsonov
Tank Archives: Heavy Trials – Peter Samsonov
Tank Archives: Heavy Tank Costs – Peter Samsonov
Tank Archives: T-150 Revival – Peter Samsonov
Tank Archives: Tank Plans for 1941 – Peter Samsonov
Tank Archives: Mass Breakdown – Peter Samsonov
Tank Archives: KV-3 Evolution – Peter Samsonov
Tank Archives: Tank RMA – Peter Samsonov
Tank Archives: Kirov Experiments, June 1941 – Peter Samsonov
Tank Archives: Kirov Factory Prototypes, March 1941 – Peter Samsonov
Tank Archives: KV-3 in Evacuation – Peter Samsonov
Tank Archives: Heavy Trials – Peter Samsonov

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