Weak Spots and Hit Zones

All of you have already read the great deal of penetration tests I have posted. However, what practical use do they have? Getting a copy of those tests to every soldier is just not possible (especially since all of those were classified), and it's not like they will remember them anyway. The solution is in the form of easily printable and distributable diagrams. These often also include characteristics of the tank itself.

This diagram is from the Partisan's Companion. Since the PzI was hopelessly obsolete, the only thing it could fight were partisans without anti-tank weapons. The diagram instructs the reader to throw grenades at the roof and tracks, throw incendiary bottles on the engine deck and shoot at the gun and observation ports.

The PzII gets similar treatment. The reader is instructed to damage the gun, tracks, and gas tanks. 

The PzIII is next. The crosshair with 3 circles indicates where to throw incendiary bottles (at the engine deck and observation ports). The crosshair with one circle and a shell indicates where to hit with guns, AT rifles, grenades (side, turret, gas tank, gun, machine gun port, tracks). It also lists how far you can shoot from.

1. 45 mm gun: 200 meters.
2. 57 mm and 76 mm guns: all effective combat distances.
3. AT rifle: 150-200 meters.
4. Large caliber machine gun: all effective combat distances when aiming at the sides and rear.
5. Incendiary bottles at 15-20 meters.
6. AT grenades from 15-20 meters.

PzIV. Gun, engine deck, and gas tanks are indicated. This time, there are no penetration ranges given. 

"Weak points of a German tank with a 75 mm gun". The picture clearly shows a StuG. The format of the diagram and all of the data is the same as the PzIII. The only difference is "destroy the enemy crew with a large caliber machine gun" pointed at the rear of the crew compartment. 

Now we get to the more detailed series. The small bullets represent AT rifles. The large pipe-like shell represents AP and HE from all guns. Red shells with white insides represent AP-HE shells, while completely red shells represent AP. The number on the shell indicates the caliber. The APCR shaped shell indicates APCR from the 45 mm gun.

The image tells you to fire at the front with the 85 mm gun from 1000 meters. The 57 mm gun can take the Panther from 500 meters frontally, 1000 meters from the side, or 1500 meters at the side of the turret. APCR from the 45 mm gun can be fired at the side from 500 meters. The rear of the turret can be shot with the 76 mm gun from 1000 meters. Any shells should be fired at the cupola, the gun, the tracks, the wheels, and the front of the turret. Additionally, grenades should be thrown at any flat surface and hatches. 

Sadly, I don't have a very detailed diagram for a Tiger. This one is very basic. The straight arrow represents all weapons. The curved arrow represents incendiary bottles. The grenade icon represents AT grenades. The  shell icon represents guns of all calibers. The diagram is pretty straight forward. Shoot the gun, machine gun port, tracks, commander's cupola, gas tanks (indicated by the dotted line). 

This image basically says the same thing as above. Throw grenades at the side of the tank, throw incendiary bottles at the back. The title bravely states "If your aim is precise, the enemy tank will not remain intact!" (this rhymes in Russian).  

It's the Ferdinand's turn. The red APCR shell is 45 mm, the black APCR shell is 76 mm. A large AP shell has its caliber written on it. A large tube-like shell is AP and HE of any caliber. A red tube-like shell is HE from any caliber.

The diagram instructs you to shoot 85 mm shells from the side and rear at 1000 meters. Shoot the undertrack hull with 45 mm APCR at 500 meters. Shoot the gun with 45 mm AP or APCR. Shoot the sides with 76 mm APCR and AP at 300 meters. Shoot the sides with 57 mm shells at 500 meters, or the rear at 1000 meters. Shoot any caliber AP or HE at the tracks, or HE from any caliber at the front. Throw grenades and incendiary bottles at the engine grille and hatches. Looks like nobody the creators of this chart about 152 or 122 mm guns.

Another Ferdinand guide shows the location of the crew, engine, ammo rack, and electric motor. 

Last but not least, if you run into a Rheinmetall Neubaufahrzeug, here's how to take it out! From 0-10 meters, the tank crew cannot see you. From 10-35 meters, throw various kinds of grenades. From 35-40 meters, use portable flamethrowers. At 40-60 meters, use rifle grenades. Use armour piercing bullets from 60-80 meters (rifle) or 80-100 meters (machine gun). From 100-150 meters, use an AT rifle. From 150-200 meters, use a large caliber machine gun. 

Cheating at Statistics

Some individuals that played too many video games like to use kill to death ratios in order to calculate how good a particular tank or unit was in battle. Despite the fact that tanks don't exist in a bubble, and are assisted by aircraft, artillery, and infantry, the very idea of a kill differs between sides. You would think that unlike penetration, the idea of a kill is much more universal, but you would be wrong. For example, the Germans counted losses, at least for aircraft, this way:

So we total those up, and get 85% damage, less than one plane lost. I'm no airplane expert, and maybe the missing propeller, bent engine, fallen off bits, and generally being on fire are all reparable by German technicians. However, even if you don't know the source of the photographs (Russian archives), the Red Army uniforms should give it away. Two of these airplanes are in Soviet territory, and thus 100% lost, and yet, out of the three lost planes, barely one is recorded. In a similar fashion, there are instances of shot up/ burnt out tanks that were beyond repair, or worse, left on Soviet territory, that are listed as "in long term repair".

Accuracy Revisited

A while ago, I wrote an article comparing the accuracy of a few guns: the D-25, 88L/56, 88L/71, and ML-20. That article lacked a few details, which I will explain here.

The article talked about how the Germans calculated gun accuracy: using a percentage figure for how often you can expect to hit a 2 meter by 2.5 meter target at a certain distance. Such a measurement is useful for when you are fighting a tank that is 2 meters tall and 2.5 meters wide, and not really in any other case.

The Soviet measurement of accuracy is deviation. You will see many deviations in test documents, but the most important figure, the one that actually makes it into artillery tables and textbooks, is the expected deviation. The average deviation comes in 3 components: vertical, horizontal, and distance. For direct fire, vertical and horizontal are important, for indirect fire, distance and horizontal.

Expected deviation is similar to the 50% radius, except in only one direction. 50% of the shells will land on the closer side of the expected deviation figure, 50% of the shells will land on the further side. Using the two expected deviation figures, you can create an oval inside of which 50% of your shells will go.

Let's revisit the guns in the previous accuracy article. The D-25 has a 50% radius of 24 cm. However, you can see that the distribution of shots in that radius is not circular, it is an oval. I don't have the exact data for the D-25's average deviations, but you can clearly see that the result would be an oval that is a little shorter than it is wide. It is pretty trivial to deduce that the value of the deviations should be approximately 24 cm.

A non-circular result is very common. The ML-20 in that same article has a 50% radius of 32 cm at 1000 meters. However, the average deviations are different from that: 22 cm for vertical and 33 cm for horizontal.

Now, on to some new guns! Artillery tables contain expected deviations for lots of distances and propellant charges, but I will obviously not list all of them. The deviations will be given for 1000 meters, at a full charge, with as many shells as I have tables for. Deviations are taken from the appropriate Soviet artillery table. I have the full ones, so if you need them, ask. For each gun, I will also give the distance at which it can hit a German target 50% of the time with the regular AP shell, to compare it with the German accuracy metric.

Let's start with a classic, the 76 mm F-34 gun, mounted on the T-34-76 models 1941 and 1942:

• HE shell OF-350, O-350A, and D-350 smoke grenade:
• Vertical: 30 cm
• Horizontal: 30 cm
• Trend: horizontal deviation grows much slower than vertical deviation.
• AP shell Br-350A and Br-350B
• Vertical: 30 cm
• Horizontal: 30 cm
• Trend: horizontal deviation grows a little slower than vertical deviation.
• HEAT shell UBP-353A
• Vertical: 50 cm
• Horizontal: 50 cm
• Trend: deviations grow at the same rate.

Looking at a very extreme range, the F-34 has an average deviation of only 1 meter at 3 km. That means that the German 2x2.5 meter target would still be hit more than half the time. Jentz writes that the Tiger could hit the target 53% of the time at that range. Pretty comparable.

The 122 mm model 1938 howitzer (M-30) has the following deviations:

• HE shells OF-462 and O-462A, smoke shell D-462
• Vertical: 50 cm
• Horizontal: 60 cm
• Trend: vertical deviation grows a little faster than horizontal deviation.

The range at which the gun can hit the above German target 50% of the time is 2000 meters. 

The 45 mm model 1942 gun isn't quite that accurate (model 1932 and 1937 results are identical):

• AP shell Br-240 and shrapnel O-240 and O-240A
• Vertical: 50 cm
• Horizontal: 60 cm
• Trend: horizontal deviation grows faster than vertical.
• APCR shell Br-240P
• Vertical: 50 cm
• Horizontal: 50 cm
• Trend: horizontal and vertical deviations grow at the same rate.

The deviation gets to around 1 meter in each direction at 2000 meters, not that there is much a 45 mm gun can penetrate at that range. 

Here is a gun we haven't seen before: the T-60's ShVAK 20 mm autocannon:

• AP incendiary and fragmentation-incendiary shells:
• Vertical: 70 cm
• Horizontal: 70 cm
• Trend: vertical deviation grows faster than horizontal deviation.

The distance at which a German target has a 50% hit ratio is 1500 meters.

The 12.7 mm DShK was in a T-40 tank, that's tank gun enough for me!

• B-32 AP bullet
• Vertical: 76 cm
• Horizontal: 59 cm
• Trend: vertical grows faster than horizontal.
• BZT-44 AP-incendiary bullet
• Vertical: 98 cm
• Horizontal: 67 cm
• Trend: vertical grows faster than horizontal.

The 50% distance is also 1500 meters.

That's all I have for now on the Soviets, so now let's take a look at some foreign guns. The first up is the British 40 mm 2-pounder.

• AP shell and AP shot
• Vertical: 40 cm
• Horizontal: 20 cm
• Trend: horizontal deviation grows much faster than vertical deviation, despite starting out smaller.

This gun hits the German target 50% of the time at a distance of about 2250 meters.

Now, some American guns. First, the 75 mm M2, from the M3 Lee.

• AP shells M61 and M72
• Vertical: 30 cm
• Horizontal: 30 cm
• Trend: vertical deviation grows much faster than horizontal deviation.
• HE shells M48 and MK1
• Vertical: 40 cm
• Horizontal: 30 cm
• Trend: vertical deviation grows much faster than horizontal deviation.

The range at which this gun hits a German target 50% of the time is about 2250 meters.

The other gun on the M3 Lee, the 37 mm M5:

• AP shell M51
• Vertical: 40 cm
• Horizontal: 40 cm
• Trend: vertical and horizontal deviations grow at the same rate.

The range at which this gun hits a German target 50% of the time is a bit less than 2000 meters.

Next, the German guns. The 3.7 cm PaK gives the following results:

• AP Pzgr
• Vertical: 50 cm
• Horizontal: 50 cm
• Trend: vertical and horizontal deviations grow at the same rate.
• HE Spgr
• Vertical: 50 cm
• Horizontal: 30 cm
• Trend: vertical grows much faster than horizontal.

The gun loses enough penetration to not be of any use before it can fail to hit a 2*2.5 meter target 50% of the time, (the table only goes up to 1500 meters). 

The German heavy 105 mm model 1918 gun has the following deviations:

• HE 19 KPS and FES (deviation given in meters)
• Vertical: less than a meter
• Horizontal: less than a meter
• Trend: vertical deviation grows faster than horizontal deviation.
• AP Pzgr. rot.
• Vertical: 40 cm
• Horizontal: 20 cm
• Trend: vertical deviation grows much faster than horizontal deviation.

Due to the rapidly growing vertical deviation, it is not possible to accurately gauge the 50% distance. It would be somewhere just over 2000 meters.

In conclusion: the average deviation for most guns is more or less in the same range, 30-50 cm at 1000 meters. Even with the largest deviation (98 cm on the the worst machine gun bullet), a gun is going to hit any remotely tank-sized object more than half the time. Penetration is the issue here, as a lot of these guns can shoot much further than they can usefully penetrate anything.

The myth of superior German accuracy is, once again, proven false. The average deviation of the D-25 is comparable to the 88L/71, and the long-range accuracy of the F-34 is the same as the 88L/56.

Update: I found the complete artillery table for the 88L/71 KwK 43 gun. It is posted here. 

Unconventional Anti-Tank Warfare

Sometimes, you have to make do with what you have, even when fighting tanks. And sometimes, all you have are ordinary tools. In that case, what you do might show up in a newspaper, and then, with the help of artists from "Combat Pencil", a magazine.

"1. Soldier Kulishev was out scouting one night. An enemy tank crawled out of the forest. He threw a bundle of grenades, and the tank stopped.

2. The tank opened fire, but no one answered. Kulishev took off his boots and silently climbed up on the tank.

3. The hatch opened, and a fascist tanker peeked out. Kulishev hit him in the head with his shovel. The fascist fell back, and the hatch closed.

4. Not wasting time, Kulishev blocked the machine guns with branches, covered observation ports with clay, and blocked the air intakes.

5. The fascists started choking and climbing out of the tank. Kulishev knocked out a second one with his shovel. The third one surrendered. This is how, with bravery, initiative, and quick wits, soldier Kulishev defeated a tank one on one. 

Izvestiya, from July 17th, 1941"

The illustration shows a PzI, but, seeing as how he took out three crewmen, it was most likely a PzII. 

Here is another issue of the magazine. The tank-related story is the one on the bottom.

"Three German tanks entered Pinsk. The fascists miscalculated, and ran out of gas. Pinsk partisans surrounded the Germans. Some swift and strong blows with a mallet, and the barrels of their machine guns were useless. However, the fascists were protected by armour. How do you get them out? Pinsk blacksmiths and workers brought mallets and hammers, and started hammering at the armour. The German fascists, unable to withstand the noise, surrendered.

Pravda, July 12th"

F-34 vs German Tanks

Many sources point to the gun of the T-34 as a weakness, as it was incapable of harming a Tiger at over 500 meters. While this is true, it is misleading. While the T-34's 76.2 mm F-34 AP shell was, indeed, not very good against a Tiger, it was much more than enough against the overwhelming majority of German tanks. This article contains the results of testing its AP and HE shells. The "Report on the shooting of German tanks with AP and HE shells from tank guns" (CAMD RF 38-11355-832) contains the data we need.

First up, as always, is the Pz 38(t). The first shot is fired from 800 meters, with a devastating effect. The 76 mm shell penetrates the turret platform from the front, tears off the front plate, and shatters it into pieces. The fragments then enter the crew compartment.

The testers switch to an HE shell. They fire at the front of the tank hull from 800 meters. The front plate is bent by 40 mm. The welding seam holding it front plate burst (300 mm in length). The two front wheel carriers are torn off (each is held on by 4 bolts). 12 bolts popped off the front armour plate.

The next shell is aimed at the front of the turret from the same distance. The front armour plate is torn off in an area right of the gun. Fragments of the front plate enter the turret. The next shot is aimed at what's left of the turret platform from 900 meters. The remainder of the front plate is shattered by the HE shell, and the pieces fall inside the tank.

Another shot from 800 meters, this time at the side. A 200 mm breach is formed in the outer armour plate, 300 mm breach in the inner one. A shot from 950 meters makes a breach 100 mm in diameter, and results in 90 mm long cracks running through the side armour.

The next target is the side of the turret, from 950 meters. The turret is torn off, and displaced 150 mm. The turret ring is destroyed. The right side of the turret is destroyed.

The next target for the F-34 is the PzIII. The loader switches back to AP. The gunner fires from 900 meters. The front armour is penetrated (entrance diameter 120 mm, exit diameter 165 mm). The tank's gearbox is destroyed. Notice the large diameter of the breach compared to the shell's caliber. This is a sign of over-hardened or poor quality armour.

The next target, again from 900 meters, is the sloped portion of the front armour. The armour plate is fragmented in an area up to one meter away from the breach. The welding seam holding the plate bursts over a length of 1.5 meters. The armour fragments enter the crew compartment.

Another shot from 900 meters, this time from the side. A torsion bar limiter is torn off. A hatch is torn off. The tire of one of the wheels is torn off.

The testers switch back to HE. The first shot from 900 meters shatters the left side of the turret platform over a span of one meter. Another shot makes a breach in the lower hull 240 mm in diameter, as well as a breach 300 mm in diameter in the bottom of the PzIII. An idler is knocked off. The gas tank is punctured.

Another shot makes a 400 mm breach in the side of the tank, knocks out the rear wheel shock absorber, and damages the engine and radiator with the fragments. Another shot at the right side of the turret tears off the turret hatch, destroys the turret ring, and bends the side armour by 60 mm. Fragments of the armour "damage everything inside the turret". The last shot bends the side armour by 50 mm, tears off the right side of the turret platform, and shatters it into three pieces.

Conclusions: "The 76 mm AP shell penetrates the 60 mm of front armour at 900 meters. We did not test larger distances. The 76 mm HE shell destroys the side armour and turret from 900 meters."

The PzIV is tested next. Its front armour is penetrated at 500 meters (entrance diameter 90 mm, exit diameter 100 mm). From 800 meters, another penetration. The front armour plate is shattered into two pieces. Another shot from 800 meters penetrates the front. The testers switch to firing at the side at 800 meters.

The side is penetrated. The 20 mm armour screen is torn off the bolts that hold it. The shell keeps going, and penetrates the other side of the hull, and its armour screen. Total penetration is 80 mm. Another shell penetrates the side, but only one side this time. It knocks off the wheel carrier.

The gunner aims at the turret. The hatch of the turret is torn off with a direct hit. The side of the turret bends inwards 50 mm. Another shot impacts the commander's cupola, tearing it off, and throwing it 5 meters. The hatches on top of the cupola are also torn off, and thrown 30 meters. Another shot to the side of the hull forms a 130 by 350 mm breach.

Conclusions: "The 76 mm AP shell can penetrate the front of a PzIV at 900 meters. We did not test larger distances. The 76 mm HE shell destroys the side of the turret and hull at any range."

From conclusions of the document:
"The 76 mm long-range HE-fragmentation steel grenade fired from a 76 mm gun (F-34) model 1940 installed in a T-34 tank, on impact with the Czechoslovakian 38t tank, side or rear 30-20 mm German tanks PzIII, StuG, and PzIV, destroys armour plates from 1000 meters, damaging the tank and crew with the fragments.
The 76 mm AP shell, when fired from a 76 mm gun (F-34) model 1940, penetrates the front armour of German tanks PzIII, PzIV, and Pz 38(t) from 800-1000 meters. The penetration ability from over 1000 meters was not checked.
...
The 76 mm model 1940 (F-34) gun is an effective weapon against all German tanks, based on its AP penetration and HE shell destructive properties."

According to calculations of NII-48 in topic 2VV-2 "Investigation of the armour of tanks of the German army" (CAMD RF 38-11355-778), the following are the distances at which an F-34 can defeat the armour of a Pz 38(t):

• 90 degrees
• Turret and hull front: 1970 meters
• Turret platform front: 1970 meters
• 80 degrees
• Turret and hull front: 1970 meters
• Turret platform front: 1940 meters
• 70 degrees
• Turret and hull front: 1900 meters
• Turret platform front: 1860 meters
• 60 degrees
• Turret and hull front: 1690 meters
• Turret platform front: 1600 meters
• 50 degrees
• Turret and hull front: 1320 meters
• Turret platform front: 1250 meters
• 40 degrees
• Turret and hull front: 880 meters
• Turret platform front: 840 meters
• 30 degrees
• Turret and hull front: 490 meters
• Turret platform front: 420 meters

Tactical diagram for a Pz38(t). The F-34 is shown as the double dotted line (front only)

For the PzIII, a much larger number of armour groups was tested, to the point where it would be massively inconvenient to transcribe the full chart (if you absolutely must have it, let me know), but here it is for a slightly angled tank, at 80 degrees:

• Upper front plate: 800 meters
• Lower front plate: 1800 meters
• Turret platform front: 1970 meters
• Turret front: 1970 meters
• Upper rear: 1940 meters
• Middle rear: 1900 meters
• "All other parts of the tank can be penetrated with a 76 mm AP shell at any distance, at any angle". 

The conclusions made are as follows: "The protection from 76 mm AP shells is unacceptable. Even its front is penetrable at 900-1200 meters when standing at 45 degrees, and exposing many more vulnerable parts."

Tactical diagram for a PzIII tank. The F-34 is shown as a dotted line for the front and back.

For a PzIV, similar conclusions (again, at 80 degrees):

• Side with armour screen: 2000 meters
• Turret and hull front: 1970 meters
• Turret platform front: 1970 meters
• "All other parts of the tank can be penetrated with a 76 mm AP shell at any distance, at any angle".

The conclusions made are as follows: "The protection from 76 mm AP shells is unacceptable. Even its front is penetrable at 1100 meters when standing at 45 degrees, and exposing many more vulnerable parts."

Tactical diagram for the PzIV tank. The F-34 is shown as a dotted line for the front and sides.

The same table is made for a StuG III, but only the front armour plate. The result is the same as a PzIII: vulnerable at 1970 meters, 1100 meters at a 45 degree angle.

CAMD RF 38-11355-776, a NII-48 article on domestic armour quality, also discusses experimental HEAT shells. These shells were capable of penetrating 30 mm of medium hardened armour and 45 mm of highly hardened armour at a distance of 1600 meters, at every tested angle (maximum tested was 45 degrees).

Red Rambo

Sometimes people have creative ideas about things, and sometimes those ideas end up in archives.

"We propose, that the 20 mm caliber would be used much more widely, if the question of its use, and the construction of the weapon that fires it, was approached from a different angle. The mass of the system should be reduced, barrel pressure lowered, recoil reduced, and the gun turned into an infantry weapon: a hand cannon. Of course, the gunpowder charge would be drastically reduced, which will result in loss of muzzle velocity and penetration effect."

The 20 mm autocannon was used in the T-60 tank, as well as on Soviet aircraft. It would take quite a Rambo character to carry one. Although, maybe it was meant for this guy:

"On July 13th, 1941, Red Armyman Ovcharenko was transporting ammunition for the 3rd company in the Pesets region, and was 4-5 kilometers from his unit. In that region, two armoured cars, 50 German soldiers, and 3 officers surrounded him.

A German officer exited the car, and ordered Ovcharenko to raise his hands, took his rifle, and started questioning him. Ovcharenko had an ax in his cart. He grabbed the ax, chopped off the officer's head, and threw three grenades at a nearby car. 21 German soldiers were killed, the rest ran in panic. Ovcharenko pursued a wounded officer through a garden in the Pesets village, caught him, and also chopped his head off. The third officer ran away.

Comrade Ovcharenko calmly collected the documents of the dead, the officers' maps, papers, diagrams, notes, and delivered them to the regimental headquarters. The ammunition was delivered to his company on time. Comrade Ovcharenko continues his combat service, promoted to a machine gunner."

Edit: I have found the full text of the award order!

Ovcharenko was recommended for the Hero of the Soviet Union medal, combined with the Order of Lenin.

Penetration, Part 3

I posted penetration tables before (part 1, part 2), but I am not even close to collecting the data for every gun. Here are some more guns, some we have seen before, and some we have not.

CAMD RF 81-12104-9

The first gun is a 45 mm model 1937. It can penetrate 30 mm at a 30 degree slope at 1000 meters, but 40 mm at the same slope at only 150 meters. This performance is better than in part 1 (a different model 45 mm gun is used) and worse than in part 2 (no indication of what model tank gun is used).

Next are the L-11 and F-32 76 mm guns. They can penetrate 40 mm sloped at 30 degrees from 900 meters, but 50 mm sloped at 30 degrees at only 300 meters. This is more or less consistent with the findings in part 2.

Next, we see some unfamiliar faces. The 76 mm model 1902/30, model 1938 (also referred to as a model 1939 in a different part of the document, making it unclear what gun this is), and F-34 guns. They are capable of penetrating 50 mm of sloped armour at 800 meters (quite an improvement over the shorter 76.2 mm guns), or 60 mm at 400 meters.

Here's something brand new. The 76 mm AA gun model 1931 (which was trialed inside a T-34 under the index S-54 in 1943) can penetrate 70 mm of armour sloped at 30 degrees at a distance of 1000 meters.

The 107 mm M-60 gun can penetrate 100 mm of armour at a 30 degree angle at 900 meters (although here it can penetrate that armour at 1000 meters).

The 122 mm model 1938 howitzer (M-30) penetrates 30 mm of sloped armour at 1000 meters. The HE shell breaches the armour, the shell explodes, and strikes the insides of the tank with shell and armour fragments.

The 152 mm model 1938 howitzer (M-10) is tested with three shells. The first is a naval HE (half-AP) shell. It can penetrate 100 mm of "reduced quality" flat armour at 500 meters, or 90 mm of the same armour at 30 degrees. A newly developed AP shell doesn't work so well: at 50 meters, it can only dent an angled 90 mm plate, but is capable of breaching it if it is flat. The resulting penetration is less than a caliber. The old concrete piercing shell can penetrate a 70 mm plate at 500 meters, but only if it is flat. The same plate at 30 degrees cannot be penetrated.

The 122 mm model 1931 gun (A-19) penetrates 100 mm of armour at 30 degrees from 900 meters with a concrete piercing shell.

The 152 mm model 1937 gun-howitzer (ML-20) is also tested with several shells. The naval HE (half-AP) shell penetrates 120 mm of armour at 1800 meters, and 100 mm of armour at 30 degrees from 2000 meters.  A new concrete piercing shell penetrates 100 mm of armour at 230 meters. The old AP shell cannot penetrate 90 mm of armour at 500 meters, but could penetrate 80 mm of armour at 30 degrees at 2600 meters (that's not a typo, really, 2600). The shell breaks up and penetrates the plate in pieces.

Now, we get to the big guns. The 152 mm model 1935 Br-2 gun, with a naval HE (half-AP) shell, can penetrate 180 mm cemented armour at 1900 meters, and 152 mm if the plate is angled.

The 203 mm model 1931 howitzer (B-4) can penetrate 102 mm of armour with its light concrete piercing shell (100 kg) at 500 meters, and 27 degrees. The heavy concrete piercing shell (146 kg) can penetrate that same plate at the same angle at 1800 meters. In either case, the shells break up, and penetrate the plate in pieces.

The 280 mm Br-5 mortar, with its 240 kg concrete piercing shell, can only dent 102 mm and 90 mm armour plates at 1700-1800 meters. The rounds shatter into pieces.

World of Tanks History Section: KV-1

In the middle of the 30s, anti-tank guns became popular in armies of the world. This was due to several reasons. One was that 3 inch divisional guns were ineffective against with a mobile target like a tank. Another was that anti-tank rifles were not that effective against armour either. After penetrating armour, the bullet had very little kinetic energy left, and was frequently unable to damage the internals of the tank. However, light and rapid firing weapons of 20, 37, or 47 mm could easily transform any tanks of the era into scrap. Experience in the Spanish Civil War highlighted this.

After analyzing this experience, the Commissariate of Defense ordered the creation of a heavy tank, with armour thickness of at least 60 mm, in 1938. At that point, the thickest armour the only heavy Soviet tank had was 30 mm.

At that point, military minds were certain that a heavy tank needs at least two guns: one to combat infantry, and one to combat tanks. This is why the new tank was initially planned to have several turrets. First 5, like the T-35, then three. Finally, engineers decided on two turrets. Two heavy tanks started development. Both were developed at the Kirov factory in Leningrad. S. A. Ginsburg's construction bureau was developing the T-100, and J. Y. Kotin's SKB-2 was developing the SMK (Sergei Mironovich Kirov).

At the time, the multi-turret construction became heavily criticized. Vehicles of this type were complicated and unreliable. The tank commander had difficulty commanding two guns at once. The gunners effectively had to pick their own targets. This was hardly a rational setup.

Along with the multi-turreted SMK and T-100, it was decided to make another, single turreted tank. The project was sent to the SKB-2, along with several fifth year interns from the Military Academy of Mechanization and Motorization. Under the guidance of engineers L. E. Sychev and A. S. Ermolayev, they developed a single turreted tank named KV (Kliment Voroshilov). The final stages of the project were completed under N. L. Duhov.

The KV was based on the SMK tank. The suspension was shortened by one wheel, and both guns (45mm and 76mm) were placed in the same turret. The crew was decreased to 5. Removal of the second turret lightened the tank significantly, allowing the front armour to grow to 75mm. The tank was powered by a 500hp V-2K engine.

In December of 1938, at the meeting of the projects commission that was evaluating the SMK project, Kotin and the factory director, I. M. Zaltsman, proposed the to build a KV as well as a prototype of their multi-turreted creation. In February of 1939, the permission was given.

The project was polished and the prototype was built by August. On September 1st, the KV took its first trip to the factory testing grounds. After defects were discovered and corrected, the tank was shipped to Moscow for a demonstration to the government and further testing at Kubinka. Further evaluations showed that that KV matched the SMK in speed, and surpasses it in cross country performance. Crew was also down to 5, from the SMK's 7. The tank was physically smaller, allowing it to use terrain to its advantage. On the other hand, several defects were found in the transmission, and the V-2 engine was new enough to be far from perfect.

The tank was sent back to work out the defects, but the Winter War started, and the Red Army tripped up at the concrete fortifications of the Mannerheim Line. The Soviet Union had no breakthrough tanks short of the T-28, whose 30 mm of armour was vulnerable to Finnish AT guns. Experimental KVs and SMKs were sent to Finland to undergo trial by fire.

Before going into battle, the KV was modified. The 45mm gun was swapped out for a DT machine gun. The KV's first battle was on December 18th, during which the tank demonstrated the advantages of its thick armour. 10 hits were received from 37 mm guns, zero penetrations. However, one hit the gun, which had to be replaced.

The SMK's performance was much less exemplary. Technically, one cannot fault the crew or the engineers; the tank was immobilized by a hidden mine. Regardless, the KV took the spotlight, and was adopted by the Peoples' Commissariate of Defense on December 19th. The Kirov factory was ordered to solve existing defects and begin mass producing the KV starting January 1st, 1940.

The KV's 76 mm gun was found to be insufficient for penetrating concrete bunkers. An order was issued to investigate the possibility of installing a 152 mm howitzer on the KV. This was achieved, and resulted in the KV-2 modification, which will receive its own article. The KV with a 76 mm gun was retroactively renamed KV-1.

In 1940, the Kirov factory was to release 50 KV-1 tanks. Even after getting rid of newly found defects, this order was very realistic. However, the order was increased to 230 tanks, which was problematic. The factory director tried to explain his position, but the pressure from the top was too great, and he found no other way than to report that the factory was meeting the needs of the Motherland. This deception was uncovered, but the volume of work was deemed too great after all, and Zaltsman only received a warning.

Work on the KV-1 continued; improving the transmission, air filters, turret rotation mechanism, and low reliability of tracks and road wheels took all of 1940. Only in July, 350 changes were added to the blueprints.

Two factories were to build KV-1s: Kirov factory in Leningrad and the Chelyabinsk Tractor Factory. After WWII started, the production of KV tanks clustered in the Urals, especially after the Kirov factory was evacuated to Chelyabinsk.

At the start of WWII, the Red Army had 630 KV tanks of both modifications. Despite all efforts, their reliability was still lacking, and factories were constantly failing to produce enough spare parts to keep all divisions equipped. A large portion of KV tanks was constantly incapable of combat, as they were undergoing repairs.

All things considered, the KV (and T-34) tanks became a harsh surprise for the Germans. They were nicknamed "Ghost" due to their perceived invincibility. Even though the KV was a formidable opponent, the Germans figured out how to combat it effectively.

The KV was a powerful tank, but it was also a problem-prone one. By the start of the war, it did not attain the required levels of reliability. Furthermore, the lighter T-34 was seen as more satisfactory to military commanders. The KV was created as a temporary tank, always destined to be replaced a few years later by a more perfect tank, but it remained in production due to the war. When the Germans started rolling out Tiger and Panther tanks, the KV was deemed ineffective. In 1943, the KV-85 was developed that could combat new German tanks, but it was not widely deployed, since the newer and more capable IS was already being built.

Original article available here.

Re-arming German Tanks

The image of disciplined German soldiers methodically destroying their tanks so that the enemy does not get them is spread through popular history, but, in reality, was not true. The Red Army captured plenty of fully functional tanks, some in the first battle they ever participated in. They captured so many, that the issue of re-arming them came up. Re-arming German tanks with domestic guns would solve the problem with ammunition supply, if not the problems of parts and high-octane gasoline.

The question was first raised in 1942.

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"According to the information supplied to you by deputy chief of the 2nd department of the Artillery Committee of GAU RA, engineer 2nd class comrade Getman on the necessity of re-arming captured tanks and SPG, and the discussion with engineers Sinilshikov and Pererushev, we decided that the following installations were possible:

1. 76 mm F-34 tank gun on the PzIV tank.
2. 45 mm tank gun on the PzIII tank.
3. 45 mm tank gun or 20 mm ShVAK autocannon on the Pz38(t) tank.
4. 122 mm howitzer M-30 on the StuG SPG.

Currently, Sinilshikov is only dealing with re-arming the StuG. His team already started developing a project. I am sending you a copy of the M-30 schematic, and if you do not object, please pass it on to comrade Sinilshikov. I am also sending you sketches of other turrets with German guns installed, to be used as you deem necessary. Keep me informed on your progress."

The M-30 project is the only one of these that went anywhere, creating the SG-122 (Self Propelled Howitzer, 122mm). 21 SG-122s were built out of StuGs and PzIIIs, but by that time the SU-122 was no longer used, and the equivalent SG-122s were sent to tank schools. Additionally, a project to install a 76 mm tank gun on the StuG was launched, creating the SU-76I, in 1943. 201 were built. 

A project to re-arm Tigers and Panthers was also launched. The Panther would receive an 85 mm gun and the Tiger a 100 mm gun. 

Here is a blueprint of a Tiger turret with a D-10T and a TsH-17 sight.

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By 1945, the obsolete tanks were dropped and estimates on the work necessary were made.

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A PzIV took 80 man-hours to convert to a ZiS-5 or a F-34. A Panther getting an 85 mm gun took 120 hours. A Tiger getting the D-10T took 90 hours. A fragment of the blueprint shows the true name of this chimera: T-VI-100.

However, by 1945, victory was near and the tank shortages of 1941/42 were long behind. Captured tanks were no longer needed by anyone except museums, and work on re-arming them stopped. 

Tank Plans for 1941

I've written before that the USSR was planning to make the KV-3 tank its primary heavy tank in 1941, and one of the KV-3, 4, or 5 in 1942, but just how many KV-3s were they planning to build? Was it going to be just a few pre-production models, or a full scale manufacture?

Full scale manufacture it is! GABTU's plans for 1941 order the Kirov factory to produce 500 KV-3s, 400 KV-1s, and 100 KV-2s. Those KV-3s are quite expensive, 40% more expensive than a KV-1.

Plans change, of course. In reality, the Kirov factory built 611 KV-1s, 204 KV-2s, and just one KV-3, if you count the T-150 as a KV-3.

Going through unfulfilled orders, another unbuilt tank pops up, the T-34M. The T-34M (factory designation A-43) was a modernized version of the T-34, with features that would be seen in Soviet medium tanks several years after, like torsion bars, a 5 man crew, a commander's cupola, a planetary gear transmission, and internal shock absorption.

Source: https://yuripasholok.livejournal.com/1833508.html

The scan is a bit cut off, but the production of T-34s wanes to only 40 units over the month of September, and is fully replaced by T-34Ms by October. It is interesting to point out that 380 out of the 800 T-34Ms were armed with a ZiS-4 gun, instead of the F-34 gun that the overwhelming majority of T-34s received. 300 of the tanks were also to be equipped with a flamethrower, aside from their main guns (65 F-34 armed T-34Ms and 235 T-34Ms with a ZiS-4). That was one way of compensating for the deficiencies of the 57 mm HE shell.

We also see that, unlike the KV-3, the T-34M is not that much more expensive than the tank it is replacing. As for the prices themselves, they shouldn't be relied on in any kind of analysis. The document itself notes that these prices are just approximate (since production has not started yet). Additionally, this is way before most simplification and cost-cutting measures were taken. According to Ural Train Factory (UVZ) data, a T-34 cost 246 900 rubles in 1941, and 142 100 rubles in 1944.