KV-4 (Object 224) Strukov - Tank Encyclopedia (2024)

Soviet Union (1941)
Super Heavy Tank – Blueprints Only

The KV-4 Soviet heavy tank emerged already before Operation Barbarorssa, specifically the spring of 1941, when geopolitical tensions between the Germans and Soviets were reaching a boiling point. Against this backdrop of uncertainty and escalating rumors of new German heavy tanks, Soviet engineers at the SKB-2 undertook the design of the KV-4 heavy tank, indexed as Object 224. Conceived as a preemptive response to the perceived threat of potential German super-heavy tanks, it was to have up to 130 mm of armor, weigh over 75 tonnes and be armed with the new 107 mm ZiS-6 gun. Nearly 20 different KV-4 designs were proposed, with the winning design being awarded to N.L. Dukhov. One of the lesser appreciated designs that history has left behind was the design by N.I. Strukov. Much like his KV-4, Strukov was also has been forgotten.

Development

–Dear reader: A more detailed development analysis of the KV-4 program can be found in the KV-4 Dukhov article–-

KV-4 designs

Placement	Name	Drawings	Mass (t)	Dimensions (m) (LxWxH)	Armament	Crew	Top speed (theoretical)	Armor	Reward /Rubles
1	Dukhov KV-4		82.5	8.150 3.790 3.153	107 mm ZiS-6 45 mm K-20 2x 7.62 mm DT machine guns	6	40 km/h	Front top plate: 135 mm Front bottom plate: 130 mm Side plate: 125 mm Top and belly: 40 mm	5000
2	Kuzmin, Tarotko, Tarapatin KV-4		88	9.26 3.78 3.175	107 mm ZiS-6 45 mm K-20 2x 7.62 mm DS-39 machine guns	6	36 km/h	Front: 125 mm Side: 125-100 mm Top and belly: 40 mm	3000
3	Tseits KV-4		90	8.85 4.03 3.62	107 mm ZiS-6 2x 7.62 mm DS-39 machine guns Unspecified flamethrower	7	45 km/h	Front hul upper plate: 50 mm Front hull bottom plate: 125 mm Turret:130 mm Side plate: 125 mm Top and belly: 50 mm	2800
4	Sychev KV-4		95 – 100	9.23 4.00 3.40	107 mm ZiS-6 (F-42) 45 mm 20-K 2x 7.62 mm DT machine guns	6	40 – 45	Turret: 135-125 mm Hull: 105 mm Top and belly: 40 mm	2000
4	Ermolaev KV-4		90	8.22 4.00 3.25	107 mm ZiS-6	6	35	130 mm
			95	8.52 4.00 3.25	107 mm ZiS-6 45 mm 20-K	6	35	130 mm	2000
5	Shashmurin KV-4		92	9.50 4.00 3.85	107 mm ZiS-6 (F-42) main cannon (112 or 102 rounds) 76 mm F-11 secondary cannon (120 rounds) 2x 7.62 mm DT machine guns (400 rounds) Unspecified flamethrower (hull)	7	35 km/h	Front top plate: 125 mm Side plate: 125 mm Top and belly: 50 to 40 mm	1500
6	Buganov KV-4		93	7.70 3.80 3.90	107 mm ZiS-6 45 mm 20-K	6	50 km/h	Front 125 mm	1000
6	Moskvin KV-4		101	9.573 4.03 3.74	107 mm ZiS-6 45 mm 20-K	6	40 km/h	Front 130 mm	1000
7	Pereverzev KV-4		100	9.5 3.8 3.82	107 mm ZiS-6 45 mm 20-K 2x 7.62 mm DT machine guns	6	39 km/h	Front: 125 mm	500
7	Bykov KV-4		98.6	9.5 4.03 3.65	107 mm ZiS-6 45 mm 20-K 7.62 mm DS-39 machine gun	8	36 km/h	Front 130 mm	500
7	Kalivod KV-4								500
N/A	Fedorenko KV-4		98.65	8.10 4.03 3.70	107 mm ZiS-6 45 mm M.1938 3x 7.62 mm DT machine guns Unspecified flamethrower	6	35 km/h	Front upper plate: 140 mm Side plate: 125 mm Turret: 125 mm Top and belly: 50 to 40 mm
N/A	Kreslavsky KV-4		92.6	9 4 3.225	107 mm ZiS-6 45 mm Mod.1937 20-K coaxial 3x 7.62 mm DT machine guns	6	45 km/h	Turret: 130 mm Front hull plate: 130 mm Front upper plate: 80 mm Side plate: 125 mm Rear plate: 130 mm Top /bottom: 50 -40 mm
N/A	Kruchenykh KV-4		107.7	9.13 4.03 3.78	107 mm ZiS-6 45 mm 20-K 4x 7.62 mm DT machine guns	9	30 km/h	Front: 130 mm
N/A	Mikhailov KV-4		86.5	9 3.6 3	107 mm ZiS-6 (F-42) 45 mm Mod.1937 20-K (hull-mounted) 3x 7.62 mm DT machine guns	6	50 km/h	Turret: 130 mm Hull: 130 mm Belly and belly: 50 – 40 mm
N/A	Marishkin KV-4		86.4	8.7 3.6 3.5	107 mm ZiS-6 45 mm 20-K	7	40 km/h	Front: 130 mm Upper frontal: 80 mm
N/A			91	8.5 4.0 3.6	107 mm ZiS-6 45 mm 20-K	6	45 km/h	Front: 100 – 125 mm
N/A	Turchaninov KV-4		89.5	9.8 4.0 3.0	107 mm ZiS-6 45 mm 20-K DT machine gun	7	35 km/h	Front: 125 mm
N/A	Strukov KV-4		92	8.6 4.0 3.8	107 mm ZiS-6 45 mm 20-K	6	50 km/h	Front: 80 – 130 mm
N/A	Unknown KV-4
N/A	Unknown KV-4

On 11 March, 1941, the GABTU (Main Directorate of Armored Forces) received intelligence from Soviet sources about new German heavy tank projects. Despite the Soviet Union and Nazi Germany being nominal allies at the time, tensions were high, necessitating a strategic response to any technological advancements by the opposition.

The intelligence report, titled “The direction of development of the German armed forces and changes in their state,” outlined various tank projects. In the realm of heavy tanks, three models were highlighted:

• Mark V (36 tonnes, 75 mm gun, 2x machine guns, ≤ 60 mm armor)
• Mark VI (45 tonnes, 75 mm gun, 20 mm gun, 3x machine guns, ≤ 70 mm armor)
• Mark VII (90 tonnes, 105 mm gun, 2x 20 mm gun, 4x machine guns, unknown armor)
• The report also mentioned unconfirmed information about 72-tonne French tanks, possibly the Char 2C, at the Renault factory, and 60-80 tonne tanks under construction at Škoda and Krupp.

While the Germans were indeed developing heavy tanks, such as the VK30.01(H), VK36.01(H) and VK65.01, tensions led the Soviets to respond. Thus, the Kirov Leningrad plant’s SKB-2 design bureau was tasked with the development of a new super heavy tank, which could withstand incoming fire from the German 105 mm Flak 39 gun. The new tank was given index Object 224 or simply 224.

The KV-4’s technical requirements, issued on 21 March, 1941, specified a weight of around 70-72 tonnes, frontal armor of 130 mm, side armor of 120 mm, and 40 mm on the belly and top. The main armament was to be the ZiS-6 (previously F-42) 107 mm gun, complemented by a 45 mm gun and three DT machine guns and a flamethrower. The powerplant aimed for a 1,200 hp engine, but due to unavailability, the temporary fix was an 850 hp V-2SN. The development costs were estimated at 3,100,000 Roubles.

By April 7, plans shifted. The KV-3 program was upgraded, fitting it with 120 mm of frontal armor and a 107 mm gun, and receiving index Object 223. The KV-4 requirements were increased to 75 tonnes, and the armor was increased to 125 mm at the sides. Simultaneously, the KV-5 was also requested, armed with the same gun as its counterparts, but with 170 mm of frontal and 150 mm of side armor, and weighing at least 100 tonnes.

Due to the loose specifics of the KV-4’s requirements, its design would be established via a design competition, initiated by head designer J. Y. Kotin, resulting in at least 21 designs. In May 1941, the competition results were ready and N.L. Dukhov’s design won first place, receiving 5,000 Roubles and his design would be the mainframe for the KV-4. In total, at least 21 designs were submitted, with 11 receiving compensation. One design which was not given any placements was that by N.I. Strukov. Unfortunately, there is not much information on who N.I. Strukov was. Judging by the obscurity of his name, he was likely a young designer who, with the start of the war, was tasked with tank maintenance or production, however, this is entirely speculative.

Design

Strukov’s KV-4 used a standard layout, with the driver in the front of the hull, turret and fighting compartment in the center and the engine and final drive in the rear of the hull. The secondary turret was stacked on top of the main turret, a design element used on other KV-4 designs, which allowed for a shorter hull compared to having the turrets in a battleship layout like on other KV-4 designs or the SMK. However, this meant that the main turret was very large and the height of the tank was increased to a whopping 3.8 meters. Many of the elements in the hull were similar to other KV tanks, such as the stepped front plates, rear engine cooling system, the seven steel roadwheels per side sprung by torsion bars and frontal idler. The ammunition for the main gun was stored underneath the turret, on the hull floor, as well as between the fighting compartment and the driver’s position. Ammunition for the secondary 45 mm was stowed vertically on the hull floor. The two fuel tanks were mounted on each side of the engine which offered the tank a theoretical range of 200 km.

The main turret had a rhomboid shape with the edges rounded off due to it being constructed out of stamped steel plates. The secondary turret had a very similar design to the turret on the BA-21 armored car, just enlarged to fit the 45 mm 20-K gun.

The engine on the KV-4 was to be the 1,200 hp M-40 aviation engine with a V12 cylinder layout and four TK-88 turbochargers.

Crew

The tank had a crew of six men, namely the commander, who was also the gunner of the 45 mm gun, secondary loader, main gunner, main loader, and lastly the driver and bow machine gunner/radio operator, both seated in the hull.

The commander of the tank was seated in the secondary turret on top of the main gun. He sat to the left of the gun and had a cupola in the center for improved vision and target acquisition. To the right of the secondary gun was the loader, tasked with loading the 45 mm gun and 7.62 mm coaxial machine gun.

In the main turret was the main gunner, seated to the left of the 107 mm gun. On the opposite side was the loader. The ammunition was placed far away from the gun breech, in the hull, along the floor of the fighting compartment, or behind the driver. This would have made loading the gun especially cumbersome considering the distance but also the size of the shells, at 120 cm long.

The driver sat on the left side of the hull, and aside from the tank’s controls, he was able to fire both a ball-mounted DT machine gun or a flamethrower. The radio operator was seated on the right side of the hull and also had access to a DT machine gun. While it is unconfirmed if this truly was the radio operator, it is odd to assume that the commander would have had this task, considering he was also a gunner for the 45 mm gun. This extra crewman in the hull could have also been the tank mechanic, a role found on previous Soviet multi-turreted heavy tanks, like the SMK and T-100.

Armament

The 107 mm ZiS-6 was the main armament of all KV-4 tanks. It was developed at Plant No.92 by V.G. Grabin in a very short time. Due to its excellent penetration capabilities, it would equip all of the new Soviet super heavy tanks. In the summer of 1941, the gun was tested on a KV-2, using a KV-3 gun mantlet. There, the excellent power was proven, being able to penetrate 120 mm of armor angled at 30° from 1,600 meters.

The secondary armament was the 20-K model 1937 or 1938 anti-tank gun, the same which was mounted on most Soviet light tanks of the time. While certainly obsolete in tank warfare by mid-1941 standards, it would have proven useful against infantry and soft-skin vehicles and in decreasing the wear and ammunition use of the main gun. For infantry defense, three DT 7.62 machine guns were offered, two in ball mounts in the front of the hull and one mounted coaxially to the 45 mm. A flamethrower of unspecified model was also mounted in the hull, to the left of the driver.

In terms of ammunition, the main gun had 100 spare rounds, the 45 mm had 168 rounds and the machine guns had 10,000 spare rounds.

Fate

After the competition, progress on the KV-4 was slow, and the final design which was due in August was further delayed to September. However, by June 22, 1941, with the German invasion underway, the drawings were not submitted.

In light of the circ*mstances, the KV-3’s advanced stage allowed its continued development as a stopgap measure until the KV-4 and KV-5 were ready. The KV-4 and KV-5 would be tested against each other by early 1942, with the winner slated for production. Development of the KV-4 was stopped on 26 June, but development of the KV-5 continued until August, when the SKB-2 designers were relocated to ChTZ in Chelyabinsk due to the approaching German forces. Only the KV-3 was considered to be revitalized. However, due to more immediate wartime issues concerning tank production, maintenance and development of more sensible tank designs, the KV-3 was also forgotten by spring 1942.

Conclusion

After the results of the KV-4 competition were reported in early May, progress on the tank slowed down significantly, and by the end of June 1941, the program was officially canceled even faster than what it was started. Unlike the KV-5, where the designers continued work, the KV-4 would remain largely forgotten until historians started scavenging through the archives. Even so, some KV-4 proposals were set aside from the very beginning, such as Strukov’s KV-4 design, which did not receive any consideration in the competition. Sadly, this single blueprint is all that remains of N.I. Strukov’s legacy.

Sources

Breakthrough tank KV – Maxim Kolomiets
Supertanki Stalina IS-7 – Maxim Kolomiets
KV 163 1939-1941 – Maxim Kolomiets
Confrontation – Ibragimov Danyial Sabirovich
Bronevoy Schit Stalina. Istoriya Sovetskogo Tanka (1937-1943) M. Svirin
Second Tank Industry
Constructors of Combat Vehicles – N.S. Popov
About the forgotten creators of Soviet armored power. (historyntagil.ru) – S.I. Pudovkin
German Lion | Warspot.ru – Yuri Pasholok
Крупный калибр для крупных КВ | Юрий Пашолок | Дзен (dzen.ru) – Yuri Pasholok
Tank building on the verge of common sense | Warspot.ru – Yuri Pasholok
Large caliber for large HF | Yuriy Pasholok | Yandex Zen – Yuri Pasholok
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Tank Archives: KV-3 Mulligan – Peter Samsonov
Tank Archives: Heavy Tank Costs – Peter Samsonov
Tank Archives: ZIS-6 Characteristics – Peter Samsonov