EVALUATION OF THE T-34 AND KV TANKS BY ENGINEERS OF THE ABERDEEN PROVING GROUNDS, SUBMITTED BY FIRMS, OFFICERS AND MEMBERS OF MILITARY COMMISSIONS RESPONSIBLE FOR TESTING TANKS

T-34-76 that was delivered in USA for evaluation

The tanks were given to the U.S. by the Soviets at the end of 1942 for familiarization.

The condition of the tanks

The T-34 medium tank after driving 343 km, became completely disabled and that could not be fixed. The reason: owing to the extremely poor air filter system on the diesel, a large quantity of dirt got into the engine and a breakdown occurred, as a result of which the pistons and cylinders were damaged to such a degree that they were impossible to fix. The tank was withdrawn from tests and was to be shelled by the KV and American 3" gun of the M-10 tank (M10 "Wolverine" SP antitank gun - Valera). After that, it would be sent to Aberdeen, where it would be analyzed and kept as an exhibit.

The heavy tank KV-1 is still functional. Tests were continued, although it had many mechanical defects.

T-34-76 that was delivered in USA for evaluation

The silhouette/configuration of the tanks

Everyone, without exception, approves of the shape of the hull of our tanks. The T-34's is particularly good. All are of the opinion that the shape of the T-34's hull is better than that of any American tank. The KV's is worse than on any current American tank.

Armor

A chemical analysis of the armor showed that on both tanks the armor plating has a shallow surface tempering, whereas the main mass of the armored plating is made of soft steel.

In this regard the Americans consider that by changing the technology used to temper the armored plating, it would be possible to significantly reduce its thickness while preserving its protective ability (the situation with American armor was even worse. Engineers in Aberdeen have criticized their armor on Shermans. Soviet engineers have agreed with them because during the comparative trials Soviet ZIS-3 gun could penetrate Sherman's galcis from 1100 metres - Valera). As a result the weight of the tank could be decreased by 8-10%, with all the resulting benefits (an increase in speed, reduction in ground pressure, etc.)

T-34-76 that was delivered in USA for evaluation

Hull

The main deficiency is the permeability to water of the lower hull during a water crossings, as well as the upper hull during a rain. In a heavy rain lots of water flows through chinks/cracks, which leads to the disabling of the electrical equipment and even the ammunition.

The Americans liked how the ammunition is stowed.

Turret

The main weakness is that it is very tight. The Americans couldn't understand how our tankers could fit inside during a winter, when they wear sheepskin jackets (Americans tested the T-34 with a two-men turret - Valera). The electrical mechanism for rotating the turret is very bad. The motor is weak, very overloaded and sparks horribly, as a result of which the device regulating the speed of the rotation burns out, and the teeth of the cogwheels break into pieces. They recommend replace it with a hydraulic or simply manual system.

T-34-76 that was delivered in USA for evaluation

Armament

The F-34 gun is a very good. It is simple, very reliable and easy to service. Its weakness is that the muzzle velocity of AP round is significantly inferior to the American 3" gun (3200 feet versus 5700 feet per second).

Optic

The general opinion: the best construction (please notice - the best construction doesn't mean the best at all - Valera) in the world. Incomparable with any existing tanks or any under development.

Tracks

The Americans like very much the idea of a steel tracks. But they believe that until they receive the results of the comparative performance of steel vs rubber tracks on American tanks in Tunis and other active fronts, there is no reason for changing from the American solution of rubber bushings and pads.

The deficiencies in our tracks from their viewpoint results from the lightness of their construction. They can easily be damaged by small-calibre and mortar rounds. The pins are extremely poorly tempered and made of a poor steel. As a result, they quickly wear and the track often breaks. The idea of having loose track pins that are held in place by a cam welded to the side of the hull, at first was greatly liked by the Americans. But when in use under certain operating conditions, the pins would become bent which often resulted in the track rupturing. The Americans consider that if the armour is reduced in thickness the resultant weight saving can be used to make the tracks heavier and more reliable.

Suspension

On the T-34, it is poor. The Christie's suspension was tested long time ago by the Americans, and unconditionally rejected (American "Shermans" and "General Lees" had very poor suspension as well. At the same time the British used Christie's suspension and were quite satisfied - Valera). On our tanks, as a result of the poor steel on the springs, it very quickly (unclear word) and as a result clearance is noticeably reduced. On the KV the suspension is very good.

Engine

The diesel is good and light. The idea of using diesel engines on tanks is shared in full by American specialists and military personnel. Unfortunately, diesel engines produced in U.S. factories are used by the navy and, therefore, the army is deprived of the possibility of installing diesels in its tanks.

The deficiency of our diesels is the criminally poor air cleaners on the T-34. The Americans consider that only a saboteur could have constructed such a device. They also don't understand why in our manuals it is called oil-bath. Their tests in a laboratory showed that:

• the air cleaner doesn't clean at all the air which is drawn into the motor;
• its capacity does not allow for the flow of the necessary quantity of air, even when the motor is idling. As a result, the motor does not achieve its full capacity. Dirt getting into the cylinders leads them to quickly wear out, compression drops, and the engine loses even more power. In addition, the filter was manufactured, from a mechanical point of view, extremely primitively: in places the spot-welding of the electric welding has burned through the metal, leading to leakage of oil etc (that claim was accepted, and later T-34 variants received the new, better, "Cyclon" filter - Valera). On the KV the filter is better manufactured, but it does not secure the flow in sufficient quantity of normal cleaned air. On both motors the starters are poor, being weak and of unreliable construction.

Transmission

Without a doubt, poor. An interesting thing happened. Those working on the transmission of the KV were struck that it was very much like those transmissions on which they had worked 12-15 years ago. The firm was questioned. The firm sent the blueprints of their transmission type A-23. To everyone's surprise, the blueprints of our transmission turned out to be a copy of those sent. The Americans were surprised not that we were copying their design, but that we were copying a design that they had rejected 15-20 years ago. The Americans consider that, from the point of view of the designer, installing such a transmission in the tank would create an inhuman harshness for the driver (hard to work). On the T-34 the transmission is also very poor. When it was being operated, the cogs completely fell to pieces (on all the cogwheels). A chemical analysis of the cogs on the cogwheels showed that their thermal treatment is very poor and does not in any way meet American standards for such mechanisms.

Side friction clutches

Out of a doubt, very poor. In USA, they rejected the installation of friction clutches, even on tractors (never mind tanks), several years ago. In addition to the fallaciousness of the very principle, our friction clutches are extremely carelessly machined from low-quality steel, which quickly causes wear and tear, accelerates the penetration of dirt into the drum and in no way ensures reliable functioning.

General comments

From the American point of view, our tanks are slow (Americans got the T-34 with a 4-speed gearbox. With a such gearbox, T-34 could use the 4th speed on a firm and even surface - i.e. on roads. Thus, the max speed on the cross-country was 25.6 km/h. On later modifications there was a 5-speed gearbox to be installed. This gearbox allowed to drive with a 30.5 km/h. - Valera). Both our tanks can climb an incline better than any American tank. The welding of the armor plating is extremely crude and careless. The radio sets in laboratory tests turned out to be not bad. However, because of poor shielding and poor protection, after installation in the tanks the sets did not manage to establish normal communications at distances greater than 10 miles. The compactness of the radio sets and their intelligent placement in the tanks was pleasing. The machining of equipment components and parts was, with few exceptions, very poor. In particular, the Americans were troubled by the disgraceful design and extremely poor work on the transmission links on the T-34. After much torment they made a new ones and replaced ours. All the tanks mechanisms demand very frequent fine-tuning.

Conclusions, suggestions

1. On both tanks, quickly replace the air cleaners with models with greater capacity capable of actually cleaning the air.
2. The technology for tempering the armor plating should be changed. This would increase the protectiveness of the armor, either by using an equivalent thickness or, by reducing the thickness, lowering the weight and, accordingly, the use of metal.
3. Make the tracks thicker.
4. Replace the existing transmission of outdated design with the American "Final Drive," which would significantly increase the tanks manoeuvrability.
5. Abandon the use of friction clutches.
6. Simplify the construction of small components, increase their reliability and decrease to the maximum extent possible the need to constantly make adjustments.
7. Comparing American and Russian tanks, it is clear that driving Russian tanks is much harder. A virtuosity is demanded of Russian drivers in changing gear on the move, special experience in using friction clutches, great experience as a mechanic, and the ability to keep tanks in working condition (adjustments and repairs of components, which are constantly becoming disabled). This greatly complicates the training of tankers and drivers.
8. Judging by samples, Russians when producing tanks pay little attention to careful machining or the finishing and technology of small parts and components, which leads to the loss of the advantage what would otherwise accrue from what on the whole are well designed tanks.
9. Despite the advantages of the use of diesel, the good contours of the tanks, thick armor, good and reliable armaments, the successful design of the tracks etc., Russian tanks are significantly inferior to American tanks in their simplicity of driving, manoeuvrability, the strength of firing (reference to muzzle velocity), speed, the reliability of mechanical construction and the ease of keeping them running.

The head of the 2nd Department
of the Main Intelligence Department of the Red Army,
major-general Khlopov