KV-4 (Object 224) Tseits

Soviet Union (1941)
Super Heavy Tank – Blueprints Only

The KV-4 heavy tank program was started in April of 1941, based on an illusion of Soviet Intelligence services, which claimed that the Germans were working on a 90-tonne heavy tank. Design was undertaken at the LKZ factory via a competition of engineers. Amongst them was senior engineer N. V. Tseits, who designed one of the most successful KV-4 designs, being awarded third, and later, second place.

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	Pavlov & Grigorev KV-4		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 Soviet intelligence services sent a report to the Main Directorate of Armed Forces (GABTU) regarding German tank development. Amongst several other topics, heavy tanks had been discussed, of which a 90 tonne heavy tank armed with a 105 mm gun which was apparently under development.

This came as a large surprise to the Soviet military officials, which immediately realized their lack of preparation in this regard. At the time, the KV-1 was the main heavy tank of the Soviet armored forces, but it was completely unprepared for service, let alone combat. Its problems would become apparent at the start of the German invasion of the USSR, highlighting its poor mobility and mechanical unreliability. Work began as early as 1940 on creating a heavier and better armored KV-1, most notably the T-150, KV-220, and later the KV-3. Here, it is relevant to remember that even the KV-220, armored with a 85 mm gun, could have stood up to even the Tiger I, which entered service over a year later, had its crucial mechanical problems been fixed.

Shortly after, on 21 March 1941, the GABTU sent out the requirements for the development of the KV-4, designated Object 224, or just 224. It was to be a 70 to 72 tonne heavy tank, armed with the 107 mm ZiS-6 in the turret, as well as a secondary 45 mm 20-K and at least 3 DT machine guns. Armor was to be of 130 mm at the front and 120 mm towards the sides and rear. Propulsion was provided by a 1,200 hp M-40 engine, also developed at LKZ. Crew was to be of 6 men. On 27 March 1941, the deadline for the tank design was set to 17 July, not including the prototype building and armament testing, which were set as late as October of the same year.

Yet, in an unanticipated turn of events, on 7 April 1941, the GABTU rethought the requests on the KV-4. The weight was raised to 75 tonnes, and armor as thick as 135 mm. Side and rear armor was to be 125 mm thick. The blueprints’ deadline was also narrowed, to 15 June. It was at this time that the KV-5 was requested, a tank that was to weigh at least 90-tonnes, have 170 mm of armor at the front and 150 mm at the sides. Additionally, the KV-3 was ‘revived’ and improved to fulfill a stopgap role until the KV-4 and KV-5 tanks were ready for production.

At LKZ, the SKB-2 design bureau began work on 10 April. Head of the project was the famous J. Y. Kotin, who, after seeking approval and funding from factory director I. M. Zaltsman, decided approach the design of the tank in an unusual way, by creating a competition between the SKB-2 engineers. The top few designs would get a financial rewards. Over 20 engineers competed, submitting over 20 individual designs. The winning design was that of N. L. Dukhov, which was essentially an enlarged KV-220. Second place went to the K. I. Kuzmin, V. I Tarotko and P. S. Tarapatin trio, who submitted a tank with the main gun in the hull and secondary gun in a small turret. Third place went to N. V. Tseits, who submitted a tank with a very low hull, but large turret, to offset the lack of hull space.

N.V. Tseits

Nikolai Valentinovich Tseits* was born in Moscow in 1884 and studied engineering at the Bauman Moscow State Technical University, graduating in 1922. In 1925, he started working at the Ordnance-Arsenal Trust and from 1928 onwards worked in the Kazan German-Soviet tank facility. In 1930, he was arrested on counter-revolutionary charges and sentenced to 10 years in labor camps, but the charges were dropped in 1932, after working at a automobile and tractor design bureau. From 1934, he worked at the experimental plant No.185 and, from 1937, at the SKB-2 design bureau of LKZ, where he was the oldest, most knowledgeable and, in turn, most respected engineer. Through his tank design career, he worked on the T-28, T-29, T-35, SMK, KV-3, KV-5, and, lastly, the KV-13. In 1942, after working non-stop for months on the KV-13, he was granted 1 week leave by head engineer J. Y. Kotin, which he used for hunting. Upon his return to ChKZ in Chelyabinsk, he felt unwell and died shortly after at the factory medical office from an unidentified cause. According to the memoirs of N. F. Shashmurin, who was in the room before his death, Tseits had gifted him a slide ruler to remember him by. Tseits was 68 years old at the time. He was awarded the Order of Lenin and Order of the Badge of Honor.

*the spelling Tseits is an anglicized version of the Cyrillic name Цейц.

Design

In terms of general layout, Tseits kept his design traditional, with the engine towards the rear and turret in the center of the hull. What was not traditional, at least for a Soviet tank, was the final drive, which had been moved to the front, as opposed to having it combined with the engine. Another unusual feature was the very low hull roof. In order to offset the low hull, the turret was large in all directions, so much so that it had to be ‘lowered’ into the hull, with the turret ring being below the level of the driver’s head. The height of the turret allowed for the main gun ammunition to be stowed vertically, in great numbers, with 100 to 120 rounds stowed on the turret side walls and underneath the turret ring. A secondary turret was placed on top, armed with a DT 7.62 machine gun.

The 1,200 hp M-40 engine, with 4 TK-88 turbochargers, was housed at the rear of the hull, resembling modern MBTs, as opposed to a design from 1941. The air cooling was directed via a protruding chamber, at the rear, as opposed to a curved plate, as on most KV tanks. The driveshaft ran from the engine over the torsion bars and underneath the fuel tanks that were in the center of the hull, underneath the turret ring. The final drive, brakes and gearbox were placed at the tip of the hull, at the feet of the driver and bow machine gunner.

Crew

As designed, the tank was to have a crew of 7 men: commander, main gunner, main loader, loader assistant, driver, bow machine gunner and radio operator/secondary turret operator.

Unfortunately, exact positions for all the crewmen are not given, so some speculation is required. The driver and bow machine gunner were both seated inside the hull. Here, the hull roof was lifted to allow for placement of the 7.62 mm bow machine gun in a ball mount and to give room for the 2 crewmen’s heads. The driver had 3 periscopes for vision, in addition to the vision slit in the hull. The rest of the crewmembers were likely placed in the roomy turret. The gunner was to the left of the gun and the commander to the opposite side, on the right. Behind them were the 2 main loaders, each tasked with loading the gun from the opposing sides of the turret walls. The ammunition stowage did not have any rotation system, similar to later autoloaders, thus requiring several loaders to reach all sides.

Armor

The turret was made from curved armor plates into a semicircle 125 mm thick. The only exception was the front of the turret, which consisted of a single, angled, flat plate, 130 mm thick. On it was the gun mantlet. The roof of the turret was partly angled at the front and 50 mm thick. The lower frontal plate was 130 mm, as was the front of the driver’s cubicle. The upper frontal plate, angled very steeply, sas just 50 mm thick. Hull sides and rear were 125 mm thick. Other areas were 50 to 40 mm thick.

Armament

The main armament was the ZiS-6 107 mm gun, previously named F-42. It was designed by the famous V. G. Grabin in record time at Stalin’s personal request for the new heavy tanks. The gun was tested, after many delays, in June 1941 on a KV-2 with a KV-3 mantlet, and after good performances, entered production. According to Grabin’s memoirs, around 800 barrels had been built, and subsequently melted down after the failure of the KV-3, KV-4. and KV-5 programs. The gun could fire an 18.8 kg one-piece shell at 800 to 840 m/s.

KV-5

Tseits’ design was greatly appreciated and placed 3rd in the competition, losing only to Dukhov’s design and the design by the K. I. Kuzmin, V. I. Tarotko, and P. S. Tarapatin trio. However, shortly after, the latter design, which placed second, was ‘disqualified’, likely due to the design not respecting original technical specifications and requirements. This, in turn, moved Tseits’ design up to second place.

On 7 April, in addition to changing the specifications of the KV-3 and KV-4, the GABTU requested an entirely new tank, larger and heavier than the already 80 to 90 tonne KV-4. It was to weigh at least 90 tonnes, have armor as thick as 170 mm at the front and 150 mm at the sides. J. Y. Kotin initially intended to start its development in the same way as on the KV-4, via a competition between engineers. But, as the requirements were similar (and equally vague) to the KV-4, it was decided to save time and use the results from the KV-4 competition. As a result, Tseits’ design, now being on second place, was chosen as the basis for the KV-5, and N.V. Tseits was chosen as senior machine designer of the project. Other engineers that placed high in the competition were given different roles in designing different segments, such as K.I. Kuzmin (head of design group), L. E. Sychev, A. S. Ermolayev, L. N. Pereverzev, and V. Bykov among others.

The design was kept very similar to Tseits’ KV-4 design, such as the large turret and low hull, but major changes were made, including moving the final drive to the rear, making the turret a pentagonal shape (much easier to weld straight plates compared to stamping them into a curve), as well as the driver and bow machine gunner being seated into individual ‘pods’.

Conclusion

The KV-4 design created by N.V. Tseits was, arguably, the most successful KV-4 design. While N.L. Dukhov’s design did win the competition and was to become the final variant of the KV-4, Tseits’ design was the basis of an even more powerful tank, in the form of the KV-5. However, considering the KV-5s nearly pointless birth, short life and unmourned death, it is not much of a gratification to a series of projects considered by the designers themselves as madness.

KV-4 Tseits Specifications
Dimensions (L-W-H)	8.85 – 4.03 – 3.62 m
Total Weight, Battle Ready	90 tonnes
Crew	7 (Commander, gunner, driver, machine gunner, radio operator, loader, turret mechanic/loader assistant)
Propulsion	1,200 hp diesel V-12 M-40 with 4 turbochargers
Speed	45 km/h (hypothetical)
Armament	107 mm ZiS-6 (F-42) 2x 7.62 mm DS-39 machine guns Unspecified flamethrower
Armor	Front hull upper plate: 50 mm Front hull bottom plate: 125 mm Turret front:130 mm Side plate: 125 mm Top and belly: 50 mm
Total Production	0, blueprints only

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