Sunday 30 November 2014

SU-76I Trials

"To the State Committee of Defense, comrade V.M. Molotov

I report on the results of the proving grounds trials of the experimental SPG that uses a 76 mm tank gun mod. 1940 (F-34) on the chassis of a captured German medium tank PzIII (or StuG) produced by factory #37 according to the GOKO decree issued on January 19th, 1943, #2758ss.

Trials were held at the Sofrino proving grounds from March 13th to March 20th of this year in the amount of 434 shots and 280 kilometers, supervised by the commission led by Lieutenant-General of Artillery, comrade Tikhonov.

The prototype supplied for trials satisfies tactical-technical requirements.

The major characteristics of the 76 mm SU-76 SPG are as follows:
  1. Armour:
    1. Front: 45 mm at 45 degrees
    2. Side: 25 mm at 20 degrees
    3. Rear: 25 mm at 20 degrees
    4. Roof: 10 mm
  2. Ammunition capacity: 95 shells
  3. Vertical gun angles: -5 to +15 degrees
  4. Horizontal gun angles: +/- 10 degrees
  5. Height of the fighting compartment: 1760 mm
  6. Bore axis height: 1870 mm
  7. Crew: 4
The design of the SPG is very good. The stability when firing is good. The SPG is easy to service. The accuracy is satisfactory. The performance of the vehicle matches that of the PzIII, recorded in the service manual of the latter, and are characterized by insufficient traction of tracks with a slippery frozen road, which results in drifting and slipping. The reliability of rubber tires and drive sprocket is insufficient. This deficiency requires the speed to be limited at 25 kph. When moving on icy or frozen terrain, it is necessary to install V-shaped German spurs. The commission decrees that the SU-76 SPG is adequate for tasks delegated to this type of self propelled artillery, has passed trials, can be recommended for adoption by the Red Army, and must be produced immediately, provided that satisfactory tires can be found or produced domestically, spurs, spare road wheels and sprockets, and careful quality control and re-checking of all PzIII and StuG tanks used in production. 

I consider the tested SU-76 76 mm SPG to be ready for adoption by the artillery branch and mass production.

GAU KA Chief, Colonel-General of Artillery, Yakovlev"


Note that the SU-76I weighed only 22.5 tons, compared to 22 tons of a mid-production StuG or 20 tons of a late production PzIII, so excess weight can't be blamed for this fragility of the suspension. 

Saturday 29 November 2014

Picky Commissariat

"Minutes of PB#114 on January 20th, 1930, p. 4: Report by the Ordzhonikidze commission (Ordzhonikidze, Voroshilov, Kuybishev, Uryvayev, Tolokontsev, Postnikov, PB#113 from January 15th, 1930, p. 25).

Decision:
  1. Approve, with some corrections, the following proposals of the commission:
    1. Accept that there are currently no tanks or tractors that must begin production at tank and tractor factories that satisfy the People's Commissariat of Military and Naval Affairs, and that it is necessary to produce documents describing specifically what kind of vehicles the Commissariat needs and how they are to be produced at tractor and automotive factories.
    2. In order to study various types of fast tractor/tank engines and tractors abroad that meet the Commissariat's needs, as well as to study the methods by which high speed tractors are built, propose that a commission composed of Halepskiy, Osinskiy, and Budnyak spends up to 500,000 roubles abroad to purchase speedboats, tractors, and various engines, as well as familiarize themselves with their production.
    3. The final decision on production of tanks and speedboats at Soviet factories is delayed until the commission returns.
    4. Propose that the commission, regardless of its trip, work on issues of tanks and tractors in a unified automotive production process.
    5. Propose that the commission continuously supply information while abroad.
  2. Assign the commission composed of Rukhimovich (chair), Kalinovskiy, Tolokontsev, Yakovlev, Mezhlauk, and Postnikov to discover what kind of high speed tractors we have and organize trials, considering the experience of trials held by the People's Commissariat of Agriculture, VSNKh, and People's Commissariat of Military and Naval Affairs, and also figure out the state of affairs with the German tractor."

Friday 28 November 2014

World of Tanks History Section: Chinese Eastern Railway

The year is 1929. China has been in a civil war for 18 years. The country became a quilt of territories, controlled absolutely and aimlessly by field commanders. For instance, Zhang Zuolin controlled Manchuria, but he died in a train explosion in June of 1928. His son, Zhang Xueliang, nicknamed "Young Marshal" succeeded him. He needed to swiftly attain respect and solidify his power. The easiest way to do this was by attacking a weak neighbour.

However, Xueliang didn't want to quarrel with China's formal leader, Chiang Kai-shek, or with Japan: this was too dangerous, and could cost him his new territory, or even his life. The Young Marshal turned his sights to the Chinese Eastern Railway, controlled jointly by the USSR and China. The railroad passed through his Manchurian territory. Why not turn this joint venture into his personal one?

Manchurian Raid

Main institutions of the railroad were swiftly captured, and their Soviet staff arrested. From there, Xueliang opened fire on Soviet territory. He inherited hundreds of thousands of men, artillery, aircraft, and even tanks, light Renaults purchased in France. The Soviets, not without cause, were worried that he might attack the country's Far Eastern regions.

The situation required a swift and complete solution. A Special Far-East Army (ODVA) was creased.

On the night of November 17th, the Manchuro-Jalainur operation began. Elements of the ODVA crossed the Chinese border. Their mission was to deliver coordinated attacks from the north and east, take the Jalainur fortified region, and surround the garrison of the large city with the same name as the province: Manchuria.

This was not an easy task. Chinese fortifications were built to withstand 152 mm shells, and were partially surrounded with barbed wire. Veterans' memoirs mention trenches up to 4 meters deep in most dangerous directions, minefields, and avalanche traps. The 9000 men of the garrison had 50 mortars, 50 machineguns, bomb launchers up to 150 mm in caliber, and about 20 77 mm guns.

For the Soviets, this would be the first large scale offensive since the Civil War.

Small Support enters the battle

Armoured vehicles fought under Soviet banners before, but these were Tsarist era armoured cars, modernized Gulkevich armoured tractors, captured Renaults, Whippets, and "rhombuses". Other weapons were in no better condition, commanders complained that machineguns would jam after 5-6 bursts, half of their grenades did not explode. There weren't enough binoculars, watches, equipment, horses, or men.

The main ace up the Red Army's sleeve was supposed to be an MS-1 company (9 vehicles). These were the first mass produced tanks in the Soviet Union. In order to retain the element of surprise, their deployment was done in utter secrecy. Not even Soviet infantry knew they would be supported by these tanks.

The operation began. Advance infantry silently took out the guards and attacked. Fighting erupted with several dugouts near the railroad. The Chinese soldiers in them resisted fiercely, remaining in position even as tanks approached, but the dugouts were built poorly. They had large dead zones where an enemy could crawl up form, and straight ventilation shafts, convenient for throwing grenades down.

Despite initial successes and presence of tanks, it was not easy to penetrate the fortified region. MS-1 tanks could not cross the wide trenches and had to find their way around. Since tanks and infantry never learned to cooperate, the tanks, as it said in a report, "wandered around the battlefield and were unavailable to command". Another quote from these reports, which is really applicable to any country in any era: "Tanks acted decisively and without regard for self-preservation, but infantry supported them weakly, and did not display sufficient activity."

Jalainur was not taken on November 17th, and the offensive lost its momentum. A pause was necessary to let infantry rest and pull up artillery.

Correcting mistakes

On the next day, November 18th, tanks acted in three tank platoons, and in tight cooperation with infantry. If there were no tanks, it's doubtful that Soviet artillery would be able to pull up within half a kilometer of the fortifications to open fire point-blank, or that infantry would be able to get close enough to fill them with grenades. Fierce resistance could have stretched out the operation, cost many lives, and given enough time for reserves from Manchuria to pull up.

The fact that Soviet artillery was unable to destroy Chinese fortifications and batteries was an unpleasant surprise. The condition of the Chinese forces was a saving factor: Chinese guns had shells of questionable quality, and were placed in trenches with a limited range of movement. Artillery tactics, according to Soviet specialists, were quite primitive. Each pillbox fought bravely, but independently, with no cooperation. Chinese soldiers fought fiercely until the last bullet, but shot poorly, and used few grenades. Most of the casualties came from bomb launchers.

The tank company suffered 7 losses in those battles (all for technical reasons, the Chinese did not manage to knock out a single tank). With infantry support, the tanks managed to take the fortified region and capture many trophies. Rifles alone were not counted in singles, but in train cars.

As a result of the battles, tankers had many suggestions. They requested canister shot for their guns, radios and flares for communication. In the future, the tankers would have liked heavy tanks, specially designed to break through enemy fortifications. It was deemed necessary to throw up a smokescreen when attacking.

A failure at the railroad would have negatively impacted the international standing of the Soviet Union, which was especially critical in the chaos of the Great Depression and upcoming changes in the world. With only one tank company, and not even the best or most fearsome tanks, the Soviet Union was victorious in its first trial of its military might on the international scale. The MS-1 may not have been the best Soviet tank, but it was the first, and did everything that was expected of them at the Chinese Eastern Railway.

Author: Evgeniy Belash

Evgeniy Belash is a historian, an author of books and articles on the First and Second World Wars. His best known work is "Myths of the First World War". He is the author of a book "Tanks of the Interbellum" on the participation of armoured vehicles in military conflicts in the 1920s and 1930s.

Sources:
  • RGVA materials
  • I.I. Fedyuninskiy, Na Vostoke, Moscow, Voyenizdat, 1985
Original article available here

Thursday 27 November 2014

AA T-34

In my article on various T-34s with automatic cannons, I mentioned a T-34 with two 23 mm MP-6 guns. Here's a little more about this project.

"We reply to your inquiry #145751s with notes on the tactical-technical requirements on the MP-6 and DS mount in a T-34 tank.

On requirement 1: since the modernized tank turret needs significant changes to accomodate the MP-6 and DS, requirement 1 needs to be changed to the following:

"The 23 mm MP-6 guns and 7.62 mm DS coaxial machinegun are installed in a T-34 turret, which can be modified to ensure the comfortable operation of the weapons."

On requirement 13: the time it takes to reload and unload the guns will be tested on an experimental mount.

On requirement 14: the amount of ammunition carried is approximate, as we still don't know the size of the magazine.

On requirement 18: instead of an automatically opening roof, it is more reasonable to have a mantlet that covers the port. Do not specify this in the technical requirements, we can figure it out in the design.

On requirement 21: confirm that the guns come with shell catchers. We consider it reasonable to supply the shell catchers with the guns like it is done for other guns.

The specification to do with ammunition belts is unclear, as we consider the tank version of the MP-6 to be the magazine-fed version, according to the dimensional blueprints send to us by OKB-16.

Aside from the aforementioned changes, we request requirement 24 to be added:

"24: the factory is allowed to change the requirements, having reviewed the requirement in each case with Red Army BTU."

For detailed development of the project, the aforementioned blueprints are insufficient. We need the following materials:

1. Blueprints with all dimensions of the assembly.
2. Working blueprints of the barrel, hydraulics, and spring, in order to armour them.
3. Blueprints of the shells and magazines.
4. A description of the system and a service manual. It is imperative that you send us one of these assemblies and magazines with real or practice ammunition.

Additionally, we must point out that the DS slot must be redesigned and the ball mount be removed, so that the machinegun is easy to mount in the mantlet.

Chief Engineer Makhonin
Chief Designer Morozov"

CAMD RF 38-11355-297

Wednesday 26 November 2014

German SPG Reviews

The following is a report from the artillery regiment of the Das Reich SS division, included in Zamulin's book "Forgetten Battles of the Fiery Salient".

"Artillery support of tank attacks in the 1943 offensives gave a lot of materials for operational research. One issue is especially relevant: is it reasonable to further develop SPGs, given the presence of 150 mm mortars on self propelled mounts (10-barrel mortars)? This is easily answered by asking the question: What is the mission of artillery in a tank attack, and what existing weapons can complete that mission?

The mission consists of the following tasks:
  1. Suppression or destruction of enemy AT guns, especially if they are deeply echeloned.
  2. Blinding of the enemy AT guns in order to strike with tanks past points of heavy resistance.
  3. Dispersion of enemy tank attacks.
  4. Attacks on areas occupied by the enemy (forests, villages).
Currently, Hummel, Wespe, and self propelled 150 mm mortars are available for these missions. A careful comparison of the drawbacks and advantages of these weapons can resolve the issue of their use.

Hummel SPG

Advantages:
  1. Sufficient gun caliber.
  2. Rapid readiness for battle.
  3. Long range.
  4. The gun is suitable for fighting small targets.
  5. The gun is suitable for counter-battery fire.
Drawbacks:
  1. The chassis is completely unsuitable for its load.
  2. The large size of the vehicle makes it vulnerable to attacks from the air.
  3. All guns must fire from one position in order for fire to be concentrated quickly. This means that mobility is low, which is not always suitable in a dynamic battle.
  4. The horizontal traverse angle is inadequate.
  5. The gun has poor maneuverability in battle or on the road.
  6. There are not enough guns for effective use of smoke, and often not enough smoke shells.
  7. There is a shortage of technical personnel.
  8. Due to the poor maneuverability, the gun's use in defensive battle is questionable. In winter, the engine must be running day and night in order to always be ready to turn the gun.
Wespe SPG

When a large amount of 75 and 88 mm guns are available, the Wespe is of no use. It is known from experience that the caliber of these guns is too small for a good smoke effect or ability to fight enemy tanks. From a technical point of view, unlike the Hummel, the Wespe is very reliable.

150 mm self propelled mortar

Advantages:
  1. The 60 barrels of one battery are easily concentrated on one target.
  2. It is easy to fire on areas, blind, or suppress AT guns.
  3. The smoke effect is strong.
  4. There is a large effect on the morale of the enemy.
  5. The effect against massed tank attacks is sufficient.
  6. The mortars are less visible from the air due to their size.
  7. Producing a 150 mm mortar is several times easier than producing a 150 mm howitzer, and the 150 mm mortar unit required less men.
Drawbacks:
  1. The 150 mm mortar is of no use against small targets.
  2. The range is low and dispersion is high.
  3. It is useless in counter-battery roles.
  4. It is not always possible to supply enough shells.
The comparison makes it clear that the 150 mm self propelled mortar is more suited to the issue of supporting a tank attack. One unit with two batteries of 6 mortars each is sufficient for battle. This matches the firepower of 7 units with 18 Hummels each."

The same officer that composed the report also writes that:

"Every knocked out SPG means the loss of one gun, which is unknown in towed artillery. There, the gun is hooked up to another tractor immediately.
...
Experience...clearly shows the superiority of towed artillery versus self propelled artillery. After six months of battle, artillery units still have functional suspensions on 95% of their guns, whereas the self propelled unit only has 25% readiness. If our regiment was supplied with SPG units, this means that the division would not be supplied with artillery support in the majority of cases."

Tuesday 25 November 2014

85 mm Guns

Rival D-5 and S-31 guns might appear identical to the casual observer, but in reality, they had many subtle differences. The following data sheet contains the some data values regarding the KV-85 and IS-1 tanks that reveals some of them.



IS tank, S-31 gun
IS tank, D-5 gun
KV-1S tank, S-31
KV-1S tank, D-5
Tank length
8460
8420
8210
8450
Tank width
3060
3060
3270
3270
Height (gun horizontal)
2700
2700
2600
2600
Height (gun elevated)
3280
3160
2600
3365
Clearance
380
380
380
400
Width between tracks
3060
3060
3265
3265
Track in contact with ground, length
4540
4700
4600
4600
Track in contact with ground, width
650
650
650
650
Vertical gun angle
-2 to +21
-3.5 to +22
-3.5 to 15
-2.75 to 23
Horizontal gun angle
360
360
360
360
Bore axis height
1900
1945
2070
1965
Gun dead zone (m)
50
23
42
35
Shell mass
AP: 9.2 kg HE: 9.54 kg
Total round mass
AP: 15.85 kg HE: 16.2 kg
AP muzzle velocity
800
800
800
800
Muzzle energy (ton-meters)
300
300
300
300
Penetration at 1000 meters at a 30 degree angle
83-98 mm

As we can see, there are some differences in the size of the tanks that accommodate the gun, as well as various features, most notably gun depression. The IS can depress the D-5 more than the S-31, and even though the KV-85 can depress the S-31 slightly more, the higher bore axis gives that gun a much larger dead zone. Additionally, 15 degrees of gun elevation is quite unacceptable for a breakthrough tank that is expected to fight in urban conditions.

Monday 24 November 2014

World of Tanks History Section: Operation Uranus

The fall of 1942 was coming to an end. Paulus' 6th Army was gnawing through Soviet defenses on its way to Stalingrad, Berlin was demanding that all remaining resistance be wiped out. Could any of Paulus' soldiers or officers known that in a few hours, only a few hundred kilometers away, their fate and the fate of the city on the Volga would be decided? Doubtful, but nevertheless, the strike groups of the South-West and Stalingrad Fronts were ready to strike.

Before the offensive

That night, the Soviet staff were much more nervous. This was the first attempt at an encirclement of this magnitude since the start of the war. Additionally, so far all attempts to attack have been unsuccessful. For instance, summer battles wore down the 4th Tank Army to the point that it was the subject of a morbid joke: "Fourth tank army? More like four tank army."

This time, everything that could be used in an offensive was gathered. Sadly, in the late fall of this difficult year, this wasn't much. Even the corps of the 5th Tank Army, the ace up the sleeve of the South-West Front, bore little resemblance to optimal strength. For instance, the 119th Tank Brigade had 39 tanks out of 63.

There were also doubt (later confirmed) about the amount and condition of trucks that were going to "feed" the attacking tanks.

On the other side of the mechanized pincer, the Stalingrad Front, there was also no shortage of problems. "Readiness of tank units for battle, with the exception of 90th and 235rd Tank Brigades, was low. Tank drivers had little experience, and most of them have never seen combat before. Gunners had little practice. Motorized infantry was poorly trained to perform offensives, and there was little cohesion within units due to their hurried assembly."

The only hope was that the Germans weren't the same as they were in the summer. Also, the first strike wasn't aimed at the Germans.

The pincers close

At dawn on November 19th, artillery shells and Katyusha rockets rained on the positions of the 3rd Romanian Army. When infantry hit after the barrage, the Romanian front slowly started to fall apart. Tank units didn't enter battle until the afternoon. Quickly penetrating the remains of the Romanian defenses, they marched on.

Soviet losses were relatively low that day, but a battalion of the 159th Tank Brigade "excelled" that day. An order received at noon that changed the direction of attack deviated from the explored route and went straight into a minefield. By itself, this was not a problem, as the tanks carried two platoons of sappers with metal detectors, but when the first two T-34s blew up on mines, the battalion commander falsely assumed that he was under attack and ordered tanks to rush forward. As a result, ten T-34s were immobilized within minutes. These losses were disappointing, but were insignificant compared to the overall success of the day. The most important thing was the the 5th Tank Army was able to successfully move forward for nearly the entire day.

Serious resistance was only encountered late in the day, at the Ust-Medvinskiy farm. According to the reports of the brigade, the farm was occupied by a "German infantry battalion, serving as a blocking squad for the Romanians, as well as remnants of Romanian forces". In reality, this was the German 22nd Tank Division, moving up from behind the Romanians.

If this was a fully formed division, this counterattack could have been a serious hazard to teh Soviet plan. Fortunately, the defenders of Stalingrad "shaved off" some of its numbers, and it had about thirty tanks remaining. By noon of November 20th, two Soviet tank brigades knocked the Germans out of Ust-Medvinskiy, capturing "many cars, motorcycles, 2 supplies warehouses, and a spare parts warehouse". The Germans retreated south of the farm and fortified there. Attempts to knock them out from the front cost one destroyed tank and two knocked out. After this, the commanders of the 5th Tank Army sent units around the main German defensive lines.

On November 20th, the Stalingrad Front moved into an attack. It didn't have its own tank army. The 4th and 13th Mechanized Corps had to encircle the enemy. They had a relatively easy time punching through the Romanian defenses. The 4th Corps managed to make a clean break, but the number of the other one proved unlucky. First, a reserve German motorized division was sent to greet them. Second, their vehicles once again ended up on an enemy minefield by accident, taking significant losses.

Nevertheless, most Soviet tanks were driving deeper and deeper into the German rear.

In a Blitzkrieg fashion

This was the riskiest moment in the operation. The tanks rushed forward, the infantry was finishing the last of the Romanians, and lagged behind. Supplies were lagging too. There was a distinct shortage of trucks. The tanks were akin to snails that carry everything they own on their backs. For instance, the 117th Tank Brigade had 150 shells per tank, 100 of which were inside, and the rest were in boxes on its sides. Some tanks also carried 200 L fuel drums.

These supplies could not have lasted the entire operation. The Germans helped out or rather, their warehouses did. Captured supplies, especially gasoline, allowed trucks to be loaded with the most important thing: ammunition. Several trucks from the motorized infantry battalions were transferred to carrying supplies, and the riflemen were moved to tank riders.

Who knows what could have happened if the Germans were able to throw a fresh tank division in to battle. However, the 6th Tank Division that was sent into the crisis zone from France was still far away.

At dawn on November 22nd, advance units of the 26th Tank Corps reached a bridge across the Don near the city of Kalach. The capture resembled something from 1941. When Soviet tank silhouettes appeared in the pre-dawn twilight, the bridge guards simply could not believe that the enemy was here, in the deep rear. The Germans did not have enough time to blow up the bridge or put up a meaningful fight. This valuable crossing fell into Soviet hands without a fight.

Kalach itself was taken the next day. By that time, the 26th Tank Corps only had 35 tanks left out of 160, barely half a brigade! Nevertheless, the tankers fulfilled their mission.

That day, the 4th Mechanized Corps of the Stalingrad Front captured the city Sovetskiy. The trophies consisted of German warehouses and supplies, but most importantly, the railroad that was supplying the German 6th Army was cut.

On November 23rd, at 16:00, tanks of the 4th Mechanized Corps met up with the 26th Tank Corps. The pincers closed, trapping Paulus' army. The two month long agony of the German forces trapped at the Volga began.

Andrei Ulanov is an historian and an author of books and articles on the Great Patriotic War. His most prominent works are "Order in Tank Forces" and "First T-34s" (co-authored with Dmitriy Shein). Currently, he is working on books on AT measures of Soviet infantry and combat use of T-34 tanks in 1942.

Sources:
  • CAMD RF, specifically fond 3398 (1st Tank Corps), opis 1 (operations)
  • A. Isayev, Neivzestniy Stalingrad
  • V. Adam, Katastrofa na Volge
  • F.V. Mellentin, Tankoviye srazheniya 1939-145 gg Boyevoye primeneniye tankov vo Vtoroy mirovoy voyne
Original article available here

Sunday 23 November 2014

Unique T-34 Turret

Iam-Krasnoyarsk found an interesting picture.


At first sight, it's a simple model 1942 T-34 turret used as a bunker. However, looking at the barrel length, it's far too short. This isn't a simple T-34, it's using the F-32 gun from early KV-1 tanks! However, the F-32 gun that was meant for a heavy tank didn't fit into a medium tank's smaller turret that easily. It's clear that whoever made this emplacement had to do some work adjusting the turret "cheeks". Instead of being the common quarter-spherical shape, the side is now a 90 degree angle, forming a cylinder. 

Saturday 22 November 2014

Doodles

You may be an artist one day, and a soldier the next. Does that mean your desire to draw disappears? Not at all, it just retreats to the background, and surfaces whenever it can. You've already seen the art of the 16th Tank Brigade, but that was one drawing on the cover of a report. Some people had more spare time than that. For instance, a report of a sapper unit has illustrations in every section!



The 3rd Guards Tank Army is no slouch in the art department. Their infographics were decades ahead of their time!


The picture shows the amount of scrap metal collected during their drive Westward. October and December were excellent months for the unit's recycling program, with many German tanks collected on the battlefield (552 tons and 556.5 tons, respectively), but November was not such a great month. Only 20 tons of scrap metal was collected, enough to fill just one train car. 

ZiS-23 and ZiS-24 Status

Remember these massively overpowered guns and how they were cancelled in 1942 for lack of a valid enemy? This is how far their designers got in building the actual things.

"Fulfilling decree of the USSR SNK and Central Committee #P32/116, Stalin factory #92 developed blueprints for the ZiS-23 85 mm antitank gun and, on its own initiative, ZiS-24 107 mm antitank gun. All parts aside from the barrels were produced for both systems, and M-60 and ML-20 mounts were prepared for installation. The barrels were ordered at factory #221, and were never received by factory #92. No further work on the ZiS-23 and ZiS-24 was done. The following was spent on designing the ZiS-23 and ZiS-24 components:
  • ZiS-23
    • Design: 43,979.71
    • Parts production: 73,387.03
    • Total cost: 117,366.74
  • ZiS-24
    • Design: 21,033.22
    • Parts production: 62,481.04
    • Total cost: 83514,26
I ask you to order the payment for the design and production of ZiS-23 and ZiS-24 systems.

Factory director, Elyan
Assistant chief engineer, Sheffer"

Thursday 20 November 2014

Repairs Instructions

"Order to the forces of the South-West Front #0252

July 31st, 1943

The experience of the tank forces of the South-West Front demonstrates that their success largely depends on the correct organization of marches, repairs, and supplies of lubricant and fuel.

Many corps travelled significant distances between their railroad station and final destination with no losses. Most corps travelled 500-600 kilometers with battles, and counted an insignificant amount of tanks that fell behind or were unable to participate in combat, while several tank units and marching companies had up to 30% of the tanks fall behind.

The issue of repair bases in proximity to the main forces was, for the most part, resolved correctly. Moving through the axis of the tank corps, front line repair units managed to restore almost 70% of all broken down and knocked out tanks in time for battle.

Despite the largely effective efforts by repair units of corps, armies, and the Front, several of them worked ineffectively at certain times.

Tanks that required major repairs were not evacuated and delivered to the railroad station in time, and were instead stripped for parts and left in a condition useless for repairs. Crews allowed components to be removed without the permission of their commander. These tanks were also not immediately recorded as scrapped and were not removed from the unit's inventory. When the battle was over and the unit left the army or Front, it left behind tanks that were not written off and could still be restored.

Tank unit commanders did not transfer crews in a timely manner from tanks that needed to be sent for repairs. Experienced crews were left with their tanks with no documents and supplies. In some cases, the crews, complete with their commanders, spent their time idle in villages.

In order to improve the organization of repairs and evacuations and increase the speed of preparing tanks for combat, and in order to combat repeated instances of tanks falling behind, I order:
  1. Do not allow repair units to fall behind the tank forces. Technical companies and platoons (of brigades, regiments, and battalions) must only be used to restore tanks that require minor repairs in battle and preventative maintenance outside of battle. Keep them no more than 25-30 km away during offensives and 5-10 km during defense.
  2. Use the Corps field repair base for medium repairs. If the technical companies and platoons are occupied, instruct the corps repairs to perform minor repairs as well. Keep them 35-40 km away during offensives and 20 km away during defense. Tanks that need medium repairs that cannot be repaired at field repair bases must be transferred to army or Front level bases or to damaged vehicle storage yards. The evacuation means of the corps must be used to transfer tanks from brigade level storage yards to army level yards, or railroad stations.
  3. Field repair bases, evacuation companies, and storage yards should be kept 40-50 km away from the front when attacking and 30 km when defending. They should be used as means of reinforcing the corps. Form storage yards in the paths of tank columns. Tanks that are discovered which are in need of minor or medium repairs should be immediately transferred to army or Front level repair bases. When tanks are repaired, send them to their unit.
  4. Front field repair bases and army repair battalions should be moved out to specific directions for reinforcement of army repair means, kept 80-100 km away during offensives. Tanks that are repaired by Front field repair bases should be sent back to their units. If the tank's unit has moved more than 50 km away or has left the vehicle for more than 3 days, consider the tank abandoned and send it to the Front's reserve after repairs, informing the unit's commander of its status. Dedicate repair trucks to tank units.
  5. The field tank factory is a reinforcement of the Front, and should be used to perform major repairs. It should be positioned up to 150 km away from the front line. In order to accelerate repairs of tanks, it is only acceptable to remove a component from another tank under the condition that it is replaced with a nonfunctional component. Those that are guilty of stripping down tanks for parts will be severely punished.
Begin with restoring tanks that will take the least amount of work, starting from the front lines, and headed towards the rear.

In all conditions of battle, have at least 2 refills of fuel and lubricant.

Repair trucks must have 40 kg of oil and 80 kg of fuel to aid tanks that have fallen behind due to a lack of fuel.

Increase the quality of tank repairs. Tank unit commanders must perform testing of the replaced component upon reception.

Tanks that have fallen behind of were knocked out must be retained until the arrival of a repair unit or transfer to a storage yard. When the tank is transferred to a repair unit, remove the ammunition. The optical devices must be removed and stored until the vehicle is shipped for major repairs. Tank crews that do not contact their unit within 4 days of their tank being lost are considered deserters. Each instance of a breakdown or tank falling behind must be investigated immediately by a technical commission, and measures must be taken. Compose a technical condition act for every tank damaged in battle no later than one day after the event.

Tanks that cannot be restored should be excluded from the unit's inventory, with a copy sent to the Tank and Armoured Forces Directorate of the army or Front within 2 days.

All re-assignments of tanks between corps or armies must be reported to the Tank and Armoured Forces Directorate of the Front.

All personnel are responsible for storing, using, and keeping track of the vehicle they are trusted with.

This order should be distributed down to the tank commander and mechanic-driver."

Collection of Combat Documents from the Great Patriotic War, vol. 15, doc. 37.

Wednesday 19 November 2014

World of Tanks History Section: Fury, the Tank that Knox Built

The M4 Sherman medium tank was a real workhorse of the American army. Its M4A3E8 modification, nicknamed "Easy Eight" by the tankers, was the pinnacle of this family of tanks.

The creator of the tank was the talented, but largely unknown engineer Harry Oxford Knox. His vehicles dominated in American tank development for over ten years! Who was he, and what did he contribute to the American tank school of thought?

Before the Tank

Harry Knox was born on January 19th, 1875, next to Westfield, Massachusetts. He graduated from the Springfield Technical Institute in 1894. Knox was obsessed with cars, and built his first gasoline engine in that year. Initially, Harry worked at the Overman Bicycle Company, where he made engines for three-wheeled cars. Later, he decided to start his own business.

In 1900, the Knox Automobile Company was formed. At first, Knox made three-wheelers, but later he switched to four wheel cars. From 1906, his company also produced fire trucks. The company made passenger cars until 1914. The production of trucks lasted much longer, until 1927, when the company ceased to exist. Some of its products survived to this day.

Car to Tank

Some sources mention that Harry Knox took up tank design, but few mention how deeply he delved into it. His work for the military began in 1924. At the time, the American Ordnance Department burned its bridges with John Walther Christie, another tank designer that rose from the car business.

Unlike Christie, who was difficult to work with and frequently drew the attention of the press to himself and his vehicles, Harry Knox was not a public man. As mentioned above, even some tank historians have not heard his name. Nevertheless, this unknown car designer was a key figure in American tank building.

His influence can be seen by looking at the patent bureau archives. The famous rubber-metallic track link, a suspension using volute springs, a single block front transmission used on American tanks for over 10 years, all of these things were thought up by Harry Knox. He had nearly a hundred inventions to his name which were used in American tanks and half-tracks.

Knox didn't just patent components, but entire tanks. For instance, Knox was the author and owner of the T1 Cunningham patent. Cunningham was just a subcontractor of the Ordnance Department. Christie looks like a nobody next to Knox and his inventions.

Left in Shadow

Why is this man unknown? This question is answered by any of Knox's patents. They all begin with the disclaimer that the invention is created for the government, and can be used with no limitations. Knox was left in the shadow of his patrons in the Ordnance Department.

The inventor had a sufficient salary, plus he likely received generous bonuses. On the other hand, the Ordnance Department was rid of the headaches that come with invention due to a "court" inventor that, unlike Christie, didn't hound them for royalties. By the way, one of Knox's patrons was John Christmas, a man that played a key role in the exile of Christie and his tanks from the American army in the early 30s. Christmas is even listed as a co-author in several of Knox's patents.

Having such powerful patrons, the inventor didn't need to worry about competition. Yes, Knox's T1 tank and the T2 medium built on its basis lost to Christie's M1928 on all fronts, which appeared at the worst possible time. Christie's tank ruined the planned purchase of 250 T1s, and Knox had to radically redesign his vehicles. This resulted in light T2 and T5 tanks, which became the basis of nearly all American tank development from 1935 to 1945.

Light M2, M3, M5, medium M2, M3, M4, M7, the heavy M6, and even the superheavy T28, all of these tanks were made with suspensions and other components designed by Knox. His idea of a bogey with a rubber-metallic track was used on American halftracks. Knox's designs were also used by the Marmon-Herrington company, including the M22 Locust.

Knox's fame started to wane in the middle of the 1940s, when it was clear that his designs were obsolete. Torsion bars replaced springs, the transmission was moved to the rear of the tank. This change was partially influenced by the KV-1 tank, which was sent to the US in the fall of 1942 for trials. Knox's last patent is dated 1951.

The star of American tank building died in 1957, leaving his mark in history as only the creator of one of many car companies. Harry Knox's tank legacy awaits its researchers...

Article author: Yuri Pasholok

Yuri Pasholok is a historian, a specialist in the area of WWII armoured vehicles. He is the author of countless articles in various publications related to tanks, as well as the books Panzerkampfwagen Maus and Stalin's Steel Balls. He is also a historical consultant for World of Tanks.

Tuesday 18 November 2014

German Experience in 1942

I have written many times that penetration achieved on paper is no match for penetration achieved in combat. The Germans seem to have been in agreement, issuing a document describing effective ranges from various weapons against T-34 and KV tanks on June 21st, 1942. A translated version of the captured order containing this data is stored in CAMD RF 208-2511-1049.

Type of gun
Type of shell
Range
Tank
Effect
Notes
50L/60 tank gun
PzGr. 39
600-700
T-34 (turret)
Penetration. Ammunition can explode and the tank can burn.
At long ranges, it is still possible to jam the turret and destroy the gun.
PzGr. 40
300-400
T-34 (turret)
Penetration only.
Same as above.
PzGr. 40
600-700
KV-2
Penetration.
The armour is about 80 mm thick. At longer ranges, the gun can be damaged.
50L/42 tank gun
PzGr. 40
Point blank
T-34
None.
It is possible to jam the turret or damage the gun.
75 mm gun (PzIV)
Hollow charge
Up to 700 m.
T-34 (turret)
Penetration.
Crew can be knocked out by the shockwave.
Hollow charge
Up to 2000 m.
T-34
Suppressive fire.

Hollow charge
Up to 800 m.
Type II (all parts)
Penetration.
Tank is easily ignited.
75L/43 tank gun
PzGr. 39
Up to 800 m.
T-34
Penetration of the front turret and hull.
Under favourable conditions, the side can be penetrated at 1200 meters.
PzGr. 39
Point blank
KV-1 (side)
Penetration.

Light field howitzer
PzGr. Rot
600
T-34
Damage to the gun.
23rd TD reports that the shell can be effectively fired from up to 1000 m. at tracks. Fire from reverse slopes.
PzGr. Rot
400
T-26
Penetration.

PzGr. Schwarz
300
T-26
The turret is destroyed.

105 mm leFH 18
PzGr. Rot
1200
KV-2
Front armour screen penetrated.

PzGr. Schwarz
1000
BT
Penetration

PzGr. Schwarz
1000
T-34
Penetration of the front hull.

50 mm Pak 38
PzGr .40
300
T-34 (turret)
Penetration
23rd TD reports effectiveness. At 800-1200 meters, the angle of meeting the sloped armour is more favourable.
PzGr. 38
300
T-34
Penetration

PzGr. 38
300
KV-1 and KV-2
Penetration of side and rear hull.
When shooting the rear at up to 1000 meters, there is a chance to set the tank on fire.

"The casing of PzGr. 40 frequently bursts, and the shell jams.

Rules of using AT guns: Fire from all weapons at proper distances. In cases of massed tank attacks, move the guns into the open. Against the T-34 tank, artillery fire must be concentrated, even if the armour cannot be penetrated with shells."

This document doesn't really tell us anything that we didn't know. The short 50 mm gun is ineffective at fighting T-34s, even with APCR. The longer gun of the same caliber is a little better, but only then against the turret, and not the hull (explaining the short life of up-armoured T-34s). APCR doesn't do as much damage to the insides as APHE. In this case, where the 50 mm APCR can penetrate the T-34's turret, it doesn't cause detonation of the ammunition like APHE does. 

It's interesting to note the obsession with the T-34. Heavier KV tanks are also present (as well as a drizzle of light tanks), but the T-34 receives greatest attention, with more rows dedicated to its destruction, plus additional instructions to fire even if it's ineffective.

The report contains descriptions of tactics I have already posted, along with some new points. For instance, they praise Soviet artillery.

"Enemy artillery has achieved successes in control and concentration of fire. There are cases of massed artillery fire. Because of this, we are forced to loosen our formations.

Reserve positions, ranging guns, and "migrating" guns are used skilfully. Artillery positions are masterfully camouflaged."

It is also noted that the amount and effectiveness of Soviet tank units has increased. In connection with this, tactics must be revised.

"Tanks must be constantly, up to the moment of the breakthrough, be supported by artillery fire (sometimes smoke). If possible, dive bombers must also be used.
...
It is necessary for tank units to occupy favourable positions (preferably reverse slopes), wait for enemy tanks, and then fire on them. These tactics bring greater success than excessive heroism demonstrated by frontline units."

And in the end, one little tidbit that will prove to be the curse of German vehicles for a few years to come: "There are many cases of breakdowns when they need to tow vehicles of equal or greater mass."

Monday 17 November 2014

SU-76 Ergonomics Trials

"An act composed at the Order of Lenin, Order of the Labouring Red Banner, and Order of the Red Star Kuybishev factory #38, on April 15th, 1943

We the undersigned compose this act to record that we have performed ballistics trials of the 76 mm gun mod. 1942 (ZiS-3) on an SPG built on a modified T-70 tank, indexed SU-38.

The firing was performed at the factory shooting range with proof HE shells.

  1. Firing from the right limit: The gun is aimed as far to the right as possible. 3 shots are made. The loader was to the right of the gun during two shots, and to the left of the gun for the third shot.
  2. Firing from the left limit. The gun is aimed as far to the left as possible. 3 shots are made.
  3. Firing from the center position. The hatches and doors are closed. The gun elevation is approximately 0 degrees. The brakes are off. The firing is done to measure the rate of fire, using shells from the left rear rack. Rate of fire: 5 shells during 17 seconds from the "fire!" command. During the five shots, the aim was insignificantly shifted.
During the firing, the 4 man crew was in their places. Extracting shells did not impede the work of the crew. 

Remarks: the side plates of the gun's armour deformed due to improper installation. It is necessary to move the spare vision block from the wall of the right rear ammunition rack to a safer place.

Overall conclusions: consider that the trials gave satisfactory results. The conditions of work at all horizontal gun angles are satisfactory and provide the necessary rate of fire as defined by tactical-technical requirements.

Commission members:
Chief engineer, Terentyev
Factory proving grounds chief, Mironov
Deputy chief engineer, Kozyakin
Department of application chief, Weissberg
SU-38 chief engiener, Kuritz
GAU KA representative"

Sunday 16 November 2014

World of Tanks History Section: Swinton's Land Battleship

In the end of 1915, the European theater was in crisis. Opposing forces had such deep and powerful defensive lines that any offensive would come at a cost of many lives, and would have miserable success. Tends, sometimes hundreds, of thousands would die to take a few hundred meters. In order to exit this dead end, a new means of waging was was needed. One of the many proposals was the tank. Of course, no one used the term in the process of development. The projects were called "self-propelled pillbox-fort", "land battleship", etc.

As for the requirements of the new battle machine, one of the most important criteria was its off-road performance. The field of battle is difficult to traverse. It is covered in trenches, barbed wire, craters. For armoured cars, common in armies of the time, this terrain was impassable. Only tracked vehicles could deal with such obstacles.

Attempts to build such vehicles in Britain already happened, but the land forces were staunch conservatives, and constantly told inventors that they have no need for such vehicles.

Winston Churchill, at the time the First Lord of the Admiralty, displayed an interest in these new projects. Even his influence was not enough to change the army's mind. Churchill had to do it himself. In February of 1915, he created a Committee of Land Ships at the Admiralty, a small department with engineers, polticians, and naval officers. The committee was tasked with developing vehicles that would later be called tanks. The committee was headed by the head of the Naval Construction Directorate, Tennison D'Encur.

The commmitee had many projects and ideas. Mobile shields, steam-powered tractors, amazing vehicles made of two parts, connected together with a flexible chain (land ship "Pedrail"), three-tracked armoured tractor "Killen-Strait", with three wooden tracks. All of this needed to be examined and evaluated, and, if the idea was deemed worthwhile, built and tested. The finances of the committee came from the Admiralty's special treasury, which existed thanks to Churchill's timely understanding of the potential of the new weapon.

The most reasonable and promising project chosen by the committee was Ernest Dunlop Swinton's land battleship. Swinton used the American Holt tractor as a base, which turned out to be the right choice, as no other tractor measured up to the requirements for tanks.

Under the committee's patronage, Swinton successfully completed His Majesty's Land Battleship "Centipede" (also known as "Big Willy" or "Mother"). On February 2nd, 1916, at Marquis of Solsbery's estate, the vehicles was demonstrated to the cabinet of ministers, Admiralty, and General Staff. The trials were successful enough that the army agreed that these tanks need to be built. On February 8th, Big Willy was shown to King George V, who was so impressed, he shook the driver's hand. The land ship, finally and irreversibly, was given the green light.

In order to maintain secrecy, the workers assembling hulls were told they were making mobile water tanks. The name stuck, and since then, 20th century's most menacing fighting machine was called a tank. On September 15th, 1916, the tanks created panic when they arrived on the battlefield at Somme. The effect was mostly psychological, as the Mk. I tanks had neither outstanding reliability nor firepower. The first battle with tanks showed that the way out of positional war was found, and should be developed further. At that point, no one could have guessed how tanks would change the art of war.

Original article available here.