T-50 Problems

August 17, 2016, 4:54 pm

"To the People's Commissar of Medium Machinebuilding, comrade Malyshev

I report that the proving grounds trials of the T-50 produced at factory #174 cannot be completed in the timeframe allotted by your order #009ss issued on January 7th, 1941, due to a series of design defects discovered in the trials process.

The main defects are:

Unsatisfactory lifespan of track links (cracks in the track eyes and breaking of the track teeth). Track links start to break at 300-400 km.
Weak design of the drive wheel (destruction of the hub, high wear and cracks on the crown after 250-300 km).
Destruction of the bevel gear and pinion and bending of the 3-4 gear fork on the gearbox after 1500 km.
The hull floor is insufficiently robust (it vibrates and there is a sagging of 11 mm) and the turret platform roof bends.
The installation of armament and observation devices was not performed in accordance to notes made by the Model Commission (no new turret was designed).
Insufficient thickening of the observation device prisms (poor visibility, easily covered in snow.
Installation of electrical equipment is poorly laid out, which creates radio interference and does not protect the wiring from mechanical damage.
Radio communication at maximum range and the intercom were not tested.
It is difficult to shift from 2nd to 3rd gear.
The oil temperature in the gearbox is high (100-115 degrees at an exterior temperature of -15 to -19 degrees).

During trials, the Commission presented a list of defects to the factory that should be corrected before trials are completed. Measures have been taken by the factory, but the resolution is dragging on.

Because of this, I ask you to:

Order the factory to correct all known design defects by February 10th of this year and provide a new turret for penetration trials from February 10th to [cut off].
Increase the length of warranty trials to 2500 km for more thorough testing of assemblies, the transmission, and suspension after changes made to their design.
Extend the Commission's deadline to February 15th to compete the trials and test the communications equipment.

Deputy Chief of the GABTU, Major-General of the Technical Forces, Lebedev."

CAMD RF 38-11355-62

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Faster, Better, Longer

August 18, 2016, 6:58 pm

≫ Next: Easy Modernization: T-45 and Others

≪ Previous: T-50 Problems

"April 13th, 1939
#227064

To: Director of the Kirov factory, comrade Zaltsmann
CC: Military Representative of the AU at the Kirov Factory, Military Engineer 2nd Grade Buglak

Work on producing an experimental prototype of a tank gun 30 calibers in length is, for some unknown reason, lagging behind all reasonable timeframes, despite being a relatively simple job.

The L-11 prototype presented to the AU was not built according to my specifications, both in design and materials.

I ask to inform me of the reason for your negligent treatment of this job. Since so much time was lost, the elevation and trigger mechanisms of the system must be urgently finished and tested with the goal of quickly discovering the suitability of using it in a tank.

The issues of other deviations in the system (materials, thermal hardening, moderator, etc) will be decided after the end of trials. At the same time, I ask you to build a separate breech wedge, piston, tail rod, and moderator according to my requirements and technologies already used in production of the L-10.

Chief of the RKKA AU, divisional commander Savchenko
Acting Military Commissar of the RKKA AU, battalion commissar Sidorov"

V. Lehn. Collection

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Easy Modernization: T-45 and Others

August 19, 2016, 3:25 pm

≫ Next: Schwere Panzerbüchse 41

≪ Previous: Faster, Better, Longer

GABTU had to reach a compromise on many issues when it accepted the T-60 tank for service. It was obvious that this tank is inferior to the T-50 in nearly all characteristics, but its production could be set up very quickly and it could be produced by the thousands. However, GABTU was seriously worried about the tank's armament. Trials of the 20 mm TNSh gun showed that its penetration was equal to the DShK high caliber machinegun. It is not surprising that the issue of improving its armament was raised even before the first prototype was built. This modernization went in several directions, one of which resulted in the T-45 tank.

Competitor from Gorkiy

In September of 1941, the Artillery Committee of the Main Artillery Directorate (GAU Artkom) initiated work on installation of more powerful armament into the T-60 tank. Management of design groups from Molotov GAZ and factory #92 "Novoye Sormovo" (called "OAO Nizhniy Novgorod Machinebuilding Factory today), one of the leading tank and artillery cannon factories at the time, was called to a meeting to discuss this issue. These two factories were built in the same city, about 10 km between gates. If the development was a success, this would significantly simplify cooperation.

When replacements of the TNSh are discussed, it is often mentioned that the gun was picky and jammed often. Of course, there were such cases, but they were often connected with improper use of the system. Some complaints were the result of factories taking certain liberties in producing ammunition. There was even a decree issued by the GKO (#627, September 4th, 1941) prohibiting factories from making changes to the gun or its ammunition without the approval of the People's Commissar of Armament. Another important factor is that the program to improve the T-60's armament began in September of 1941, and complaints about the TNSh started arriving only in October. Before that, the complaints were not about the gun.

Diagram of a 45 mm gun in the T-60 turret, designed by the factory #92 design bureau.

After studying captured tanks, it was decided that the T-60 would be re-armed to use the mod. 1938 45 mm tank gun. According to the requirements, the stock turret had to be retained. Initially, the GAZ and factory #92 design bureaus worked together on the project, but there were disagreements. As a result, each factory would provide their own variant of the re-armed turret. Model prototypes were due in December. In the case of the GAZ modernization, the process ended with the creation of the T-70. This article will discuss the fate of the factory #92 project.

The design bureau's engineers, under direction from V.G. Grabin, decided to use the existing layout of the turret as much as possible. The sight was placed in the middle of the gun mantlet, with the DT machinegun to the left and the 45 mm gun to the right. The commander's seat was displaced to the rear of the turret, between the cannon and the machinegun, just like in the T-60. The trigger button for the gun was on the turret traverse flywheel handle, and the trigger for the machinegun was on the elevation mechanism flywheel handle.When the project was presented, factory #92 already had blueprints for the 45 mm gun mount. After a tank was received, it would be possible to begin producing it in metal.

T-60 with the ZiS-19 gun

Meanwhile, factory #92 had other ideas about arming the T-60. The factory began development of the 37 mm ZiS-19 tank gun in August 1941 on its own initiative. The gun had the same ballistics as the 37 mm automatic AA gun mod. 1939 (61-K or ZiK-37), and use the same ammunition. The new tank gun consisted of only 153 parts (to compare, the 45 mm gun consisted of 436 parts). The mass of the 37 mm gun was 235 kg with the mantlet, compared to the 403.3 kg of the 45 mm 20-K.

37 mm ZiS-19 tank gun.

It's not surprising that, along with installation of the 45 mm gun, the design bureau promoted the idea of installing its own gun into the T-60 turret. Towards the end of 1941, this was seen as the more promising variant. The designers had their reasons, and it's hard to argue with them.

The 45 mm gun mod. 1938 was much heavier than the TNSh. Installing it made the turret unbalanced. As a result, it was difficult to turn the turret at high gun elevations. A 30 kg counterweight was proposed on the brass catcher, but the massive weight made the already not excessively roomy T-60 turret even more cramped. Operating the turret traverse mechanism became more difficult.

The same gun in three quarters view.

After a review of modernization projects, factory #92 was tasked with the production of a ZiS-19 prototype by January 15th, 1942, and a completed tank with the gun was expected for trials on February 1st. Working blueprints were developed between December 20th and January 13th. The prototype was built between January 12th and January 19th. On January 14th, blueprints of the ZiS-19, a list of parts, and main characteristics were sent to GAZ. On January 27th, a turret with the gun arrived at factory #92 (the gun was installed on January 19th).

ZiS-19 in the stock T-60 turret, February 1942.

The installation of the ZiS-19 in the T-60 turret was done with minimal changes, according to the requirements. Compared to the 45 mm rearmament project, the changes were negligible: only the seat was shifted to the left, like on the GAZ project. The gun system and cradle were installed in a modified gun mount. Thanks to the compact recoil mechanism on top of the gun, the ZiS-19 did not take up much space compared to the TNSh. The stock TMFP sight was retained, as well as the machinegun mount. A new welded gun mantlet was attached to the mount with bolts.

ZiS-19 gun at maximum elevation.

As it often happens, the deadlines were missed. Gunnery trials began on February 21st and ended on February 24th, 1942. In total, 181 shots were fired from various elevation angles. The recoil length was 140-170 mm. Trials showed that the robustness of the system, recoil mechanism, breech, and semiautomatic mechanism was satisfactory. The effort required to operate the traverse and elevation mechanisms was within acceptable norms. At the same time, there were complaints about the comfort of using the system. Due to the limited size of the turret, the gunner could not straighten out or stand up. The seat was deemed uncomfortable, and a saddle-like seat that flipped back was suggested.

The gun mantlet was similar to the one installed in the T-60.

According to Artkom instructions written on February 27th, 1942, two tanks should be sent to the Gorohovets proving grounds by March 9th: the T-60 with a 37 mm gun from factory #92 and a T-60 with a 45 mm gun from GAZ. In reality, events developed differently. Since there were many complaints about the commander's station, the design bureau made a significant amount of changes to the design, which took time. As a result, the new tank only arrived at the Gorohovets proving grounds on March 27th. By that time, it underwent significant changes.

The second variant of ZiS-19 installation in the T-60 tank. As you can see, the turret differs from the stock one significantly.

The resulting design had little in common with the original turret. The only part that was unchanged was the bottom part. The hatch was moved from the roof to the rear, and replaced with an observation device from the T-70. The turret gained a new wedge shape. The gun mantlet became cast, similar to the T-70's gun mantlet. The layout of the armament was also similar to that of the T-70: the sight was shifted to the left and the DT machinegun was installed in its place. These changes increased the volume of the turret, but using the stock T-60 turret was no longer possible. As for GAZ, their tank arrived only on April 18th, and it was not a T-60 armed with a 45 mm gun, but a T-70.

The new turret was not particularly roomy.

Trials of the ZiS-19 in the new turret began on April 19th. Results showed that due to the higher muzzle velocity, the lifespan of the ZiS-19 was shorter than the 45 mm gun. Penetration, rate of fire, and precision were similar, but the ZiS-19's HE shell was far inferior. Since one of the main tasks of light and small tanks was fighting infantry, this characteristic was very important.

Nevertheless, the 37 mm gun performed well, and if all its established defects could be resolved then it could be used on the T-70. The simplicity of the ZiS-19 at almost half the weight of its competitor was commended. There was a big problem, however: by the time trials were complete (July 19th), the T-60 was out of date. In early June, a GKO decree was issued ordering the removal of the T-60 from production at factories ##37, 38, and 264. The gun was also too late for the T-70; by then work was underway to create a 45 mm tank gun with a lengthened barrel, better known as the VT-42. That design seemed much more promising.

T-45

Thanks to work of several Russian historians, an impression was created that the T-45 was a competitor of the T-70. In reality, this is not true at all. The history of the tank begins in the spring of 1942 as the "T-60 that didn't want to go".

On March 9th, 1942, GKO decree #1417 "On organization of T-70 tank production at factories #37 and #38" was issued. According to this document, the production of the T-60 tank that was achieved with such difficulty at factory #37 was over, and the T-70 would be produced instead. The factory was not prepared for this turn of events. Factory management spent a whole month trying to convince the NKPT that factory #37 was incapable of producing the T-70. Finally, on April 12th, 1942, GKO decree #1581 "On production of T-60 tanks at factory #37" was issued, according to which production of the tank was retained until August 1942.

Experimental T-45 light tank, June 1942.

Meanwhile, the factory encountered another problem: the engines. Over the first quarter of 1942, GAZ shorted them 664 units. As a result, the assembly plant of factory #37 stood idle for 8 days in April. Meanwhile, 230 hulls (100% of quota) were produced, and the lack of engines was blocking production. The possibility of using the ZiS-5 engine which was considered during the design of the 060 hull back in July of 1941 came in handy.

Factory #37's design bureau got to work on installing the ZiS-5/ZiS-16 engine into the tank. The core of the group was composed of designers who worked at the 22nd department (experimental tank related developments) of factory #37 before its evacuation to Sverdlovsk. In spring of 1942, N.A. Popov came to head the design bureau, who was the senior designer on the T-40 project. He replaced G.S. Surenyan, who headed the 22nd department before the evacuation, as well as the design bureau after.

The tank engine was taken from a ZiS-16 bus, which traveled 35,000 km by that point without refurbishment. The tank version of the ZiS-16 engine was indexed ZiS-60. Compared to the ZiS-16, the new engine had a different exhaust collector, flywheel housing, and the crankshaft cone with an attachment for the ventilation fan. The ignition mechanism from the T-60 and a reinforced radiator were used. In addition to the new engine, the tank was equipped with a new gearbox that had different gear ratios. The exhaust system was also changed.

The design of the T-45 differed little from the T-60.

The tank with the new engine began trials on May 19th. The tank was artificially loaded to 6800 kg, which was equal to the mass of the tank that the factory design bureau was working on. The result of the trials, which lasted until June 9th, showed that the maximum speed of the T-60 with the ZiS-16 was 40.5 kph, 1 kph higher than expected. The engine was not as loaded as the GAZ-202, was not as loud, and there was no difficulty in servicing it. The main problem was the cooling system, which was deemed inadequate (to be fair, the T-60 with the GAZ-202 engine also had cooling issues). Overall, the idea of installing the ZiS-5 and ZiS-16 in the T-60 was deemed successful. In order to full test out the design, five tanks with new engines were ordered.

At the same time, factory #37's design bureau was working on a deeper modernization of the small tank. The issue was first raised at a meeting of the People's Commissariat of Tank Production on May 14th. The proposal was made by factory #37 and passed on through Military Engineer 1st Class Afonin and consisted of installing a 45 mm gun in the T-60 and increasing its armour to 35 mm. By the time the topic was discussed, the vehicle in question, indexed T-45, was almost ready.

The military was opposed to the idea. The development was considered irrational, since a more powerful gun and thicker armour would increase the load on the engine and transmission. The project was given the green light thanks to the chief engineer of the T-50 tank, S.A. Ginzburg, who was serving as the deputy chief of the technical department of the People's Commissariat of Tank Production at the time. Since April of 1942, Ginzburg was pushing the idea of building a light assault gun on the T-60 chassis at factory #37, and he had common interests with the factory's management. Ginzburg was present at the meeting where the proposal was made, and definitely had an influence on the decision. The minutes contain the following note: "Test this tank over 200 km. Send the results to GABTU. Don't make any more of these tanks for now."

As in the modernization of factory #92, the 45 mm gun was shifted to the right in order to make the turret less cramped.

It's easy to explain the T-45: factory #37 didn't want to built the T-70. In order to built it, 1140 new parts would have to be mastered, and 545 new stamps made. 825 new devices and 2300 new instruments were needed. In comparison, the T-45 needed only 224 new parts, 104 stamps, 175 devices, and 255 instruments, plus 132 parts, 85 stamps, 149 devices, and 433 instruments from the T-70. Production of the T-70 also meant that twice as many engines would have to be used, and Gorkiy was already having trouble with supplies. In this situation, an attempt to create a simpler tnak with more powerful armour and armament and equipped with a locally sourced engine seemed very logical.

The main external difference of the T-45 from its predecessor was the turret with a bustle, which carried a 45 mm mod. 1938 tank gun and a coaxial DT machinegun. A simplified version of the T-60 turret traverse mechanism was used to turn it. The sides of the turret were 35 mm thick, which was equivalent to the T-70. The armour of the hull was left at the level of the T-60, with the exception of the upper front plate, which was thickened from 15 mm to 25 mm. If necessary, the thickness could be increased to 35-45 mm, making it equivalent to the T-70. The hull was mostly the same as the T-60. The main difference was in the driver's hatch, which now turned sideways.

Curious fact: even though the Sverdlovsk T-60s had welded hulls, the T-45s used rivets.

Since the factory only had one ZiS-16 engine, the T-45 used the weaker but much more common ZiS-5 (the engine was taken from a truck that already traveled 12,000 km). The top speed dropped to 37.2 kph. In case of successful trials, the factory could begin producing T-45 tanks with ZiS-5 engines, and switch to the ZiS-16 once production at the Miass factory began. Aside from the new engine, the T-45 used the gearbox and final drives from the T-70. Since the mass increased to 7 tons, reinforced torsion bars were also installed.

The first stage of trials began on May 20th, and opened with gunnery trials. A rate of fire of 7-8 RPM from standstill and 3 RPM on the move was reached. Servicing the gun was easier than on the T-60, the turret became roomier. However, the heavier turret resulted in deformation of the turret platform roof. Despite this defect, all 25 shots hit the target. The production vehicle would have its TMFP sight replaced with the TOP sight from the 45 mm gun.

Even though the T-45 turret was built on the base of the T-60 turret, the results were noticeably different.

Mobility trials were carried out from June 6th to June 13th. In total, the tank traveled 1505 km, of those 189 km over asphalt, 805 over stone, 410 km over gravel, and 110 km over dirt roads. The trials led to complaints about the ventilation fan mount, which broke twice. The engine also often worked at high RPM, which could lead to premature breakdowns. There were also some instances of track links breaking, which is less of an indication of poor design and more of a result of low quality shipments from factory #183. There was also a tendency for road wheel tires to layer. Despite a series of complaints, the trials were deemed a success, especially considering that the tank was driving with a foreign engine, and a used one at that.

The reports on trials of the T-60 with the ZiS-16 engine and the T-45 were sent to GABTU towards the end of June. By that time, both this tank and the T-60 with the ZiS-19 gun looked hopelessly obsolete. Nevertheless, the tank got to fight. According to correspondence, the single T-45 was sent to the Western Front in late September of 1942.

Original article by Yuri Pasholok.

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Schwere Panzerbüchse 41

August 20, 2016, 7:11 pm

≫ Next: 76 mm Regimental Gun Penetration

≪ Previous: Easy Modernization: T-45 and Others

In 1942, the Allies captured an interesting anti-tank weapon designed for the German army and actively used on all fronts of WWII since 1914. Its distinguishing feature from other anti-tank rifles and cannons was its conical barrel, the caliber of which was larger at the breech than at the muzzle.

Officially, the gun was called 2,8 cm schwere Panzerbüchse 41 (2,8 cm s.Pz.B. 41). German nomenclature placed it into the small arms category, but both the Red Army GAU and the military ministries of Great Britain and the United States classified it as artillery. The difference in classification comes from the fact that this weapon has all the characteristics of a cannon: carriage (upper and lower), shield, mount with a recoil brake, but the aiming was done by hand, by moving the gunner's body and moving the barrel up and down.

Captured 2,8 cm s.Pz.B. 41 on trials in the USSR.

Various samples were captured by the Allies at different times, and were tested independently on various proving grounds. In the USSR, the GAU was in charge of trials. The guns were disassembled and carefully studied, instructions on assembly and disassembly were written, blueprints drawn up. Interestingly enough, Soviet, American, and British documents are almost entirely identical. The s.Pz.B. 41 was studied and recorded in 1942. The British included a description of the gun in a reference of enemy weapons in December of 1942.

History

In the early 20th century, 1903-1907, German professor Karl Puff worked on improving the muzzle velocity of sells. He proposed variable caliber barrels that were slightly conical. In order for the shell to not get stuck in the barrel, it had a special directing rim that engaged the rifling tightly. As the barrel narrowed, the rim was compressed into a special indentation in the shell. This kind of projectile used the energy from burning gunpowder more effectively that traditional firearms, but the lifespan of the barrel was shorter and making it was complicated.

Gerlich's conical barrels and bullets for them (US patent 1944883).

After the end of WWI, Hermann Gerlich continued Puff's experiments in creating an infantry weapon with a high muzzle velocity. The biggest difference from earlier designs was that the bullets had two rims instead of one. This increased the stability of the bullet in flight, preserving its high speed. Several carbines with Gerlich's conical barrels were tried and tested in the late 20s and early 30s. These weapons set records for muzzle velocity that still haven't been beaten, but the drawbacks of the design (high cost and low lifespan) were still unsolved.

In 1934, Gerlich died in strange circumstances, and all technical documentation and results of his experiments ended up in the hands of Mauser engineers in Obendorf. In 1939, they created a light universal infantry weapon that used Gerlich's principle, with a 28/20 mm conical barrel, named Gerät 231 or MK.8202. Initially, the system was supposed to be fully automatic, but that feature was later dropped.

Captured 2,8 cm s.Pz.B. 41 with a first type carriage on trials in the USSR.

An experimental batch was produced in the summer of 1940, which was sent out for field trials. After correcting some defects that the trials revealed, the gun was accepted into service with the Wehrmacht with under the index 2,8 cm schwere Panzerbüchse 41.

When the Germans faced T-34 and KV-1 tanks in their war with the USSR, it turned out that the s.Pz.B. 41 could penetrate them in favourable circumstances, although the probability of that was low. By 1943, it was obvious that the weapon does not meet requirements for anti-tank guns. However, it remained in use until the end of the war as a measure against lightly armoured vehicles and trucks, as well as the suppression of machinegun nests and cannons.

s.Pz.B. 41 on a wheeled carriage. The carriage design and shield configuration are visible.

The 2,8 cm schwere Panzerbüchse 41 was produced at the Mauser factory in Obendorf. The cost of one unit was 4500 Reichsmarks. The productions schedule was as follows:

1940: 90 units
1941: 339 units
1942: 1029 units
1943: 1324 units

In 1942, a tank variant of the 2,8 cm schwere Panzerbüchse 41 was designed to replace the 2 cm KwK guns, named 2,8 cm Kampfwagenkanone (2,8 cm KwK 42). 24 units were built, but by 1942 it was no longer reasonable to arm tanks with this gun, and the idea was rejected.

Technical Characteristics

The weapon was designed to combat tanks and armoured cars, as well as destroy armoured and unarmoured emplacements. Thanks to the simplicity of aiming and loading, relatively low weight, and small size, the gun was mobile and maneuverable.

Diagram of the barrel and breech. (Enemy weapons. Part III. German light anti-aircraft and anti-tank guns. The War Office. December 1942)

The weapon used a quarter-automatic mechanism, automatically closing the breech, which allowed for a rate of fire of up to 10 RPM (by German data) or 12-15 RPM by GAU's data (20 unaimed shots). Effort on the breech lever was about 5 kg. The loading operation could be done in 0.8-1 seconds.

The quickly removable barrel consisted of a monobloc tube with a removable muzzle brake and connected to the breech with a screw connection and then affixed with a clip.

Cutaway of the s.Pz.B. 41.

The breech connected to the cradle which housed the recoil mechanism. The horizontal sliding breech was equipped with a safety and hangfire protection. The breech opened manually and closed automatically once a round was chambered.

The first guns were equipped with an open sight attached to the counterweight, but later an optical sight was used. The gun could only fire directly with either type of sight.

To deliver the s.Pz.B. 41 to a position inaccessible by wheels, it could be disassembled (without instruments) into parts that could be carried by the crew. Regardless of the carriage type, it had five parts: the shield (two pieces), barrel and muzzle brake, carriage with breech and counterweight, upper and lower mounts, and the limber/trailer.

The crew consisted of five men: commander, gunner, loader, and two ammunition carriers. Firing the gun was very loud, so the use of earmuffs was mandatory.

Transporting the s.Pz.B. 41 in parts through the mountains.

When the gun was transported in parts, the commander carried the barrel, the gunner and loader carried the upper and lower parts of the mount, and the ammunition carriers took the carriage and gun shield. The limber was not carried. Ammunition was carried in cases of 12. The case was identical to the 3.7 cm Pak one, only the label on the cover was different.

The weapon had the following characteristics:

Muzzle velocity: 1400 m/s
Effective range: up to 500 meters
Barrel length: 1.7 meters
Number of rifling grooves: 12
Caliber: conical, 28/20 mm
Mass of the shell: 121 g AP, 91 g HE (according to GAU data, 93 g)
Mass of the barrel and muzzle brake: 37 kg
Mass of the shields (both): 22 kg
Lifespan of the barrel: 500 shots

2,8 cm Sprgr.-Patr. 41 and 2,8 cm Pzgr.Patr. 41 shells, illustration from "Artillery ammunition of the former German army. Reference. USSR Armed Forces GAU. Ministry of Defense of the USSR publisher, 1946"

Available ammunition types included:

2,8 cm Panzergranatpatrone 41 (2,8 cm Pzgr.Patr. 41) – armour piercing
2,8 cm Panzergranatpatrone 41 (Üb) (2,8 cm Pzgr.Ptr. 41 (Üb)) – practice
2,8 cm Sprenggranatpatrone 41 (2,8 cm Sprgr.-Patr. 41) – high explosive
2,8 cm Platzpatrone (2,8 cm Pl. Patr) – blank
2,8 cm Exerzierpatrone (2,8 cm Ex. Patr.) – dummy

The penetration of the 2.8 cm Pzgr.Patr. 41 was as follows:

	German data	Soviet data	British data	American data
100 m, 90 deg	94 mm	Up to 75 mm	84 mm
100 m, 60 deg	69 mm	40-50 mm	69 mm
500 m, 90 deg	66 mm	Less than 40 mm	Less than 65 mm
500 m, 60 deg	52 mm	25 mm	Less than 53 mm	Less than 53 mm

Soviet penetration data was extrapolated based on the Jacob de Marre formula (K=2400).

Gun Shield

The gun shield consisted of two independent shields: the main shield and the gunner's shield. Each was composed of two plates, 4.5 mm and 5.5 mm thick. The plates were joined by bulletproof bolts, the same as on the Pak 38 and Pak 40. The space between the two plates was 46 mm. The edges were made wavy so the gun was easier to conceal.

Two s.Pz.B. 41 guns with different shields, the first type on the left and the second type on the right (Canadian War Museum in Ottawa and the French Tank Museum in Saumur, respectively).

The main shield was positioned in the front and protected the crew. It was attached to the upper mount with shock-absorbing pins. The gunner's shield was attached to the breech and protected his head during shooting. Both shields are removable. During transport, the gunner's shield was attached to the main shield. The main gun shield of the first 90 s.Pz.B. 41s produced differed slightly from the rest of the production run (the shape of the gun opening is different).

Cradle

The box-type cradle was permanently attached to the upper mount. The upper part of the cradle directed the recoil mechanisms. The rod that cocked the hammer during recoil was also attached to the cradle, as was the counterweight. The counterweight also contained the trigger mechanism and sight. The counterweight was hollow and had instruments inside.

Cradle and counterweight.

The rear of the counterweight had two handles used for aiming the weapon and the trigger mechanisms. The handles were very comfortable and the size and form of the handles followed the shape of the hand. The gunner could firmly hold the gun and could fire at any time without letting go of the handles.

Moving the gun in the vertical plane took 3-5 kg of effort. Turning the gun took only 1-2 kg. This type of aiming method allowed the gunner to traverse a 60-70 degree arc in one second, whereas a flywheel based aiming mechanism would take about 15-20 seconds. An experienced gunner could aim at a new target within 2-3 seconds, whereas the 3.7 cm Pak or Soviet 45 mm gun would take 6-12 seconds (8-9 seconds on average).

Carriage

Two types of carriages were designed for the weapon (the cradles and barrel remained the same). The upper and lower mounts were different.

Lafette mit Fahrgestell: a carriage with wheels. Consisted of the cradle with recoil mechanisms, upper mobile mount with shock absorbers, lower immobile mount with the trails, shield, sight, and wheels with suspension.

Wheels and suspension.

The box type trails were the same, with the exception of the parts that joined them together in travel position. A bar with a ball joint limited how far the trails could be spread. Spades were welded to the rear of the trails.

The trails were attached to the lower mount, which acted as a foundation for the upper mount and was attached to the suspension.

Trails, upper, and lower mounts.

The upper mount could rotate independently of the lower mount, and held up the oscillating part of the gun (cradle, breech, and barrel), the oscillation dampener, and the main shield.

The gun could fire either from the wheeled mount or from the ground, which drastically decreased its height. In both cases, the trails were deployed. The wheels were the same as on the Infanteriekerren 8 cart.

The gunner's position depended on the gun's position. If the gun was on wheels, the gunner was kneeling, otherwise it was only possible to fire while prone.

Firing with wheels removed.

The wheel section was equipped with a leaf spring and rubber foam-core tires, and was designed to move the s.Pz.B. 41 over short distances. The gun was often hitched to the Infanteriekarren 8 cart, which was used as ammunition storage. Two men could easily transport the gun on wheels over a distance of 300-500 meters or more, walking and partially running. At the GAU proving grounds, soldiers could transport the s.Pz.B. 41 500 meters over loose sand in 5.5 minutes. It took 5-7 seconds to prepare the gun to fire after being transported on wheels.

When transported over large distances, the Sd.Ah.32/2 (Sonderanhänger für schwere Panzerbüchse 41) trailer was used, equipped with special ramps to wheel the gun in.

s.Pz.B. 41 gun and Infanteriekarren 8 cart. The gun was brought into position in this manner.

Only 90 units of these carriages were made. Surprisingly enough, the guns captured and tested by the Soviets and the British both used this carriage.

Technical data of the s.Pz.B. 41 on a carriage of the first type:

Total length: 2580 mm
Mass with wheels: 223.2 kg
Mass without wheels: 162.22 kg
Horizontal range: 60 degrees
Vertical range: +25 to -15 degrees
Lower and upper mount weight: 57 kg

Mountain soldiers with s.Pz.B. 41 guns in transport position on Sd.Ah.32/2 trailers.

After 90 units were made, field trials showed that the design does not meet the army's requirements and is too heavy. Starting with the 91st gun, the s.Pz.B. 41 was made with a different carriage.

Leichter Feldlafette (leFl): a lightened carriage with a different upper and lower mounts, as well as the wheel base. A hollow pipe design and use of lighter alloys allowed a significant reduction in weight. The different design meant that the elevation and traverse angles changes.

Lightened carriage with ammunition containers.

Instead of a wheels base with leaf springs, the lighter carriage had smaller removable wheels. The mass of each wheel and its axle was only 5 kg. These small wheels were enough to move the gun into positions.

The spreadable trails were also discarded. Instead, one removable pipe trail was used, reinforced with a T-bar and ending with a wide spade. Two oval pipes bent into a complex shape were used as side rests. The lower mount was simplified. The upper mount was now made from a cast swivel. The function of the upper and lower mounts did not change.

s.Pz.B. 41 on a lightened mount. The wheels are collapsed, and you can see the rear trail of the carriage.

It was possible to fire with the wheels on or off. In the latter case, the stability of the system was improved and its height decreased. It was not necessary to remove the wheels completely to fire from the ground, only to loosen a bolt (without any instruments) and turn the wheel on its axis. The overall length of the gun remained the same, the mass with wheels and without was 147 kg and 137 kg respectively.

A lightened trailer to transport the new mount, the Sonderanhänger für schwere Panzerbüchse 41 auf leichter Feldlafette (Sd. Ah. 32/3), which only weighed 85 kg. Wheels from the Infanteriekarren 8 cart were used.

Lightened Sd. Ah. 32/3 trailer for transporting the s.Pz.B. 41 with a lightened carriage (Saumur tank museum).

The s.Pz.B. 41 with a new carriage and trailer weighed a little more with the trailer than the old type of carriage did without it.

After being accepted into service, the s.Pz.B. 41 was sent to motorized units, tank divisions, SS units, independent anti-tank squadrons, airborne units, and mountain units.

s.Pz.B. 41 gun on an Sd.Kfz. 250 halftrack, Grossdeutschland division («Schützenpanzer» by Bruse Culver & Uwe Feist. Ryton Publications).

Installation of this gun on lightly armoured vehicles using various improvised mounts was very common. Many photographs exist of these guns being used on various modifications of Sd.Kfz. 250, Sd.Kfz. 251, and Sd.Kfz. 221.

The last time these guns were used during WWII was during the fighting in Berlin in 1945.

See detailed photos of the s.Pz.B. 41 here.

Original article by Vadim Antonov.

↧

76 mm Regimental Gun Penetration

August 22, 2016, 4:36 pm

≫ Next: IS-2 #1

≪ Previous: Schwere Panzerbüchse 41

"To the People's Commissar of Defense, comrade I.V. Stalin.

I report that HEAT shells for the 76 mm mod. 1927 regimental cannon developed by the GAU Artkom on the basis of captured German shells were tried on May 23rd at the Sofrino proving grounds.

During trials against a 50 mm cemented plate, half of all fired shots resulted in complete penetrations with a diameter of 30 mm against both a flat plates and plates angled at 30 degrees.

This increases the armour piercing effect compared to the stock armour piercing shell of the 76 mm mod. 1927 regimental gun which, at a range of 200 meters, penetrates 32 mm and 28 mm of armour angled at 0 and 30 degrees respectively.

Considering the positive result of the trials and the simplicity of HEAT shells, I ask you to order the People's Commissariat of Ammunition to put these shells into production according to GAU blueprints and requirements.

The HEAT shell will allow the 76 mm mod. 1927 regimental cannon to combat enemy medium tanks at a range of up to 1000 meters.

Deputy People's Commissar of Defense, Colonel-Generalof Artillery, Voronov
GAU Chief, Colonel-General of Artillery, Yakovlev
GAU Commissar, Divisional Commissar Novikov"

RGASPI 644-2-64

↧

IS-2 #1

August 23, 2016, 8:53 pm

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≪ Previous: 76 mm Regimental Gun Penetration

"Shipment act #2
March 28th, 1943, Chelyabinsk

We the undersigned, Military Representative of the GBTU TU Engineer-Major I.P. Skriptsov on one side and OP-2 plant foreman of factory #100 Nosov and factory #100 OTK chief A.N. Kubintsev on the other side compose the current act to accept the IS-2 tank by the military representative of the GBTU TU and the surrender of the tank by factory #100 after factory trials.

The IS-2 tank was produced and assembled by the Kirov factory with:

V-2K-13 #KP-302312 diesel engine
U-11 tank gun, barrel #6
Machineguns #6269 and 4B-248
10-R type radio station #G-458
Toolkit according to the attachment

The tank's documents and files were presented along with the tank. The tank was assembled according to experimental blueprints and technical requirements. The sights were calibrated, the vehicle was tuned, fueled, and oiled according to attached instructions.

Tank accepted by:

Military Representative of the GBTU TU Engineer-Major I.P. Skriptsov

Tank surrendered by:

OP-2 plant foreman of factory #100 Nosov
factory #100 OTK chief A.N. Kubintsev"

CAMD RF 38-11355-1401

↧

Self Propelled Heavy Howitzer

August 24, 2016, 4:06 pm

≫ Next: New Shells

≪ Previous: IS-2 #1

"Tactical-Technical Requirements for Supreme Command Reserve Self Propelled Artillery

The main purpose of Supreme Command Reserve Self Propelled Artillery is the destruction of pillboxes and dugouts with direct and indirect fire, destruction of fortifications in settlements and railway stations, destruction of headquarters and concentrations of enemy personnel and vehicles.
Supreme Command Reserve Self Propelled Artillery should satisfy the following requirements:

Minimal dimensions, mass, and bore axis height.
Ability to fire from short stops without deploying trails.
Maximum speed of 8-12 kph.
Ground pressure of 0.5-0.8 kg/cm².
Maximum grade of 30 degrees.
Fuel capacity for 100 km of travel.
Maximize the use of existing tank and tractor components (engine, transmission, suspension, gun mount, instruments). Most of the manufacturing process should consist of assembly and metalworking.
Clearance: 350-400 mm.

The oscillating part and upper mount of the 203 mm mod. 1931 howitzer (the use of the Br-2 gun is also possible) with the following characteristics:

Caliber: 203 mm
Muzzle velocity: 607 m/s
Maximum pressure: 2350 kg/cm²
Shell mass: 100 kg
Explosive load: 15.09 kg
Maximum elevation: 60 degrees
Horizontal range: +/- 3 degrees (of the artillery system +/- 4 degrees)
Recoil resistance: 60 tons
Recoil length: 850-875; 1300-1400 mm
Mass of the gun and mount: 17746 kg
Mass of the barrel and breech: 5200 kg
Bore axis: 1880 mm

The armour of the SPG must provide:

Protection of the engine (front) and transmission from penetration by the 76 mm gun (thickness must be 70-75 mm).
Front armour must be 70-75 mm thick.
Armour around recoil devices must be 30 mm thick in the front and 10 mm thick on the sides.
Armour protecting the crew from the sides must be 25-30 mm thick.
The breech and roof are unarmoured.
The angle of the armour must be designed with the latest achievements in tank and shipbuilding.

No less than 30 rounds of ammunition must be stowed onboard.
The crew must be completely protected while loading. It is acceptable to replace the crane with a special tray.
The firing devices and sights must allow for rangefinding, keeping in mind that there will be no forward observers or fire correcters.
The rate of fire, convenience of service, and cooperation of the crew will be tested on the model.

Chairman of the NKV Technical Council, Satel"

CAMD RF 81-12038-90

↧

New Shells

August 25, 2016, 3:01 pm

≫ Next: World of Tanks History Section: Battle at Lukhanino

≪ Previous: Self Propelled Heavy Howitzer

"State Committee of Defense Decree #6434s
August 21st, 1944
Moscow, Kremlin

The People's Commissar of Armament (comrade Vannikov) must:

Produce a trial batch of 10,000 45 mm incendiary shells for the People's Commissar of the Navy according to NKV blueprints by November 1st, 1944.
Complete development of 100 mm incendiary and HE-I shells and perform trials before October 1st, 1944.
After satisfactory results with the 100 mm shells, develop 130 mm incendiary and HE-I shells by a deadline negotiated with the People's Commissar of the Navy.

Deputy Chair of the Committee of Defense, L. Beria"

RGASPI 644-2-377

↧

World of Tanks History Section: Battle at Lukhanino

August 26, 2016, 8:46 pm

≫ Next: Improved T-34-85 Armour

≪ Previous: New Shells

The Voronezh Front, protector of the south flank of the Kursk salient, found itself in the way of a powerful German offensive. However, this scenario played out quite unlike what German commanders expected. Most problems were faced by the 48th Tank Corps, which got stuck at the first Soviet line of defense on July 5th, 1943. Even 200 Panthers, thrown into battle near Cherkasskoye where Grossdeutschland division was spinning its wheels did not improve the situation.

Only late in the evening, having joined forces with the 3rd Tank Division, the German unit managed to enter Cherkasskoye. Soviet forces were fully expelled only by the next morning. The offensive had to be developed further, along the Belgorod-Oboyan highway, right through Lukhanino.

Crossing with Teeth

The Lukhanino village spread across both shores of the Pena river with a bridge connecting the two halves. The Germans needed this bridge. Colonel I. Yakovlev's 10th Mechanized Brigade was ordered to defend it with its 8 T-70s and 29 T-34s. The brigade's infantry fortified inside the village and on its outskirts; the tanks took up positions to the east. Twelve 76 mm guns deployed behind the front lines. Soviet soldiers spent all night digging trenches for themselves and their tanks, camouflaging their materiel. Lukhanino was becoming a fortress.

One of the motorized regiments from Grossdeutschland received orders to capture the crossing in the village. It was reinforced with an impressive amount of tanks and assault guns. The Germans attempted to take Lukhanino from the march. Up to 40 tanks and SPGs participated in this attack, but soldiers from the 10th Mechanized Brigade deflected the attack, destroying several enemy vehicles.

Enemy commanders, enraged by this failure, called in artillery support and began storming the village again and again. Yakovlev's dug-in brigade proved a tough nut to crack. Motorized infantry, tankers, artillerymen, and mortar crews cooperated skilfully, inflicted losses on the enemy, and kept them out of the village. The effort put into camouflage during the previous night paid off: the Germans did not always understand where shells were coming from. Soviet T-34s that fought German tanks maneuvered on the battlefield, evading return fire. Tankers would take several shots from one position, move, and then keep firing.

During the evening of July 6th, soldiers from the 10th Mechanized Brigade deflected 8 attacks, each with up to a battalion of infantry (500 men) supported by 30-50 tanks and SPGs. No fewer than 10 enemy tanks were knocked out. Lieutenant Tutveridze and Lieutenant Godyn's crews performed particularly well, destroying three tanks each. Losses of the 10th brigade consisted of four knocked out T-34 tanks.

The Germans moved additional forces to Lukhanino, but only managed to capture the southern outskirts. A river stood between German and Soviet forces. Even during the night, the Soviets had to fight off several attacks.

Main Strike

The Germans had poor luck when fording Pena, not just in Lukhanino but also in nearby Zavidovka. Enemy commanders decided to forego a second attempt on the latter, but the 3rd Tank Division was sent to reinforce Grossdeutschland at Lukhanino. Its arrival was expected in the morning of July 7th.

Our forces noticed that a significant German tank force was forming on their left flank, regrouped, and waited. This time, the Germans attacked the village from three directions. The enemy dislodged the 10th brigade from several positions, but no significant progress was made.

The Germans concentrated their forces for a decisive offensive. About 300 tanks and SPGs attacked the defensive lines between Lukhanino and Syrtsev. At Syrtsev, the Germans managed to reach the village and hold height 230.1 to the east. The 1st and 3rd Mechanized Brigades were forced to retreat north, which exposed the left flank of the 10th brigade in Lukhanino.

Meanwhile, Yakovlev's brigade kept staunchly fighting for their "river fortress". Elements of Grossdeutschland attacked several times with up to two infantry battalions and 40-60 tanks and SPGs. Lukhanino did not budge. The commander of the German 48th Corps, von Knobelsdorf, was seriously bothered by the failures around the village. He ordered a powerful attack on its positions in the second half of the day on July 7th to suppress the brigade's resistance and take Lukhanino.

The German attack began at 14:30. Two regiments of infantry (no fewer than 3000 soldiers) and tanks from the 3rd division hit the village from the west and the center. At the same time, up to two battalions of infantry with tanks continued their offensive from the south. Another 30 tanks from Grossdeutschland attacked from height 230.1 towards Yakovlev's rear. Panthers formed the spearhead of the attack, PzIVs behind them. Warriors from the 10th Mechanized Brigade were under attack by numerically superior forces from all sides. They had to collect all their willpower and demonstrate all of their courage and skill.

Tanks and infantry coming from height 230.1 was met with fire from T-34s and artillery. After a swift battle, at least 10 burning German tanks, including Panthers, littered the battlefield. The German attack rolled back to the hill.

Meanwhile, on the northern side of Lukhanino, the infantry battle became a fierce deadlock, periodically turning into a hand-to-hand melee. Soldiers fought over every house, the Germans widely used flamethrowers, both sides pelted each other with grenades. Numerical superiority allowed the Germans to take one half of Lukhanino and even form a foothold on the northern Soviet shore, but they were unable to exploit that breakthrough. Our artillery and mortars quickly pummeled any groups of enemy infantry.

Soviet Il-2 aircraft made a timely appearance in the skies above Lukhanino, carrying out several successful attacks against the enemy in the village. German infantry, caught in a rain of shells and bombs, was forces to cease their offensive and even pull out from their foothold back on the southern shore. Soviet infantry took back the northern part of Lukhanino.

The battle calmed by evening. Colonel Yakovlev's soldiers fought off 11 enemy attacks and held their ground. Another section of the Kursk salient held out, and Operation Citadel skipped another beat.

Original article by Aleksandr Tomzov.

↧

Improved T-34-85 Armour

August 29, 2016, 4:28 pm

≫ Next: RES Anti-Tank Rifle Cost

≪ Previous: World of Tanks History Section: Battle at Lukhanino

"To: comrade I.V. Stalin

In order to increase the robustness of T-34-85 turrets, factory #183 developed a new turret design with thicker front and sides (90 and 75 mm vs 52 mm).

The weight of the new turret is equal to 4800-4900 kg, as opposed to 4500 kg weight of the turret with 52 mm thick sides produced at factory #112. As a result, the mass of the T-34-85 tank with thickened armour is 32.3-32.4 tons as opposed to 32.0 tons for a T-34-85 tank with 52 mm thick turret armour.
The mass of the tank with thickened turret armour (32.3-32.4 tons) is within the tactical-technical characteristics approved by the State Committee of Defense on December 15th, 1943, for T-34-85 tanks (32.0-32.5 tons).

We deem it necessary for factories #183, #112, and #174 to begin producing T-34-85 tanks with the new turret with thickened walls.

The new turret with thickened walls requires the use of 71-L type steel with a higher nickel content than the currently used 8S steel.

The attached decree draft contains a schedule for gradually changing production to T-34-85 tanks with a thickened turret and transfer of 100 tons of nickel to the NKTP in the 2nd quarter from state reserves.

We ask you for your decision.

L. Beria
V. Malyshev
Ya. Fedorenko"

"State Committee of Defense Decree #5690s
April 20th, 1944
Moscow, Kremlin

On improvement of T-34-85 turret armour

In order to improve the robustness of T-34-85 turret armour, the State Committee of Defense decrees that:

The People's Commissariat of Tank Production (comrade Malyshev) must produce T-34-85 tanks with front and side turret armour thickened to 90-75 mm.

At factory #183: beginning on April 1st, 1944
At factory #112: beginning on July 1st, 1944
At factory #174: beginning on October 1st, 1944

Order the Main Directorate of State Material Reserves (comrade Danchenko) to free up and release to the NKTP 100 tons of nickel by April 25th, 1944.
Central Planning will reimburse the Main Directorate of State Material Reserves the requested amount of nickel in the 3rd quarter of 1944.

Chair of the State Committee of Defense, I. Stalin"

↧

RES Anti-Tank Rifle Cost

August 30, 2016, 7:46 pm

≫ Next: Beginning of the KV-1S

≪ Previous: Improved T-34-85 Armour

"Calculations regarding the cost of development of the 14.5 mm anti-tank rifle for GAU
Order #40
Code 73-P

Item	Calculations	Total
Direct spending
Main materials	Steel, other materials	1,400
Purchased parts	3 barrels, 500 rub. Each	1,500
Salaries
Machinists	1650 man-hours*3.01	4,970
Millers	650 man-hours*3.10	2,020
Planers	350 man-hours*2.50	870
Tracers	50 man-hours*3.00	150
Metalworkers	1400 man-hours*3.15	4,410
Fitters	500 man-hours*3.57	1,790
Auxiliary plant workers	100 man-hours*3.30	330
Total		14,540
Engineering-Technician works
Lead Designer	5.5 man-months*2000	11,000
Designers	3 man-months*1000	3,000
Engineer-Technologist	1.5 man-months*1200	1,800
Senior Engineers	2 man-months*1200	2,400
Engineers	0.5 man-months*1000	500
Total		18,700
Design Department Workers
Drafter	3 man-months*400	1,200
Tracer	2 man-months*300	600
Total salaries		35,040
Total direct spending		37,940
Additional spending
Work at the plants		35,040
General factory spending		17,520
Special spending
Instruments and devices		1,000
Proving grounds and transport costs		600
Ammunition for preliminary trials	1000 * 25 rubles	25,000
Trips to trials		4,000
External services		260
Total		30,860
Total additional spending		83,420
Total factory spending		121,360
3% interest		3,640
Total cost		125,000

Lead designer Rashkov

Chief of the Planning and Production Department, Rodin"

Via kris-reid

↧

Beginning of the KV-1S

August 31, 2016, 7:52 pm

≫ Next: RBG-82

≪ Previous: RES Anti-Tank Rifle Cost

"Preliminary conclusions on the KV-1S tank, equipped with the 8-speed gearbox, new turret with a commander's cupola, and reduced mass of 42.5 tons.

The objective of raising the average speed and improving handling with the KV-1S was achieved.

The 8-speed gearbox works normally and provides reliable operation of the KV tank.

The final drives need to be tuned in accordance with all design changes developed at the Kirov factory design bureau.

The commission recommends to put the KV-1S into production with the mandatory introduction of all changes requested by the commission.

Signed:
From GABTU:
P. K. Voroshilov
Shpitanov
Skribtsov

Kirov factory director Makhonin
Chief tank designer Kotin
Factory #100 director Voroshilov
Factory #100 chief engineer Maydelman"

RGASPI 644-2-88

↧

RBG-82

September 1, 2016, 5:51 pm

≫ Next: Czech from Russia

≪ Previous: Beginning of the KV-1S

"To comrade I.V. Stalin

A group of designers at SKB-36 of the People's Commissariat of Oil (comrades Ostrovskiy and Grigoryan), under orders from the GAU, designed and tested an 82 mm anti-tank rifle and the rocket propelled HEAT projectile for it: the RBG-82.

During proving grounds trials, experimental prototypes of RBG-82 grenades demonstrated satisfactory precision at 200 meters and were capable of completely penetrating 150 mm of armour at 30 degrees.

The obtained results show that the proposed design of an 82 mm rocket propelled anti-tank rifle can be effectively used against enemy tanks, SPGs, and other armoured vehicles.

To conduct battlefield trials of the proposed RBG-82 grenades and make a decision regarding their use in the Red Army, I propose this GOKO decree draft to produce 2000 grenades.

We ask for your decision. A sample of the anti-tank rifle and a hull of a grenade is attached.

L. Beria
B. Vannikov
N. Yakovlev
October 26th, 1944"

RGASPI 644-2-409

↧

Czech from Russia

September 3, 2016, 4:13 pm

≫ Next: ZIK-20: Assault Alternative

≪ Previous: RBG-82

By the end of the Second World War, T-34-85 tanks became one of the most common type of tank in the Czechoslovakian army. The first tanks of this type were received by the Czechoslovakian corps in early 1945, and up to 130 tanks of this type were received in total. They took part in the liberation of Prague and later became the backbone of the post-war Czechoslovakian army. Shipments continued after the war. Photos show tanks that were clearly made after May 9th, 1945. T-34-85 tanks became the first to receive the famous tricolour insignia.

Fruit of Compromise

The T-34-85 was a very modern tank at the end of WWII, but it was no secret that the tank would soon be obsolete. The Czechoslovakian military realized this too. On October 17th, 1945, a meeting of the General Staff was held where its commander, Divisional General Bohumil Boček approved the tactical-technical requirements for the Tank všeobecného použití (TVP), a main battle tank. The requirements were clearly inspired by the T-34-85, but the implementation details varied significantly.

Development of the TVP was behind schedule. The military-technical institute (Vojenský technický ústav, VTU) where the tank was being developed presented a concept in March of 1946. CKD and Skoda were supposed to develop their own tanks based on it. The result was the Skoda T 40 project, a significantly different tank from the initial TVP. This project, presented in December of 1946, was already unsatisfactory by next year. As a result, the TVP was reworked in 1948, and resulted in the Skoda T 50 and CKD T 51. SPGs were also designed on the chassis of these tanks.

Soviet produced T-34-85 at Czechoslovakian army exercises in Milovice, 1952.

Time went on, but none of the projects moved past paper. It is not surprising that the military's patience wore thin. Even though work on the TVP continued until 1950, the General Staff already made their decision, and it wasn't in favour of either Skoda or CKD.

This decision is often called politically motivated. It's true that between February 20th and 25th communists took key posts in the Czechoslovakian government, which led to turnovers. On June 14th, Klement Gottwald, a communist, became the president of Czechoslovakia. All these events had an impact on the USSR, including the military.

However, politics was the last thing that influenced the decision of the General Staff. The rapidly ageing fleet of armoured vehicles had to be rejuvenated, and many units were desperately in need of at least some kind of tank. Things got bad enough to modernize captured German StuG 40 and PzIV vehicles. In all the time since the war, Czechoslovakian industry did not build a single new tank or SPG. The only solution in this case was to enlist the help of a political and military ally.

In the early 1950s, many T-34-85 received headlight protection like this tank. Some Czechoslovakian tanks also received Notek headlights.

In July of 1949, Czechoslovakia received a license to produce T-34-85 tanks. The reasons why this tank, seemingly obsolete since 1945, was selected for production are quite simple. One was that the Czechoslovakian military was very familiar with the T-34-85. Second, even though it was far from the best tank, this was not critical in the late 1940s. Finally, the tank was easy to produce, and starting up production would not be difficult.

One might ask why Czechoslovakia obtained a license for the T-34-85 and not the superior T-54. The answer is simple: the USSR was only beginning to produce the tank by 1949, and the design only solidified by the early 1950s. Even if the USSR was willing to share such a new vehicle, it would have taken much more time to begin production. With the T-34-85, Czechoslovakian factories received experience in producing a tank that weighed over 30 tons. Vehicles this heavy were not built in Czechoslovakia during the war or before it.

Mass Production on the Move

Technical documentation for the T-34-85 was delivered in November of 1949. The sender was factory #183 from Nizhniy Tagil, the developer of the T-34-85. The tank that was going to be produced in Czechoslovakia differed from the ones that came from the USSR. The last Soviet T-34-85s were built back in 1946, and the design was improved after that. it is not surprising that the Czechoslovakian T-34-85 differed from its Soviet brother.

T-34-85 produced at ČKD Sokolovo, May 1952.

Conversion of the ČKD Sokolovo factory in Prague to produce the T-34-85 began in January of 1950. Using a locomotive factory as a foundation for tank production seems reasonable, since it already had the necessary lifting equipment. Specialists from the USSR were sent to help in the conversion of the factory.

The Skoda factory in Pilsen supplied the V-2 engines. The armament was produced by another Skoda factory in Dubnica nad Váhom. Like CKD Sokolovo, the SMZ factory used to make locomotives. Finally, the hulls were made at Závod J.V.Stalina (ZJVS) in the Slovakian of Martin. The new tank was, without a doubt, Czechoslovakian, as its components came from both Czech and Slovak factories.

Czechoslovakian T-34-85 from the Lešanská technical museum with late type optics. Note the quality of the cast turret finish.

The first post-war tank did not go easy. The first Czechoslovakian T-34-85 was built on September 1st, 1951. By October, another seven tanks were built, two of which were sent to brief trials. 25 T-34-85 tanks were completed by the end of the year.

The first tanks came out rather unpolished, which is common for new production. Many complaints came in about the clutch, transmission, and other components. This was mostly caused by the fact that the necessary level of quality was not immediately reached. It took time to fine-tune the technical processes. Full-fledged production of the T-34-85 only began at CKD Sokolovo in February of 1952.

These headlights and guards were used on Czechoslovakian T-34-85s in the 1950s and 60s.

As mentioned before, the tank was not a clone of the Soviet design. The tank inherited factory #183 style cast road wheels, even though some tanks received stamped ones. As for the turret, it came out closer to those of factory #174 (Omsk).

Various other small parts also separated the Czechoslovakian tank from its Soviet brothers. The quality of the finish of the hulls and turrets is the most obvious. Castings from Martin were very carefully finished. The turret is most obvious, as it lacks the roughness that is characteristic of cast turrets.

The hull of the tank also differs slightly. The hinges of the rear plate were increased, and the armoured covers of the exhaust pipes have a more complicated design. Another characteristic element for Czechoslovakian tanks is the port for a field telephone, positioned in the rear left of the hull. A mount for a tow cable was added on the left, and the front headlight received a guard. Early tanks also received clones of German Notek lights.

This image shows the wavy exhaust pipe covers and field telephone port characteristic for Czechoslovakian T-34-85s.

951 tanks were assembled at CKD Sokolovo. Production continued until December of 1953. Despite the common opinion that Czechoslovakian tanks were better than Soviet ones, these tanks show the opposite picture. Out of 81 tanks delivered to the Czechoslovakian army in 1951-1952, 280 breakdowns were recorded, 250 of which were directly caused by poor manufacturing quality. Soviet produced tanks, the last batch of which arrived in 1949, were much more reliable.

The Czechoslovakian military made their conclusions. In May of 1952, the first T-34-85 left the factory at Martin, and mass production began here in September. These tanks were more indicative of Czechoslovakian quality. In 1952, both factories produced 352 tanks, and 1050 the next year. In 1953, CKD Sokolovo went back to building locomotives. The T-34-85 became the last tank built by CKD on Czech territory. Martin became the core of the Czechoslovakian tank industry. 1785 tanks were assembled here.

Draft of a 100 mm gun in the T-34-85, April of 1954.

The question of modernization was quickly raised. In many ways, this was connected with the start of production of the SD-100, the Czechoslovakian version of the Soviet SU-100. The 100 mm D-10 gun, named 100 mm vz. 44 S in Czechoslovakia, had greatly superior penetration to the 85 mm gun on the T-34-85. It was natural to want this gun in a tank, especially since the dimensions allowed it. Work was organized at Konštrukta Trenčín in Slovakia, and later in the Military Technical Institute.

First (top) and second (bottom) variants of installation of a 100 mm gun in the T-34-85 turret.

Work on the T-34-100 began in 1953. On April 6th, 1954, the Military Technical Institute presented designs of the T-34-85 armed with a 100 mm gun. The tank was practically unchanged, only the front of the turret was redesigned.

The first variant was simpler from a production point of view. Most of the turret was unchanged. Since the gun was moved forward, a forward section was bolted to the turret. The gun was equipped with the TS-20 sight. The coaxial machinegun mount was also changed. The second variant required a more thorough redesign of the front part of the turret, but it had superior protection.

According to calculations, the rate of fire of the 100 mm gun would have been 8 RPM, but this is hard to believe. The budget for this design was 780,000 kroner, 160,000 of which were used for the design, the rest were spent on production of a prototype.

Water hazard crossing device.

The issue of further work was up in the air for two months. Potentially, this modernization could increase the firepower of the tank. However, there were downsides to this. The situation was similar in many ways to what happened in the USSR 9 years before.

In 1945, a T-34-85 with a 100 mm LB-1 gun entered trials. The TsAKB collective, headed by V.G.Grabin, managed to install the gun without changing the turret at all, and it could still shoot. However, crew conditions were rather cramped. Further development of the subject ceased.

Konštrukta Trenčín did not end up even building a prototype. The General Staff still wanted a 100 mm gun in the T-34-85, but not the 100 mm kanуn vz. 44 S. Now they had their sights on the AK 1, which was meant for the latest incarnation of the TVP. In addition to all its other features, the gun had a loading mechanism and a vertical stabilizer.

These wishes did not even reach the draft stage, and the T-34-100 program was closed on June 30th, 1954. By that point, Czechoslovakia had a license to built T-54 tanks. The last T-34-85s left Martin in late 1956, and the first T-54s were finished the next year. With their arrival, the Czechoslovakian army finally solved the issue of modern tanks.

International Life

Out of 2736 T-34-85s that were built. the Czechoslovakian army kept only 1437: 731 from CKD Sokolovo and 706 from ZVJS Martin. The rest of the tanks were exported. The last two years of production at Martin were sent entirely abroad.

In 1956, the Czechoslovakian army had 1701 T-34-85 tanks. This includes tanks that were received from the USSR. Domestically produced T-54 tanks gradually pushed them out. In 1967, Martin was already building T-55s. 1120 T-34-85 tanks of all types remained in the army. Some tanks were written off and sold abroad, some were converted into engineering vehicles. By late 1970, the number of T-34-85 tanks dropped to 780 and continued to decrease.

Czechoslovakian T-34-85 tank in a movie, 1960s. The tank has a Notek headlight.

The career of the T-34-85 in the Czechoslovakian army was uneventful. It served as a learning tool for many tankers. It served as a foundation for experiments with various equipment, including an underwater driving system. T-34-85 tanks produced in Czechoslovakia had a different fate abroad. These tanks had many battles ahead of them, the first of which stated before production in Martin ceased.

Captured Egyptian T-34-85 tanks in Haifa, 1957.

On March 21st, 1953, the dead Klement Gottwald was replaced by Antonín Zápotocký, which led to certain changes in the country's political policy. T-34-85 tanks became available for export that year. On September 21st, 1955, Czechoslovakia and Egypt signed an agreement for shipment of a variety of vehicles and armament. The T-34-85 was, of course, present among them.

In total, Egypt received 820 tanks, 230 of which fought in battles for the Suez canal. Fighting began on October 29th, 1956. Egypt was opposed by Israel, France, and Great Britain. Both sides took heavy losses in vehicles, and Czechoslovakian T-34-85 tanks were among the trophies collected by the anti-Egyptian coalition.

The next fight for T-34-85s was halfway around the world. Cuba bought about a hundred tanks, both Soviet and Czechoslovak production. The purchases came straight from the Czechoslovakian army's warehouses and came as a great discount: 67%. Fidel Castro guessed correctly: those tanks came in handy. The famous battle in the Bay of Pigs happened in April of 1961, when forces opposing the revolution, equipped and supported by the CIA, landed in Cuba. At the time, Cuba only had 10 T-34-85s, mostly Soviet built. Their enemies were M41 Walker Bulldogs, which were inferior in every respect. One T-34-85 was destroyed, but the "gusanos", as the counterrevolutionaries were nicknamed, lost all of their tanks. One of them can be see today on display at Patriot park.

Knocked out T-34-85, Golan Heights, 1967. The tank has an AA DShK machinegun turret.

The second largest buyer of Czechoslovakian T-34-85 tanks was Syria. 120 tanks were sent there. These tanks underwent the most changes compared to any Czechoslovakian T-34-85. The most noticeable difference was the massive DShK turret on top of the commander's cupola.

The Syrian T-34-85s had their trial by combat in early June of 1967, during the Six Day War. A significant part of these tanks was either knocked out or captured by the Israeli army. Egyptian T-34-85s went into battle as well. In total, the Arabs lost 251 tanks of this type. Some captured tanks were later converted by the Israelis into pillboxes along the border with Syria and Jordan. Their engines and suspensions were removed, and the driver's compartment was replaced with a large ammunition rack.

There were also calmer regions where Czechoslovakian T-34-85s were sold. For example, Romania and Bulgaria received 120 tanks between them. 30 tanks were sent to India, Iraq, and Yemen. However, the latter ended up in battle after all. Czechoslovakian T-34-85s fought in Lebanon, where they ended up in the 1970s.

Czechoslovakian production T-34-85 in Lebanon.

Domestic production of the T-34-85 was a good move for Czechoslovakia. It was their first medium tank that reached mass production. In addition, Czechoslovakia never made tanks in these amounts before. Production of the T-34-85 allowed Czechoslovakia to raise their tank production to a new level and return to the international arms market.

There was, however, a downside. Domestic tanks were not built or even truly developed. Production of licensed Soviet tanks turned out to be much easier, since it avoided significant costs in development and building of prototypes.

Original article by Yuri Pasholok.

Walkaround of a Czechoslovakian T-34-85 used in Syria.

↧

ZIK-20: Assault Alternative

September 4, 2016, 12:17 pm

≫ Next: Iron Discipline 2: Discipline Harder

≪ Previous: Czech from Russia

On April 15th, 1942, the plenary assembly of the Artillery Committee of the GAU met to discuss further development of self propelled artillery. The decisions worked out in this meeting became key in wartime development of Soviet SPGs. Among others, requirements were confirmed for a heavy SPG that would replace the 212 bunker buster. Work began on this SPG on the KV-7 chassis at UZTM, headed by L.I. Gorlitskiy. By the fall of 1942, the U-18 project was ready, but by that point, a competitor was developed at Sverdlovsk.

Competitor from the Bottom Floor

In February of 1942, artillery production from the Ural Heavy Machinebuilding Factory (UZTM) was transferred to factory #8, which was evacuated in the fall of 1941 from Kaliningrad (modern day Korolev) to Sverdlovsk. The factory director was B.A. Fradkin, same as before the evacuation. F.F. Petrov was appointed chief engineer of the new factory.

New developments of the factory #8 design bureau received the index ZIK (Zavod Imeni Kalinina, Kalinin factory). The first product of the newly minted design bureau was the ZIK-1 85 mm gun for installation in the T-34 and KV-1. Various tank and anti-tank guns bore the ZIK index, as well as howitzers, Supreme Command Reserve artillery, and SPGs. It just so happened that no ZIK project was ever accepted into service, but it would be incorrect to say that Petrov's designers worked for nothing. Factory #8 design bureau's works, including the D-1 howitzer, were later brought to life by the factory #9 design bureau, formed in the fall of 1942.

ZIK-1, the first gun designed by the factory #8 design bureau.

As the summer of 1942 dawned, the design bureaus of the two factories began competing. The fact that Gorlitskiy's UZTM design bureau and Petrov's factory #8 design bureau were located on the 5th and 4th floors respectively of the UZTM factory management building put a spicy twist on the situation. Both UZTM and factory #8 worked on a wide spectrum of self propelled artillery, including light, medium, and heavy SPGs, as well as SPAAGs. UZTM's design bureau worked on orders from the top, while Petrov's collective completed several projects on their own initiative.

The project to install a 152 mm ML-20 into the hull of the KV-7 assault tank made its way to the factory #8 design bureau. According to documents, technical task #5400072 for the "installation of the oscillating part of the 152.4 mm howitzer model 1937 (ML-20) into the KV-7 tank" was issued by the GAU Artillery Committee on June 4th, 1942.

This information doesn't mesh well with a letter from the chief of the Artillery Committee, General-Colonel V.I. Hohlov, addressed to the chairman of the NKV Technical Council, professor E.A. Satel. The letter is also dated June 4th, 1942, and according to the letter, work was already underway. In parallel, the factory #8 design bureau was working on installing the M-30 and U-11 122 mm howitzers into the T-34, ZIK-11 and ZIK-10 respectively. The due dates for these projects were not yet established, and work was moving at its own pace. Due to the importance of this work, the letter proposed establishing a deadline for the draft on June 15th and delivery to Moscow for approval by June 20th. However, these deadlines were not met. In reality, documentation on the ZIK-10 and ZIK-11 was only completed in August.

Sketch of the ZIK-20 from the attached memo.

As for the heavy SPG indexed ZIK-20, work dragged on for even longer. A major cause of this delay was the fact that GAU and GABTU tried to also pawn the development of the equally desired Br-2 armed bunker buster onto the factory #8 design bureau. On June 23rd, 1942, the Deputy People's Commissar of Tank Production, A.A. Goreglyad, wrote a letter to the chief of the GAU, General-Colonel N.D. Yakovlev. The letter proposed tasking the NKV with the production of two prototypes of the 152 mm mod. 1937 gun with a muzzle velocity increased to 750-780 m/s by lengthening the barrel and adding a muzzle brake. Petrov is directly connected to this delay, as his design bureau was responsible for this artillery system.

The initiative, supported from the top, played a cruel trick on the project. As mentioned above, the design bureau of factory #8 was working on various projects in different categories, and ended up overloaded with work. It's not surprising that with this kind of workload, the ZIK-20 was delayed. In addition to all that, 152 mm bunker busters disappeared from the list of GAU and GABTU's experimental work in the summer of 1942, returning only in the middle of August.

In the KV-7's Footsteps

Unlike the U-18 SPG, which was nearly absent from correspondence, the ZIK-20 was actively discussed by GAU and GABTU. Work on the heavy SPG was headed by T.A. Sandler, the chief engineer of factory #8 (head of QC at factory #8 before evacuation). Since the ZIK-20 index was not yet assigned, there was some confusion. Artkom's documents from the second half of 1943 put UZTM and factory #8 projects in one basket, and this position migrated to correspondence and UZTM's reports. As a result, many researchers confused the U-18 for the ZIK-20. Since there were next to no drawings of either vehicle, a big mix-up came about.

ZIK-20 cutaway, September of 1942.

The difference between the ZIK-20 and its competitor from UZTM was the rather arbitrary use of the chassis, which was outlined in the tactical-technical requirements. Only the gun was designed in Sverdlovsk, the chassis was designed by ChKZ. The requirements stated that the KV-7 would serve as the base, and already produced hulls would be used for production. The designers of the U-18 chose this path, but ZIK-20's designers had a different idea.

The explanatory memo attached to the ZIK-20 project, as well as blueprints of the SPG, arrived to the Artillery Committee for review on September 11th, 1942. The explanatory note contains a rather interesting explanation: "The thickness of the sides of the turret is 75 mm. In our understanding, we took the KV-7 as the base, not any specific prototype of it, but we assumed that any KV tank with an immobile turret counts as a KV-7."

The "immobile turret" of the new tank was reminiscent of the KV-7, but no more than that. The new casemate was noticeably longer, completely encompassing the turret ring, and 17 cm taller than that of the KV-7. The fighting compartment and driver's compartment remained joined. Essentially, instead of installing the ML-20 in the KV-7, the factory #8 design bureau proposed an entirely new SPG on the KV-1 platform. The new casemate meant that the hulls already produced by factory #200 were of no use. Also, the ZIK-20's mass was higher than the mass of the KV-2, reaching 53 tons. The explanatory memo mentioned optimistically that it was only 4 tons heavier than the KV-1. It would appear that the factory #8 design bureau was unaware that the KV-1 was being removed from production at the end of August of 1942 in favour of the KV-1S due to its exceptional mass.

The same vehicle from the top. Even though the size of the fighting compartment increased compared to the KV-7, it was still rather cramped for 6 crewmen.

The completely new casemate wasn't the only novelty on the ZIK-20. The gun-howitzer that gave the name to the SPG was presented as minimally changed compared to the ML-20, but still had certain nuances to its design. First of all, the muzzle brake was removed, which was a good decision for an SPG. The vehicle would fight in close quarters with the enemy, and a muzzle brake which raised a cloud of dust when firing was not needed. Its removal caused other changes in the system. The elevation and horizontal traverse mechanisms were changed, and the variable recoil mechanism was removed. The idea of installing an ML-20 gun with minimal changes was also discarded.

Perpendicular cutaway of the ZIK-20. The ammunition rack, positioned on the floor, noticeably reduced the height of the fighting compartment.

On September 15th, the ZIK-20 project was reviewed during a meeting of the NKV Technical Council. The design bureau chief. F.F. Petrov, was presenting the project. His report also included the explanatory memo, blueprints, and calculations. The idea of removing the muzzle brake, which would give away the SPG's position, was approved. Even though Petrov raised the issue of introducing a telescopic sight, his project, unlike the U-18, did not have it. The ML-20 gun was also shifted forward on the ZIK-20 compared to the U-18, which could potentially overload the front road wheels.

The layout of the fighting compartment prompted many questions from the audience. Compared to the KV-7, the angles of the sides were reduced, which reduced the odds of ricochet on impact. Even though the height of the fighting compartment was 1895 mm, the crew had to work in cramped conditions. 395 mm of that height was consumed by the two layer ammunition rack on the floor, which was also uncomfortable to use. In addition, the shells stored along the sides of the fighting compartment increased the chances of detonation if the armour was penetrated. The idea of placing fuel tanks along the sides of the vehicle also caused doubt. A series of questions was asked about the effectiveness of ventilation and protection of the SPG from the rear, where there was not even a pistol port (unlike the U-18, which had a rear DT machinegun).

Gun mantlet design.

Despite all of these drawbacks and the fact that the ZIK-20 had nothing in common with the KV-7, the project was approved. In this case, time was the decisive factor. Even though the U-18 was simpler than its competitor, the project was several days late.

Dreams of Large Guns

In late September of 1942, the assistant to the chief of the 2nd department of the Artkom, Engineer-Major P.F. Solomonov, began working on the support of the ZIK-20 project. This was no easy task, as the ZIK-20 was designed on the KV-1 chassis, and ChKZ began producing KV-1S tanks in September. Solomonov traveled to Chelyabinsk where he had a meeting with Kotin and designers of experimental factory #100. A decision was made at that meeting to reject the idea of using KV-7 hulls completely. Factory #100 and ChKZ agreed to produce a chassis and mount the artillery system and fighting compartment equipment for the Artkom. To improve cohesion, ChKZ sent two designers to factory #8.

This is what the ZIK-20 would have looked like according to the project.

Having arrived in Sverdlovsk, Solomonov reviewed the blueprints and gave the designers necessary directions for changes. On September 25th, tactical-technical requirements were finalized. According to them, the ZIK-20 on the KV-1S chassis would weigh 45.5 tons. Mostly, the characteristics were left the same as on the initial project, but the complaints made during the Technical Council meeting on September 15th.

The factory was tasked with completing the blueprints and building a wooden model of the SPG by October 25th. A brigade of modelers and carpenters was assigned by personal order of factory director B.A. Fradkin. Designer A.G. Usenko was put in charge of the construction. In order to ensure that the project had the required number of designers and draftsmen, factory #8 workers were recalled from agricultural and forestry projects.

It would seem that the 152 mm SPG on the KV chassis was finally getting off the ground after being stalled for half a year. Despite a change of chassis from the KV-1 to the KV-1S, the overall concept did not change, and the project could be finished on time. ChKZ representatives made trips to factory #8 to familiarize themselves with documentation, and work on this subject neared the practical stage. However, the production of the model dragged on, and in late October, an event happened that had a serious effect on the project.

According to decree of the State Committee of Defense (GKO) #2457ss issued on October 30th, 1942, factory #8 was being split into two institutions. One of them, factory #8 would work on AA guns. The other, factory #9, was responsible for howitzers and tank guns. L.R. Gonor was appointed the director of the new factory, with P.I. Maloletov as the factory party organizer. The design bureau of factory #9 was headed by F.F. Petrov.

Wooden model of the ZIK-20, December 1942.

The splitting of the factory into two had a negative impact on building a full sized model of the ZIK-20, but not on other work by the newly formed factory #9. In October, before the split, a large amount of design work on various artillery systems was done under Petrov's supervision. The main idea behind these projects was the use of more powerful barrels on ML-20 and M-30 chassis. At least two of them were built in metal, and one of them was put into production under the index D-1. In the context of this article, the seventh project is the most interesting. Among towed systems, there was a 152 mm Br-2 high power gun and 203 mm U-3 howitzer on the ML-20 mount. Both systems received massive muzzle brakes.

It was logical to transplant the Br-2 into the ZIK-20, since it used the oscillating part of the ML-20 already. According to the design, all that was needed was to chance the cast breech and change the spindle in the recoil brake. according to calculations, equipping the ZIK-20 with the Br-2 increased its mass to 48 tons. However, the design bureau had other ideas about what to put in the ZIK-20:

"Since the 152 mm Br-2 has the same mount, cradle, breech, and recoil brake as the 203 mm howitzer, installing the Br-2 into the cradle of the tank version of the MK-20 opens the possibility of, if necessary, installing the 203 mm B-4 howitzer monobloc barrel and, of course, it will be even easier to install the 203 mm U-3 howitzer."

The biggest hurdle was that the base variant of the ZIK-20 was still the priority. Even with this variant, many issues arose with its production. Due to the reorganization of the factory, design work was delayed. The new factory had no modeling plant, which made things difficult. The wooden full scale model of the ZIK-20 was only finished by December 15th.

The ZIK-20 with a Br-2 gun could have looked like this. The vehicle was designed with the KV-1S as the chassis and a commander's cupola.

GAU chief General-Colonel of Artillery Yakovlev, People's Commissar of Tank Production Zaltsmann, and People's Commissar of Armament Ustinov set the date of review of project documentation on January 3rd, 1943. It occurred on ChKZ territory, and this was not just a conclusion, but a competition with a project provided by the Kirov factory. As a result, the Chelyabinsk vehicle, indexed KV-14, turned out to be better and simpler than the one from Sverdlovsk. Its history deserves a separate article.

Original article by Yuri Pasholok.

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Iron Discipline 2: Discipline Harder

September 5, 2016, 6:55 pm

≫ Next: Tank Improvements

≪ Previous: ZIK-20: Assault Alternative

"1st Mountain Infantry Division
11th Army

Division headquarters, August 8th, 1941

Divisional Order
Based on Corps order #47 issued on July 31st, 1941

Discipline
Several times, I have witnessed the following scenario: a covered up light car passes traveling troops or drives towards them, paying no attention to the dust that is being kicked up, which makes movement of troops difficult.
The car is packed with a disorganized pile of briefcases, covered with a stolen mattress, with bottles of wine and other goods sticking out.
It is obvious that these scenes offend and enrage fighting units.
I demand that all commanders combat this behaviour in a decisive manner.
Dogs
Head command categorically prohibited taking along any dogs, with an exception made for especially rare breeds of hunting dogs. Since then, every single dog I encounter is allegedly a valuable hunting dog.
I order that only dogs with documents stating that they are valuable hunting dogs are allowed. These documents can be issued only for well trained dogs, for owners who have owned dogs for a long time and have significant experience in handling them. NCOs do not qualify.
Promotions

Lieutenant Colonel von Teisen, commander of the 111th Battalion, 98th Mountain Infantry Regiment, is appointed commander of the 13th Mountain Infantry Regiment, effective on August 1st, 1941. Ordered by Army Supreme Command, Human Resources department, 2nd division (A) August 1st, 1941.

Issue of Automobiles
High command asked to communicate the following order to subordinate units:
"The amount of vehicles breaking down has reached an unacceptable degree. The cause of these breakdowns is excessively fast driving over bad and unpaved roads. The established speeds (item 442 in Supreme Command Order #39) must be decreased. It will be possible to reduce required repairs by 50% if:

The speed of driving is chosen according to road conditions.
Cars are not overloaded.
Commanders of all ranks must ensure that at no time are cars driven faster than the conditions of the road allow. In cases of disobedience, take decisive measures and punish offenders.

Approved: Kopp

Signed: Lanz

Translated: Technician-Intendant 1st Class Borisova

Approved: Senior Lieutenant Ozeretskovskiy"

Via gistory.

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Tank Improvements

September 6, 2016, 3:47 pm

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"To comrade I.V. Stalin
comrade V.I. Molotov

In accordance with State Committee of Defense decrees ##1878ss and 1879ss issued on June 5th, 1942, the Kirov factory and factory #183 completed trials of improved KV-1 and T-34 tanks.

As a result of production and trials of prototypes, the following data was obtained:

KV-1 tank (Kirov factory):

The weight of the tank was reduced to 42.5 tons.
The engine cooling system was improved.
A new 8-speed gearbox was produced and tested successfully.
A new turret with a commander's cupola was produced.

In connection with the altered KV-1 production schedule and the large amount of work being performed at the Kirov factory in connection with producing the T-34, I ask for approval to produce 100 KV-1S tanks with the old improved gearbox and suspension. The remaining 50 KV-1S tanks will be built in full compliance with the June 5th GKO decree.

T-34 tank (factory #183):

The following were produced and trialed:

New 5-speed gearbox.
Turret with a commander's cupola.
Reinforced idler with a new adjustment mechanism.

In accordance with the conclusions of the T-34 tank test commission, the 5-speed gearbox is recommended for production.

As for the turret and the new idler, the commission requires that they be improved.

I ask you to allow the People's Commissariat of Tank Production to:

Perform additional work on the T-34 turret and idler.
Put the new 5-speed gearbox into production at the Kirov factory and UVZ (newly organized production line).
Announce a decree on September 15th to:

Put the 5-speed gearbox into production at all factories currently producing T-34 tanks.
Put the turret with a commander's cupola into production at all factories currently producing T-34 tanks.

Introducing the 5-speed gearbox into production immediately would sharply reduce the amount of T-34s produced over the next two months, which would be a big blow for the front.

The GKO decree draft is attached.

People's Commissar of Tank Production. I. Zaltsmann

August 18th, 1942"

RGASPI 644-2-88

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T-40 Tow Hooks

September 7, 2016, 2:36 pm

≫ Next: 70th Anniversary of Tanker's Day

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"To the Chief Engineer of Ordzhonikidze factory #37, comrade Kozyrev
CC: BTU 3rd Department Chief, Military Engineer 1st Class Afonin

RE: T-40 tow hooks

There has lately been an increased frequency of cracks when towing using the front tow hook.

We ask you to consider the replacement of the front tow hook. Instead of attaching it to the front plate, use the sides as a foundation like on the T-20. In parallel, perform additional testing of the current design.

Send your ideas regarding this issue and the results of any additional testing to us.

Chief Engineer Shuvalov"

CAMD RF 38-11355-251

↧

70th Anniversary of Tanker's Day

September 8, 2016, 10:46 am

≫ Next: World of Tanks History Section: Battle for Teploye

≪ Previous: T-40 Tow Hooks

70 years ago, on September 8th, 1946, elements of the 4th Guards Kantemirovka Tank Division drove across Red Square in the first Tanker's Day parade.

In the documentary footage of the parade, all mentions of Stalin were edited out, including the name of the IS-3 tank, but interestingly enough, not the name "Stalingrad".

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World of Tanks History Section: Battle for Teploye

September 9, 2016, 5:24 pm

≫ Next: The Last Soviet Heavy Tank Destroyers

≪ Previous: 70th Anniversary of Tanker's Day

The Germans understood that the summer offensive against the Kursk salient will not be an easy one. German commanders took their time planning Operation Citadel, moving the start date several times. Meanwhile, the Red Army was digging in, wrapping the terrain in barbed wire and sowing mines. The Germans were also preparing, knowing that their units will be warmly received. Their hopes rested on new types of tanks: Tigers and Panthers, Ferdinand tank destroyers and Brummbar assault tanks.

On the north side, the Orel direction, Walter Model's 9th Army formed an armoured club. On July 5th, 1943, he sent his infantry into battle, supported by tanks, SPGs, and aircraft. Model held his main armoured force in reserve, hoping to exploit a breakthrough. On the first day of battle, the Germans reached the second line of Soviet defenses. By July 6th, main events were unfolding in two paces: near the Ponyri railroad station and in the Teploye-Olkhovatka sector. The events of the latter are, unfortunately, not as studied as well as the former.

Trial by Fire

While feeling out the weak points in Soviet defenses on July 7th, Model decided to strike in the direction of Teploye and Olkhovatka in addition to Ponyri. At 13:30, about 200 tanks (including Tigers) and assault guns, supported by a significant infantry force, attacked the Soviet positions. The first attack was deflected, and several more "thrusts" followed in the afternoon, each with about 40-50 tanks and SPGs. This was only the beginning.

As reserves pulled up, the Germans prepared for a even more powerful offensive in this direction. A simultaneous attack by three tank divisions was planned on July 8th to punch through Soviet defenses. The key objective was to attack in the center, capture Teploye, and prepare for a subsequent offensive. This objective was given to the 4th Tank Division.

The enemy struck at the joint between the Soviet 13th and 70th Armies. Lieutenant-General I.V. Galanin was responsible for the defenses in this weak point. The general assembled a special combat group out of the 140th Rifle Division, 3rd Tank Destroyer Brigade, and the 19th Tank Corps. This group would be the rebar in the reinforced concrete of Soviet defenses. Soviet tankers dug in and camouflaged their tanks in preparation for an attack.

On the morning of July 8th, the enemy struck Galanin's forces with powerful artillery and air strikes. After that, at 6:00, two German infantry regiments and fifteen assault guns began to chew through Soviet defenses. Meanwhile, the main forces of Model's three tank divisions took up initial positions and began forming up for an attack. This did not go smoothly: several tanks and SPGs were lost to Soviet mines even before they reached the battlefield.

Height 238,1: Death's Hill

One of the first obstacles in the Germans' path was the Red Army stronghold on height 238.1. Its defenders were chiefly made up of elements of the 1st Anti-Tank Rifle Battalion from the tank destroyer brigade, between 72 and 108 rifles. In addition, the height housed a mortar battery, a platoon of submachinegunners, and two 76 mm anti-tank guns commanded by Captain G.I. Igishev.

The defenders saw a grandiose and frightening picture from their positions: 200 German tanks and SPGs accompanied by APCs and trucks with infantry took up initial positions, split up into groups, and prepared for an attack. A group of tanks from the 4th Tank Division drove directly at the height. These were the latest modification of PzIV tanks, armed with long 75 mm guns and reinforced with additional armour. The balance of forces was not in the favour of the defenders, but none of them were even thinking about retreat.

The gun crews waited until the German tanks drew closer and opened fire from 500-600 meters. Four tanks were destroyed with direct hits. The Germans did not manage to discover who was shooting at them and paused the attack. After a small pause, the attack was resumed. Even though Igishev's artillery destroyed four more tanks, German infantry pulled up, and, using their superior numbers, managed to reach the gun positions and destroy them. Igishev died in battle, earning the title of Hero of the Soviet Union posthumously.

Having captured height 238.1 and the eastern outskirts of the nearby Samodurovka village, the Germans moved out to Teploye.

Heat at Teploye

Attacking well prepared defenses is a tough job, and the Germans felt it. Over five hours, attack after attack petered out against elements of the 140th Rifle Division and 3rd Tank Destroyer Brigade at Teploye. This was done with skill, rather than with sheer firepower. If the tanks were accompanied by infantry, artillery and small arms fire separated the two, leading to an unenviable fate for the latter. When the tanks reached the trenches, they were pelted with grenades and Molotov cocktails.

By noon, the Germans managed to tear through the defenses of the 140th division and reach Teploye, the armoured "rebar" from the 19th Corps, namely the 79th Tank Brigade. 30-40 Soviet tanks held the village for several more hours before being forced to pull back and take up defenses to the south of the village under pressure from a larger enemy force.

The German success was not satisfying: the road ahead was closed. Enemy infantry was separated from its armour by a hurricane of fire, the tanks kept taking losses from Soviet tanks and anti-tank guns. By the evening, the Germans managed to make a dent in Soviet defenses, but there was no breakthrough.

Finally, the Germans attempted one final, fierce attack. The remaining 90 PzIVs and 1 Tigers attacked following an artillery strike.

The infantry from the 140th Rifle Division did not engage the tanks. They let them pass, engaging the accompanying infantry and stopping its progress. As a result, the enemy tanks were left without support and came under fire from T-34 tanks which were shooting at their vulnerable flanks. Attempts to turn towards the threat were met with fire from anti-tank guns.

The main attack stalled, and the enemy was forced to retreat past height 238.1. The enemy's losses were disheartening: just the 4th Tank Division lost half of its 90 tanks and 298 men that day. This was not the end. Four more days of fierce fighting raged at Teploye. The Germans did not manage to penetrate Soviet defenses. On July 12th, soldiers of the Red Army began a decisive counteroffensive on the north side of the Kursk salient, putting an end to the German Citadel.

Original article by Aleksandr Tomzov.

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