Saturday 28 September 2019

The Golden Standard

The fate of the Soviet T-29 medium tank was a complex one. The development of a 20-ton amphibious PT-1 tank began in April of 1933. First the tank was developed in two variants, later this number grew to four. The T-29-4 and T-29-5 had the highest priority. The T-29-2 was skipped. There are plenty of strange aspects such as this in the T-29's history.

Initially the T-29 was being developed in Moscow by the technical department of the Economics Directorate of the United State Political Directorate (EKU OGPU) under the direction of N.A. Astrov. N.V. Tseits also too part in the development. Like Astrov, he spent a portion of his career working from prison. Later, development moved to Leningrad, and Tseits moved after it, eventually becoming the chief designer on the T-29 project. Such a debut promised a complicated fate for the T-29.

Two in one

From the beginning, the types of T-29 were very similar. For instance, the T-29-1 and T-29-3 were the same aside from armour and mass. According to the design, the T-29-1 had 15 mm front armour and 13 mm side armour. Its mass was estimated at 14,970 kg. The T-29-3 had 20 mm of front armour and 15 mm of side armour. The mass grew to 15,415 kg. Like the IT-3 tank destroyer, the design that became the starting point for the T-29, these variants had only one turret. A DT machinegun was installed in a ball mount in the front.

The T-29-5 during factory trials. In early 1935 the vehicle did not yet have a frame antenna.

The T-29-4 and T-29-5 had three turrets. The T-29-4 had the same armour as the T-29-3. Its mass grew to 17,185 kg. The top speed of the T-29-1, T-29-3, and T-29-4 was 60 kph on tracks and 80 kph on wheels. The T-29-5 would have been the heaviest variant. The thickness of its front hull and turret armour was 30 mm, which allowed it to deflect even low caliber artillery shells. The thickness of the sides increased to 20 mm and the mass grew to 20,145 kg. The top speed of this tank would have been 50 kph on tracks and 70 kph on wheels.

One of the reasons why the T-29 project appeared was the desire of the Directorate of Motorization and Mechanization (UMM) to have a backup plan. The situation with medium tanks in the Red Army was tough. The T-12 and then the T-24 were developed by the Main Design Bureau of the Artillery Arsenal Trust (GKB OAT) under the direction of S.P. Shukalov. These vehicles were not the best, and production of light convertible drive BT-2 tanks began instead of producing them.

Experience with attracting foreign designers also proved poor. The medium (sometimes called heavy) TG-1 tank (also known as TG or "G tank")developed under the direction of Eduard Grotte turned out to be advanced, but not very polished.

Finally, work on the T-28 medium tank began in 1931. The work was directed by S.A. Ginzburg, who had a pretty rich tank building experience at the time. Semyon Aleksandrovich also had experience abroad as a part of a purchasing commission.

Like the PT-1, the T-29 had a bulge in the front for the idlers.

Unlike Shukalov, who was categorically against using foreign solutions, Ginzburg studied foreign tanks carefully. This applied both to tanks seen abroad and German tanks tested at TEKO in Kazan. This opinion was also shared by N.V. Barykov, who headed the Experimental Design and Machinebuilding Department (OKMO) at the Bolshevik factory as of February 1932. Barykov also had connections to the TG project.

In 1932 Ginzburg moved from Moscow to Leningrad where he began to work under Barykov. This pair of talented engineers played a vital role in Soviet pre-war tankbuilding.

Information about the Medium Tank Mk.III played a direct role in the development of the T-28. The mass of 16-17 tons indicates that the source of inspiration. However, do not forget how closely Soviet and German engineers were working together in those years. The T-28's suspension migrated from the Krupp Grosstraktor nearly wholesale. The track links and other elements were based on those used in the T-26, as the ones on the German tank proved poor. The T-24 also had an effect on the T-28, as Ginzburg was closely tied to that project as well.

The mass of the T-28 grew during development, and it's hard to call the Grosstraktor's suspension good. The idea of development of another medium tank was quite sound, especially since the convertible drive scheme was very popular at the time.

The rear turret machine gun can be seen from the back.

N.A. Astrov was in charge of the development of the T-29 by the end of 1933. Meanwhile, the Auto-Tank Bureau (ATB) in Moscow did not have enough industrial capacity to build the T-29 nor the PT-1A. The OKMO was brought in to help starting in November of 1933. On November 19th, 1933, the experimental factory received the task to produce the gearboxes, final drives, and other transmission elements for these tanks. Many components were produced at the Red Putilovets factory, which later became the Kirov factory. The OKMO and ATB began tight communication.

On December 20th the technical department of the EKU OGPU and the OAT experimental factory signed a contract for the production of experimental PT-1A, T-29-4, and T-29-5 tanks. The deadline was April 15th, 1934. On January 2nd, 1934, an order to send specialists from Moscow to Leningrad was given. That is how Tseits ended up in Leningrad. 

The projects gradually changed their shape. Development of the T-28 also affected the T-29. Its main turret, gun mount, rear, and a number of other elements changed in step. Nevertheless, the two projects were fairly different. Unlike the T-28, the T-29's turret only fit two crewmen. The chassis was completely different, a further development of the PT-1 chassis. Not all road wheels were powered, only the second, third, and fourth on each side.

T-29-5 during army trials. October 1935.

Due to nonstop changes to the blueprints the timeline for production kept slipping. In April it was decided that the new due date will be August 15th, 1934. Even this deadline was missed. It was not the experimental factory's fault as much as that of the subcontractors. The T-29-5 made its first steps on December 12th, 1934. A number of trial runs followed up to December 15th, when several defects were discovered. A decision was made to redo the final drives.

The T-29-4, which was originally planned to be finished by September 15th, was also just built at that time. Meanwhile, the Tank Department of the EKU OGPU had been disbanded for about half a year at this point. The OKMO was also reorganized into the experimental factory #185. Astrov moved to the role of the head of the design bureau at factory #37. Even the customer of the prospective tank changed. On November 22nd, 1934, the UMM was renamed to the ABTU. Tseits became the lead engineer of the T-29. Factory #185's "foreign visitor" became its own project.

Another name entered the mix in early 1935: Koshkin. Despite some opinions, Mikhail Ilyich had a direct link to these tanks. He began to work at factory #185 in 1934 after completing his studies at the Leningrad Polytechnic Institute. His thesis was directly linked with the T-29. By the spring of 1935 Koshkin was already the deputy chief of the design bureau, Ginzburg's deputy. This kind of career growth in such a short time was no accident.

Crossing a trench.

The difference between the T-29-4 and T-29-5 was not great. The dimensions were the same, 6530x3055x2850 mm. The mass of both vehicles grew during production. The T-29-4 ended up weighing 21 tons, the T-29-5 was 24 tons. That was the price of thick armour. Externally, the T-29-5 can be distinguished by a different idler and a frame antenna on the turret (the T-29-4 had an antenna in the hull). The T-29-4 also used T-28 tracks, while the T-29-5 had T-35 tracks. The T-29-4 tank deserves a separate article, even though the military made its choice against it in March of 1935. Work on the T-29-4 continued, but at a low priority. On March 26th, 1935, an order was given to produce three T-29-5 prototypes in 1935. This was essentially preparation for mass production. Factory #185 began to prepare for cooperation with other factories. This task was given to Koshkin.

A summary of this cooperation was ready by May 19th. 25 different factories took part in production, including Bolshevik, factory #7, Izhora factory, and others. Work on the pilot tank began on May 5th. Astrov had nothing to do with this tank.

This photo shows the frame antenna on the turret.

The T-29-5 continued trials while preparations for production were underway. The tank covered 1724 km by October 8th, 1935, of those 1010 on wheels and 714 on tracks. A top speed of 81 kph was achieved on wheels. The tank drove for another 375 km during army trials from October 19th to 29th. Some statements in the report are confusing, such as the claim that the T-29 was a further development of the T-28, which is untrue.

In these trials a top speed of 79 kph on wheels and 58 kph on tracks was recorded. Barykov, who was present at the trials, wrote that the vehicle was capable of a speed of 60-63 kph on tracks. The average highway speed was 51.8 kph. This value dropped to 42.6 kph on a snow-covered highway. The tank's average speed in swampy terrain was 19 kph. The results of the trials were impressive: the tank was faster than the T-28 and about the same as the T-28A even on tracks.

The T-29-5 knocking down trees.

The military trials did not only reveal advantages. The driver's station was deemed too small, especially in width. The gun turret was also too narrow. The narrow turret ring left much to be desired. The machinegun turrets were too low. There were other complaints that had to be corrected on the pilot tank. The study of the fighting compartment was a continuation of the firing trials that were held from September 22nd to 24th. The KT 76 mm gun scored 18-53% hits when firing at a speed of 12-15 kph. To compare, the T-28 scored 50-60% hits in these conditions. Such a low score can be blamed on the T-29's gun mount, which there were many complaints about.

Despite all this, the T-29-5 was a promising design. It was also an example of successful cooperation from a large amount of factories. Koshkin received the Order of the Red Star in April of 1936 for successful coordination of production of T-29-4, T-29-5, and T-46-1 prototypes. Other employees of factory #185 were also decorated. It appeared that the tank had a bright future ahead.

Too long, complicated, and expensive

Work on improving the T-29-5 began long before the army trials. Ginzburg and Barykov sent a letter to the NKO and ABTU in late June of 1935. The letter had to do with the design of the turret. A new turret was designed, widened from 1410 to 1520 mm. Like the previous turret, it held two crewmen.

Nevertheless, it was clear that the commander, who also acted as the radio operator, turret machine gunner, and loader, was overloaded with duties. Factory #185 presented two other alternatives. The first included a commander's cupola. The overall height of the vehicle increased to 3000 mm. The second proposed widening the hull by 360 mm and installing a T-28 turret. Both cases increased the mass of the tank. The first variant increased the mass to 25 tons, the variant with a T-28 turret to 26 tons. The T-28's mass at that moment was 25.2 tons. In addition to changing the turrets the designers proposed replacing one of the DT machineguns in the machinegun turrets with a DK machinegun or small caliber cannon.

T-29 blueprint, December 1935.

Work was being done to organize cooperation between factories in parallel to these changes. There were issues here too. For instance, the Izhora factory was adamant that design of the hulls should be done by its own design bureau instead of factory #185. The gearbox was also widely discussed. Not surprisingly, the deadlines for the T-29-5 production slipped. When factory #185 technical requirements to produce a hull and turrets only one set was expected.

The same vehicle from above. The main turret is noticeably different. The hull also changed significantly.

The blueprints of the reworked T-29-5 were complete by mid-November 1935. Meanwhile, the ABTU had high hopes for the new tank. It was assumed that the T-29 would become the main tank at the Kirov factory in 1936 and replace the T-28. It's hard to say that the T-28, the most numerous pre-war medium tank, was bad, far from it. However, it did have a number of drawbacks, including in the suspension. The suspension behaved poorly at high speeds, especially when crossing vertical obstacles at a speed of over 15-18 kph.

Production of the T-28 at the Kirov factory was not going well in 1935. Only 32 tanks were delivered, a rate of just over 2.6 per month. The tank was not only very complicated, but very expensive. As of 1938 the T-28 cost 380,000 rubles per unit. This was the price of 3 BT-7s or almost 5 T-26es. The only tank that was more expensive was the T-35, at a cost of half a million rubles, but it was produced in very small batches. The ABTU saw no future in the T-28 in 1935. The fact that the tank remained in production into 1940 was only caused by issues with developing a successor. Fantasies of some writers about a modernized T-28 as a replacement for the T-34 have no basis.

Overall layout of the T-29 as seen from above.

The changes raised the mass of the T-29 to 25-26 tons. The tank became 10 cm longer and about 10 cm wider. The top speed on tracks was reduced to 55 kph, and the top speed on wheels was also somewhat reduced. Based on the experience with the T-29-4 and T-29-5 conversion from tracks to wheels would take about half an hour. This was achieved by mechanization of the process of pulling up the tracks to the fenders.

Designers at factory #185 put in a lot of work into improving the crew conditions. Two exhaust fans were added into the turret platform roof. The gun turret was enlarged and working conditions inside were improved. Air intakes on the sides formed characteristic "ears". Changes were also introduced into the driver's compartment to improve his working conditions.

The pilot T-29 tank, 1937. Despite rumours, only one such tank was built.

The fact that blueprints were ready did not mean that work on building the tank would speed up. The ABTU signed a contract with the Kirov factory for 10 tanks in 1936, but as of June 1936 the Kirov factory and factory #185 continued to work out issues revealed during trials and updating blueprints. Not even one tank could be built in such conditions. I.A. Khalepskiy, the head of the ABTU, bombarded the factories with letters in which he demanded that work must be expedited, like he did in late 1935. The letters had about as much effect.

A meeting was held in June of 1936 regarding the use of the DM diesel engine in the T-28 and T-29. The engine was expected to give 670 hp at 2800 RPM. The Auto-Tractor Research Institute (NATI) was working on this topic, but this idea did not move past correspondence.

The tank in wheeled mode, seen from the left.

G.A. Bokis replaced Khalepskiy as the head of the ABTU in July of 1936 and continued the bombardment with letters. The pilot T-29 received new armament in October of 1936. By the ABTU's request the PS-3 gun replaced the KT in the tank's turret. This gun had an equally complicated fate. A decision to use surface hardened armour was made some time earlier. Also the tank was supposed to have smokescreen generators, installed along the sides. A torrent of finger-pointing erupted in the fall-winter of 1936 between factory #185 and the ABTU. In this case the factory was in the right: the ABTU demanded that the tank should receive a three-man turret in the late summer of 1936, despite rejecting a similar proposal from factory #185 prior to that. The tank never received such a turret.

Constant changes introduced into the new tank meant that production 10 tanks in 1936 was impossible to achieve. Assembly of the pilot tank only began in November of 1936. Even this process was not without problems. In December factory #185 discovered issues in the hull blueprints. As a result, the gun turret that was already finished was scrapped. These mistakes were a consequence of disagreements with factories that did not deem it necessary to stay up to speed on the tank's design. More and more requests came in, for instance to develop conical turrets for the T-28 and T-29 tanks. These requests were caused by the experience in Spain.

Tank on tracks, seen from the right. The smokescreen generator tank can be seen from this side.

Koshkin was sent to the HPZ (named factory #183 as of December 30th) on December 25th, 1936, where he headed the design bureau. As of the T-29, the pilot took its first steps on December 21st. The mass grew to 28.5 tons as a result of all the changes. The tank was largely identical to the pilot blueprints, aside from the changes listed above. The calculated top speed was 56 kph on tracks and 57.4 kph on wheels.

The drive synchronizer showed itself well in trials. Thanks to this device, the tank could continue to drive if it lost one track. The device even allowed the tank to turn in this condition.

Trials of the synchronizer that allowed the tank to drive with only one track installed.

Factory trials lasted until December of 1937. The tank travelled for 1761 km. Of those 1022 were spent on wheels on a highway, 640 on tracks on a highway, 5 on wheels off-road, and 94 on tracks off-road. In winter on a snow-covered highway the average speed was between 24 and 38.4 kph. In the summer the average highway speed was 31-38.8 kph.

Trials showed that the real average speed could have been higher, 40-50 kph, if not for the rapid wear of the road wheel rims. The report claims that the speed would have increased if the issue was resolved, but there is some doubt. The rims were not destroyed for no reason. The old design likely would not work as well on a tank that was 1.5 times as heavy as the original. The design of the chassis did not change much since the PT-1, which was only 14 tons. The reserve of the running gear and suspension was exceeded.

The tank at the Kirov factory.

The two-man turret was another drawback of the tank. The military also wanted a tank with surface hardened armour (the pilot tank had homogeneous armour). A laundry list of small defects was composed. However, the overall verdict was positive. The tank was faster and more reliable than the T-28. The T-29 could drive off-road without issues at a speed of 20-25 kph while crossing bumps 0.5-0.6 meters in height. The T-28's running gear began to take damage when driving at 15-18 kph across 0.2-0.3 m deep bumps.

The T-29 also had an easier suspension to service. Studies made by factory #185 showed that the T-29 was the most stable gun platform of all available at that time. As for the issues with rims, they would be solved by widening the wheels. Nearly 5 years after development began the tank was ready for production.

Road wheel rims were destroyed during trials.

The T-29's road to production closed in the spring-summer of 1937, at least in its current state. The military wanted a tank with a three man conical turret. The Kirov factory began developing a tank called T-29C (Cemented). Work on this tank, also developed by Tseits, deserves a separate article.

The T-29 was also very expensive. The first prototype cost nearly two million rubles, the cost of the second would have been about a million. Of course, the mass produced tank would have been cheaper, but it would still have been significantly more expensive than the T-28. The second pilot tank was never built and the T-29 was finally killed by decree #198ss of the Committee of Defense within the Council of People's Commissars on August 7th, 1938. Work on the T-46, AT-1, and SU-14 was ended at the same time. The last change in the T-29's design was made in the summer of 1938: replacement of the PS-3 gun with the L-10.

The L-10 gun was installed on the tank shortly after it was cancelled.

The story of the T-29 ended badly for most of its participants. Khalepskiy and Bokis were executed. The chief designer of SKB-2 at the Kirov factory, O.I. Ivanov, met the same fate in May of 1937. A number of designers who worked on development the T-29 tank were also convicted. One of them was Tseits, even though he was leading the work on the SMK heavy breakthrough tank at the time. Nikolai Valentinovich Tseits met the start and end of the T-29's development in prison. However, Tseits, Ginzburg, and a number of others got lucky. They eventually returned to their work. Tseits, for instance, worked on the KV-4 and then KV-5 in March of 1941. This episode reflected poorly on his health.

Combat of a prototype tank

The poor outcome of the T-29 project did not mean that it was a waste of money. Koshkin, who played a big part in the T-29 project, used this experience in the development of the A-20. Influence of the T-29 can be seen in the running gear of the new tank, especially the road wheel drives. The T-29 had an influence on other vehicles as well. The T-29CN (further development of the T-29C) had a torsion bar suspension that was later used on the SMK and KV.

Proof that the T-29 was present at the NIBT Proving Grounds as of August 1941.

The fate of the T-29 tanks was different. The T-29-4 was the least lucky of all. It was disassembled in 1938. The T-29-5 was used for testing various assemblies, after which it was passed onto factory #185. The tank with serial number 217 ended up in Kubinka in the summer of 1941. The tank was sent off to the 13th Army after repairs on February 13th, 1940. It is not known whether or not it had time to fight in the Winter War. It definitely saw battle a year and a half after.

T-29-5 at factory #100, 1942.

Both T-29 tanks ended up at the NIBT proving grounds by August 22nd, 1941. On September 29th the T-29-5 was sent to Kazan where a branch of the proving grounds was based. In 1942 the tank was sent to Cheyabinsk, where it ended up at factory #100. Tseits also happened to be in Chelyabinsk, working on the KV-13.

The pilot T-29 along with the A-20 and a number of other tanks from the proving grounds ended up in an independent tank company under the command of Captain Karpenko. The company was included into the Mozhaisk fortification region. As of October 8th, "Semyenov's company" (that was the designation in NIBT documents) had 2 T-26 tanks, and one each of T-40, T-29, A-20, AT-1, BA-10 and BA-20. The auxiliary vehicles were also interesting: 5 ZIS-22, 2 ZIS-5, mobile workshop type A, and a Japanese Type 94 truck. "Semyenov's company" fought like this until the end of October, at which point the T-29's trail ends.

Information that the T-29 ended up in the 22nd Tank Brigade is not correct. It was the A-20 that ended up in this unit, and fought here until December 3rd, 1941. The tank was knocked out on that day near the Pavlovskaya Sloboda village, where it was evacuated to a repair base.


  1. Experience with attracting foreign designers was poor. Classic understatement. Considering the number of citizens and foreigners who were jailed as a insurance policy it is a wonder as many Communist zealots did move to the Soviet Union. As for the T-29 it seemed average for it's day. Perhaps a little faster than most tanks of it's size. But it is easy to see why the Russia eventually chose the sloped armor T-34. The designers of the T-29 may have failed but they didn't deserve their fate.

    1. The experience wasn't poor because nobody would come to the USSR, far from it. The Soviets paid well, it's just that nobody in the world really had any idea what a proper medium tank is supposed to look like. That's why the T-28, strange as it was, ended up as the most numerous medium tank of the interwar period.

    2. By the time Stalin's big purging period kicked off in '36 the USSR was already largely past the point where they needed to bootstrap their technology and industry with foreign consultants anyway.

    3. Peter perhaps you misunderstood me. My point was that despite mistreatment, Stalin had no shortage of pro Westerners moving to the Soviet Union with visions of a Communist Utopia in their heads. The T-29 was as good as anything being built in Europe or America. A few years of use could of ironed out the mechanical bugs. The designers did not need to be punished with death and prison. Imagine a world where in 1965 in response to the market success of the Ford Mustang, the designers of the Plymouth Barracuda or Chevy Nova feared being sent to jail for producing a inferior product. Not that I felt the Plymouth was inferior. I loved my black 64 Valiant convertible with push button automatic.

    4. Oh, definitely. It was bad timing: 37-38 was the height of Stalin's paranoia and any perceived slight had a good chance of becoming lethal. Many high ranking AFV designers and administrators were arrested and executed for sabotage, even though we now know that anything they built was as good if not better than what was being built in the West.