Saturday, 28 February 2015

Two Years of Blogging

Another year gone by, and what a year! My total page views have grown from 387,261 to 879,901, or by nearly 500,000 this year (an average of 1349 views per day this year), with 700 published articles (or 341 this year). The demographics remain roughly the same: US at first place and Germany in second. The United Kingdom moved up from fourth place to third, pushing down Poland. Canada remains in fifth place. A newcomer, France, took sixth place, with Finland, Australia, and Russia shifting down. The Netherlands remain in tenth place, while Korea that used to be in ninth dropped off the charts.

World of Tanks related resources remain my main source of traffic, with Company of Heroes falling in relevance, overtaken by War Thunder as my second biggest fans. Military history enthusiasts from Russian and English language communities continue to be a source of traffic as well. In addition to guest articles on FTR, I wrote an article for a more generalist gaming website The Mittani, and will be writing more in the future. I also gave an interview to Tank and AFV News, which is a website I heartily recommend to all fans of modern or historical armour.

In addition to non-interactive content, I added a penetration calculator utility, which is sure to come in handy.

Here's to another wonderful year!

DT Modernization, 1942

"Variant #1 of the DTM modernized V.A. Degtyaryev tank machinegun

Brief description
  1. Variant #1 of the modernized DT machinegun involves design changes to the gas system, which allows simplification of the ball mount. The goal of this modernization is to protect the machinegun gas system from bullets and shrapnel with minimum modifications to the mount.
  2. The following parts were changed as a result of the modernization:
    1. The gas tube was moved closer to the breech, and is now covered entirely by the ball mount.
    2. The frame bar and plunger were replaced with one lengthened plunger, attached directly to the frame.
    3. The cap of the ball mount was removed.
  3. In other ways, the design is identical to the nonmodernized DT tank machinegun."

Friday, 27 February 2015

German Tank Reliability

I already looked at Soviet and Lend-Lease tanks, so let's take a look at what was happening on the other side of the front lines. ORO's "Survey of Allied Tank Casualties in World War II" attempts to shine some light on the issue.


Well that's not very helpful. Let's see what Guiderian has to say about this.


Yikes, that's twice as much as even the worst Soviet figures. Some more information, still fairly vague, can be extracted from the document.


50% losses from breakdowns is a pretty bad figure, but it's hard to expect anything else considering the Panther's short lived components. Robert Forczyk has some unkind words dedicated to the Panther's reliability in his book Panther vs. T-34 Ukraine 1943: "...5th Guards Tank Army was able to move its T-34s 300 km on their own tanks to the front between July 7-9 and still had about 90 percent of its tanks operational. No Panther unit could ever have moved this distance without losing most of its tanks to mechanical breakdown.
...
Although the Panther's AK 7-200 transmission was nominally superior to the clumsy transmission on the T-34, about 5 percent broke down within 100 km and 90 percent within 1,500 km in combat."

Thursday, 26 February 2015

World of Tanks History Section: In the Service of the White Guards

At the end of WWI, the former Russian Empire was engulfed in another war, a civil war. It differed in degradation of tactics and a decrease in the technical level of forces involved. There were, however, exceptions. Modern weapons occasionally came into play, including tanks.

War with Limited Possibilities

The first tanks sent to the White Guard, 20 French Renault FT-17s, arrived in Odessa on December 18th, 1918. They were followed by heavy Mark V tanks and medium Whippets (85 vehicles in total on all fronts). In theory, among all the chaos, two or three working tanks were a weapon that could defeat any enemy. In reality, tanks faced many problems.

There was a lack of trained crews, so it was necessary to rely on British and French specialists. The first White Guard tankers were taught by foreign instructors. Several foreign volunteer units fought until 1920, but after that, only Russians kept fighting in tanks.

The biggest obstacle was the vast size of the fronts. During the offensive of Petrograd by N. Yudenich's army in the fall of 1919, tanks had to go into battle up to three times per day. Over only four days, "Captain Kromi" traveled 160 kph, "Brown Bear" a little less at 155, and "First Aid" traveled 130. For early tanks, these were very long distances. They wore out both the mechanisms and the crews.

There was no semblance of a normal supply line. In the chaos of the civil war, some tankers in the White Army, a rare and elite force, did not even have complete uniforms. One of them recalls: "I arrived at the tank battalion and received my clothing: a sailor's shirt, torn in many places, black pants in terrible condition, and a pair of boots with no soles. I had no cap, no socks, no underwear." Later, the English gifted him a fresh uniform. Unlike their tank crews, Russian crews did not receive a salary, had poor rations, and could not buy tobacco. Fuel had to be transported by horse carts.

Tank Fist of the White Army

Aside from obvious advantages, the appearance of tanks on the battlefield gave a psychological advantage. Even with heavy guns, the enemy did not know how to defeat moving armoured targets. Tank crews insisted that they took fire from 107 and even 220 mm guns, but the shells caused them no harm. "Cut through enemy obstructions, entered their trenches, and, despite a powerful artillery barrage, remained there for 25 minutes, allowing infantry to follow with no losses" was a typical excerpt from a tank commander's award order at the time.

The first tank attacks appeared unstoppable, despite their crude tactics. Loud tank engines gave away their location and cooperation with infantry and aircraft was questionable, but tanks achieved victory after victory. With his tanks, Denikin conquered Tsaritsin and the Donbass.

Red infantry still had no anti-tank weapons. Regular bullets bounced off armour. At most, bits of paint and metal that flaked off the inside scratched the tankers' faces and hands. Methods for anti-tank combat became more and more desirable. A vehicle knocked out by G. Briedres' Latvian gun battery was showed off in Petrograd as evidence that tanks were vulnerable.

By 1920, tactics of White tanks improved significantly. In Wrangel's push out of Crimea, tank units used concealment tactics, were equipped with trucks and motorcycles, and even had an electric generator and a medical unit. Cooperation with sappers and artillery was set up, as well as regular technical service for the vehicles. As a result, the Red front failed, and Wrangel broke through into Northern Tavriya.

A record of a battle at the Preobrazhenka farmstead describes how cavalry and artillery tried to destroy a tank. Cavalrymen dismounted, and hid among tree lines with grenades and machineguns. At first they threw grenades from a large distance, then from thirty paces, with little effect. The tank was not affected by rifle or machinegun fire. One of the Red Armymen walked in the tank's dead zone, knocking on the armour with a grenade, then climbed up on top, but was wounded by an explosion of his own grenade. Horse-drawn gun batteries went into action. In theory, the batteries were supposed to line up in a semicircle and shoot up the tank from the sides. However, fire from one thousand paces was imprecise, so one battery moved up to 500 paces. The tank was knocked out by fire from two batteries, but was then towed away by a second one.

Red Triumph at Kakhov

The culmination of tank use in the civil war happened at the Kakhov foothold on October 14th, 1920. The White offensive under Wrangel's command lined up according to best tactical practices and had a fair chance at success. In the early morning, artillery thundered, and 12 tanks attacked the Red positions with horsedrawn artillery, armoured cars, and infantry.

In an advantageous position, the Whites made several mistakes. They attacked 2.5 hours before dawn. Tanks could not see each other and had to fight individually. Artillery and aircraft could not offer timely support, and White infantry was preoccupied with Red infantry and was unable to help out its tanks.

Red Armymen were wisened by experience from previous attacks and came prepared. The foothold was reinforced with three lines of trenches, anti-tank ditches, mines, and even flamethrowers. Armoured cars armed with cannons were pulled up to the front. Red artillery knew how to fight tanks by this point. Special "dagger" batteries were used, firing from short distances. The result was the capture of five tanks. Wrangel's forces were defeated, and his army lost all hope for a successful offensive.

Article author: Evgeniy Belash

Sources:
  • Report on the British Military Mission, South Russia by Gen. Holman, 8 October 1919. CHAR 16/29, CCAC.
  • With Lieutenant Colonel Hope Carson in Estonia and Russia. Baltic Defence Review 2/1999.
  • I.M. Gostev, Tanki v grazhdanskoy voyne na severe i pamyatnik v Arhanhelske, Arkhangelsk, 2011.
  • Ya.P. Krastyn, Latyshskiye strelki v borbe za sovetskuyu vlast 1917-1920, Riga, Academy of Sciences of the Latvian SSR 1962.
  • R.N. Reden, Skvoz ad russkoy revolutsii. Vospominaniya gardemarina 1914–1919. Moscow, Centropoligraf, 2006
  • A. Trembelovskiy, Epizody iz zhizni 3-go otryada tankov. Pervoprokhodnik #3 October 1971, Pervoprokhodnik #4 December 1971, Pervoprokhodnik #6 April 1972
  • H. Williamson, Farewell to Don, Moscow, Centropoligraf, 2007 
  • Etapy bolshogo puti. Vospominaniya o grazhdanskoy voyne. Moscow, Voyenizdat, 
  • S.L. Fedoseev, Russkiye protiv tankov, Bronya #4, 2011
Original article available here

Wednesday, 25 February 2015

Lend-Lease Support Vehicles

CAMD RF 38-11355-3046

"List of steamships with samples of English tank armament

Steamship Benjamin N. King #5282
Bill of Lading 180: two "Churchill Crocodile" flamethrower tanks
Bill of Lading 97: flamethrower equipment for "Churchill Crocodile" tanks - 24 places
Bill of Lading 119: two "Sherman Crab" minesweeper tanks
Bills of Lading 119,18: equipment for "Sherman Crab" minesweeper tanks - 87 places
Bill of Lading 209: two AEC armoured cars 

Steamship Samaritan #5283
Bill of Lading 144: one "Churchill Crocodile" flamethrower tank
Bill of Lading 148: flamethrower equipment for "Churchill Crocodile" tank - 11 places
Bill of Lading 143: one "Sherman Crab" minesweeper tank
Bills of Lading 143, 123: equipment for "Sherman Crab" minesweeper tank - 26 places
Bill of Lading 147: one AEC armoured car. Packaging for flamethrower and minesweeper equipment is labelled in both Russian and English: "Flamethrower Crocodile" and "Minesweeper Crab".

April 20th, 1943"

In 1944, Soviet engineers were sent to England to familiarize themselves with some support vehicles. Here are photographs of them examining some bridgelayers on the Covenanter chassis. 

CAMD RF 38-11355-2193

Ultimately, the engineers went with Valentine bridgelayers. The Covenanter was a much less reliable platform, and the Red Army already had Valentines in its supply chain.

Monday, 23 February 2015

MS-1 Rebuilding

A while ago I posted some photos of how not to restore an MS-1. Today, you will see how it should be done, by forums poster interest68.

In 2002, he initiated a search for an MS-1 hull near the Russian-Chinese border, where several of these tanks were installed and then torn out of the ground when they became completely obsolete even as bunkers. He succeeded, although the brutal treatment of the tank was evident: the roof of the fighting compartment and turret were missing.

Major Igor Maltsev is the MS-1 hull. Top: Evgeniy Rybakov, Rafik Kudzhayev, Captain Vitaliy Zykov.

The tank is being dug out during April of 2003.

The turret was found separately, in another border zone, spotted accidentally from the window of a moving car. The turret is equipped with a mantlet for two DT machineguns instead of a cannon.


The hull and turret, dug up in and indoors.

In order to avoid the abominations linked to above, new road wheels must be made. If you want to see how to make MS-1 road wheels out of T-55 shock absorbers, look no further than these blueprints.


 And here's what the finished product looks like:


Many photographs and materials are examined to recreate the track precisely. Here is a wooden mockup.


The original engine is long gone, but a Komatsu excavator offers a suitable replacement.


While tracks are out for casting, the restoration team is working on the hull. There is a new roof and engine compartment bulkhead.



The hull roof is ready, and the turret ring is populated with ball bearings. The turret spins when placed on top, but not freely. The bearings are not lubricated, and the underside of the turret is still covered in debris.


The suspension is nearly complete! There were financial difficulties in the process of casting an entire new set of tracks, and so it was necessary to use the excavator track.


The front idlers and axles are being put in place.


The tank is ready for a test drive!


The most important part is done, now to spice up the interior. 


Insides are done, but the armament still needs some finishing touches.



interest86 writes about his completed vehicle: "After installing the gun and machinegun, the turret became very cramped, and it was not a place for someone with my frame. The vehicle is very inconvenient for the crew in general. The driver has no back to his seat, and this is very difficult. One immediately gets the idea to insert an improvised back after a few minutes out of something like a board, which can be easily inserted between the shelves and fighting compartment bulkhead.


After years of labours, the tank is up and running!



More words from the man responsible for this feat: "The work took about three years, but preparing for the restoration took even more time. We needed to retain all technical subtleties, so it was not just a copy, but as close to possible to the original. It is known that this tank participated in the events at Lake Hasan. To this day, no more than 5 tanks of this kind remain. Experts already admit that our tank is the closest to the original."

Achievements and Predictions, 1929

"Report of the Artillery Directorate of the Supplies Directorate on achievements from 1925 to 1928

Part 2: Scientific research work on improving armament (Artkom)
Moscow, 1929
  1. The army's technical strength is a consequence of the technical and cultural condition of the country.
  2. Between exiting the World War in 1917 and until the end of the Civil War, the USSR was completely cut off from the West for four years. This, as well as the destruction of industry and a lack of materials and production capacity impeded any development of an armament improvement program.
  3. Artkom places three principles into the development of artillery technology, same as in the West: surprise, mass, and depth.
  4. The principle of surprise is achieved in the following ways:
    1. Increasing mobility, primarily operational mobility (wide use of mechanical transport, development of railroad artillery).
    2. Development of methods that permit opening lethal fire immediately (such as use of land or air observers).
  5. The principle of mass involves admitting that artillery can only be effective when used in massed amounts. It is necessary to strengthen artillery as a type of forces and establish a powerful Supreme Command reserve, as well as centralized control of artillery in battle.
  6. The principle of depth is achieved by increasing the range of all guns and increasing the horizontal and vertical field of fire.
  7. Requirements for new artillery systems that solve the issues of modern war are composed considering the following factors:
    1. Widespread use of aircraft.
    2. Group infantry tactics and use of defense in depth, using both natural terrain and artificial fortifications.
    3. Widespread use of tanks.
    4. Use of chemical weapons.
  8. Considering the above, it is suggested that a new system of armament should be developed and taken as the baseline.
    1. Existing weapons should be evaluated from the point of view of the new system.
    2. A realistic plan of improvements should be adopted, and weapons that cannot be adapted to the new system must be found out.
    3. A realistic plan for development of new designs that satisfy the new system must be created.
      However, this path is long, so the first stage is defined by Artkom to be:
      1. Modernization of existing designs.
      2. Creation of new designs, made necessary by tactics of modern battle.
  9. Modernization is defined by Artkom as changes made to a design that improve its characteristics according to the new tactical-technical requirements without interfering with production and acceptable according to economic and supply considerations.
  10. In order to better describe work performed in the past years on modernization and development of new designs, let us briefly describe the state of armament in 1925, analyze it, and attempt to evaluate the modernization work based on this analysis.
...

In 1925, support tanks with a special domestic tank motor were sent to the Bolshevik factory with the aim of producing the first batch in 1928. Work proceeded mostly as follows:
  • 1926: working blueprints were finished, production began.
  • 1927: trials were performed, the first production batch was organized.
  • 1928: mass production of the MS-1 began, working blueprints of the T-12 maneuver tank were completed, work on a one-man tank began.
Modernization of existing B and M tanks was scheduled.

Existing tank Modernization Replacement
B tank (breakthrough) Planned T-12
S tank (maneuver)



M tank (support) Planned One-man tank

Foreign achievements


Maneuver
Support
England
USSR
Czechoslovakia
USSR
Vickers
T-12
KN convertible drive
MS-1
Mass (tons)
12.2
16
8.5
5.9
Crew
5
4-5
2
2
Fuel capacity (liters)
410
-
100
100
Range (hours)
10
8
8
11
Cannons
1
1
1
1
Machineguns
4
3 coax
1
1
Maximum speed
25
25.5
14.2
16
Front and side armour (mm)
14
22
13
16
Roof armour (mm)
8
12
10
8
Maximum traversible trench width (meters)
1.83
2.6
1.8
1.8
Maximum fording depth (meters)
1.2
1.2
0.8
0.8
Maximum grade (degrees)
40
40
35
40
Armament of tanks and armoured cars

In 1926, the following weapons were available:
  1. 37 mm Hotchkiss tank gun
  2. 57 mm Hotchkiss tank gun
  3. 0.303 inch Hotchkiss machinegun
The last two weapon types were captured.

As a result of proving grounds trials, it was discovered that existing cannons and machineguns were hard to use, and a series of improvements for the 37 mm Hotchkiss gun was defined. 
Orders were made for a 45 mm tank gun that could replace captured armament. Work began on using Fedorov machineguns instead of captured ones.

1927:

A special shoulder stock was designed for the 37 mm Hotchkiss gun, with sights and a trigger mechanism, and production started for existing tanks. At the same time, changes were made to the gun mantlet to increase horizontal traverse range.
A new mount for 37 mm Hotchkiss guns was designed and tested for new tanks and armoured cars.
A mount for two coaxial Fedorov Avtomats was tested, and a mount for the Degtyaryev machinegun was designed. Orders were made for a high power 37 mm tank gun.

1928:

The Degtyaryev tank machinegun mount was designed and entered production for both new vehicles and replacement of machineguns captured vehicles. Production of a special 37 mm tank gun started.
A 45 mm gun is being tested for maneuver tanks and replacement of captured B tanks.
A universal stock for 37 mm Hotchkiss guns with an optical sight was designed.

Supplies of tank columns:

Aside from battle vehicles, it is necessary to equip tank units with tracked tractors and trailers, capable of following a tank unit on marches and transporting personnel (commanders, scouts, communications personnel, support personnel) with their belongings and supplies (ammunition, fuel, lubricant, etc). The speed of these tractors should be no less than that of tanks, and their off-road performance should allow them to follow tanks on any terrain.

It is necessary to limit the number of different types of these tanks due to our limited manufacturing capacity and to reap the benefits of having one chassis. This suggests that such a tractor should use as many existing tank components as possible.

Initially, a light tractor based on the standard MS-1 tank was developed, with a maximum speed that is equal to the maximum speed of the tank, even when it is towing a trailer. The trailer is in development, with the aim to make it compatible with existing trailers in order to provide mechanized transport for artillery.

Conclusions
  1. By 1929, after four years of research, design, construction, and trials, tank building work is underway at three factories. The RKKA will receive its first domestically designed support tank, smallest in its weight class, with an air cooled engine, with high off-road performance, high speed that allows it to support infantry and cavalry on marches and in battle, armour that is invincible against regular riflemen, with armament that allows it to complete objectives for the tanks of this type (fighting infantry and enemy positions at ranges of effective fire during tank attacks). Tanks are capable of fighting against tanks with analogous armour at straight shot ranges. Experimental 37 mm guns that are more appropriate for a modern battlefield are in development, and orders for production will be made after they finish trials.
    Simultaneously with production of the tank, the issue of tractors and auxiliary vehicles is being solved.
  2. An experimental maneuver tank has been designed and is being assembled.
  3. The first tankette is finishing trials. Its components and design, first used in our industry, will be studied in the summer of 1929 to obtain data required for a design to be assembled in 1930 that will be acceptable for use by the army.
  4. When the three required types of tanks are completed, the issue of arming the RKKA with tanks that match our closest enemies will be resolved.
  5. The path of motorization of the RKKA is inevitable, as we cannot afford to provide an advantage to our enemies. This challenges the AU to design new tanks that fully match the requirements provided by the RKKA, which need significant technical and tactical research to define.
  6. Artkom's current priority is increasing the movement speed of support tanks without decreasing other combat characteristics.
The issues of radio communications, AA defenses, poison gas protection, smokescreens, and transport on wheeled trailers on roads will be solved in the near future."

V. Lehn collection

The B tank in question is a British MkV tank. Presumably the S tank is a Whippet, and M tank is an FT-17.

Sunday, 22 February 2015

T-34 Modernization

"Decree of the Committee of Defense within the Council of Commissars of the USSR
Moscow, Kremlin

On the production of T-34s with torsion bar suspensions

The NKSM (factory #183) must produce two experimental T-34 tanks with the following features by April 1st, 1941:
  1. Individual torsion bar suspension.
  2. Road wheels with internal shock absorption.
  3. 1600 mm turret ring with protection from jamming and lead fragments.
  4. A commander's cupola on the main turret with a dead zone of at most 10 meters.
  5. A 5 man crew, of which 3 are in the turret (commander, gunner, loader) and two are in the hull (driver, radio operator).
  6. Maximum speed: 65-70 kph.
  7. New 600 hp V-5 engine (modernized V-2-K).
  8. Other tactical-technical characteristics remain the same as defined by decree #428 on December 19th, 1940.
  9. Perform factory trials by April 1st, 1941. Present the tanks for proving grounds trials on May 1st, 1941. 
NSKM and NKO must supply the KO with suggestions on producing this improved T-34 tank.

NKSM (Mariupol factory) must produce two hulls and two turrets by February 1st, 1941.

Chair of the Committee of Defense within the Council of Commissars, K. Voroshilov
Secretary of the Committee of Defense, M. Pugayev"

Saturday, 21 February 2015

Preferred Seating

Sure, you can fit a lot of riders on a tank, but surely some of those soldiers ride more comfortably than others? VIF2NE poster Ryadovoy-K shares his experience on the subject. The advice is specific to the BMP-2, but the theory can be applied to any vehicle.




"We had to ride the "two" often and many times, and most importantly, for long stretches of time. All soldiers knew what places are good and what places are bad. Riding in a bad place for half a day delivers no pleasure, only problems.

The best spot is marked in red, but only if the infantry commander's hatch is open. However the driver could forbid this. Old vehicles could have a bad rubber seal, and once you open that hatch, it will leak during rain. Drivers slept on their seat and the seat of the infantry commander, and nobody wants to get wet. Further down the list: orange and yellow. Riding atop the front of the turret is good. You can sit well and see well. Light green is good when the BMP is fully functional and the wind is not coming from the front or the right. A BMP that's acting up could spew oil from the exhaust collector, and when the wind is blowing, you end up breathing in the exhaust.

Red with a stripe is worse than riding on the front of the turret, but it will do. If nobody is sitting on orange, you can lean on the turret, and it's easy to hold onto the gun when the vehicle lurches. Others say that they would place a seat from a car here, and it would become the best spot.

Blue: sitting behind the turret is inconvenient, as you're sitting against the direction of motion, and during the summer dust gathers there like with a vacuum cleaner and causes you problems. Yellow with a stripe: you can lean on the turret and hold onto the gun, but the proximity of the exhaust times the direction of air makes a significant drawback.

Black with a stripe and blue with a stripe. People sat here when the BMP carried one to two squads at the same time. It's uncomfortable (there is nothing to lean on with your back) and you feel the vehicle lurching more strongly.

Black, purple, gray, white: we tried not to sit here at all. In the first two, sitting against the direction of motion is uncomfortable, and during the summer you will choke on dust. The gray and white spots can only be occupied when the rear hatches were open, but this is not allowed, as dust will collect inside the vehicle. On old vehicles, this also causes leaks (the rider compartment was also used for sleeping, and nobody needed water pouring in).

The worst option is green with a stripe. Sitting right next to the exhaust causes a torturous pain in your eyes and difficulty breathing.

The gunner sits in the green spot and the commander sits on the light blue spot."


Thursday, 19 February 2015

SU-76, Grabin Style

The factory #37 design was far from the only attempt to mount a 76 mm gun on a light tank chassis. Grabin, the man who invented the ZiS-3 in the first place, has his own idea about how to make it mobile.


"Attachment to the IS-10 SPG sketch

This is an attachment to the sketch of an IS-10 SPG, which consists of a 76.2 mm ZiS-3 divisional gun on a T-70 tank. The use of a ZiS-3 in a T-70 tank achieves a powerful self propelled gun with minimal changes to the gun or tank. In the event that higher penetration is needed, the barrel can be replaced with one from a 57 mm AT gun."

Wednesday, 18 February 2015

Valentine and Matilda Delivery Quality

"To the Deputy Chair of the Council of People's Commissars of the USSR, comrade A.I. Mikoyan

A series of defects was discovered at Gorkiy and during subsequent use in the army in MkII (Matilda heavy tank) and MkIII (Valentine medium tank) tanks that arrived from England.
  1. Out of 137 tanks that arrived at Gorkiy, 58 broke down due to frozen water in the engines. Additionally, 20 tank batteries (4 batteries per tank) broke due to freezing of the electrolyte, due to its reduced density.
    We must use imported parts to repair all 58 vehicles, but there are not enough engines and batteries, and we require additional supplies to repair 30 tanks. English representatives confirmed that a portion of the tanks arrived at Arkhangelsk with water in the engine cooling system.
  2. The MkII tank has a compressor for controls and the gearbox that works poorly in winter temperatures. It is necessary to ensure that the compressor works flawlessly in our winter on subsequent shipments.
  3. Many cases of track pin breakages were observed in battle conditions on both tank types, as well as breakages of idler ball bearings on MkIII tanks when moving across rough terrain.
  4. The track faces of both types of tanks are smooth, and the tanks slide around. It is necessary to weld grousers to these tracks.
  5. On MkII tanks, the front sloped (left and right) plates are torn out of the tank when towed. It is necessary to reinforce them.
  6. The MkIII tank has many small defects, such as:
    1. The water drainage valve does not allow for all water to be drained from the engine cooling system. It must be placed in the lowest point of the water pipes.
    2. The vertical position of the compensator coil of the water drainage pipe means that all water cannot be removed from it.
    3. The radiators overcool in winter conditions. It is necessary to install warming shutters.
    4. Rubber tires on the road wheels often slide off. It is necessary to attach them in a more reliable way.
Tanks are not evenly supplied with instruments. Some have more, some have less. It is necessary to equip them according to established norms.

I ask you to report the above to English representatives that supply us with tanks so that the aforementioned defects can be resolved.

GABTU Chief, Lieutenant-General of the Tank Forces, Fedorenko
GABTU Military Commissar, Army Commissar 2nd Grade, Biryukov"

Tuesday, 17 February 2015

T-29 Torsion Bars

The T-29 is a fairly well known successor to the T-28, largely being the same tank but on a Christie suspension. It is also fairly well known that T-28 has a prototype with torsion bars. However, here's a rare combination of the two, a T-29 with torsion bars (Object 115).


"Torsion bar suspension (designed by personal initiative)
  1. Design of the "torzion" bar suspension on the T-29 tank.
  2. A proof of concept of the "torzion" bar suspension (1937-1938)"
And yes, it is written "torzion" in the original, including quotation marks.

Monday, 16 February 2015

Valentine MkIX Trials

The Red Army has been a fan of the Valentine tank for many years, so when a new modification with a 57 mm gun that solved both the problem of an ineffective AP shell, one was naturally ordered for trials.

Valentine MkIX tank at Kubinka, March 1943

Valentine MkIX observation range (driver).

Valentine MkIX observation range (turret).

"Firing in place and on the move

Gunnery trials were performed at ranges of 500 and 1000 yards (457 and 914 meters) at targets 4x6 meters in size. Each group had 10 shots. There was no time limit on firing. Aiming was done using the telescopic sight. The weather was clear, visibility was 2000-2500 meters.

Results are given in table #4.



Range (yards) # of shots # of hits Mean vertical deviation, cm Mean horizontal deviation, cm
In place 500 10 10 11 8
In place 1000 10 10 18 16
Moving at 10 kph 400-500 10 10 95 75

Comparing the data in table #4, one can see that:
  1. Mean vertical deviation is higher than mean horizontal deviation in all cases. This is explained by a wobble in the elevation mechanism and a turning of the flywheel when the firing lever placed on the flywheel is pulled.
  2. Mean deviation when firing from the move is 11 times greater than when shooting from a standstill from the same distance. This happens due to the stiffness of the suspension and the insufficient traction of the tracks on the ground, which leads to the tank slipping and the turret wobbling, which makes it difficult to aim the gun.
Maximum rate of fire in place and on the move

The maximum aimed rate of fire was measured at a range of 700-1000 yards (640-914 meters). Aiming was performed using the telescopic sight using the mechanical aiming mechanisms. Each group consisted of 5 shots. The weather was clear, visibility was 2000-2500 meters.
Results of trials and hits on target are given in table #5.

Condition # shots


Result Time


RPM % hit
Hit Close miss Overshot Undershot Deviation in direction
In place. Range= 1000 yards 5 3 2 - - - 30 sec 10 60%
Moving at 9-10 kph, at 0 degrees, at one target 5 2 2 - 1 - 1 min. 51 sec. 2.7 40%
Ditto, at two targets 5 1 1 1 2 - 1 min. 47 sec. 2.8 20%
Ditto, at three targets 5 - - 2 3 - 2 min. 4 sec. 2.5 0%
Average













2.7 20%
Moving at 15 kph, at 0 degrees, at one target 5 - - 3 2 - 2 min. 24 sec. 2.0 0%

Summary
  1. The English Valentine IX tank differs little from the Valentine III tank. The main difference is the use of a 6-pdr gun in the Valentine IX, a lack of coaxial machinegun, and thinner side armour.
  2. The speed and maneuverability of the two tanks are nearly identical, with the exception of range, which increased in the Valentine IX by 90% due to external gas tanks.
  3. The 57 mm gun on the Valentine IX has an unreliable recoil brake.
  4. Unsatisfactory results when firing from the move, 20% hits, are achieved due to significant wobble in the aiming mechanisms.
  5. A lack of HE grenade for the 57 mm gun limits the usefulness of the gun.
  6. A lack of coaxial machinegun limits the usefulness of the tank when fighting enemy infantry.
Conclusions
  1. Valentine IX and Valentine III tanks are equivalent technically.
  2. The armament of the tank makes it only useful against enemy tanks.
  3. The lack of an HE grenade and a coaxial machinegun makes the tank unable to fight enemy infantry and fortifications.
  4. The reliability of the 57 mm gun needs to be tested on a series of samples."
CAMD RF 38-11355-1540

Sunday, 15 February 2015

Replaceable Tires

"USSR NKTP
All-Union State Special Machine-building Trust
April 4th, 1935
#37-372-1232s
To the director of the Voroshilov factory, comrade Dufur
Copy: director of the Kirov factory, director of factory #185, RKKA ABTU

Despite the quite obvious necessity of switching to T-26 tanks with removable road wheel tires in 1935, the issue is still not resolved. The necessity of using removable tires is confirmed by both trials (in a 3000 km run, only two road wheels broke for reasons not connected to their tires) and the unsatisfactory robustness of the enlarged road wheels on that same vehicle, SU-5, and other vehicles on the T-26 chassis.

The claim that the production will be too costly is countered by the necessity to restore the old casting molds, which will be more expensive than making new casting molds for the simpler removable tires.

Finally, the cost of use will not increase if one considers the significant gain in reliability and decrease in rejections of manufactured components. The tire will be molded on a separate simple mold, as opposed to a complicated combination mold.

Considering the aforementioned points, I consider it necessary to immediately switch to removable tires for the T-26, for which:
  1. The director of the Voroshilov factory, comrade Dufur, in cooperation with the Kirov factory, must develop a plan to produce production together with the aim of switching to production of removable tires in the fourth quarter of 1935.
  2. The directory of factory #185 comrade Barykov must sign a contract with the Kirov factory to supply road wheels for the production of the SU-5 and other experimental vehicles on the T-26 chassis.
The full plan of shifting production to road wheels with removable tires and the cost of this transition should be given to me for approval no later than April 15th of 1935.
Director of the Special Machine-building Trust, Neimann"