Wednesday, 31 December 2014

A Case for the SG-122

"An explanatory memo attached to the SG-122 self-propelled 122 mm howitzer

In March of 1942, the Separate Design Group organized by the NKV Technical Council in order to work on self propelled guns designed an SPG consisting of a mod. 1938 122 mm howitzer on top of a captured German StuG. This project, indexed SG-122, was approved by the Technical Council and Artkom.

An Artkom plenum that was examining issues of self propelled guns in early April of this year also remarked that it is necessary to rapidly begin production of the SG-122.

The People's Commissar of Armament, comrade Ustinov, signed order #217s to organize the production of experimental prototypes at factory #592 and the creation of a special design bureau.

...

Specifics of the self propelled SG-122 gun
  1. High firepower: The 122 mm shell and its HE action combined with sufficiently high muzzle velocity (512 m/s) and high rate of fire (10-12 RPM) make the SG-122 a powerful weapon against enemy pillboxes, field fortifications, machinegun nests, and other fortifications.
  2. Protection: The use of an armoured casemate results in less casualties compared to towed artillery.
  3. Mobility: It is possible to follow tank units and open fire at fortifications from a short range in order to destroy them and clear the path for tanks.
  4. Versatility and agility: The SPG can fire when stationary and on the move, quickly shift fire, turn on its tracks, and aim approximately using a simple aiming device for the driver (made of two planks). Variable propellant loads and high angles of elevation make indirect fire possible, making it possible to destroy closed or far away targets, as well as hull down targets.
  5. Stability: The mass of the SPG is sufficient to fire without deploying trails.
  6. Maneuverability: The small increase in mass (2 tons) does not reduce maneuverability characteristics.
  7. Protection of the crew from fumes: When shooting at a high rate of fire, gas masks can be worn, connected with extended hoses to the outside air, bypassing chemical filters, which can be switched on in case of a gas attack. Trials show that wearing gas masks has almost no impact on the rate of fire. If the hatches are open or the engine is running, it is possible to fire quickly without gas masks.
  8. Use of 9-R Radios and PTU-4 bis.
The SPG has sufficient room, dimensions, and an unoccupied crewman (vertical loader/radio operator).

Re-arming StuGs can be done at the factory with readied components and cut armour (from captured or destroyed tanks) in 10-12 days. 

Re-arming will not take a large amount of effort, as all components are simple and are mostly produced with cutting or electric welding. The M-30 howitzer is installed with few changes (including the stock sight). 

As the design bureau of factory #592 has demonstrated, it is possible to similarly re-arm A-34 tanks with a 122 mm howitzer. 

More detailed data regarding the SG-122 can be found in the manual and factory trials report.

Chief engineer of factory #592, Lomakhin
Chief designer of factory #592, Sinilshikov"

Tuesday, 30 December 2014

More Ferdinand Penetration Tests

You may recall two previous article where the Ferdinand's armour was tested: against the 152 mm ML-20 and 122 mm D-25. Today, thanks to Yuri Bakhurin, I bring you the results of the rest of the test.

First, we have the 45 mm gun. Naturally, it can't do anything to the Ferdinand's thick side. AP shells shatter when hitting the armour, cores from APCR shells sink into the armour without penetrating.


Next, the 6-pounder from the Churchill. Penetration is achieved at ranges of 300 meters, but firing from 500 meters yields little results. Shells either get stuck in the armour or shatter.


Now, the Sherman's turn. M-72 shells from the 75 mm gun cannot penetrate the side or rear armour. The M-61 shell fares better, penetrating the side at 500 meters.



Next, the Soviet 85 mm gun. These shells are easily able to pierce the side of a Ferdinand, causing spalling on the inside.



The proving grounds also had a Panther, and decided to see if it could take on a Ferdinand. Turns out, it could. The vertical front armour can be penetrated by the Panther's gun.


The front of the casemate, however, proved too tough of a challenge. The shells made 170-180 mm dents and could not penetrate all the way,.


75 mm APCR can penetrate even this tough armour.


Penetration through the side. Note the jagged outline of the hole, caused by spalling.


Spalling damage from the inside. The large hole is from an AP penetration, the small hole is from APCR penetration.


The Ferdinand had a chance to take revenge on the Panther. The 88 mm shell ricocheted, but led to a breach and spalling in a 300 mm by 250 mm area.


The results of these trials were used to compose this guide on fighting the Ferdinand.

Monday, 29 December 2014

German Experience in the Spanish Civil War

"DOKUMENT
Oberkommando des Heeres.
Berlin, den 30. 3. 1939.
Gen St d H Nr. 130/39 g. Kdos. O. Qu. III
125 Ausfertigungen. Prüfnr. 56

The following is a report on the participation of the German Army in the Spanish Civil War and the lessons learned.
...
7. Tank forces

The use of obsolete Spanish and foreign armoured cars for reconnaissance was unsatisfactory due to insufficient off-road performance.

Italian light machinegun tanks were successfully used by infantry for close reconnaissance. Spanish infantry did not use their tanks in this manner. According to German observers, the tank could achieve better and quicker results after a successful breakthrough than just patrols on foot.

As an offensive weapon, tanks were used little in Spain, in small amounts of less than 50 vehicles and without appropriate support from artillery or trained infantry.

Aside from valuable and vast technical experience with vehicles, there are several points that must be analyzed carefully due to the specifics of this war. For instance, it was impossible to organize cooperation between tanks and infantry or artillery for both White and Red forces. From the Red side, Russian tanks broke off from infantry and were destroyed by Spanish nationalists, which threw incendiary bottles and hand grenades at them, and which could only be prevented by accompanying Red infantry due to the tanks' small numbers.

The German machinegun tanks [PzI] were not used in large units. The tanks were subordinated to infantry in small groups and supported it from line to line like an armoured infantry gun. Machinegun tanks could not achieve a decisive effect, since infantry was often incapable of capturing and holding territory, or did not deem it necessary. They were defenseless against sudden appearances of gun tanks [T-26], except at very short ranges.

It was already known since the World War that a gun tank has an advantage over a machinegun tank in a duel, and this was also true in Spain. On the other hand, the fact that machinegun tanks could penetrate Russian tanks at 100 meters and the effect of antitank guns led to Russian tanks approaching to a range of 1000 meters and firing from the spot, rarely moving closer. Gun tanks were frequently a decisive factor of the success of the Reds.

In general, it can be said that our ideas of tank-compatible terrain are very limited. It was possible to find out impassable obstacles and drive around them. It was harder for small tanks used in Spain due to many small obstacles, low stone garden walls, rough terrain with bushes, small but sudden changes in elevation, small rivers, and heavy wet silty soil.

Unlike in peacetime training and especially demonstrations, tanks in periods of long war should be taken care of just like horses, and should, if possible, avoid even small obstacles in order to not break down at a crucial moment.

During street fighting in Madrid, tanks had difficulty in streets with barricades, as they could not use their speed or fire at upper floors or roofs. Tanks armed with flamethrowers were used effectively in street fighting.

Foreign opinion suggests that tanks are effective when applied suddenly, in large amounts, and against an enemy that is already wavering, along with artillery support. Armour and armament are more important than speed or range. A tank unit needs means of fighting enemy tanks. All tank attacks not protected from tank or anti-tank guns, or done without an infantry escort, led to heavy losses and achieved success only through chance.

Light tanks are effective only with flamethrowers, their machinegun fire is inaccurate on the move. However, machineguns with special ammunition are being developed.

In general, tanks in Spain are used in insignificant amounts and without support from other types of forces. Anti-tank artillery, which was often used in small numbers, only sometimes surpassing the enemy, was often ineffective.

8. Anti-tank defenses

Due to a small amount of tanks and anti-tank guns used, experience gained was primarily technical and tactical. The use of anti-tank guns in Spain was always according to principles of the 14th company of an infantry regiment. Principle of use as an anti-tank unit were not applicable. Based on experience, including in Madrid, anti-tank guns have proven their reliability. They have shown that they can successfully fight Russian gun tanks. Based on the actions of Russian tanks in Spain (firing from 1000 meters and use for special tasks that arose in Spanish conditions), the limited range of anti-tank guns is insufficient. As a temporary solution, the sight scale should be increased to 1000 meters, but having a long range anti-tank gun is preferable.

He-112 fought armoured cars successfully. The S-30 machinegun with 2 cm armour piercing rounds is sufficiently effective.

If an anti-tank defense is well organized, many tanks will be lost, as it was shown that anti-tank guns surpass tanks in rate of fire, precision, and shot power, while being small and hard to notice even while firing.

Due to a lack of artillery in Spain, anti-tank guns were successfully used during offensive and defensive action as infantry guns against machinegun nests, concrete bunkers, and assaults on settlements, in combination with machinegun tanks. This was an infrequently used method, as it was feared that gun positions will be discovered ahead of time.

According to reports, it is adequate to have one gun every 200 meters when defending. This is adequate for limited amounts of tanks used in Spain, but not for massed use of tanks.

Red anti-tank trenches 500 meters long or more turned out to be completely impassable. They were made in mountain roads using explosives. Presence of other obstacles like concrete walls with closed off passages or streets covered in felled trees paralyzed movement.

Due to an extended front line and a lack of experienced sappers, anti-tank mines were not tested in large amounts.

In close combat, bottles with a flammable liquid and sulphuric acid were used effectively. Tanks that were hit caught fire and were knocked out."

Militägeschichte. 1976. № 3. S. 332-334.

Sunday, 28 December 2014

Weakest Link

Using a captured tank you like doesn't only grant you its strengths, but also its weaknesses. Re-equipping the vehicle with domestic components is a partial solution, but in some cases, eliminating the weakest link is just not possible.

"To the Chief of GBTU USA, Major General of the Tank Engineering Service, comrade N.N. Alymov
October 5th, 1943
#148902s

If a tank's engine is removed at the regimental repair yard, no matter how good the rest of the tank is, it cannot be restored and leaving it in inventory would be dishonest. As practice shows, it is impossible to find vehicles in which main components are damaged but engines are not, as the engine is the weakest and most easily worn out part of the vehicle.

I ask you to confirm your agreement to write off vehicles from repair base inventory when the engine is removed.

Factory #37 director, Zelikson
Factory #37 chief engineer, Kozyrev"

The letter doesn't straight up say what tank this is, but the date and factory make it obvious. In the summer of 1943, factory #37 was just ramping up production of the SU-76I, an SPG made using captured StuG and PzIII chassis. Seems that German engine problems weren't exclusive to their larger vehicles.

Saturday, 27 December 2014

World of Tanks History Section: Archer

As soon as heavy German tanks hit the battlefield, British military minds thought of new weapons to fight them. In the middle of 1942, the QF-17 17-pounder 76.2 mm high penetration gun entered production. An idea arose to install this gun in a tracked tank destroyer.

British Tachanka

Out of all tanks currently available, only the Valentine could lift enough weight. It was decided to use it as a platform for the new gun, installing it in a casemate with limited traverse. The first modifications of the vehicle used a traditional layout, but the center of mass was shifted due to the long gun, and front wheels were overloaded. The gun was flipped around, spreading the weight out equally. The length of the vehicle was reduced drastically, as the gun only stuck out a little bit over the engine compartment.

A downside of this layout was a difficulty of use: the driver looked in one direction, and every other crew member looked in another. This made maneuvering in battle difficult. Additionally, the fighting compartment became very cramped. As a result, the gun could only traverse slightly in each direction and the vehicle had to turn often.

Another, more critical, downside was that the gun breech was placed above the driver's seat. If he wanted to keep his head, he had to leave his position before the shooting started, or leave the vehicle entirely, as there was not much room inside. It is not difficult to imagine how much this added to the aforementioned problems.

The vehicle was indexed "Self Propelled 17 pdr, Valentine, Mk I", more often known as the Archer.

Happiness of Artillerymen

Production of the vehicle began in the middle of 1943, but it arrived in the army much later, in October of 1944, when the fighting on the Western Front was at its most intense. The vehicle was adopted by artillery units of the British and Canadian armies.

It is unknown what tankers would have thought of such an untraditional vehicle, but the artillerymen were satisfied. It was no wonder: even the uncomfortable Archer provided much greater protection for its crew than the towed 17-pounder they had to use before. It is also known that they often preferred the Archer over the more traditional Achilles, due to the Archer's smaller profile.

The small size and low profile of the vehicle determined the most common tactic for its application: ambushes. The Archer took its position, aimed in at an area, and waited until German tanks approached to a viable combat distance. Then the crew of the Archer would fire a few times with minimal intervals between shots, and retreat to another prepared position. These tactics compensated for the limited traverse angle, and the position of the driver was even an advantage, as the Archer could retreat at maximum speed without wasting time on turning around.

Universal Soldier

The high penetration of the QF-17 bailed Archer crews out of trouble many times. It could successfully penetrate nearly any enemy vehicle at any distance with aimed fire. Not only that, but there is even a recorded event of an Archer firing at a Tiger, but missing their first shot. The Tiger retreated behind a building. The Archer's commander received the location of the enemy from a scout airplane, and fired directly through the building, destroying the Tiger through its side.

Aside from fighting tanks, Archers were used to support infantry, destroying field fortifications, machinegun nests, and other obstacles. Using an HE shell with a reduced muzzle velocity, the Archer could fire from entrenched positions, hiding the weakly armoured hull from harm.

Archers were used in Western Europe and Italy, remaining in the army until the end of the war. After victory, Archers remained in use for some time. It is known that the British Army on the Rhine kept then Archers until the mid-1950s. Some Archers were sold to Egypt, where they fought in local conflicts, including the Suez Crisis in 1956-57.

The rapid evolution of armoured vehicles rendered the 17-pounder quite unexceptional, denying the Archer its trump card, the penetration of the gun. This led to the vehicle's rapid disappearance from the battlefield.

Article author: Aleksandr Grebnev. Aleksandr Grebnev is an editor, translator, columnist, and article author for a number of magazines and websites. He took part in the localization of computer games, specifically military and historical ones. Currently, he is a historical consultant and a member of the Wargaming archive group.

Sources:
  • Chris Henry: "British Anti-Tank Artillery, 1939-45", New Vanguard, Osprey Publishing, 2004
  • Peter Chamberlain, Chris Ellis, "British and American Tanks of the Second World War", (AST, Astrel, 2003)
Original article available here.

Friday, 26 December 2014

Rocket Bike

If you've looked into the Soviet M-72 motorcycle, you would probably know that they put all sorts of stuff on top of it: machineguns, anti-tank cannons, light mortars. Today, you can add rocket launchers to that list.

"Report #6877
On the RUM-12 launcher trials

Objective: discover the feasibility of arming motorcycle troops with 82 mm rocket launchers.

Trials were carried out at the Sofrino artillery proving grounds on September 8th, 1941, following NII-3 #1454s directives signed on September 6th, 1941.

Trial details:

The RUM-12 was designed and assembled by factory #487. The launcher consists of a motorcycle with 12 stock aircraft 840 mm rocket rails mounted instead of the sidecar, equipped with pyropistols.

An aircraft ring sight is installed for aiming, as well as a shield to protect the shooter from gases and a control device to activate the pyropistols.

24 rockets were supplied by NII-3, of which:
  1. 12 were equipped with TNT warheads and AM-a. detonators. The rockets were equipped with BPP 203/50-1/36-K propellant (22 rods per charge) and a 12 gram DRP primer.
  2. 12 were equipped with sulfur warheads. An 18x33 mm TNT charge was inserted, and a stock AM-a detonator was used.
Conditions of trials:

Two groups were fired off to determine groupings.
  1. 12 rockets with fast-burning BPP propellant. The rockets did not have ballistic caps on, and the vanes had additional rods welded to them. The angle of elevation was 3.5 degrees.
  2. 12 rockets with stock nitroglycerin propellant. The rockets used ballistic caps and stock vanes. The angle of elevation was 3.5 degrees.
Results of trials:

Precision of rockets with fast-burning propellant:


Rockets fired
Acceptable shots
Elevation
Mean deviations
Average range
Length (m)
Length (arc)
Width (m)
Width (arc)
Required
Length
Width
12
6*
3.5 degrees
158.1
1/12
35.7
1/52
1/10
1/50
1854

* 6 shots were practice shots. The first tore off two rockets with the exhaust, deformed the vanes on some rockets, and punched through the detonator membrane on one of the rockets. In order to avoid the aforementioned problems, the rest of the shots were made from a partially loaded launcher (3-6 rockets).

Precision of rockets with regular nitroglycerin propellant:

Of 12 shots fired, 6 dipped, falling about 50 meters from the launcher. The other six were significantly scattered width-wise. The dispersion was not measured. No damage to vanes was observed, even thought the rockets were shot from a fully loaded launcher. One shot tore off a pyropistol, likely due to poor assembly at the factory.

During firing from both the first and second groups, the motorcycle was shifted sideways noticeably. The angle of elevation was altered negligibly.

Conclusions:
  1. 82 mm rockets with fast burning BPP propellant can be effectively used by motorcycle forces, given that the AM-a detonator is replaced with another detonator (try using the GMVZ detonator).
  2. Stock 82 mm rockets can also be used, but with reduced effectiveness, due to their tendency to dip when fired from short ground based launchers.
  3. It is necessary to:
    1. Increase the stability of the motorcycle.
    2. Improve the aircraft ring sight. The sight supplied with the launcher could only be used with a quadrant, which had to be installed on the launcher itself, due to a lack of mounting surfaces on the sight."

Thursday, 25 December 2014

Fury

If you've seen the movie "Fury", you may remember a scene where the crew of the immobilized titular tank remains to repel a German assault. Complaints have been made that the scene wasn't particularly realistic, as the crew did not favourably position themselves properly before battle. Here's an award order for someone that handled a similar situation in a much better way.


"Award Order
  1. Name: Skvortsov, Aleksandr Egorovich.
  2. Rank: Guards Senior Lieutenant.
  3. Position and unit: Tank commander, 254th Tank Battalion, 50th Tank Brigade.
    Is recommended for the title of Hero of the Soviet Union.
  4. Year of birth: 1919.
  5. Nationality: Russian.
  6. Party affiliation: VLKSM.
  7. Participation in the Civil War or subsequent combat in defense of the USSR: Participated in the Patriotic War from June 22nd, 1941 to August of 1941, then from January 1st 1943 to February 23rd, 1943.
  8. Wounds or concussions: wounded 3 times.
  9. In RKKA since: 1937.
  10. Commissioned at: Popov RVK, Kursk Oblast.
  11. Prior awards: Order of the Red Star.
  12. Permanent address of the awardee or family: Plobushnya village.
Brief and specific summary of heroism:

In battle against the German occupants, in the region of the Ocheretino village, comrade Skvortsov and his crew demonstrated examples of courage, bravery, and heroism. Comrade Skvortsov's T-34 tank ran for 308 hours of the required 225, but his engine was too worn out to go any further. Comrade Skvortsov was ordered to remain in place and watch for the enemy coming from Andreevka and Mihailovka. Upon the enemy's appearance, repel him with fire. After all ammunition has been expended, take the armament off the tank, destroy it, and escape with the crew.

On February 24th, 1943, the 110th Motorized Infantry Brigade of the 10th Tank Corps was retreating through Ocheretino. In order to cover their retreat, comrade Skvortsov remained in the tank with his gunner, Senior Sergeant Gnusarev. The driver, Starshina Luzin, was placed on top of a house with a submachinegun to watch for enemies, and the radio operator Lovanov was placed in ambush with the task of keeping infantry off the tank. Covering the retreat of the brigade, the heroic crew met the enemy with fire from the tank, submachinegun, and machinegun.

Over the course of an 8 hour long uneven battle, comrade Skvortsov destroyed 8 German tanks from his immobilized tank, 3 of which burned, one AT gun, 3 cars towing carriages and guns, 4 trucks of submachinegunners, and up to two infantry companies. Machinegunner comrade Lobanov destroyed up to 60 enemy infantrymen, driver comrade Luzin killed up to 10 infantrymen, while observing the enemy and correcting tank fire. He pointed out the AT gun firing at the tank to comrade Skvortsov, which was promptly destroyed. After 8 hours, when all ammunition was expended, comrade Skvortsov blew up the tank, took off the machinegun, and led his crew out to safety and reunion with the 10th Tank Corps.

Overall, fighting near Kramatorsk and Ocheretino from February 2nd to February 24th, 1943, comrade Skvortsov destroyed 11 tanks, 2 AT guns, 3 AT rifles, 3 75 mm guns, 3 SPGs, 15 cars, 5 observation points, 1 HQ, and up to 500 enemy infantrymen.

For exemplary completion of a battle objective and display of initiative, bravery, and courage, comrade Skvortsov is worthy of the title of Hero of the Soviet Union.

Commander of the 254th Tank Battalion, Major Berezin"

CAMD RF 33-793756-44

I am going to omit the next page of the award, which is just confirmations of his worthiness of the title from each level of command above him, up to the Award Commission of the People's Commissariat of Defense.

This document also contains a mention of the reliability of the T-34. I already have a record of T-34-85s pulling 250-300 engine-hours in 1945, but no figures from earlier in the war, until today. As you can see, Skvortsov's tank reached 300 engine-hours back in 1943, with an expectation of 225 engine-hours. The jump from 100 expected engine-hours in 1941 seems to have happened fairly quickly, and then remained this way for the rest of the war.

Wednesday, 24 December 2014

World of Tanks History Section: Kitten with Long Claws

The medium member of the German cat family, the Panther, entered service in 1943. The best adjective to describe it would be "controversial". This tank was complicated, expensive, and picky in use, especially during its early production. However, anyone that went up against a Panther in battle would not have described it as an easy opponent. This is why improvements to the Panther were being made until 1945 and the complete collapse of German economy.

Initially, the Panther's gun was a high velocity 7.5 cm piece, which confidently penetrated Allied vehicles at ranges of 2000 meters. In early 1945, Colonel Holtzhauer from the department of armoured vehicles and motorization reported that Daimler-Benz developed a Panther variant armed with the 8.8 cm KwK 43 gun, the same gun as on the King Tiger, one of the most menacing guns of WWII.

Narrow Turret for a Big Caliber

In 1945, Germany planned to begin production of a new Panther variant, Ausf. F. For this version, Daimler-Benz engineers designed a new turret, the Schmalturm (narrow turret) that had a number of advantages: it was cheaper to make, better armoured, and had a smaller front plate. The gun mantlet took the shape of a truncated cone, which reduced the chances of ricochet into the thin roof, improving the safety of the driver.

Despite having 120 mm of front armour, the narrow turret was 100 kg lighter than its predecessor. The decreased dimensions did not make the insides much more cramped. The new design was technologically simpler, as it took about 30-40% less time to make it.

The project mounting an 8.8 cm gun in the Panther used this new turret, slightly modified. Even with this massive weapon, the vehicle was only a ton heavier than a regular Panther. Engineers had to widen the turret ring to let the crew handle long and heavy shells in the fighting compartment.

Aside from Daimler-Benz, another industry giant was working on installing an 8.8 cm gun in the Panther: Krupp. After comparing the two projects, the department of armoured vehicles and motorization determined that Daimler-Benz should complete their turret and Krupp should work on the cannon.

What Was Finished

1945 was agony for the Third Reich. Common sense would suggest that there would be no way to begin production of new types of tanks. German industry, shaken by Allied bombings and working on a starvation diet could barely manage with vehicles that were already in production.

There was no chance that the Panther with an 8.8 cm gun could have seen combat. So many changes were needed that the turret remained a wooden mockup until May of 1945. In August of 1945, it was found in a Daimler-Benz assembly plant.

The Panther with a larger gun was left buried in the ruins of the Third Reich. It was hard to say what effect it would have had in battle if it was produced, for example, in late 1944. One thing can be said for certain: it would not have helped Germany win the war.

Original article available here.

Tuesday, 23 December 2014

Artillery Targets

The accuracy of tank guns has been a widely discussed topic of this blog, but the targets of these tests remain behind the scenes. Here is how they were set up.


A Soviet long distance 4 meter by 4 meter target, made of many wooden planks. 


An American target, made from cloth and a wooden frame. It is much lighter than the Soviet one, as it is meant to move around for training exercises.

And now, a more modern one. Livejournal user deletant discovered it on an abandoned proving grounds in Russia.


This device moves back and forth over a rail of BMP tracks using an electric motor, and was likely used to carry a target back and forth. Click the link above to see many more photos of the proving grounds, including abandoned ISU-152s used as stationary targets.

Monday, 22 December 2014

World of Tanks History Section: WZ-111

After WWII, China's tank fleet consisted of a diverse collection of worn-out vehicles that could only be called an armoured force with some difficulty. The country had no domestic tank production at all. However, it had excellent relations with the Soviet Union. The brotherly socialist cry for help was heard, and massive shipments of Soviet vehicles for the People's Liberation Army began. T-34-85s, SU-100s, IS-2s and APCs began their service under Chinese flags.

Independent Development

In parallel, China was developing its own heavy tanks. The WZ-111 began development in 1957, as a replacement for the IS-2. Soviet industry greatly influenced its design. The vehicle, first indexed 111 and then WZ-111 after passing trials, was obviously designed with the IS-3 as an inspiration. The front-mounted bowl turret, piked front armour, sloped sides, all taking after its "older brother".

Several guns were considered for the vehicle: 130 mm M46, 122 mm D-25TA, 100 mm D-10T. It is difficult to establish which gun was ultimately selected, as there is little available information on this project.

The tank never reached mass production. Only one hull was built. Work on the turret was not finished before the project was closed. It is likely that the tank entered trials with only a dummy weight in place of the turret. Currently, the WZ-111 hull in the People's Liberation Army Museum is topped with a thin sheet metal structure, designed to prevent snow or rain from getting inside.

Victim of circumstance

Why did this tank not reach production? There were several reasons. One was that the development of a heavy tank is one of the most difficult tasks for engineers, and Chinese science and industry was not as developed as it is today. Heavy tanks are expensive to built and difficult to maintain. Chinese military minds could not ignore the fact that foreign militaries build limited amounts of heavy tanks, and the development of new ones all but ceased. Additionally, even the limited amount of information on this project reveals that it suffered from design flaws.

Another explanation for the unfortunate fate of this design was the purchase of several T-54s from the Soviet Union, along with a production license. The T-54 was a mass produced, mature design which did not need extensive trials, and Soviet engineers were available to help with ramping up production.

One way or the other, the WZ-111 remained on paper along with other domestic designs.

Original article available here.

Sunday, 21 December 2014

IS-3 Reloads

If you've read my article on the history of the IS-2 and IS-3 tanks (and you probably should), you may remember a mention that the IS-2 can fire at a rate of 4-6 RPM. Some people have questioned this statement. How can a tank using such huge shells fire that quickly? If it could fire so fast, why could the IS-3 and IS-4 not do the same? The answer, as always, is standards.

I've written about rate of fire tests previously, in an article on the KV-9 and an article on the KV-100. Both reveal a critical component of Soviet testing. The KV-9 can fire as fast as every 12 seconds, but the rate of fire recorded in the test was only 2 RPM! The KV-100 test, which is invalidated due to all shells being loaded from the turret bustle, hints at the reason for this. The rate of fire recorded by the Soviet standard is using all ammunition racks, even the most inconvenient ones. This is illustrated well in Yuri Pasholok's book SU-152 and other SPGs on the KV tank chassis. Google around for the rate of fire of a SU-152, and you might find numbers ranging from 1.5 to 2 RPM. However, during trials, loading a shell from the most convenient rack took as little as 16 seconds (p. 132) and firing off the 10 most conveniently placed shells (half of the vehicle's ammunition) could be done with rate of fire of 2.8 RPM (p. 133). The rest of the rounds would take longer to load, but there were few instances where it would be necessary to empty the entire ammunition rack in one go. The loader would refill the ready racks when the fighting died down a little, and would be able to fire quickly once more in a few minutes.

Hopefully, that explained the "how can an IS-2 fire so fast" question. Now, for the next question. Why couldn't the IS-3 match the rate of fire of its predecessor? The short answer is "sure it could". The Domestic Armoured Vehicles series of articles from the Tekhnika i Vooruzheniye issue #11 for 2012 describes the rate of fire testing on an IS-3.

"...from June 20th to July 12th, 1951, trials were held, the results of which showed that the average aimed rate of fire with a trained loader could reach 3.6 RPM (the technical requirement was 2-3 RPM). The average cycle lasted 16.5 seconds and consisted of removing a shell from the brass catcher (2.9 seconds), loading a round (9.5 seconds), correcting the aim and firing (3.1 seconds) and the recoil brake returning the gun to the firing position (1 second).
...
The trials evaluated the possible approaches to ammunition racks of the gun and tested methods for loading it. The most accessible were the 17-shell rack around the turret ring, positioned towards the loader next to the fan, and the five-round rack located on a frame attached to the central contact device, as they allowed for the gun to be loaded in any position."

1. An HE shell is taken from the 17-round turret rack.

2. Another HE shell is taken from the 17-shell turret rack.

3. Propellant is taken from the 5-round rack.

4. The sixth HE shell is taken from the 17-shell rack.

5. Propellant is retrieved from an ammunition rack next to the engine compartment bulkhead.

The test and photos reveal a lot about the details of the test. For instance, we can see that loading the gun takes only 9.5 seconds, the rest, aside from the gun's return to its initial position, can be skipped if you're testing maximum rate of fire, instead of maximum aimed rate of fire. Just dumping shells downrange and worrying about the brass later can already obtain a rate of fire of 6 RPM. However, the 9.5 second figure is the average figure, for all racks. As you can see in the photo, bending down to get a 122 mm shell from the bottom of the fighting compartment can be really inconvenient. Meanwhile, the loader doesn't have far to reach in order to get to his closest ammunition. The book doesn't say how much faster loading from the turret as opposed to the hull is, but with ammunition this heavy, it has to be noticeable. It should be pretty clear that even with aiming, the IS-3 can fire much more quickly than the rate it was required to achieve according to its technical project.

Edit: Here's a little tidbit that I found, Mikhail Svirin himself writes: "The practical rate of fire [of the IS-2] in place was up to 5 RPM, on average 2.5 RPM, 1.5 RPM in motion."

Saturday, 20 December 2014

Modern Soviet Tank Ergonomics

The Armoured Journal yields another article of interest, this time on human factors of tanks by M.N. Tikhonov and I.D. Kudrin: Human Factors and Scientific Progress in Tank Building, submitted on May 18th, 1991. The article mostly contains very general thoughts on things that are rather obvious to us now (ability to fight in irradiated environments, tanks that are able to drive for longer without stopping being more tiring for their crews, etc), but there is a table of something we've seen before, a table of ergonomic factors of some tanks!

Table 2. Volume occupied by one crewman in a tank, meters cubed.

Only the volumes are given this time for various tanks (commander, gunner, driver, loader, who is of course absent in the T-64 and T-72). It's not as detailed as what we've seen before, but at least we can compare these four tanks.

Comparing the heavy and medium contemporaries, the heavy T-10 and medium T-55, one might expect the heavy tank to be roomier, but no such luck here. The volumes for each crewman are comparable. The commander in the T-10 has a slightly more luxurious workspace, but its gunner is slightly more cramped. The driver of the T-10 also has a slight edge over his medium comrade, but the loader in the T-55 lives a life of royalty, as he has nearly twice as much space to work with as the T-10 loader. 

Moving on to the next generation, the changing of priorities is noticeable. The article talks about how increasing penetration of modern ammunition tipped the scales away from armour. The most effective defense, now more than ever, was "don't get hit", and Soviet tanks became shorter and stouter to avoid this fate. However, the loss of one crewman meant that the change didn't impact the crew too negatively. For instance, the commander's workspace decreased to the levels of a driver of the old generation tanks, but the gunner's workspace actually grew in side by a significant amount. There was also much more room for the driver.

As for the two modern tanks, they aren't too different. The "budget" T-72 is a little smaller across the board than the T-64. The commander barely loses any space at all, but the gunner and driver both suffer significantly more. Still, they are doing much better than their T-55 counterparts.

Thursday, 18 December 2014

Kummerdorf and Ardelt

The close relationship between British and Soviet technicalbranches outlived the war. For instance, the British were allowed to investigate the Kummersdorf proving grounds, which were in the Soviet occupation zone. 


SVAG Archive

"Report on the technical research executed by English command to investigate German armament in the Soviet zone.

1. Kummersdorf proving grounds.

The Kummersdorf artillery proving grounds was built in 1873, and is the oldest proving grounds in Germany. The proving grounds is a scientific research organization tasked with studying new cannons, small arms, and gunpowders.

Since 1937, Kummersdorf tested small arms, small caliber cannons, and gunpowders. Testing of larger caliber artillery was moved to the main German proving grounds, Hillersleben (near Magdeburg).

The proving grounds consists of about 250 buildings, including laboratories, workshops, warehouses, etc.

Presently, all equipment from the proving grounds has been removed by GAU KA and prepared for shipment to the Leningrad Artillery Proving Grounds and Moscow small arms proving grounds. The following remains on the territory of the proving grounds:
  1. Artillery that is of no interest or value: 150 units.
  2. Ammunition: 40 train cars.
  3. All structures, including 65 reinforced concrete pillboxes.
2. Kummersdorf tank proving grounds

The tank proving grounds is a scientific research organization tasked with studying tanks. Presently, the equipment from the proving grounds has been removed by the Red Army armour directorate.

3. The new Mauschen (German name) or Maus (English name) tank

In 1944-45, the German Mauschen tank was tested at the tank proving grounds. Only two were built. 

Brief information:
  • Length: 8.5 meters
  • Width: 3.5 meters
  • Track width: 1.0 meters
  • Front hull armour: 210 mm
  • Front turret armour: 300 mm
  • Side hull armour: 150 mm

Mass: 180 tons. Engineer Mani claims that the actual weight is only 120 tons.

Armament: two guns, 128 and 75 mm.

One tank was destroyed by the Germans at Stammlager, the other remained at the proving grounds, where it was also disabled.

Presently, the Red Army armour directorate has built one tank out of the two broken ones and has shipped it to Moscow for study (loaded to ship from the Kummersdorf station on August 15th, 1945)

4. No one who directed these trials remained at the proving grounds, and it is not known where they can be found.

According to locals, the chief of the department of tank and engine testing, Colonel Esser, surrendered to the Americans.

5. Ardelt factory and new "Leichter Waffentrager" vehicle

The factory was owned by four Ardelt brothers, who, according to engineer Renke Wilhem, are presently on Allied occupied territory. Presently, the factory is being dismantled by the Commissariats of Shipbuilding, Heavy Machinebuilding, and Armament.

Before the Second World War, the factory made cranes. During the war, it had a torpedo launcher plant, two munitions plants, and opened a plant to build light tracked SPGs with 360 degree turrets and 88 mm guns in the end of 1944. They were designed to fight enemy tanks. This SPG was called "Leichter Waffentrager".

Ardelt had to choose a design from two Leichter Waffentrager proposals (Krupp and Ardelt), and produce the best one (both designs are attached). According to the assembly foreman, the factory was building Ardelt SPGs.

Only 4 Leichter Waffentragers were built, one was destroyed by the Germans, and three were sent to fight against the Red Army.

All blueprints of the Leichter Waffentrager were collected by a representative of the People's Commissariat of Armament, Major Sudakov, and sent to the Commissariat. According to a representative of the People's Commissariat of Shipbuilding, Colonel Ishenko, a full set of Leichter Waffentrager components was given to Major-General Zernov, a representative of GOKO.

Presently, the Ardelt factory has 6 Leichter Waffentrager hulls, one 88 mm gun, and 6 engines. Some data can be obtained by external inspection:
  • Length: 5.5 meters
  • Width: 2.8 meters
  • Armour thickness: approximately 10 mm
  • Armament: 88 mm gun with 360 degree range
  • Engine: gasoline, 6 cylinder
Conclusions:
  1. Equipment from the Kummersdorf proving grounds has been removed, and is being shipped to the USSR.
  2. The Mauschen tank is being sent to Moscow, to the Red Army armoured directorate.
  3. The Leichter Waffentrager is an SPG with a small size, weak armour, and weak, relative to the armament, engine. It is of little interest to the Red Army."

Wednesday, 17 December 2014

American Tanks in the Korean War

I haven't come across any definitive report of on any tank in Korea, but pulling bits and pieces from various reports is enough to obtain some impression of how American armour performed.


The Sherman's deficiency in off-road conditions is no big secret, having been explored in the famous Swedish video


The inadequate HE shell of the 76 mm Sherman previously popped up in WWII era reports. When the only alternative was the 75 mm gun and tough enemy armour was plentiful, this was a drawback that could be begrudgingly accepted. However, in situations where enemy tanks were rare and powerful 90 mm guns were more common, it's hard not to be jealous. 

Speaking of anti-infantry weapons, bigger explosives weren't the only things that were needed.


The anti-tank capability of the Sherman is considered adequate.


While a 45 or a 76 mm gun would find the front armour of a Sherman a difficult target, the statement about the T-34-85 doesn't stand up during the famous Yugoslavian trials. When tested, the tanks appeared roughly matched, with the Sherman penetrating the T-34-85 from 900-1100 meters with armour piercing rounds, and the T-34-85 penetrating the Sherman from 1000-1100 meters. The tests also showed that the ZiS-3 could indeed penetrate the front of a Sherman, but only at a very close range (250 meters).

While the Sherman gets praise, the heavier tanks, not so much.




Yikes, 60% is not a good number. The phrasing of the evaluation of American tanks vs. the T-34-85 is interesting, as though the writer of the report had significantly more respect for the tanks he was fighting than the people in them, an opinion which appears in other reports as well.

Sliding Breech for the D-25

Today, it is well known that the screw breech the D-25 inherited from the A-19 restricted the maximum rate of fire. This was also already known in 1943, when the IS-2 was still undergoing trials, and work on improvements began before the tank even hit the battlefield.

"I report on the condition of development of a sliding breech for the D-25 and D-2.

A meeting was held to discuss this issue on November 22nd, 1943, with the following attendees:
  1. Factory #9 director, comrade L.R. Gonor.
  2. Chief engineer of factory #9, comrade D.A. Rykkov.
  3. Deputy chief engineer, comrade A.N. Bulashev.
  4. Chief of the experimental design bureau, N.G. Kostryulin.
  5. Deputy chief technologist, comrade D.B. Kerner.
  6. From the NKV: Chief of the Experimental Designs Department, Major-General of the Artillery Engineering Branch, comrade A.A. Tolochkov.
  7. From the Artillery Committee of the GAU: Engineer-Lieutenant-Colonel comrade P.F. Solomonov.
  8. From UPVNA GAU: regional GAU engineer for factory #9, Engineer-Colonel, comrade A.N. Abramov.
This meeting discussed two types of sliding breech: vertical-falling and horizontal. A horizontal sliding breech was decided upon for the experimental prototype, opening to the left. 

Currently, corrections are being made to the working blueprints. They will be sent to the plant today. All other blueprints for a horizontal sliding breech will be finished and submitted by November 28th of this year.

The breech design is compatible with the D-2 without any modifications (the D-2 will only achieve quarter-automatic operation).

Regional engineer for factory #9, Engineer-Colonel Abramov"

Monday, 15 December 2014

Tank Camouflage and Concealment Rules

The rules for how to camouflage your tank are a pretty frequently visited topic, but this article by Engineer-Colonel D. Sheglov and Engineer P. Yakovlev definitely mentions a few things we have not yet seen, and puts a new twist on some old tricks.

"In battle with tanks or any other kind of forces, surprise is one of the main factors of success. It takes significant effort and skill in the art of concealment order to achieve surprise when the enemy is carefully attempting to deduce our aims through constant observation.

Every commander and soldier must keep in mind the stealth of his actions and correctly use already known means and techniques, as well as discover new ones.

Tanks can be found in many ways: due to light revealing their shadow or shining off their unpainted parts, due to track marks in soft terrain or bushes, due to broken or bent vegetation, due to fresh or tramped ground where the tanks turned or stopped. At night, their lights can be seen, their engines and tracks can be heard. The task of concealment is to hide these traits, or at least reduce their magnitude.

Concealment is split into natural and artificial. Natural concealment is achieved by hiding with natural means, trees, bushes, etc. One measure of natural concealment is keeping tanks in the forest, in the shadows of trees. When placing a tank underneath a tree, it is important to check that the shadow of the tank is covered by the shadow of the tree, otherwise an observer in an airplane can still see it (fig. 1).

Fig. 1. Incorrectly (left) and correctly (right)

Artificial concealment covers techniques of hiding a tank or an armoured car, consisting most importantly of camouflage paint and camouflage netting. It is important to know how to conceal tanks with any means that the unit has, since regularly issued materials might not be available in some cases, such as during an offensive. Improvised materials can always ensure that tanks are hidden, but remember that not all materials can be used in all terrain. For instance, covering your tank with tree branches when it is on a background of freshly dug dirt does not conceal the tank, but gives away its position. Similarly, a tank covered with straw on a grassy field will hide your tank, but a tank covered in straw on a ploughed field will only arouse suspicion. 

The so called T-net is a staple of camouflage. It is a 10 by 10 meter net that has square pieces of green fabric sewn to it, frequently in the middle, and less frequently around the edges (fig. 2).


The T-net is placed atop the tank and spread out with ropes. In order to make the shape irregular, you can use wooden stakes of various heights in two-three places underneath the net. In addition to the fabric squares, scatter branches and grass over the net.

In order to make the tanks less visible on terrain and to aid other concealment methods, use three kinds of paint: green, grayish-yellow, and dark brown in a disruptive pattern. At the factory, oil paint is used. In the field, painting is done with dry chalk.

When applying disruptive camouflage in the field, follow the following rules:
  1. Paint should be applied to all parts of the tank except the tracks.
  2. The main colour of the tank should be green, 50-60% of the surface. After that is yellow, 25-30%. Then dark brown, 15-20%.
  3. Paint spots should be variable in size and shape (fig. 3).

Temporary disruptive camouflage can be applied with dry coloured chalk. This chalk is made at the factory, and is meant to rapidly colour vehicles, equipment, and other materials.

When these regulation paints are missing, improvised paint can be used. Since they are made with water, they do not prevent the tank from rusting, so they may only be applied on top of painted metal.

The following materials can be used to make paint:
  • Dark brown paint: use crushed wood coals in combination with crushed brick. Dilute the powder with glue or casein. It is also possible to use natural or artificial varnish. This paint can also be made from filtered soil combined with varnish.
  • Earth gray: use filtered road dust or clay, diluted with water and glue. 
  • Green: use various plants (leaves, grass) burned with boiling water, then dried and crushed. Cover the tank with glue, varnish, tar, or bitumen, and sprinkle the powder where necessary. The best plants for this purpose are nettle, fern, and clover.
Disruptive camouflage can alter the tank's shape and reduce visibility on multicoloured terrain. There will be instances where the terrain is monochrome, and a single colour on your tank is preferable. In this case, paint all tanks in the colour of the background.

In open terrain, use T-nets, covering the net with improvised material. If no net is available, position the tanks according to terrain. For instance, on ploughed land, place the tanks parallel to the furrows. This method will make the tank less visible by changing the shape of its shadow, as it will fall on the dark and light parts of the furrow.

If the landscape is irregular and has many features, place the tanks in their shadows to hide them. Make sure the shadow of the tank does not peek out of the shadow of the terrain.

Try to move in unfavourable conditions for enemy aircraft: fog, low cloud cover, rain, night. When movement during the day is necessary, use the terrain to your advantage. The commander of the tank unit and his crews must examine the map or the terrain itself and determine the most covered routes: forests, bushes, ravines. On open terrain, the movement must be done in short marches from cover to cover one echelon at a time.

During movement, it is necessary to confuse the enemy. For instance, each tank group should travel on a different road. These methods should be used on open terrain, when the possibility of discovery is at its highest.

A good way to confuse the enemy is to leave an imitation of a base in an area that you have already left. In order to do this, use half-covered tank models, half-models, and flat cutouts (fig. 4).


When leaving your base, imitate movement in false directions. For this, one or two tanks should make a trail leading to a concealed area close by, and a fake tank should be left in this direction, pretending to have broken down or fallen behind. For added realism, put it by the side of the road in some light concealment, to imitate repairs. 

When moving on the open road in daylight, drive on the side of the road with shade, and cover the headlights with covers, paper, or rags so that they do not shine. 

When choosing a place to stop, pick an area in the forest or in bushes near the edge of a ravine. Burned villages are also very good places to stop. Put your tanks underneath trees near walls of buildings that are still standing or hide them among structures. Choose a location with the aim that the approach to it is covered and it can be driven to from the main road in places with trees or bushes. Hide your track marks.

Practice discipline, do not move or walk about unnecessarily. Never bunch up your tanks or place them in rows, as this will make your stop more noticeable. Good techniques still do not guarantee that your maneuver will remain a secret. Even the best hidden tank can be given away by its uncamouflaged tracks or movement of soldiers or groups, and cancels out good camouflage techniques and puts your unit at risk of enemy attack.

In practice, there were many cases where the enemy discovered our tanks only due to an ignorance of basic rules of concealment. For instance, one tank unit on an extended march remained hidden due to using concealment techniques, but one tank that was parked in sparse bushes without any additional means of concealment gave away the location of the unit, and it was attacked by bombers. It is necessary to remember that any violation, even a seemingly insignificant one, of camouflage rules will result in undesirable consequences."

Sunday, 14 December 2014

Super-heavy Tanks in Combat

Things like "heavy" are quite relative when talking about tanks. For instance, the Germans considered their 20-ton PzIV a heavy tank because of its gun caliber, and this classification of enemy tanks migrated into Soviet reports. Of course, when the Tiger hit the battlefield, there was some nomenclature confusion.


"The 2nd tank battalion and their motorized infantry dealt the following damage to the enemy while in his rear: destroyed two tanks (1 super heavy and one medium), 1 SPG, 4 AT guns, 8 dugouts and pillboxes, up to a battalion of soldiers and officers, and captured two."

Yuri Pasholok attributes this report to the 122nd Tank Brigade, dated March 30th, 1943. This places them at the Mga river, where s.Pz.Abt 502 was fighting at the time. As it was still partially equipped with PzIIIs, it's quite likely that the battalion could encounter a "super heavy and medium tank" together.

Stranger than Fiction

Back in the day, while playing Red Orchestra, a lot of people were complaining about a very normal looking event: tankers that ran around without vehicles to supplement their team's infantry numbers. Apparently there was enough complaining to leave tankers "anchored" to their vehicles in the sequel. Sadly, this was all too historically accurate. Kris Reid has an excerpt of an all too common situation from reports.


"...I was told that vehicles will not be sent to us within two months. Nevertheless, the Military Councils of the Army and Front do not wish to release the brigade from the Front, hoping to re-form it within the Front.

However, the brigade has already been inactive as a tank unit for a month and a half, and has been used, as I show below, as a spare unit for forming other units, or as infantry, carrying out orders in the front of the 4th Army."

Friday, 12 December 2014

Red Army Tank Armament Norms, 1934

Following up tank plans from 1931 and 1932, here are some plans for 1934. As opposed to the previous ones, these are only specifications for guns mounted on future tanks.


"I report to the 1st Department of the GAU NTU the list of armament necessary for mounting in tanks, armored cars, armoured rail cars, and APCs according to the "second five year plan tank armament systems":
  1. Reconnaissance tank: 1 machinegun.
  2. General purpose tank:
    1. 1 45 mm gun and 1 machinegun
    2. 2 machineguns and 1 flamethrower
    3. 1 76 mm gun and 1 machinegun
      All three types of tank will be produced
  3. Operational tank:
    1. 1 45 mm gun and 3 machineguns
    2. 1 76 mm gun and 3 machineguns
      Both types will be produced
  4. High Command Tank Reserve quality reinforcement tank:
    1. 1 76 mm gun and 3 machineguns
  5. Special purpose high power tank:
    1. 1 76 mm gun, 2 45 mm guns, 5 machineguns
    2. 1 152 mm gun, 1 45 mm gun, 6 machineguns
  6. Special tanks:
    1. Front line chemical tank: 1 machinegun
    2. General purpose chemical tank: 1 machinegun
    3. Operational chemical tank: 1 machinegun
    4. Sapper tank on the T-26 chassis: 1 machinegun
    5. Large sapper tank: 2 machineguns
    6. Commander tank:
      1. T-26 chassis: 1 machinegun
      2. T-28 chassis: 2 machineguns
  7. SPGs:
    1. Small triplex
    2. 76 mm AA gun
    3. 152 mm "K" howitzer
      All on the T-26 chassis
  8. Armoured cars:
    1. Reconnaissance: 1 machinegun
    2. Combat: 2 45 mm gus, 2 machineguns
  9. Armoured rail cars:
    1.  Motorized armoured wagon: 2 76 mm guns, 6 machineguns
      1. Armoured draisine: 1 machinegun
The current tank armament system also allows for a "T-34" tank, armed with a pair of ShKAS or ShVAK guns, with the option of the latter receiving a 20 mm barrel. The armament program foresees the gradual replacement of DT-29 machineguns with ShKAS machineguns as production ramps up. 

This list does not include teletank armament, as that is included in the armament program of the Communications Directorate.

UMM 3rd Directorate Chief, Lebedev"

Thursday, 11 December 2014

Rocket Gun

Opinions that Soviet man-portable rockets were just a ripoff of the Panzerfaust because of no precursors are widespread, but there desire for such a weapon long predates it.

"To the State Committee of Defense, department of Military Inventions

From Engineer M.L. Mill
Bilimbay, Sverdlovsk oblast
P.O. Box #7

Proposal

I propose that the front use an anti-tank rifle that fires RS-82 rockets.

My proposal can be operated by a single soldier, lying behind the weapon. The exhaust gases are redirected with a special device.

The weapon can be produced in a light (tripod) and heavy (wheeled mount) configuration, and weighs 14 and 20 kilograms respectively. The weapon can fire accurately at the same ranges at which an anti-tank rifle is effective (150-200 meters).

A rocket with the same weight as the RS-82 that I have developed penetrates heavy armour at this distance.

It is important to note that the weapon can be produced quickly and easily in the Urals, as RS-82 and guide rail production has already started, and the production of mounts can begin rapidly.

This weapon can be applied against tank or against pillboxes to support infantry. Due to its light weight, it can be installed on light vessels and motorboats, firing at a range of up to 1000-1500 meters against concentrations of infantry, especially in mountain regions where transporting artillery is difficult.

As of the creation of this proposal, 3 weapons have been made by the author and comrade S.V. Pakhin and tested with live rounds, indicating that improvements need to be made, which we are in the progress of doing."

RGANTD 344-1-171,173

Of course, there are pictures, but only of the heavier wheeled version.


Not exactly RPG-like, but who knows that it could have become after a few iterations of design changes, if not for a rather unfortunate weakness.

"Conclusions on the proposal of Engineer M.L. Mill titled "anti-tank rifle that fires RS-82 rockets"

The idea of devices that fire RS-82 rockets at tanks and pillboxes is not new. Similar proposals have been made in the past. Some of them have been built, but were deemed ineffective.

The problem is that the RS-82 has such a significant spread that shooting them at tanks or pillboxes is senseless.

At a range of 200 meters, the horizontal mean deviation is 3 meters and the vertical mean deviation is greater still. At a vertical mean deviation of 4 meters, the odds of hitting a 3 meter by 2 meter target are 3.4%, meaning that out of 100 shots less than 4 will hit.

Because of this, comrade Mill's device is not useful.

Chief of the 2nd Department of the GUVGMCh CVGK, Engineer-Colonel Semenov
Senior assistant of the 2nd Department Chief, Engineer-Major Shor"

While the 3.4% figure is likely for that ambitious 1000-1500 meter range, 3*4 meters at 200 meters is still pretty significant. Interestingly enough, when Panzerfausts were examined by Soviet forces, the conclusion was similar: "With a maximum range of 60-100 meters, the Panzerfaust is not, and cannot be, a serious or effective anti-tank weapon." (CAMD RF 299-3067-91)

Wednesday, 10 December 2014

Case for T-34 Torsion Bars

"To the Chair of the Committee of Defense at the Council of Commissars of the USSR, Marshal of the Soviet Union, comrade Voroshilov

Fulfilling the decree of the Committee of Defense #428 from November 19th, 1940, I present my thoughts on the transition to torsion bars on the T-34.

The springs (candle) on the T-34 are reliable, but have the following drawbacks:
  1. The suspension shakes, which reduces the accuracy of fire on the move.
  2. The wells in which the springs are housed reduce the space inside the tank, which impedes the placement of components and reduces the ammunition capacity.
  3. In order to allow for movement of the vertical balancers, the side plates have cuts in them, which reduces the robustness of armour.
The torsion bars, by preliminary calculations, give:
  1. A 20% increase in the volume of the fighting compartment.
  2. A reduction of the suspension weight by 300-400 kg.
  3. Increase in fuel capacity from 465 L to 750 L, increasing the range by 60-100 km.
  4. The hull robustness is increased (due to a lack of cuts).
  5. The reliability of torsion bars has been proven on the KV and T-40.
  6. Factory #183 has the means to make torsion bars.
According to decree #848 issued on March 31, 1940, the width of the T-34 turret has been increased by 160 mm, and further increase without increasing the size of the turret ring does not increase the accuracy of firing.

In order to improve the combat performance of the T-34, I ask that NKSM (factory #183) produces two experimental T-34s with torsion bars, a wider turret ring, a commander's cupola, and increased speed.

I ask that you approve the project.

Marshal of the Soviet Union, G. Kulik.
January 17th, 1941"

Tuesday, 9 December 2014

Museum at a Repair Base

As tank units receive reinforcements, they tend to get rid of incompatible vehicles when possible. Early on in the war, tank units seldom had the luxury to send off their junk, and often became very heterogeneous. In 1944, however, the situation was a little better, and all the notable outliers have been shuffled off to repair bases in the rear. Let's take a look at one, repair station #66 in Tbilisi.

CAMD RF 38-11355-2268

The columns are as follows. To the left of the page break is the data for the month, The first column is items remaining since from the previous month, the second is items scheduled for shipment, and the third is items actually shipped. Both are blank, so that's good. Naturally, the 4th column, items currently present, is equal to the first. The next two columns are vehicles that completed repairs and vehicles that have been QA'd and approved by the army representative. The column after that, which is partially cut off, shows the amount of vehicles that were shipped out. 

The next group of columns is the same thing, but for the previous 12 months. An extra column is tacked on to that, percent completion (although the numbers from it don't look to be percentages). 

The next block of columns lists the vehicles left at the base for the next month: total, currently undergoing repairs, waiting for repairs, and those waiting for shipment. A note to the side reads "of 58 vehicles present at the repair base, 37 cannot be repaired until the delivery of main components such as measurement devices, optics, etc"

Now that we're done with the columns, let's look at the vehicles. T-34s are to be expected, but a whopping 10 T-50s are present here! One has already been sent off earlier this year, but all 10 remain for the next month. It's likely they cannot be repaired due to a lack of parts, as the T-50 has not been in production for quite some time now.

Next we have the finely aged pre-war amphibians, one T-37 and five T-38s at the beginning of the month, with just as many left over at the end. It's likely that they are in the same position as the T-50s, but their numbers for the year are more promising: 4 and 8 received, respectively, so at least some got fixed up.

Next, some BT-5s and BT-7s. There aren't any BT-2s here, even though they pop up a bit from time to time on the front lines. After that, a single T-26T (T-26 tractor) passed through here during the previous year, two BA-64 armoured cars, one SU-76. 

Then we have a full array of Lend Lease vehicles: American (15 Lees, a Sherman, 24 Stuarts, 1 tractor) and British (62 Churchills, a Matilda, 34 "MK-1 tractors", and 6 of something called MK-7 which might be Tetrarchs). 

After this, we get to captured tanks, and there is a good number of those: 10 PzIVs, 61 PzIIIs, 8 StuGs, 18 PzIIs, 35 Renault tractors, 8 Hanomag halftracks, 9 SPGs (with 50, 75, 76, and 150 mm guns),  12 various tanks, and 10 various tractors and APCs, and 7 various armoured cars.