Controversial Commander's Cupola

Three-man turrets appeared in the USSR back in the 1930s. The T-28 and T-35 tanks already had a dedicated commander. The problem was that his abilities were limited. He only had a periscope at his disposal, which had a limited field of view. The KV-1 tank that came to replace the T-28 and T-35 kept the overall layout of the fighting compartment. As before, the commander sat in the front right and had a periscope to look through. It was clear by 1940 that this was not enough. Nevertheless, it took a while for engineers to arrive at a classic commander's cupola.

The commander's cupola on the KV-1S tank appeared a full two years after the start of the KV tank family.

A Medium Tank with a Heavy Burden

The heaviest American tank at the start of the Second World War was the Medium Tank M2. It looked like an anachronism compared to other tanks in the same class, and so it was quickly replaced by the Medium Tank M3. The M3 was also a temporary measure, and even having completed the Medium Tank M4 the American tank designers were not resting on their laurels. Work on the Sherman's successor began as the tank was just being put into production. The Medium Tank T26E1 was meant to replace the Sherman, but after a number of changes in its development cycle it entered production in a completely different weight class.

Origin of species

The concept of a new generation of tanks formed in May of 1942. The basic tank had a 76 mm gun and was lower than the M4, which allowed the designers to add more armour without exceeding the weight of its predecessor. The tank also used an automatic gearbox. The Ordnance Committee gave permission to build two prototypes indexed Medium Tank T20. 

The number of experimental tanks multiplied. Since it wasn't clear how well the idea of an automatic gearbox is going to work out, the army decided to play it safe and also build the Medium Tank T22 using components already tried and tested in the Sherman tank as well as the Medium Tank T23 with an electric transmission that showed itself well in the Heavy Tank T1E1. Each tank had three types of armament. The basic tank would get a 76 mm M1 gun, E1 variants were equipped with a 75 mm gun and an autoloader, E2 variants received the 3" M7 gun from the GMC M10. There was also an E3 variant. These tanks had the 76 mm gun but also a torsion bar suspension.

The Medium Tank T23 surpassed the Sherman in both armament and armour, but the army's appetites had grown beyond what it could offer.

SU-122 Requirements

 "Approved by Deputy People's Commissar of Defense, Colonel General of Artillery, Voronov

October 17th, 1942

Tactical-technical requirements of a 122 mm self propelled howitzer on the chassis of the T-34 tank

1. Purpose of the self propelled howitzer

The self propelled howitzer is designed to accompany infantry and tank units, destroying dugouts and fortified firing positions with direct fire from short range or with indirect fire.

2. Requirements for the artillery component

The artillery component of the SPG is provided by the stock rotating part of the M-30 122 mm model 1938 howitzer. The mounting must meet the following requirements:

1. Practical rate of fire of no less than 10 RPM in a direct fire role.
2. Elevation of 25-35 degrees.
   
3. Depression of -3 degrees.
4. Traverse of +/- 10 degrees.
5. The recoil buffer must be armoured. The armour must be at least 12 mm thick.
6. The oscillating part of the howitzer with the recoil buffer armour must be completely balanced. Increase in effort required to aim cannot surpass 10%.
7. The height of the bore axis must be no more than 1500 mm. To achieve this, a cutout in the front of the SPG is permitted.
8. The gun port must be completely covered at a gun elevation of up to 12 degrees.
9. The gun mount must allow for comfortable loading at all angles of elevation and traverse.
10. The sight is the stock sight from the 122 mm M-30 howitzer with a Hertz panoramic sight.
11. The gunner's seat must rotate with the gun. The seat's rotation in relation to the panoramic sight and aiming flywheels must allow for comfortable operation.
12. The crew consists of five men, including the driver. All crewmen must have comfortable seats.
13. The gun must have the ability to be reliably fixed for travel, preventing horizontal and vertical movement.
14. Two PPSh submachine guns must be carried as auxiliary armament.

Second Fiddle

Even though the German Pz.Kpfw.IV tank was originally created as a support vehicle (Begleitwagen) and fell short of its counterpart the Pz.Kpfw.III in many ways, it was still the heaviest tank in the German arsenal and mounted the largest caliber gun. Issues with Pz.Kpfw.III production also made it the most numerous German medium tank at the start of WWII. Despite its “secondary” designation, the Pz.Kpfw.IV did not evade the attention of the British. Intelligence agents and tankers alike strived to uncover its secrets.

A meeting in Africa

As with the Pz.Kpfw.III, the British only knew about the Pz.Kpfw.IV from rumours. There was little verified information, but one of the few things known for sure was that the tank was heavier than the Pz.Kpfw.III. Intelligence summaries referred to it as a medium tank, whereas the Pz.Kpfw.III was called a “medium-light tank”. Naturally, the British encountered the Pz.Kpfw.IV in France in 1940, but a sample could not be obtained for study due to the rapid defeat of the British Expeditionary Force. Even though there was no precise data about the armour or armament of the tank, an identification poster was still composed and distributed on December 16th, 1940.

A drawing of the Pz.Kpfw.IV Ausf.C composed according to intelligence data showing distinguishing features of the vehicle. The antenna deflector, fixed gun mantlet, pistol port in the single piece front plate, and driver’s observation slit were among the features unique to this variant of the tank.

Tiger, Tiger, Burning Bright

The British first encountered the Tiger tank on the battlefield towards the end of 1942 in Tunisia. Employment of Tigers in early 1943 resulted in a number of losses. The Germans were fairly diligent about demolishing tanks that could not be recovered, but an intact sample was found for study before too long. This vehicle and many others were studied thoroughly by British experts in order to build a complete picture of the first German heavy tank.

Man on the inside

As with the Panther, the captured Tiger tank was used for crew comfort trials. Preliminary information about crew comfort obtained during brief inspection in Tunisia was confirmed.

The commander’s workspace was tested first. The massive gun breech made his station quite cramped. From the right the recoil guard constrained his movements in every position, from the left his space was limited by either the turret traverse mechanism (in the lower and standing positions) or the turret wall (in the upper position). His seat lacked a back, and shocks during travel threw him against the hard gas mask rack. The commander had an auxiliary turret traverse flywheel, but it was poorly positioned and he had to twist his wrist to use it. His wrist also chafed against the turret travel lock as the flywheel turned. British specialists described the commander’s position as “cramped and uncomfortable”.

Tiger 131 at the start of crew comfort trials. Narrow transport tracks are installed. The British captured a full set of both transport and combat tracks.

A German Cat in King George's Court

Study of the enemy’s new weapons or vehicles is always one of the army’s highest priority objectives. The appearance of the Panther tank on the battlefields of WWII could not have gone unnoticed without the Allies’ knowledge, and the British were no exception. Information on this new tank was gathered in several stages.

Foreign sources

Rumours about a new German tank began to arrive in the UK in the summer of 1943. The British military attache in the USSR sent a translation of an article published in the Red Star newspaper on July 24th, 1943, describing the use of a new German tank called “Panterra”. There was little information on this tank, plus the author continuously mixed up the Panther and Ferdinand. More accurate information only arrived on September 7th. With hindsight, we can see that the 45 ton “German Heavy Tank, Mark V” armed with a 75 mm gun and equipped with eight interleaved road wheels per side is indeed the Panther.

These same characteristics were later published in the American Tactical & Technical Trends magazine, with one important distinction: the tank was now called a medium tank, a halfway point between the 22 ton Panzer IV and 57 ton Tiger. Despite the weight difference, the Americans considered this 45 ton tank to be an analogue of their own Sherman, which according to American sources was highly regarded by the Germans.

One of the first images of the Panther tank widely distributed among the Allies

85 mm Gun Upgrade

 

"In order to make loading of the S-31 tank gun in the KV-1S and IS-1 tanks comfortable, the following must be done:

1. Increase the distance from the bore axis to the roof to 470 mm (280 mm on the IS-1) as ramming an 85 mm shell at face height is difficult and impossible if the gun is depressed.
   On most modern foreign heavy tanks and on our SPGs the space between the bore axis and the roof ranges from 400 to 500 mm.

The USSR's Hungriest Tank

Comparative trials of four Soviet tanks were conducted in the summer and fall of 1976 according to order of the Minister of Defense of the USSR D.F. Ustinov titled "On military trials of tanks" issued on July 20th, 1976. In September, a summary titled "Minutes of trials results" was composed. This article will discuss the contents of these documents.

Tank Comfort

Vadim Elistratov is a renowned restorer of armoured vehicles, with experience of bringing WWII era tanks back to life with their original components. Since he doesn't just rebuild the tanks but also drives them, he gave his impressions on how various nations' armoured vehicles compare to one another in a recent interview with Tactic Media.

IS-1 Variants

Development of 85 mm tank guns in the USSR began on May 5th, 1943. Multiple competing variants were developed. A new tank was being designed in parallel, and when it was finished there were two 85 mm guns available for it: the S-31 and D-5.

Cabin on the Tanks

"Mechanic-driver's station

The mechanic-driver is located to the left of the ammunition rack in the front of the tank. The driver's seat is immobile. The seat can flip back and its angle can be adjusted.

The tank is driven by looking through the open hatch in front of the driver, through the slit in the hatch protected by a vision block, or through the rotating MK-IV periscope in the top hatch.

71-ТК-3 Radio Trials

"Report #027

September 28th, 1940

RE: field trials of radio equipment on A-34 vehicles

Description:

Two A-34 vehicles, #0816-4 and 0618-3 were equipped with the 71-TK-3 radio. The radio was installed in the front of the hull with the following placement of components (see photo):

1. Receiver with the frame on two mounts in front of the bow gunner/radio operator's seat.
2. Transmitter with the frame to the right of the bow gunner/radio operator's seat between the front suspension spring and first suspension spring shaft.
3. RUN-10 converter and battery are under the receiver on the front balancer beam.
4. RUN-75 converter on the right under the transmitter.
5. The antenna is installed in the right sloped hull wall. The central switch is under the radio in a bustle near the antenna port.
6. The switchboard and distribution panel are located on the front sloped plate between the driver's hatch and the MG mount.

Green Light

"Record of inspection of the T-34 tank prototype produced by NKSM factory #183 as ordered by the Committee of Defense within the Council of Commissars in decree #443 issued on December 19th, 1939

March 31st, 1940

Present:

From the People's Commissariat of Defense:

• People's Commissar of Defense, Marshal of the Soviet Union, K.E. Voroshilov
• Deputy People's Commissar of Defense, Army Commander 1st Class, G.I. Kulik
• Chief of the ABTU, Army Commander 2nd Class, D.G. Pavlov

From the People's Commissariat of Medium Machinebuilding:

• People's Commissar I.A. Likhachev
• Deputy People's Commissar A.A. Goreglyad
• Chief designer of factory #183 and the T-34 tank, Koshkin

It was established that:

Object 240 Ergonomics

There is a common misconception that the Soviet army had no regard for the conditions of its crew. This is provably false. Just as with the US army, the Red army had a medical service, which would evaluate the user-friendliness of its equipment. Tanks were no exception. For instance, the Object 240, the precursor of the IS-2 tank, was put through thorough testing by the medical service, and the faults that were discovered were corrected by the time the tank reached mass production.

"Conditions of servicing of the 122 mm D-25 gun in the IS tank

1. The D-25 gun is installed in the turret of the IS tank.
The fighting compartment has the following dimensions: turret ring diameter: 1800 mm, height in the rear part: 1520 mm, height in other parts: 1580 mm.
The height of the fighting compartment is insufficient for free work by standing people. The turret crew stands in a slouched over pose.
The short height of the fighting compartment is due to the metal crates with ammunition on the floor. The crates are covered in rubber and used as the floor of the fighting compartment.
To better evaluate the dimensions of the fighting compartment, they should be compared with those of the IS tank armed with a D-5 85 mm gun. With the same sized turret, the gun takes up much more space, which reduces crew comfort.
The width of the gunner's station is reduced by 60 mm (to 650 mm) and the breech operator by 30 mm (to 660 mm). It is narrow, but possible to work.
The distance between the deflector and the rear of the turret was 450 mm for the D-5 and is 200 mm for the D-25. It is not possible to pass behind the gun. It is also uncomfortable to load, since the casing does not fit into this opening and catches onto the rear ammunition rack. When inserting it the loader has to aim (make additional careful motions).

KV-1S OP

"Conclusions regarding Engineer-Colonel comrade Barykov's proposal

Comrade Barykov proposed:

1. The installation of 45 mm guns instead of 76 mm guns into some KV-1S tanks. The freed up space is to be used for housing a forward observer. He will have two observation periscopes and a place to put his map.
   To disguise the 45 mm gun as a 76 mm gun, an armoured sleeve will be installed over it.

Assault Gun from the Urals

December of 1942 was a key month in the history of Soviet SPGs. Work on light and medium SPGs reached the stage of preparation for production. The Ural Factory of Heavy Machinebuilding (UZTM) was chosen to produce medium SPGs. There were two reasons for this. In addition to the fact that development of the U-35 SPG was coming to an end in Sverdlovsk, there was a strong manufacturing base here. Local production of T-34s, which started here in late September of 1942, ensured a supply of chassis for SPGs.

Taking into account the factory's abilities, GKO decree #2559 "On organization of production of SPGs at the Uralmash factory and factory #38" was signed on December 2nd, even before the start of U-35 trials. According to this document, UZTM was expected to deliver the first two SU-35 SPGs (later renamed SU-122) in December of 1942.

T-34 Turrets at Factory #112

"Overall direction of turret modernization during the war

The design of the turret was changed significantly (see fig. 143).

1. In December of 1941, turrets 34.30sb-7 and 34.30sb-8 were cancelled, and turret 34.30sb-12 was introduced.
2. In January of 1942, turret 34.30sb-12 was cancelled and turret 34.30sb-12-1 was introduced.
3. In March of 1942, turret 34.30sb-12-1 was cancelled and turret 34.30sb-12 was introduced.
4. In June of 1942, turret 34.30sb-12-12 was introduced.

This rapid change in turret likely indicated that the type of turret was unsatisfactory, and the design was only deemed satisfactory after introduction of a new turret with a commander's cupola in 1943 (see fig. 145).

SG-122: Assault Gun on a Foreign Chassis

Work on SPGs, especially heavy ones, stopped in the USSR after the start of the Great Patriotic War. This was largely caused by the fact that the factories were busy with other orders. In addition, many factories were evacuated eastward. Only light SPGs were put into production at the start of the war, and these were largely improvised.

Meanwhile, due to the number of factories that switched from making artillery tractors to tanks, the artillery branch was forced to revisit SPGs towards the end of 1941. Experience gained in battle and a number of other factors meant that the new generation of SPGs that was built in 1942 was radically different from pre-war designs. This is especially true for medium SPGs, which became assault guns instead of tank destroyers. The SG-122 was one such SPG, built on the chassis of a captured German SPG.

KwK 43 and the Schmalturm

Fantasizing about what might have been if the war in Europe continued past May of 1945 is not just a widespread hobby, but a profitable business. One of the vehicles frequently depicted laying waste to hordes of Allied tanks is the Panzerkampfwagen Panther mit 8,8 cm L/71 KwK 43, combining the firepower of a heavy tank and the mobility of a slightly less heavy tank. Yuri Pasholok wrote previously about how the gun, while technically fiting in the Schmalturm turret, didn't make the crew's life particularly pleasant. Let's take a look at a blueprint.

Hellcat: Highway Tank Destroyer

The 76 mm Gun Motor Carriage M18, more commonly known as the Hellcat, is one of the best known American wartime tank destroyers. With a powerful 76 mm gun and high mobility, the vehicle was an effective anti-tank measure. A number of sources mention that several Hellcats ended up in the USSR, but that is usually all information that is offered. This is not surprising, since, unlike the GMC M10, which was accepted into service, the M18 never made it past trials. More precisely, the USSR received the pre-production prototypes, indexed Gun Motor Carriage T70. What was the fate of these vehicles?