Friday, 29 September 2017

SU-26: Blockade Long-Liver

The start of the Great Patriotic War in the summer of 1941 forced many changes onto the prospective designs of Soviet SPGs. Many branches were cancelled, and work on the ZIS-30 SPG on the Komsomolets tractor platform was urgently started. Until then, it was not considered as an SPG platform at all. However, one SPG that was designed according to pre-war plans was not only built, but mass produced. This is a vehicle best known under the name SU-26. Its real name, T-26-6, was buried deep in the archives.


Obsolete chassis

The Red Army was re-arming in the spring of 1941. Factories were starting up production of new types of tanks. According to plans, the main light tank (support tank) was going to be the T-50. It was replacing the T-26, the Red Army's oldest and most numerous tank. Production began in 1931, and factory #174 delivered its last units in 1941, in parallel with preparation for T-50 production. When the T-50 was only being prepared for production, the army had a large number of T-26 tanks.

Two-turreted T-26 on the Neva Foothold, late 1941. The chassis of these vehicles would be used for infantry support SPGs.

The most critical situation was with two-turreted T-26 tanks. The army received 1626 tanks of this type. By the spring of 1941, the Red Army still had a large number of them. 450 tanks were built with mixed armament: the right turret housed a 37 mm gun, a combination of a naval Hotchkiss gun and the PS-1 gun mount. The same gun was used on the T-18 (MS-1) support tank, and there were issues with shell supplies by 1941. The other tanks of this type only had machineguns.

Both versions of the tank were of questionable value in combat by the start of WWII. Either way, two-turreted T-26 tanks were still used in the Polish campaign of 1939 and the Winter War of 1939-40. Without a replacement, they continued to serve. In 1940-41, many of them were modernized. The air intake on the engine deck was covered with a special shield, protecting it from Molotov cocktails. For example, the Leningrad Military District had 87 tanks of this type by May of 1941.

A reasonable question came up: what to do with these tanks? On May 27th, 1941, a Council of Commissars decree titled "On self propelled artillery" was published, which set the course for SPG development. One of them included a "self propelled 76 mm regimental mod. 1927/32 gun on the chassis of a two-turreted T-26 tank". The scale of production was impressive: 1200 T-26 tanks would be converted into SPGs in 1941 and 1942. The developer of this SPG was, logically, factory #174, a producer of T-26 tanks.

However, the conversion would not happen at the same place. The plan was to convert the tanks at the Vyksa Particle Size Reduction Equipment Factory (DRO), a producer of BA-20 armoured cars. This solution was logical, as factory #174 was loaded with T-50 orders.

According to the decree, factory #174 would receive two KT tank guns. Factory #7 would renew their production. Two prototypes were expected by September 1st. Factory #174 correspondence contains the index of this SPG: T-26-6. Alongside it, development of a 76 mm SPG and SPAAG on the T-50 chassis launched at factory #174.

On June 3rd, 1941, the factory design bureau, led by S.A. Ginzburg, began working on a draft project titled "KT-26 self propelled mount on the T-26 chassis". There was also a "self propelled AA gun on the T-26 chassis", designed on personal initiative, indexed T-26-8. On June 9th, 1941, the T-26 was considered as a chassis for a 57 mm gun armed tank destroyer, but it was declined due to an overloading of the chassis and low ammunition capacity.

On May 24th, 1941, tactical-technical characteristics for a "76 mm self propelled moto-mechanized unit support gun". On May 27th, they were approved by Marshal Kulik, at the time the deputy People's Commissar of Defense. The SPG was designed to combat enemy machinegun nests, light fortifications, and personnel. Effectively, it was a return to the almost decade-old SU-1 concept. This time, the fighting compartment would be half-open. According to requirements, the T-26-6 would have armour in the front, from the sides, and on top. The designers were required to make minimal changes to the chassis. The ammunition capacity of the SPG had to be at least 50 rounds.

The requirements gave factory #174's design bureau a good amount of leeway. This led to a noticeable difference between the T-26-6 and prior SPGs on the T-26 chassis.

Production during the blockade

The start of the Great Patriotic War affected the T-26-6 program as well. Most two-turreted T-26 tanks were lost in the first months of the war. The DRO factory in Vyksa also received additional production tasks, and became too busy to produce an SPG on an obsolete platform. Finally, factory #174 was busy with the T-50, and work dragged on. However, the vehicle, or rather vehicles, on the T-26 chassis were not forgotten.

The first vehicle to enter trials was a completely different SPG, one designed on factory #174's initiative. It was indexed T-26-5, and armed with a 37 mm 61-K autocannon. Sadly, only the text of the trials report survives to this day. According to the description, the SPAAG was very similar to the T-26-6, the only difference was in the armament and armour. The T-26-5 arrived at the Scientific Research Artillery Proving Grounds (ANIOP) on July 19th, 1941. Due to the rush, the gun's armour was made from mild steel, and various elements of the platform were unfinished.

These oversights significantly impacted the results of the firing trials, which took place from July 20th to 23rd, 1941. The beams that held the platform loosened during firing. As a result, the precision of fire decreased, except at certain traverse angles. Overall, the stability of the platform was deemed satisfactory, and the T-26-5 met requirements for a SPAAG.

The factory #174 design bureau received orders to complete the development of the SPAAG, especially the attachment of the gun platform to the chassis. The platform itself cause complaints: during firing, it bent visibly, which impeded the gun traverse. As a result of the trials, a decision to produce 140 of these vehicles was made. There was one caveat: the SPAAGs would be built only if there were tanks suitable for the chassis. This was the main obstacle on the way to production. In reality, only two of these vehicles were built, and both ended up in the 124th Tank Brigade.

Trials of the T-26-5 influenced the design of the 76 mm T-26-6 SPG. Factory #174 was preparing a "duplex", one chassis for two types of SPGs. Changes to the SPAAG forced the design bureau to make changes to the platform attachments. This meant that the draft T-26-6 project underwent some changes as well. The reworked variant was presented to the Military Council of the Leningrad Front on August 5th, 1941.

Since the DRO factory was no longer a suitable production base, an alternative was found. This was the Kirov Lifting and Transportation Equipment Factory. They were already working on tanks: thanks to their heavy equipment, they were working to repair tanks that were damaged in combat. The factory already had KhT-26 and KhT-130 tanks, built on the T-26 chassis. The issue of chassis was solved.

Assembly of the T-26-6 at the Kirov Lifting and Transportation Equipment Factory.

On August 11th, the Military Council of the Leningrad Front approved the production of the T-26-6, and two vehicles were already complete by the 24th. The result was completely different from prior SPGs on the T-26 chassis, and no longer completely met requirements. The turret and turret platform were removed from the tank, and the driver received a separate cabin. The platform was attached with channel beams along the entire length of the hull. This meant that servicing the engine became difficult, but factory #174's design bureau had no other choice.

The platform carried a pedestal, to which a large turret was attached. Thanks to the pedestal, the turret could traverse 360 degrees. The turret carried a crew of 2. The turret was considered open from the rear, but recently discovered fragments of armour suggest that it was at least partially covered.

There are disagreements regarding the armament. According to requirements, the T-26-6 carried the KT gun. However, the SPG was most likely armed with the 76 mm mod. 1927 regimental gun. This theory is supported by the fact that there was nowhere to get KT guns from. Two DT machineguns complemented the main gun. Hatches were cut in the platform for access to ammunition racks and the engine.

The gun's recoil mechanisms were armoured.

A decision to put the T-26-6 into production was made on August 26th, 1941. Since stores of repaired tanks were low, a decision was made to only convert 12 tanks: 8 flamethrower tanks, and 4 two-turreted tanks. There is conflicting information on how many of these SPGs were actually built. It is frequently said that 12 were built in 1941-42, but this number doesn't mesh with the supplies of these SPGs to tank units in late 1941.

These vehicles went to the 124th and 125th brigades, and later ended up in the 122nd and 123rd brigades. According to the TO&E, each brigade received a battery of 4 SPGs. Even though, in reality, everything might have been different, one can claim with some confidence that 12 SPGs and 2 SPAAGs were in service by early 1942. Production of the T-26-6 did not end there. On June 6th, 1942, the Military Council of the Leningrad Front signed decree #00915, which requested 6 "SPGs on the T-26 tank chassis" from the factory.

There is one nuance here, which confuses historians. There was at least one other factory in Leningrad that bore Kirov's name: the Kirov factory, producer of heavy tanks. By this time, most of it was evacuated to Chelyabinsk, but the remnants in Leningrad kept functioning. Its director was M.A. Dlugach.

As you can see, there is an armour plate in the rear of the turret.

Due to the confusion, some insist that the SPGs were produced there in 1942. This was not the case. The assembler of the SPGs was still the Kirov Lifting and Transportation Equipment Factory. Director B.N. Boykin was responsible for the assembly. For a number of reasons, the Front's order was not completed, and the first secretary of the Leningrad Municipal Committee of the VKP(b), Zhdanov, repeated his order on July 1st, in decree #001025. This time, he clarified: the SPG would be built on the chassis of T-26 tractors.

By August 1st, two SPGs were still under construction. From the looks of it, there was cooperation between the two Kirov factories. The heavy tank factory records production of 5 "mounts for guns on the T-26 tractor chassis" at a cost of 44,900 rubles per unit. Most likely, the heavy tank factory produced the components, and the lifting equipment factory assembled them.

In battle for Leningrad

The first T-26 SPGs to reach the front lines were the two T-26-5 SPAAGs. They were included in the 124th Tank Brigade. As for the 76 mm SPGs, they only arrived at the brigade in early January of 1942. These SPGs also ended up in the 125th Tank Brigade, from where they were passed onto the 2nd Battalion of the 123rd Tank Brigade. In the brigade's documents, they are recorded as "T-26 tanks with 76 mm guns".

As of February 12th, 1942, the 1st Battalion of the 122nd Tank Brigade had two "SU artillery tanks". On the next day, the battalion assaulted the southern outskirts of Pogostye, as a result of which one SPG was lost. The remaining vehicle was actively used in the battalion's operations.

On March 6th, according to an order from the commander of the 54th ARmy, the tank battalion received reinforcements, including another SPG. Its likely that the vehicle arrived from the 124th Tank Brigade. That brigade lost two T-26 SPGs in battle at Vinyagolovo, including one SPAAG. During an attack by the 122nd Tank Brigade on March 9th, one SPG was knocked out, and it was towed to a disabled vehicle collection point.

The remaining vehicle kept fighting around Konduy common and Smerdynya village. According to the combat records, the combat group had two "SU"s by March 30th, meaning that the knocked out vehicle from March 9th was repaired. On April 2nd, both SPGs were sent for repairs at the brigade's workshop. The damage must have been minor, since both vehicles returned into service on the next day. On April 7th, the 122nd Tank Brigade supported the advance of the 115th Rifle Division, and on the 17th, it was removed from the front lines.

Knocked out SPG, likely from the 122nd Tank Brigade, near Pogostye, winter-spring of 1942.

The SPGs of the 122nd Tank Brigade went into action once more in September of 1942. On the 8th, the brigade supported the 53rd Rifle Brigade. The offensive, initially successful, stalled due to the enemy's increasing resistance. The swampy terrain didn't help, since the brigade constantly had to pull their tanks out of the muck.

On September 11th, the 122nd TBr was reassigned to the 2nd Shock Army of the Volkhov Front. A part of the brigade was sent to the region of Tortolovo, while the rest remained at their previous positions with the 53rd brigade. By this point, one "SU" remained, with the 1st Tank Battalion. By October 2nd, the second "SU" resurfaces in the brigade's reports. Both vehicles vanish from the brigade in the end of the month. Theis subsequent fate is unknown.

As for the 124th Tank Brigade, only one SPAAG remained in service by the fall of 1942.

An SPG from the 2nd Tank Battalion of the 1st Red Banner Tank Brigade, Leningrad, fall of 1942. As you can see, the vehicle is also camouflaged.

SPGs of this type lasted a lot longer on the Leningrad Front. As mentioned above, the first two "T-26 tank with 76 m/m gun", serial numbers T-8 and T-9, were received from the 124th and 125th Tank Brigades. This happened on January 12th, 1942. On May 5th, 1942, the 123rd Tank Brigade was renamed "1st Red Banner Tank Brigade". By then, the brigade had 4 "SU T-26". They were gathered into an artillery tank battery under the command of Senior Lieutenant, R.P. Kozlov, which was a part of the 2nd Tank Battalion.

Between July 20th and August 5th, 1942, the brigade fought near Staro-Panovo and Uritsk. During fighting at Staro-Panovo, the SPGs destroyed three dugouts, 9 anti-tank guns, a mortar with its crew, 3 MG nests, and up to 50 German soldiers and officers. Lieutenant Kozlov received the Order of the Red Banner for these achievements. Senior Sergeant A.V. Zaitsev was rewarded separately. During fighting on July 22-23, the SPG commander walked through a minefield under enemy fire, directing the path of his vehicle. For this act, he was awarded the Order of the Red Star.

After the end of combat, the brigade was sent to Leningrad, where it was based near the House of the Soviets.

T-26-6 from the 220th Tank Brigade, Operation Spark, January 1943

Vehicles produced in the summer of 1942 by the Kirov factories ended up in the 220th Tank Brigade. The first "SU battery" is mentioned in the brigade's composition on December 15th, 1942. By January 9th, 1943, the brigade counted four "T-26 SU". In this composition, the 220nd Tank Brigade's SPG battery started Operation Spark, the goal of which was the penetration of the blockade around Leningrad.

On January 16th, the vehicles began the fight for Kirov town #2. The tanks' success was not reinforced by infantry. One "T-26 SU" from the 84th Tank Battalion lost its floor from an explosion, but, according to further records, it was returned into service. The brigade fought side by side with the 142nd Naval Rifle Brigade. By the 21st, its battery had 3 "SU"s, and another one was knocked out on the following day. The SPGs remained with the brigade for a long time. As of December 24th, 1943, the 84th Tank Battalion still had one "T-26 SU". The last SPG vanished from the 220nd brigade in early January of 1944.

Fire correction.

The Leningrad SPGs from the 1st Red Banner Tank Brigade lasted the longest. As of January 1st, 1944, the brigade had three "T-26 SU-76". The SPGs were gathered into Senior Lieutenant M.I. Krasilnikov's tank destroyer battery. The fourth vehicle in the battery was a SU-76M (SU-15M). During battles for Kurgeleva, the battery destroyed 3 anti-tank guns, 8 machineguns, 2 dugouts, 1 trench shelter, and up to 40 German soldiers and officers. Krasilnikov was heavily wounded, but later returned to his post. By January 19th, when the brigade began moving out to positions to attack Krasnoye Selo, only one "T-26 SU-76" remained in its ranks. This vehicle survived the complete penetration of the Leningrad blockade.

On the 23rd, 4 "T-26 SU-76" SPGs arrived from the 12th Independent Training Tank Regiment. The battery kept fighting in the summer of 1944. On June 11th, the brigade fought at Yappilya and Halal, entered Vammelarvi, the location of the HQ of the Finnish 4th Army Corps, on the 14th, and repelled a counterattack. On June 19th, the unit took Kämärä (modern day Gavrilovo), and fought for Wyborg on the next day.

By the end of the operation, the worn down SPGs began to break down. On June 19th, one broke down for technical reasons, and all of them needed factory repairs by June 23rd. They were replaced with SU-76es.

When analyzing the performance of the T-26-6 in combat, we must remember that the Leningrad Front was a world of its own. Even in 1944, T-26, T-60, T-70, and BT tanks were widely used here. Even correcting for that, one must admit that the T-26-6 was effective in combat. These SPGs were successfully used as support weapons, destroying enemy infantry and light fortifications. It is regrettable that the idea of converting old two-turret T-26es into SPGs only came up in the summer of 1941.

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