Monday, 18 July 2022

Two Turrets from Leningrad

The creation of the two-turreted T-26 tank

The most famous Soviet tanks of the interbellum era at BT light tanks. Their high mobility, convertible drive feature, and a certain photogenic quality made them the best known Soviet tank series. One popular theory classified the BT tanks as "highway aggressor tanks" that indicated the offensive nature of the Red Army and popularized the idea that the BT tanks were the Red Army's main tanks. This is only an indicator of how wrong that theory is.

T-26 tanks armed with either only machine guns or both a cannon and a machine gun on parade in Moscow.

Much has been written about this "aggressor tank" and the claim that only the USSR worked on convertible drive tanks. In brief, everyone worked on these tanks, but few nations reached results. The claim that the BT tank was the Red Army's main tank is just amusing. The Red Army classified the BT as operational tanks. The combined arms tank, meaning the most common kind of tank, was the T-26. The T-26 was the most numerous tank in the Red Army starting from 1933 and until the start of the Great Patriotic War. This was the Red Army's workhorse in a number of military conflicts and was only the minority at Khalkhin-Gol in the summer of 1939. The T-26 was the most common tank during the Spanish Civil War and had a great deal of influence on the development of tanks in several nations. Its career lasted until the 60s in some places. This is a great success for a vehicle developed in the late 1920s.

A support tank with no alternative

The situation in Soviet tank building in 1930 was not the most promising. As an aside, it was no better in many other countries, and sometimes even worse. Tank building across the world suffered not only from a financial crisis, but also a crisis of ideas. A shortage of ideas, or rather their execution, also plagued the USSR. The task of simply producing enough tanks was more or less being completed, but with great effort. The Bolshevik factory in Leningrad, the main producer of Soviet tanks at the time, was not meeting their quotas to the point where the OGPU was involved in November of 1930 to figure out what was really happening. On November 1st 1930, Bolshevik reported that 312 T-18 (MS-1) tanks were ready, but the OGPU commission reported on November 10th that only 238 tanks were presented for a trial run, 151 of which were delivered. 82 had no turrets. There were also cases where tanks that arrived at the factory for repairs were simply taken apart and their components used to build new tanks.

T-20. This tank was a high priority project to replace the T-18 (MS-1). Its trials went poorly from the very beginning and the time for this vehicle quickly passed.

While production issues were ironed out slowly but surely, the situation around the tanks themselves was becoming more dire. The T-18 (MS-1) support tank was accepted into service on July 6th, 1927. This was not a bad vehicle for its time, but the tactical-technical requirements for this vehicle were composed in 1924. Requirements for support tanks changed by the time the first tanks of this type reached the Red Army in 1929. Discussion of two modernizations came up in correspondence in the spring of 1929. The first tank designated T-20 was a modernized T_18 with a 60 hp engine and a top speed of no less than 22 kph. This vehicle was developed by the GKB OAT under the direction of S.P. Shukalov and V.I. Zaslavskiy. The second tank designated T-19 was essentially a whole new vehicle based on the T-18. The crew grew to 3 men (two of which were in the hull). Initial requirements called for a 75 hp engine and a top speed of no less than 25 kph. This tank was developed at the Bolshevik factory. Later, requirements increased to a 90 hp engine, and later still to 100 hp. Based on the description of a support tank accepted by the Red Army on July 17-18th 1929 (7-7.5 tons, 25-30 kph top speed, 3 crewmen) they were betting on the T-19. The topic of an 8 ton convertible drive tank with a top speed of no less than 45 kph on wheels was also discussed. This was the result of inspection of the KH-60 and discussions with Joseph Vollmer. A whole slew of SPGs on the chassis of the T-19 was also planned (initially envisioned for the T-18). However, requirements are one thing, and reality is another. All-Union exercises held near Bobryusk in September of 1929 revealed even more weaknesses of the T-18. The situation around prospective tanks grew even more dire.

Work on the T-19 went on in parallel. This tank looked more promising, but work took too long and the running gear was not suitable for highly maneuverable tanks.

The Red Army took action in response to this situation in late 1929-early 1930. First, the Directorate of Mechanization and Motorization (UMM) was created on November 3rd, 1929. Tanks were therefore taken out of subordination to artillery and turned into their own branch. The UMM quickly collected a number of influential figures who knew tanks well and had leverage with tank factories. I.A. Khalepskiy who headed the UMM quickly raised the issue of buying vehicles abroad. These would not just be samples, but purchases of licenses complete with documentation and possibility of technical assistance. His question was simple: if our industry can't create its own tank, then we have to produce a foreign one. Some argue against this approach, claiming that purchase of foreign technologies leads to the destruction of one's own technical school. However, the Soviet technical school was unable to create its own modern tank, while in most nations there was no stigma around buying foreign tanks, buying licenses, or simply stealing their neighbours' designs. The latter raises an interesting point. While the T-18 was an original vehicle, the T-19 shows several characteristic features of the Renault NC and Renault D1. The Renault NC was also on Khalepskiy's list of tanks that should be purchased. The American Light Tank T1E1 that was advertised in American press was also considered for the role of the support tank.

Vickers Mk.E tanks designed for shipment abroad. The last tank has no armament. This was a Vickers Mk.E ordered by the USSR for installation of a cannon.

The reality was different. Schneider-Creusot and Renault refused to talk to Khalepskiy's commission completely, as did Skoda, who had tight ties to Schneider-Creusot. Inspection of the Light Tank T1E1 revealed an unpleasant truth. The tank was woefully inadequate. Fortune smiled on the commission elsewhere. Vickers-Armstrongs was on its list as a potential seller of tankettes, maneuver (medium) tanks, and possibly even a large (heavy) tank. It also turned out that they had a support tank for sale. It was initially called Vickers-Armstrongs 6 ton tank, and thus became known in the USSR as the "6-ton Vickers". The tank received a different name after the British military lost interest and the tank was reoriented for export: Vickers Mk.E. Poland learned of this tank back in 1927. A commission arrived and tried to negotiate the purchase of 30 tanks, but mediocre performance in trials and a price of 4000 pounds Sterling apiece (about the same as the cost of a Medium Tank Mk.II) cooled their enthusiasm. The situation with Khalepskiy's commission was very different. On one hand, the Vickers Mk.E was not a complete match for Soviet requirements. Two turrets and a machine gun only armament was not what the Red Army wanted. However, Khalepskiy's reports indicated that discussion with Vickers revealed that it was possible to install a 37 mm gun into one of the turrets. The chassis was also very promising. The fighting compartment was larger than on the T-18, the mobility was higher, and there was potential for modernization. The British were also willing to sell a license to produce the tank in the USSR. Even the price of 4200 pounds Sterling (the highest cost quoted to anyone for a Vickers Mk.E) did not scare Khalepskiy away.

Vickers Mk.E tank that went through trials between November 1930 and January 1931.

A contract for 15 Vickers Mk.E tanks was signed on May 28th, 1930. The first tank would arrive in September of 1930, 4 more in October, 4 in November, 4 in December, and the last 2 in January of 1931. The technical documentation would arrive with the first delivery. The British completed their side of the bargain without issue. Tanks built in the UK had serial numbers V.A.E.214-V.A.E.228. These tanks received the designation V-26 in the USSR. Plans made in November of 1930 called for production of these tanks at the Stalingrad Tractor Factory. There were also plans to build the T-19 there, but the T-19 was nowhere in sight and the T-20 was also greatly delayed. It seemed that Shukalov and his team didn't see the UMM or its new tanks as a threat. They might have taken some actions, since the V-26 that went through trials in December of 1930 took a suspiciously long time to start up. Nevertheless, despite the tank's issues it was still better than anything Soviet industry had to offer. By that point the T-19 weighed 8 tons, which was more than the limit set in requirements. The tank was not even built yet and work was still underway on two different types of running gear. The second kind was clearly inspired by the V-26. As for the T-20, it was in a very poor state. The first trials conducted in late October of 1930 with the engine from the T-18 revealed many issues.

Despite attempts to at least partially retain the T-19, it was clear that the V-26 was the superior option.

A meeting with STZ management held on January 16th 1931 threw more fuel onto the fire. Representatives from STZ plainly stated that the British tank was superior in terms of manufacturing simplicity. In comparison, the products of the Bolshevik factory and GKB OAT seemed pale. The T-20 continued to drive with the T-18's engine and crumbling running gear. The new 60 hp engine overheated during trials. The first T-19 tank was only 70% complete by January 15th. The military's patience ran dry, and on January 28th 1931 they formed the VOAO (All-Union Arms and Arsenal Conglomerate) KB-3, appointing S.A. Ginzburg as its chief. Shukalov's protests were powerless and ended badly for him. The decision to produce the V-26 at the Bolshevik factory was made on February 13th 1931. The tank was accepted into service with the Red Army as the T-26. This was the only correct decision, as further development of Shukalov's vehicles was senseless.

First combined arms tank

The first plans called for delivery of T-26 tanks by July of 1931. Later the deadline was pushed to August. Initially the goal was to copy the T-26 completely with only minor corrections like adding vision ports to the driver's hatch flap and the turrets. The left turret would carry a DT machine gun and the right a "high power 37 mm gun". This was the 37 mm model 1930 tank gun or B-3. The gun was in development since 1927. It was supposed to go into the T-18 and T-20, but that never happened. This gun used ammunition from the German 37 mm Tak 29 that was referred to as the "Rheinmetall gun" in Soviet documents. The muzzle velocity of this weapon was 670 m/s. It was capable of penetrating 18 mm of armour sloped at 30 degrees at a range of 1000 meters. To compare, the Hotchkiss gun could penetrate 16 mm of armour under those conditions. The B-3 was accepted into service at the same time as the T-26, on February 13th 1931. The T-26 was planned to use this gun from the very start. Bolshevik was required to deliver 300 T-26 tanks before the end of 1931 (70 in October, 100 in November, 120 in December). 200 B-3 guns were ordered.

Few photos of the pilot tanks exist. These tanks looked like the Vickers Mk.E but with new armament.

Plans and reality often diverge. First of all, there were T-18 delivery quotas, and the fourth series of this tank was supposed to be the most numerous. It also seemed as though the T-26 was a second rate tank at the Bolshevik factory. Blueprints were still being worked on by May 1st, but the hull of an experimental TMM-1 tank was already completed and work on the TMM-2 was underway. Bolshevik also built a TMM-1 tank on July 27th 1931 before they built any T-26es. M.V. Danchenko's project was favoured because it used components from the Ya-5 truck and the Hercules engine. There were some doubts about the engine of the Vickers Mk.E. It was no secret that this engine was prone to overheating. In addition, S.A. Ginzburg proposed a mix between the T-26 and T-19 in January of 1931. The running gear and transmission would come from the T-26. This idea didn't go very far, although the idea of replacing the British engine remained alive for almost the whole production run of the T-26.

37 mm B-3 tank gun. According to plans, the T-26 was supposed to be armed with these weapons.

Work on the T-26 was expedited in July of 1931. The first engine was finished and two hulls were built. A design for a welded hull was already finished, plus a new two-man turret with a 45 mm gun (an earlier variant of the one that was used later). The turret was later converted to house the 37 mm gun at the UMM's request. Nevertheless, the target of 300 tanks in 1931 would not be met. Two experimental vehicles delivered in August of 1931 were used as test benches for engines in the fall-winter of 1931. Only 17 tanks out of 120 delivered were accepted. 10 of them were pilot tanks, the rest had new turrets. These turrets were developed by the VOAO KB-3 and had cupolas with observation ports on top. This increased the room inside the turret and improved observation. The pitch of rivets on the hull was smaller than the one Vickers used. There were also changes to the lights. Even more changes were made inside the tank. Interestingly enough, it used Bosch electrical components.

A tank from the main production batch. There were many changes compared to the Vickers tank, although the new turret is the most obvious one.

The difficult situation had an impact on plans for 1932. Bolshevik was expected to deliver 800 tanks plus 120 left over from 1931. The plan ignored the interesting relationship with the Izhora factory that supplied Bolshevik with armour. The situation with guns was no less interesting. As mentioned above, the tanks were supposed to have mixed armament, but Bolshevik failed to produce the gun. As a result, UMM NTK chief G.G. Bokis sent a letter to Bolshevik on February 8th 1932 ordering them to produce T-26 tanks armed only with machine guns until orders to the contrary. T-26 tanks armed only with machine guns were a forced measure.

The main batch of T-26 tanks was supposed to look like this, but the situation with B-3 gun production made this variant an uncommon one.

Development continued regardless of these issues. A special cap was added to the engine deck in March to cover the exhaust grille. A more important change happened on February 15th 1932. NKTP order #35 factored out the tank branch of the Bolshevik factory into a new organization called Voroshilov factory #174. The OKMO (Experimental Design Machinebuilding Department) headed by N.V. Barykov was formed in December of 1931. S.A. Ginzburg became his deputy with the task of improving the T-26 design.

A bulge from the air intake can be seen on the engine deck. It was later sealed.

Work on the T-26 improved after reorganization. The design of the muffler holder changed in the spring of 1932. Observation slits in the sides of the turrets were added by the summer of 1932. The gas tank was enlarged. A hatch for accessing the gearbox was added in the upper front plate in the fall of 1932. Experiments to weld the hull and turret began at the Izhora factory in early 1932. Welded hulls were produced rarely, but welded turrets were a common sight. The Izhora factory also began to use 15 mm thick PI steel to produce hulls as of September 1932, which had an effect on the vehicle's mass. The UMM increased quotas for the T-26 tank to 1600 units, although this was going too far. Out of 1341 tanks delivered by the end of 1932 only 1032 were accepted. The plan for 1933 was even more grandiose: 1700 tanks.

The variant with machine guns became the most common type. This tank was shown at the November 7th parade in Leningrad in 1932. A pilot tank can be seen behind it.

1933 was the last year when two turreted T-26 tanks were produced. The Izhora factory was supposed to deliver 720 turrets and transition to the enlarged two-man turret that was a further development of the design finished in 1931. This turret had a turret bustle and carried the 45 mm model 1932 tank gun. 576 two-turreted T-26 tanks were built in 1933, some of which were left over from the previous year. One tank was built in 1934, another leftover. At least some of the 20 T-26 tanks built with radios that year were two-turreted vehicles. These tanks had rail antennas on the hull, similar to the German type.

Spring 1932 production tank. The cap covering the air exhaust from the engine compartment is already in place, but the muffler is still attached in the old style.

The topic of the tank with a cannon and a machine gun is an interesting one to examine separately. As mentioned above, the initial plan was to install the 37 mm B-3 gun. However, since the Bolshevik factory failed to build it, the B-3 was a rare sight on the T-26. Due to the critical situation, the same 37 mm Hotchkiss gun used on the MS-1 was installed in the right turret of the T-26. This gun was not the main armament either. About 450 tanks had mixed armament or a quarter of the production run. The first Hotchkiss guns were installed in tanks that were built to carry the B-3. They were relatively uncommon after that.

An interesting vehicle. The muffler has three bands keeping it on and the air intake cap is already removed.

Despite all of its issues, the T-26 was a great help for the Red Army as a modern vehicle capable of replacing the ageing T-18. It was capable of carrying out the tasks that tank units were expected to perform. The army's appetites only grew and so a wheeled drive was ordered in 1931. However, the tank was considered fine for infantry support in its initial form.

An unlucky T-26 that didn't get a B-3 gun. They were initially used without guns.

Let us make a remark regarding the relative magnitude of the drama surrounding production of the T-26. Tank building all around the world was in crisis in 1931-33 while this tank was in production. The annual production of tanks at the Bolshevik factory alone exceeded production of all other tanks in the world put together. Production was also more successful than at other factories in the USSR. For example, production of the BT was not set up in 1931 at all and only 396 BT-2 tanks were delivered in 1932. Just like the T-26, these tanks suffered from shortages of B-3 guns. The situation with the T-27 tankette was the most promising. Unfortunately, there was a large gap between a tiny vehicle that had questionable combat value even in the early 1930s and a fully fledged infantry support tank.

A variant of the gun mantlet used on tanks with Hotchkiss guns. Initially no external mantlet was installed at all.

Two turreted T-26 tanks were slowly phased out in favour of tanks with a single turret, but they were still kept on as training and active duty vehicles. These tanks could be very heterogeneous. Both welded and riveted turrets were used, and one tank could have one turret of one type and one of the other. Sometimes the hulls were also welded, making for a total of nine combinations. There were also different gun mantlets for Hotchkiss guns. Pioneer tools were also variable. Few were carried at first, but requirements for parts and instruments kits were composed in the second half of 1932. Individual units also made their own corrections. T-26 tanks were far from identical even before the modernization in the second half of the 1930s.

One of the few two-tureted T-26 tanks with a radio. The radio was installed in a similar way to the German radios tested at TEKO.

The two-turreted tanks had the same modernizations as single turreted ones. This was especially important in regards to the running gear, which inherited issues from the Vickers Mk.E. The rubber tires of the outer road wheels wore down quickly, plus there were issues with idlers. Work on modernization of the running gear began in the second half of the 1930s. This consisted of replacing the road wheels with new ones that had removable tires. The outer road wheels were swapped first, then all the others. Reinforced idlers were also added.

Exercises held in 1935. Most of these are early 1932 production tanks. A number of vehicles with welded turrets can be seen, including one with a Hotchkiss gun and no external gun mantlet.

The pioneer tools were also modernized to match those used on T-26 tanks with cylindrical turrets. Toolboxes appeared along the sides of the turret platform. The old jack was replaced with a new one. Attachment for a saw was added, among many other changes. Conversions done in local workshops introduced some variety, especially when it came to placement of tools.

November 7th parade in Leningrad, 1932. These are tanks produced in the second half of 1932 with tools installed according to new requirements. The jack was moved to the engine deck.

The last modernization of two-turreted T-26 tanks was performed in 1940-1941. It was based on experience of the Winter War. A number of tanks received a cap protecting the engine air intake from Molotov cocktails. 

T-26 tank knocked out in the summer of 1941. This tank has a full set of modernizations, including toolboxes.

The Red Army still had 1282 two-turreted T-26 tanks in service by April 1st 1941. Their fate was already decided. 1200 of them would be converted into light infantry support SPGs. These vehicles indexed T-26-6 were supposed to be built in Kolomna according to blueprints developed at factory #174, but the start of the war made its corrections to these plans. These veteran tanks had to go into battle as is, and their effectiveness was predictable. Most two-turreted T-26 tanks were lost in the first year of the war, although they remained in a few places, including the Leningrad Front.

Two-turreted T-26 tank at the Neva Bridgehead. This tank has a protective cover on its air intake on the engine deck. These tanks would have had a full set of upgrades, including new road wheels.

Only one two-turreted tank survived the war without being knocked out. This tank with mixed armament is on display at Patriot Park. It likely fought on the Leningrad Front. Several more tanks were either dug up during battlefield excavations or assembled from fragments. These tanks can be seen at the Poklonnaya Gora, Verkhnyaya Pyshma, at Padikovo museums. Most tanks have some traces of modernizations. Only the tank displayed at the Museum of National Military History in Padikovo was restored to the appropriate state that it would have been in initially in the spring-summer of 1932. 

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