Development history

Development History

Attempts at re-arming the T-34 were undertaken beginning in 1942, as the culmination of program of ongoing modernisation to eliminate the T-34's shortcomings. The T-43 medium tank design is the first such that should be mentioned here. It was designed taking into account improvements requested for the T-34: perfecting the suspension, increasing the size of the crew compartment, and improving armor protection. In addition, it made active use of the design work done on the pre-war T-34M tank.

The new combat vehicle was 78.5% interchangeable with the «thirty-four» series. The design of T-43's hull remained basically the same as the former's, as did the engine, transmission, chassis, and gun. Despite claims that periodically occur in print, the basic difference was an increase in the frontal, side, and rear plates to 75 mm on the hull, 90 mm on the turret.

At the end of August, a conference was held at Factory #112. It was attended by the People's Commissar for Tank Industry V. A. Malyshev, Commander of Tank and Mechanized Troops of the Red Army Ya.N. Fedorenko, and ranking members from the People's Commissariat for Armaments. In his introduction, V. A. Malyshev noted that the victory at the Battle of Kursk cost the Red Army a high price:

«Enemy tanks opened fire on ours at distances of up to 1,500 metres, while our 76 mm tank guns could destroy „Tigers‛ and „Panthers‛ at distances of only 500–600 metres. Imagine the enemy has a kilometer and a half in his hands, while we have only half a kilometer. A more powerful gun needs to be put into the T-34 quickly.»

In actual fact, the situation was significantly worse than Malyshev painted it, though attempts to correct the situation had been undertaken at the beginning of 1943.

As early as the 15th of April, the GOKO, reacting to the appearance of the new German tanks on the Soviet-German front, published order #3187ss (the «ss» suffix means top secret) «Measures for improving anti-tank defenses.» This required the GAU to put all tank and anti-tank guns then in mass production through range trials, and present findings all within a 10 day period. In accordance with this order, Deputy Commander of Tank and Mechanized Forces Lieutenant-General V. M. Korobkov ordered that a captured Tiger be used for the trials, which were conducted from 25 to 30 April at the NIIBT proving grounds at Kubinka. The trial results were of little comfort. The 76 mm armored-piercing tracer round for the F-34 Main Gun did not penetrate the German tank's side even as close as 200 metres! The most effective weapon for dealing with the enemy's new heavy tank turned out to be the 85mm 52-K Anti-Aircraft Gun model 1939. It penetrated the 100 mm frontal armor at distances up to 1,000 metres.

On 5 May 1943 the GOKO approved order #3289ss «Improving tank and assault-gun cannon armament.» This gave the NKTP and NKB the specific task of designing tank gun with ballistics of an anti-aircraft gun.

The design bureau of the factory #9, headed by F. F. Petrov, had begun development of just such a cannon as far back as January 1943. By 27 May 1943, working designs of the D-5T-85 cannon had been drawn up. It was designed along the lines of German tank/assault-gun guns and was remarkable for its low weight and light recoil. The first D-5Ts were manufactured in June. At approximately the same time, prototypes of other 85 mm tank gun were ready. The TsAKB submitted the S-53 gun (lead designers T. I. Sergeyev and G. I. Shabarov) and the S-50 (lead designers V. D. Meshaninov, A. M. Volgevskij, and V. A. Tyurin). Meanwhile artillery factory #92 submitted A. I. Savin's LB-1 gun. Therefore, by the middle of 1943 four 85 mm gun variants designed for a medium tank were ready for trials. But which tank?

The T-43 rapidly ceased to be relevant. With the 76 mm gun the vehicle weighed 34.1 tons. Mounting a more powerful, and consequently, heavier gun would entail a further weight increase with all the ensuing negative consequences. In addition, switching over factories to production of the new tank, even one having much in common with the T-34, would unavoidably cause a drop in production capacity. And production was sacred! As a result, the T-43 did not begin mass manufacturing. In 1944, an 85 mm gun was mounted on it as a test procedure anyway, and with that the program ended.

In the meantime, the D-5T gun was very successfully mated to the promising «IS» heavy tank. Mounting that same D-5T gun in the T-34 medium tank required increasing the turret ring diameter and mounting a new turret. Working on this problem were KB factory «Krasnoye Sormovo» headed by V. V. Krylov and a turret group at factory #183 led by A. A. Moloshtanov and M. A. Nabutovskij. The results were two similar cast turrets with a ring diameter in the neighborhood of 1,600 mm. They were both reminiscent (but not copied from) the prototype T-43 tank turret, which was used as the basis for design.

The course of development was negatively affected by the TsAKB's promise to install the 85 mm S-53 gun in the standard T-34 turret with its 1,420mm turret ring diameter. V. G. Grabin got factory #112 to allot him a production tank. The TsAKB recast the forward part of the turret; specifically, the gun trunnion was moved forward 200 mm. Grabin attempted to have his design approved by V. A. Malyshev. The latter, however, had serious doubts regarding the expediency of such a decision, the more so because trials of the new gun in the old turret, conducted at the Gorokhovetsky proving grounds, ended unsuccessfully. Two men, in what had become an even more cramped turret, could not effectively operate the weapon. The ammunition load was also sharply decreased. Malyshev ordered M. A. Nabutovskij to fly out to factory #112 and inspect everything. At a special conference attended by D. F. Ustinov and Ya.N. Fedorenko, Nabutovskij thoroughly criticized Grabin's project. It had become apparent that there was no alternative to widening the turret ring.

In addition to this it was also clear that the S-53 gun, which had won the competitive trials, could not be installed in the Sormovo designed turret. Installing the gun in this turret limited its elevation. What was needed was to change the turret's design, or to use a different gun, for example, the D-5T, which could easily be mated to the Sormovo turret.

According to plan, the «Krasnoye Sormovo» factory was to have produced 100 T-34 tanks with the D-5T gun by the end of 1943. However, the first vehicles of this type managed to leave the workshops only at the beginning of January 1944. This was, in fact, before the official acceptance of the new tank. The GOKO order #5020 (top secret), in accordance with which the T-34-85 was accepted by the Red Army, saw the light of day only on 23 January 1944.

The tanks, armed with the D-5T gun, were noticeably different from vehicles produced later, both in external appearance and in internal construction. It had a two-man turret and a four-man crew overall. The commander's cupola, with a two-leafed folding hatch and revolving on a ball-bearing support, had been moved sharply forward. An MK-4 observation periscope, permitting an all-around field of view, was mounted on the turret roof. The gun and coaxial machine-gun were fired using the TSh-15 telescopic elbow sight and the PTK-5 panoramic telescope. Both sides of the turret had an observation slit covered with triplex glass. The radio was located in the hull with its antenna lead on the right side, exactly the same as on the T-34. The ammunition load consisted of 56 shells and 1,953 machine-gun rounds. The power plant, transmission, and chassis underwent practically no changes. These tanks differed among themselves dependent on when they were produced. For example, early-production vehicles had one turret ventilator, while most of those produced later had two.

It should be noted that the model examined above did not, apparently, figure into statistical accounting as a T-34–85. In any case, at the present time, there exist significant discrepancies in the literature regarding estimates of the quantity of vehicles produced. The basic figure varies in a range of 500–700 tanks. In actual fact, the number was significantly lower. This can be shown by the fact that in 1943, 283 D-5T guns were produced, 260 in 1944, 543 in all. Of this number, 107 guns were used in JS-1 tanks, a 130 (not more than 100 according to other sources) were used in KV-85 tanks, and a few more were used in vehicle prototypes. Therefore, the number of T-34 tanks produced with the D-5T gun is close to 300 vehicles.

As far as the S-53 gun was concerned, its installation in the Nizhnij Tagil turret did not cause any difficulties. The S-53 was accepted by the Red Army on 1 January 1944, by GOKO order. Start-up production of these guns began in March, full-scale production in May. Correspondingly, in March, the first T-34–85 tanks armed with the S-53 left the shop floor of the Factory #183 in Nizhnij Tagil. Following this lead, the Factory #174 in Omsk and #112 «Krasnoye Sormovo» began production of these vehicles. During this time, a portion of the Krasnoye Sormovo vehicles were equipped with the D-5T gun as before.

Field trials, which continued despite the beginning of production, revealed significant defects in the S-53's recoil mechanism. Artillery factory #92 in Gorkii was ordered to put the finishing touches on it unaided. In November — December 1944, production of this gun began under the designation ZIS-S-53 («ZIS» was the code for the #92 Stalin Artillery Factory, «S» was the TsAKB's code.). In all, 11,518 S-53 and 14,265 ZIS-S-53 guns were produced in 1944–1945. The latter was installed in both the T-34–85 and the T-44 tanks.

The «thirty-fours» with the S-53 or ZIS-S-53 gun had three-man turrets, with the commander's cupola moved farther to the rear. Only the new MK-4 type observation device was installed. The commander's PTK-5 panoramic telescope was removed. The engine had been taken care of as well: the «Cyclone» air filters had been replaced with the more efficient «Multi-cyclone» type. The tank's remaining systems and assemblies were practically untouched.

Just as with the T-34, there were some differences among T-34–85 tanks connected with the manufacturing technologies available to the various factories. Turrets differed in the number and placement of the casting joints, as well as the shape of the commander's cupola. The chassis utilized both stamped road wheels, as well as cast ones with internal shock absorption.

In January 1945, the two-leafed hatch on the commander's cupola was replaced with a one-leaf hatch. In late production tanks («Krasnoye Sormovo» factory), one of the two ventilators installed at the rear of the turret was moved to the central portion, allowing for better ventilation of the crew compartment.

At the end of the war, attempts were made to improve the tank's armament. In 1945, prototype T-34-100 tanks, with the turret ring widened to 1,700mm and armed with 100 mm LB-1 and D-10T guns, underwent field trials. This project had little purpose in so far as the new T-54 Main Battle Tank with the 100 mm D-10T gun had already been tested and recommended for service.

In September 1944 the design bureau of the factory #92 offered «the new 85-mm gun ZIS-85-PM of increased power» with muzzle velocity of an AP projectile 980 m/s. The gun passed factory trials, but didn't pass the governmental trials on the Gorokhovetsky proving pround. Being too expensive the gun was considered as unsuccessful and ineffective. One more attempt to improve the T-34-85's armament was undertaken in 1945, when the TsAKB developed a modification to the ZIS-S-53, the ZIS-S-54, equipped with a single-plane gyroscopic stabilizer. This gun system, however, did not enter mass production. In spring 1945, all further tests with 85-mm tank guns were ceased because the 85-mm caliber was considered as «having no prospects». The more favorable 100-mm caliber was chose.

In the spring of 1944, prototypes of the AT-45 heavy tractor, designed to tow guns up to 22 tons in weight, were manufactured at the former #183 factory, now rebuilt after the liberation of Kharkov and redesignated #75. The AT-45 was designed based on the T-34–85. It was equipped with the same V-2 diesel, though power was decreased to 350 h.p. at 1,400 rpm. The factory built six AT-45 tractors in 1944. Of these, two were sent to the army to be tested in combat conditions. Tractor production ceased in August 1944, in connection with factory #75's preparations to produce the new medium tank model, the T-44. It would not be superfluous to note that this tractor was not the first to be based on the «thirty-four.» As far back as August 1940, the AT-42 artillery tractor design was approved. It weighed 17 tons and had a platform carrying capacity of 3 tons. With its 500 h.p. V-2 engine, it could make 33 km/h while towing 15 tons. AT-42 prototypes were manufactured in 1941, but further work on testing and production was cut short by the factory's evacuation from Kharkov.

Mass manufacturing of the T-34–85 in the Soviet Union ceased in 1946 (according to some sources, small-scale production continued at the «Krasnoye Sormovo» factory until 1950). As far as the total number of T-34–85 tanks produced at one or another factory, here, just like for the T-34, there exist areas of considerable discrepancy in the numbers cited in various sources.

Comparing figures from the two tables, the discrepancy in the quantity of tanks produced in 1944 is obvious. And this is in spite of the fact that the tables are made up of the most frequently encountered and most reliable figures. In a range of sources, it is possible to encounter other figures for 1945: 6208, 2655, and 1540 tanks respectively. However, these figures reflect tank production for the 1st, 2nd, and 3rd quarters of 1945, meaning at approximately the end of the Second World War. The discrepancy in the figures does not permit the opportunity to state for certain how many T-34 and T-34–85 tanks were produced from 1940 to 1946. The number varies from 61,293 to 61,382 vehicles.

Foreign sources cite the following figures for T-34–85 production in the USSR in the post-war years: 1946–5500, 1947–4600, 1948–3700, 1949–900, 1950–300 vehicles.

Judging by the number of zeros, the figures are most likely very approximate in character. If, in these sources, the quantity of vehicles produced in 1946 is taken to be inflated by a factor of two, and it is assumed that the remaining figures are likewise inflated, it turns out that 4,750 T-34-85s were produced in 1947–1950. Indeed, this looks like the truth. In fact, is it really possible to surmise that our tank industry stood idle for almost five years? Production of the T-44 was ended in 1947, while factories started mass production of the new T-54, for all practical purposes, only in 1951. As a result, the quantity of T-34s and T-34-85s manufactured exceeds 65 thousand.

Construction features

Construction Features

The majority of the tank's components and assemblies were borrowed from the T-34–76, so I will not dwell in detail on a description of the construction. You may find it out in article concerned T-34's Construction Features. Here I will touch briefly only on the hull and turret of the T-35–85.

Combat employment

Combat Employment

T-34–85 tanks began to reach the troops in February-March 1944. Specifically, this was about the time that formations of the 2nd, 6th, 10th, and 11th Guards Tank Corps received them. Unfortunately, the initial effect of the new tanks' use in combat was not great, because the brigades received only a few vehicles each. They still consisted largely of «thirty-fours» with 76mm gun. In addition, there was very little time in combat units for re-training crews. M. E. Katukov, who commanded the 1st Tank Army during April 1944 when it was engaged in heavy fighting in the Ukraine, wrote about precisely this problem in his memoirs.

«We lived through difficult days and happy minutes. One of these was the arrival of new replacement tanks. The army received, in small numbers true, new „thirty-fours.‛ They were armed not with the usual 76mm, but with an 85mm gun. The crews that got the new tanks were given only two hours for familiarization on them. We couldn't give them more time. Conditions at the over-extended front meant that the new tanks, with their more powerful armament, had to be sent into action as soon as possible.»

The first T-34-85s with their D-5T gun went to the 38th Independent Tank Regiment. This unit possessed a mixed complement: in addition to T-34-85s, it also had TO-34 flamethrower tanks. All of the regiment's combat vehicles were paid for by the Russian Orthodox Church and bore the title «Dmitrij Donskoj» on their sides. In March 1944, the regiment became part of the 53rd Combined Arms Army and participated in the liberation of Ukraya.

It should be noted that in the course of re-equipping tank brigades, a few organizational changes took place as well. Since a T-34–85 crew consisted of five men, the personnel contingent of the anti-tank gun company assigned to the brigade's submachine-gun battalion was converted in order to fill out the crews.

Until the middle of 1945, Soviet tank units stationed in the Far East were armed largely with obsolete BT and T-26 light tanks. By the beginning of the war with Japan, these units had received 670 T-34–85 tanks. This permitted the first battalions in all independent tank brigades, and the first regiments in tank divisions, to be equipped with them. For example, the 6th Guards Tank Army, transferred to Mongolia from Europe, left its vehicles in its former deployment (Czechoslovakia), and received 408 T-34–85 tanks from factories #183 and #174 on the spot. In this fashion, these vehicles directly participated in the rout of the Kwangtung army, comprising as they did the tank formations' striking power.

In addition to the Red Army, T-34–85 tanks equipped the armies of several other countries participating in the anti-Nazi alliance.

A T-34–85 with the D-5T gun was the first of this type used in the Polish Army. It was delivered on 11 May 1944 to the 3rd Tank Training Regiment of the 1st Polish Army. As regards combat units, the 1st Polish Tank Brigade was the first to receive these tanks, 20 vehicles in September 1944 after the fighting around Studzyanki. In all, Polish forces received 328 T-34–85 tanks from 1944–1945 (the last 10 vehicles were delivered on 11 March). The tanks were supplied by factories No. 183, and No. 112, and from repair depots. A significant number of vehicles were lost in the course of combat operations. On 16 July 1945, 132 T-34–85 tanks were reported present in the Polish army.

All these vehicles were completely worn-out and needed overhaul. Special brigades had been formed to do this. In areas where there had been recent fighting, they removed the still working components and assemblies from knocked-out Polish, as well as Soviet, tanks. It is interesting to note that, in the course of repair, several hybrid vehicles made an appearance when the armor plate beneath the turret of an earlier production T-34 would be modified, and a turret with an 85 mm gun installed.

The 1st Independent Czechoslovak Brigade received T-34-85s at the beginning of 1945. At that time it was composed of 52 T-34-85s and 12 T-34s. The brigade, operationally subordinated to the Soviet 38th Army, took part in the heavy fighting for Ostrava. After the city of Olomouc was taken on 7 May, the brigade's 8 remaining operational tanks were transferred to Prague. The number of T-34–85 tanks delivered to Czechoslovakia in 1945 ranges in various sources from 65–130 vehicles.

Two tank brigades were formed in the People's Liberation Army of Yugoslavia in the final stages of the war. The 1st Tank Brigade was equipped by the British. Its M3A3 light tanks were landed on Yugoslavia's Adriatic coast in July 1944. The 2nd Tank Brigade was formed with the help of the Soviet Union in 1944 and received 60 T-34–85 tanks.

An insignificant number of T-34–85 tanks were captured by German forces as well as by forces of states allied to Germany. The tanks, which were used by the Wehrmacht, were generally isolated individuals. This is understandable, in 1944–1945 the field of battle was left to the Red Army in the majority of cases. The fact that individual T-34-85s were used by the 5th SS Panzer Division «Viking,» the 252nd Infantry Division, and a few other units, is well known and well established. As far as Germany's allies, in 1944 the Finns, for example, captured nine T-34-85s, six of which were used by the Finnish army until 1960.

As often happens in war, military equipment sometimes changed hands a few times. In the spring of 1945, the 5th Guards Tank Brigade, fighting as part of the 18th Army on Czechoslovak territory, captured a T-34–85 medium tank from the Germans. It is interesting to note that, at that moment, the brigade's equipment consisted of T-70 light tanks, T-34 mediums, and a battalion of captured Hungarian tanks. The captured vehicle became the brigade's first T-34–85 tank.

After the conclusion of the Second World War, the T-34–85 formed the basis of the Soviet army's tank park for quite some time, almost until the mid 50's.

Outside the borders of the Soviet Union, the T-34–85 took part in combat operations on practically every continent, up to the very recent past. Unfortunately, it is not possible to give the precise number of these tanks delivered to one or another country, the more so because deliveries were made not only by the USSR, but also by Poland and Czechoslovakia.

In essence, the T-34–85 medium tank represented a significant modernisation of the T-34 tank, resulting in the elimination of the latter's major deficiency: the cramped crew compartment that prevented a proper division of labor among crew members. This was accomplished by increasing the turret ring diameter, and also installing a new, three-man turret with significantly larger dimensions than that on the T-34. The design and arrangement of the hull components and assemblies did not undergo any significant changes because of this. Consequently, some deficiencies, characteristic of vehicles with a rear located engine and transmission, remained.

In addition to this, the turret ring diameter, if the shape of the hull was to be kept unchanged, reached its practical limits on the T-34–85. This prevented mounting a larger gun system in the turret. The potential for modernising the tank's armament had been completely exhausted in comparison, for example, with the American Sherman and the German Pz-IV. At the same time, the problem of increasing the caliber of the tank's main armament was of paramount significance. It is sometimes asked why it was necessary to change to an 85mm gun, couldn't the ballistic characteristics of the F-34 gun be improved by lengthening the barrel? The Germans had done exactly this with the 75mm gun on their Pz-IV.

The answer is that German gun have been traditionally characterized by excellent interior ballistics (our barrels traditionally by exterior ballistics). The Germans obtained high armor-piercing capability by increasing muzzle velocity and using high-quality ammunition. We could only reply adequately by increasing caliber. Although the S-53 gun significantly increased the T-34-85's firepower, all attempts at designing an 85mm gun with a muzzle velocity higher than 1000 meters per second, a so-called high velocity gun, ended in failure. The reason being rapid wear and destruction of the barrel while still at the testing stage. Knocking out German tanks in a «duel» required changing to the 100mm caliber, as on the T-54 with its 1815mm turret ring diameter.

The absence of a rotating turret basket in the crew compartment was a consequence of the layout. In action, the loader worked while standing on the top of the ammunition crates stowed in the bottom of the tank. When the turret rotated, he had to move alongside the breech ring, and was hindered in doing so by the spent cases piled up there on the floor. During intensive firing, the piled-up cases made it difficult to get to the shells in their combat stowage in the bottom.

In considering the virtues and deficiencies of the T-34–85, one more very important factor should be taken into account. The daily life of any tank crew is, as a rule, completely undisturbed by the slope of the frontal armor or other hull or turret plates. While contemporary tank «aficionados» love to engage in silly arguments on these themes, they do not understand that what is significantly more important is that the tank, as a vehicle, that is, as the sum of its mechanical and electrical parts, runs smoothly, hopefully without problems while being used. Included in this are issues connected with repair and replacement of various parts, assemblies, and components. For the T-34–85 (just as for the T-34-76), everything was in order on exactly this point. The tank was distinguished by an exceptional ease of repair.

There is a rule: Do not design for easy installation and removal of the components; and following from this: complete removal of the components should not be necessary during repair. The needed high operating reliability and dependability is attained by designing the tank using off-the-shelf, design-perfected components. In so far as practically not a single one of the T-34s components met this requirement, it was laid out contrary to this rule. The roof on the engine/transmission compartment was detachable, the rear hull plate folded back on hinges. This permitted easy removal of such large components as the engine and the gearbox under field conditions. This all had colossal significance in the first half of the war, when more tanks were put out of service by mechanical malfunction than by enemy action (on 1 April 1942, for example, the army in the field had 1642 functioning and 2409 non-functioning tanks of all types. At the same time, our combat losses for March consisted of 467 tanks). In as much as the quality of components was increased, achieved to the highest degree in the T-34–85, the significance of a layout that made for easy repair was decreased, but one hesitates to call this a deficiency. More than that, the ease of repair turned out to be quite fortuitous in the course of its post-war use abroad, predominantly in Asia and Africa, at times in extreme climatic conditions, and with personnel that had an extremely mediocre, to say the least, level of training.

The presence of all the deficiencies in the «thirty-four's» design was the result of balancing compromises. These profitably distinguished this combat vehicle from other tanks of the Second World War. Simplicity, ease of use and mechanical maintenance, combined with good armor protection, maneuverability and sufficiently powerful armament were the reasons for the T-34-85's success and popularity among tankers.