Thursday 31 July 2014

Tiger II Trials: Mobility

At Ogledow, the Soviets captured a number of Tiger II tanks perfectly intact. One of the tanks was shot to bits, but another got to live. It was run through trials to see how well this mysterious new vehicle performed. This article will cover mobility trials, with gunnery trials in another article.

"Mobility Trials

According to the speedometer, the tank already travelled 444 kilometers. The following trials took place:
  1. Gunnery trials
  2. Mobility trials
Special trials could not be carried out due to the tank breaking down prematurely. During mobility trials, the tank travelled 113 km over dirt roads with many potholes and slopes up to 10 degrees. The roads were dry.

The tank was fuelled with KB-70 gasoline. The engine and transmission were filled with aircraft oil, and the suspension was lubricated with solid grease.

Results of mobility trials

Average speed:
A dry stretch of road 35 km long was used to determine average speed. The following was determined:
  1. Average speed in motion: 13.4 kph
  2. Total average speed: 11.2 kph
The tank moved mostly in fifth gear, on short flat stretches of road it could move in sixth or seventh gear. The significant difference in speeds was caused by an oil leak of the right fan, which required constant stopping to inspect and refill it.

Fuel consumption:
As a result of trials, it was determined that fuel consumption on a dirt road is as follows:
  1. For 100 km: 971 Liters
  2. For 1 hour of running the engine: 130 Liters
The tank has enough fuel to drive 90 km on a dirt road. The German instructions claim that fuel consumption for 100 km should be 700 Liters. The increased fuel consumption observed during trials is caused by a worn engine.

Engine temperature:
Figure 7 shows the graph of water temperature and oil pressure.

Figure 7: Graph of water temperature [top] and oil pressure [bottom. Time scale is in minutes, oil pressure is in kg/cm^2, water temperature is in degrees Celsius]

From the graphs, it can be seen that:
  1. The water temperature does not pass 95 degrees and stabilizes slowly.
  2. The oil pressure stabilizes quickly and holds within 6-7 kg/cm^2
Turning speed:
The turning trials were done on a grass plain with a hard clay surface. Trials showed that the planetary turning mechanism lets the tank turn well. The tank can turn in neutral gear. The following table contains data characterizing the tank's agility.

Time to turn
Engine RPM
Turning radius (meters)

It was not possible to determine the turning radius in 7th and 8th gears, as the previous turns destroyed two track links and 12 track pins. Due to brittleness, the track pins fall apart into several pieces.


After capturing the tank, it drove 110 km on its own to the railroad station. The driving occurred over the following terrain:
  • Stone highway: 60 km
  • Asphalt highway: 10 km
  • Dirt road: 25 km
  • Sand road: 15 km
During this march, the following breakdowns occurred:
  1. The ball bearing of the left idler was destroyed.
  2. The right engine group overheated.
  3. The gearbox was overheating due to insufficient cooling and external air temperature over 30 degrees.
  4. A large amount of track pins were destroyed, especially when making frequent and wide turns.
  5. The tracks become loose quickly and have to be tightened every 10-15 kilometers.
After being offloaded at the proving ground station (the speedometer showed 444 km), the right final drive jammed. Upon opening the right final drive housing, it was discovered that it was completely destroyed. The reason for this was not discovered. It was replaced with the final drive from another Tiger B.

After the conclusion of mobility trials, upon disassembly and inspection of the final drives, it was discovered that the right final drive was once again broken (the roller bearing of the drive bar was completely destroyed). Inspection of the final drives shows that their drive bar bearing design is unreliable.

During mobility trials, the following breakdowns occurred:

  1. At the 86th kilometer (530 km on the speedometer), the left drive wheel broke. All of the bolts holding the external gear rim broke. Two teeth of the external gear rim and one in the internal were broken (see fig. 8).

    Figure 8: Destruction of the gear rims of the drive wheel.
  2. On the 103rd kilometer of trials (547 km on the speedometer), the left drive wheel was once again destroyed, and the torsion bar of the front left road wheel was destroyed. All bolts holding the gear rim were destroyed, and the gear rim itself snapped in two.
The cause of the destruction of the gear rim bolts in the first case was that the balancer of the front left road wheel was bent, as a result, the road wheel was not in the same plane as the rest, and was somewhat tilted compared to the rest. The small spaces between the road wheels led to the road wheel striking the ends of the bolts when it hit an obstacle, cutting off the bolts one by one. The teeth broke due to incorrectly engaging the track after being improperly attached to the drive wheel and being worn significantly. 

The cause of the second breakdown was the destruction of the torsion bar of the left front drive wheel. After the torsion bar was destroyed, the wheel, having no rigid connection and being tilted at will, cut off the bolts of the gear rim.

Having analyzed the causes of the breakdowns during trials, it can be concluded that the Tiger B's weakest components are its final drives, drive wheels, and track pins."
CAMD RF 38-11355-2860

Wednesday 30 July 2014

Soviet Camouflage in German Eyes

I have previously written about Soviet camouflage for tanks and people. Now, let's see how effective this camouflage was through German eyes, helpfully provided in the April 22nd edition (#23) of the Tactics and Technical Trends magazine.

Tuesday 29 July 2014

World of Tanks: Today in History: Conflict at Lake Hasan

On July 29th, 1938, an armed conflict erupted between the USSR and Japan at Lake Hasan.

In 1932, Japanese forces occupied Manchuria (North-East China) and formed the Manchukuo puppet state. This triggered a round of border skirmishes. However, they were only a prelude to widespread military action.

As a pretence for the invasion of the USSR, Japan issued a territorial claim. The Japanese claimed a number of peaks in the region of Lake Hasan and Tumannaya (Tumen) river. On July 15th, 1938, the Japanese ambassador in Moscow, Mamoru Shigemitsu, handed a note to the Soviet government demanding the withdrawal of troops from the contested regions. In response, Soviet diplomats offered a map and documents of the Hunchun Treaty, signed between Russian and China in 1886, marking the Zaozernaya and Bezymyannaya peaks as Soviet territory.

However, Japanese military circles burned with the desire to test its northern neighbour. On July 20th, the ambassador made a repeat claim which was also declined. The Japanese government prepared three infantry divisions (15th, 19th, and 20th), one cavalry regiment, three machinegun battalions, individual tank units (up to a battalion in number), an AA artillery unit, three armoured trains, and 70 airplanes. 15 ships (1 cruiser and 14 minelayers) and 15 armoured boats were positioned at the entrance to the Tumen river. However, the only direct participant was the 19th infantry division, reinforced with machineguns and artillery.

The first blow was aimed at small numbers of Soviet border forces, which offered heroic resistance, but were unable to hold Zaozernaya and Bezymyannaya peaks after July 30th. The difficult terrain forced Soviet command to send its units into battle very gradually. The main opponent of the Japanese became the 39th infantry corps, composed of the 32nd and 40th infantry regiments, and the 2nd mechanized brigade, which had more than 300 T-26, BT-5 and BT-7 tanks, as well as SU-5 SPGs.

As a result of active battles lasting until August 11th, Soviet forces destroyed the Japanese 19th division and pushed them past the border. Peace talks confirmed that the proper state of the border was in accordance with existing documents provided by the Soviet side.

The Red Army lost 960 men, and a further 2752 were wounded, with 527 sick. The Japanese lost 650, with 2500 wounded, according to Soviet estimates.

A year after, a movie titled "Tractor Drivers" hit Soviet screens, featuring the song "Three Tankers" that was inspired by events in the Far East, which later became the unofficial anthem of the Soviet tank forces.

Furrowed clouds blow over the border
The harsh land is enveloped in silence
On the high shores of the Amur
Defenders of the Motherland stand

A robust shield from the enemy stands there
There it stands, brave and strong
Near our far eastern borders
An armoured shock battalion

They live, as this song tells
An inseparable friendly family
Three tankers, three joyous friends
A fighting vehicle crew
(Song fragment)

Original article available here.

Monday 28 July 2014

Repairs in the 16th Tank Brigade

From L.V. Gorchakov collection.

I've written about combat successes and heroic actions of the brigade, but none of these would be possible without a healthy amount of support from less glamorous positions. The mechanics deserve their praise too, and, as such, get included in the appendix.

"Evacuation and repairs of equipment of the 16th Tank Brigade from September 23rd, 1941 to April 20th, 1942

In the aforementioned period, the following tanks were evacuated from the battlefield:
  • KV: 9
  • T-34: 26
  • BT: 30
  • T-26: 7
  • German tanks: 5
  • Total: 77
In this period, the following repairs were performed.

Vehicle Major repairs Medium repairs Minor repairs
KV 10 16 56
T-34 3 24 141
BT 21 30 154
T-26 19 9 44
BA-10 - - 5
BA-20 - 3 40
ZiS-5s - 8 114
ZiS-6 - - 10
GAZ-AA - 8 104
GAZ-AAA - 3 48
M-1 - 8 70
GAZ-64 - - 10
ZiS-32 - - 12
M-72 - 10 88
IZh-9 - 8 56
ST-2 - 5 62
STZ-5 - 8 56
ChTZ-65 - 1 20
AT guns - 4 14
German halftrack - 1 5
Total 51* 145 1093

The numbers show that a large amount of work was done to evacuate broken down vehicles from the battlefield and repair them. Difficulty arose from the fact that the evacuation was done from the battlefield under enemy fire, due to which 15 soldiers and commanders were lost. 

The following comrades, with energy and initiative, worked in evacuation and repair of the combat vehicles.
  1. Deputy commander of the brigade's technical department, Major Zhidovetskiy
  2. Captain Demyanov
  3. Military Technician 2nd grade Simonov
  4. Military Technician 1st grade, Novichkov
  5. Captain Golmachev
  6. Military Technician 1st grade, Musienko
  7. Political Instructor Gorchakov
  8. Senior Sergeant Yartsev
  9. Military Technician 2nd grade Rosochinskiy.
Additionally, 15 soldiers, junior commanders, and technicians received gratitude and were rewarded with medals for swift and high quality repair."

*The incorrect sum is present in the original document.

Sunday 27 July 2014

1931 Tank Program

"Decree of the Politburo of the Central Committee of the VKP(b) On the Tank program

February 20th, 1931

Building on the decree from November 30th, 1930 on the tank building program that specifies the requirements before 1932: 4,000 tankettes, 13,800 small tanks, and 2,000 medium tanks, the Politburo decrees:

1. Tankette
  1. Approve the T-27 tankette with the Ford AA engine with the following characteristics:
    1. Speed: 36-40 kph
    2. Mass: 2 tons
    3. Armour: 10-15 mm
    4. Armament: 1 machinegun
    5. Engine, watercooled, 40-45 hp
  2. The tankette will be produced at automotive factory #2. The production will be mastered in 1931 by means of production of 400 tankettes. 
  3. Considering that T-27 tankettes uses Ford truck components, in addition to armour and tracks, VSNKh is assigned the issue of creating a second manufacturing base for T-27 tankettes at the Nizhniy Novgorod automotive factory, assigning 20-25% of the factory's output to them.
  4. VSNKh and NKVM must report in two months how many tankettes the factory can produce before spring of 1932.
2. Small tank
  1. Approve the T-26 (Vickers) with the following characteristics:
    1. Speed:
      1. On roads: 35 kph
      2. Off-road: 20-25 kph
    2. Mass: 7.5 tons
    3. Armour: 8-13 mm
    4. Armament: one 37 mm gun and one machinegun or two machineguns
    5. Engine: Armstrong-Sidley air cooled, 84-93 hp
  2. In order to master production in 1931, produce 300 tanks of this type at the Bolshevik factory. Prepare for organization of production at Bolshevik and Stalingrad factories with their own engineering staff.
  3. Bolshevik factory should be expected to produce 1,500 tanks per year and Stalingrad 12,000 tanks, with spare parts. The production base at Stalingrad must be ready by April 1st, 1932. The experimental plant must be ready by spring of 1932, which should produce 100 tanks per shift per year. In order to master production, the experimental plant must produce one batch of tanks in spring of 1932.
3. Medium tank
  1. Approve the powerful TG tank as the main medium tank with the following characteristics (preliminary):
    1. Speed:
      1. Maximum: 40 kph
      2. Average: 25 kph
    2. Mass: 20 tons
    3. Armour: 30/20/15
    4. Armament:
      1. 76 mm gun
      2. 37 mm gun
      3. 4-5 machineguns
    5. Engine: 240 hp, air cooled
  2. Propose acceleration of the tank building program to OGPU and NKVM, consider it the most important task in producing experimental tanks in 1931.
  3. In order to master production, produce 50-75 tanks in 1931.
  4. Considering the combat potential of this vehicle, be ready to produce 2000 tanks of this type by spring 1932.
  5. The main manufacturing base will be at the Kharkov Locomotive Factory, in cooperation with the Stalingrad on the hull, engine, and steel casting.
    VSNKh is tasked with investigating if a second manufacturing base can be set up in the Urals.
  6. After 80 T-24 tanks are produced, remove it from production and redirect the available resources to produce TG tanks.
4. Considering the possibility of a second manufacturing base for the TG tank in the Urals, cease production of small tanks at MMZ after existing components have been used.

5. Considering satisfactory results when producing T-27 tankettes with Ford AA components and preliminary successes at armouring and arming Kommunar and Caterpillar tractors to create infantry support tanks, consider it necessary to create a second echelon of infantry support tanks on automotive and tractor bases, for which NKVM and VSNKh must report in six months on the types, amount, and locations of production in 1932 and 1933.

6. On engines: supply tank factories with the following engines:
  1. T-27 tankette: Ford AA engine from the Nizhniy Novgorod automotive factory
  2. Small T-26 tank: Armstrong-Sidley engine from the Bolshevik and Stalingrad Tractor factories
  3. For medium tanks: NKVM should accelerate investigations of medium tank engines and decide on a type in 1-2 months. Due to a lack of factories capable of producing powerful medium tank engines, NKVM should accelerate the construction of a factory that can produce sufficient engines for medium tanks by spring of 1932. Initially, aim the production at M-6 and Grotte engines. VSNKh, NKVM, and OGPU should design powerful diesel engines with 240-300 hp in 1931.
7. On armour
  1. The consumption of armour by the current program is 50,000 tons of processed armour. The existing base (Izhor and Bolshevik factories) can provide 6,000 tons. 
  2. VSNKh should organize a new manufacturing base at Stalingrad that can provide 46,000 tons of processed armour starting in spring of 1932.
  3. Considering the necessity of increasing numbers of powerful medium tanks and tankettes, as well as production of second echelon infantry tanks on truck and tractor chassis, VSNKh should propose changes to the armour consumption.
  4. The currently produced armour is inadequate compared to Vickers armour, despite the presence of twice as many coloured metals and ferrite alloys in our armour. NKVM and VSNKh should finish current investigations on increasing armour quality to Vickers levels and decreasing the amount of imported ferrite alloys in two months.
8. On small steel casting

In order to complete the tank program, 55,000 tons of small steel casts are required, with the Bolshevik factory's capacity of 4,000 tons. VSNKh should build a manufacturing base at the Stalingrad tractor factory capable of producing the missing amount."

World of Tanks: Today in History: First Battle of El-Alamein

On July 27th, 1942, the Allied forces under the command of Claud Auchinleck defeated Erwin Rommel's Afrika Corps in the first battle at El-Alamein.

Italy declared war on Great Britain on June 10th, 1940. In September, its forces, commanded by Marshall Rodolfo Graziani invaded Egypt, a formally independent state that, in practice, was completely dependent on the British. They were opposed by the "Nile" army, commanded by General Richard O'Connor. The Italian successes were negligible, and their offensive stalled.

Then, Germany decided to send its forces to Africa. Help for its ally was a secondary goal. The main objective was to create strategic footholds, necessary for the conquest of more African lands. Germany also wanted to capture the Suez Canal to make life in the Mediterranean difficult for the British.

The Afrika Corps was commanded by the then unknown General Erwin Rommel. His first echelon landed at Tripoli in the middle of February of 1941. The British paid little attention to this landing. This was a poor move on their part, as before Rommel gathered all his forces, he was able to strike at Al Uqaylah, Benghazi, and then Tobruk. Until then, the British have only faced marginally trained Italian commanders, and now they were faced with a very competent German one. As a result, the first few major battles were lost by the British. General O'Connor was captured. Rommel's offensive halted in June of 1941.

From the middle of June to the middle of November, the war in Africa was rather passive. The Germans no longer had the strength to advance, and the Allied commanders needed time to recover and prepare for a counterattack. The counterattack was delivered in November. The British planned to encircle Rommel at the border of Tripolitania, but Rommel managed to evade the trap, earning him the nickname "Desert Fox". In early 1942, Rommel managed to achieve another handful of victories, the most impressive of which can be considered the taking of Tobruk, which the British considered an impregnable fortress.

In the end of June, the Germans approached new defensive lines built by the Allies at El-Alamein. Fierce fighting began, as a result of which, the British, with an advantage in manpower and vehicles, began slowing Rommel's advance.  British aircraft dealt significant damage to the German communications and supply lines.

On July 10th, the British pulled off a successful attack at Tel el Eisa, further reducing Rommel's vehicle count and capturing 1000 prisoners. The main battle occurred on July 27th. Even though Claud Auchinleck made many mistakes that cost the British many men and tanks, Rommel's offensive was stopped. Further attempts to crush the British army were unsuccessful. On May 13th, 1943, the German-Italian forces in Africa surrendered.

Original article available here.

Saturday 26 July 2014

Heroes of the 16th Tank Brigade

From L.V. Gorchakov collection.

As a part of the application for Guards status, the commander of the 16th Tank Brigade includes a summary of particularly courageous individuals within the Brigade. Here it is. People described in the previous article have been omitted, as there is no additional information here.

"A Short Summary of Particularly Outstanding Tankers, Motorized Infantrymen, AA Gunners and Mortar Crews of the 16th Tank Brigade
  1. Senior Lieutenant Antonyuk: Participated in 43 attacks. His vehicle destroyed 27 AT guns, 25 mortars, 48 machineguns, 5 tanks, one ammunition warehouse, 2 infantry cannons, 34 dugouts, 1 kitchen, and up to 1000 soldiers and officers. Comrade Antonyuk has already been awarded the Order of the Red Star and has been nominated for a Hero of the Soviet Union.
  2. Lieutenant Martynov: In one day, he destroyed 5 German tanks and captured 3 tanks in an uneven battle with a whole tank company. He was nominated for the highest government award, Hero of the Soviet Union.
  3. Junior Lieutenant Vasilyev: On April 20th, 1942, he received the order to penetrate the enemy's front line of defense to cut off the Myagry-Dubovik road. He slowly progressed through the thick forest and swamps. Due to a small amount of assigned infantry, he was cut off from his unit. In this scenario, Vasilyev made the decision to destroy the enemy positions at any cost. His reconnaissance squads reported that there were German fortifications in the area, with their gun ports turned towards the road. Comrade Vasilyev had a portion of his infantry climb up on his tank with a mounted machinegun, and with a skilful maneuver, emerged in the rear of those fortifications, destroying 10 dugouts and the fascists inside them. In order to break out of encirclement, where the tank has been for three days, it was necessary to destroy the enemy AT gun battery. In order to distract it, comrade Vasilyev retains a portion of his infantry to open fire at the battery, places a mounted machinegun on his engine deck to muffle the engine noise, and approached within 50-80 meters of the Germans' rear. Suddenly opening fire, he destroyed three guns. The remaining gun was crushed underneath the tank's tracks, providing an exit for his tank and infantry escort.
    Over three days of constant fighting, Jr. Lieutenant Vasilyev destroyed 5 AT guns, 14 dugouts, 8 mortars with crews, and killed 500 soldiers and officers. His trophies included 50000 rounds of ammunition, 8 submachineguns (6 German), 9 hand and 9 mounted machineguns, valuable documents, and one prisoner. In total, Vasilyev's record includes 9 attacks, in which he destroyed 6 AT guns, 28 dugouts, 4 AT rifles, 8 mortars, and exterminated up to 800 soldiers and officers. Comrade Vasilyev was nominated for the highest government award, Hero of the Soviet Union.
  4. Senior Lieutenant Danilov: Participated in 32 attacks, destroyed 2 tanks, 2 armoured cars, one motorcycle, 23 machineguns, 24 AT guns, 28 mortars, 6 infantry cannons, 27 earth fortifications, and up to 900 occupants. Comrade Danilov has been twice nominated for a government award, one of which, an Order of the Red Banner, he has already received.
  5. Senior Sergeant Makarov: Drove a tank into an attack 36 times, and always emerged victorious. Over the last 4 attacks, his crew destroyed: 7 AT guns, 2 mortar batteries, 2 field guns, 2 mounted machineguns, 2 dugouts, 1 earth fortification. In one of these attacks, his tank sustained damage to the turret and suspension. A skilful maneuver took the tank out of enemy territory.
    In total, comrade Makarov destroyed 1 tank, 1 armoured car, 8 machineguns, 12 AT guns, 14 mortars, 12 earth fortifications, and up to 400 occupants.
    Comrade Makarov has been nominated for awards thrice, having received two already: an Order of the Red Banner and a For Courage medal.
  6. Battalion Commissar Pochepayev: Participated in 9 attacks. His tank destroyed 2 AT guns, 18 mortars, 8 machineguns, 2 infantry cannons, 19 dugouts, and over 120 soldiers and officers.
    Comrade Pochepayev has been awarded an Order of the Red Star.
  7. Comrade Matyuhin: Tank commander, participated in 13 attacks, destroying 4 infantry cannons, 1 tank, 28 machineguns, 12 mortars, and up to 800 soldiers and officers. Comrade Matyuhin has been awarded an Order of the Red Banner.
  8. Junior Political Instructor Chistyakov: Artilleryman-sniper. In one battle, he knocked out 3 tanks with 3 shells. In total, acting as a part of Lieutenant Martynov's crew at Gontovaya Lipka, Tortolovo, [illegible] and [illegible], he destroyed 8 tanks, 12 AT guns, 1 machinegun, and exterminated up to 460 occupants.
    Comrade Chistyakov has been awarded an order twice.
  9. Political Instructor Gorchakov: His crew was in battle for two days straight. The faces of driver Totsenko, gunner order-bearer Sankevich and radio operator Korobkov were covered in soot. The frost caused snow to form on the inside walls of the tank. These men did not think of rest or food, they only aimed to catch up to the enemy fleeing in fear. In this battle, this brave crew destroyed 12 dugouts with infantry, 3 mortar batteries, 3 earth fortifications, 3 mounted machineguns, 2 AT guns, and destroyed one and captured one field gun. Up to 300 soldiers and officers were crushed or shot by the crew. Comrade Gorchakov was nominated for an award.
  10. Sergeant Pomogalov: Tank commander. In an attack on Pogostye, he enabled infantry to progress 2 kilometers into enemy territory. A group of German submachinegunners up to a company in size attempted to flank the infantry, but comrade Pomogalov predicted their maneuver. His cannon and machinegun fire killed 40 fascist submachinegunners, and forced the rest to flee.
    Comrade Pomogalov participated in numerous attacks, destroying a medium tank, 3 AT guns, 3 machineguns, 1 mortar, 4 dugouts, and up to 100 soldiers and officers.
    Comrade Pomogalov is nominated for an Order of Lenin.
  11. Major Kudryavtsev: Commander of the 1st Independent Tank Battalion. In January of 1942, on a mission from the brigade commander, he spent 13 days behind enemy lines with soldiers and commanders, blocking their supplies and exterminating fascist scum.
    On March 12th, while on a mission from the brigade commander to penetrate the Leningrad blockade, comrade Kudryavtsev, with his tank battalion, penetrated enemy fortifications and moved forward. However, as they approached the Shal fortification region, the infantry was pinned down. Comrade Kudryavtsev displayed necessary initiative and gathered infantry from various units, placing it on his tanks. He attacked the region with sudden strikes from all sides, succeeding in taking this heavily fortified area. The enemy left up to 300 soldiers and officers, 3 AT guns, 10 machineguns, 8 earth fortifications, and 10 dugouts.
    Comrade Kudryavtsev has been nominated for a government award: the Order of the Red Banner.
This is just a partial list of outstanding tankers, There are many of them, fearless Red warriors prepared to give their life for a righteous cause. 

Outstanding motorized infantrymen, mortar gunners, and AA gunners include:
  1. Political Instructor Kazachinskiy: Exterminated 70 fascists.
  2. Red Armyman Nalivayko: 50 fascists.
  3. Lieutenant Shalygin, Adjutant, exterminated 47 fascists, awarded an Order of the Red Star.
  4. Senior Lieutenant Ryabikov: Deputy commander of the motorized infantry battalion, exterminated 28 fascists. Awarded an Order of the Red Star.
  5. Red Armyman, machinegunner Verzelov: exterminated 28 fascists.
  6. Junior Lieutenant Pozdeev: commander of a machinegun platoon, exterminated 28 fascists.
  7. ..."
The rest of the list is just straightforward kill counts, which aren't very interesting. Certainly no captivating stories like with the tankers.

Friday 25 July 2014

Mobility Trials Part 3

This one is less of a complete report, and more a mishmash of off-roading and various associated activities I have accumulated.

CAMD RF 81-12086-97

"Figure 13. The moment before fording.

Figure 14. The moment before fording. The tractor begins tilting forward at a point before the third road wheel."

These two photographs are from trials of the Ya-13F light artillery tractor. While it is not particularly important to know at what point a tank begins tilting forward as it enters a sharp incline, a vehicle that is meant to be towing something behind it is a different matter entirely.

Towing a gun? Easy. What about towing a tank?


Towing was done twice, after the tank travelled 432 km and 767 km. The total distance of towing was 20 km. In the first case, an IS-122 and a KV-85 were towing an IS-122. In the second, an IS-122 towed an IS-122.

In both cases, the tank was towed over a dirt road trampled by tanks, and partially on an asphalt highway covered in packed snow, at 1st and 2nd gear, with external temperature between -5 and -9 degrees.

During towing, the engine's temperature was normal. The water temperature stabilized at 65 degrees. The oil temperature stabilized at 72 degrees.

Photo #27: IS-122 and KV-85 tanks tow an IS-122 tank on a road trampled by tanks."

CAMD RF 38-11369-351

A SU-100 undergoing mobility trials, showing the perils of a gun that is too long on bumpy terrain. The end of the gun is covered to prevent mud from getting in, but the sack cannot hide the distinctive shape of the muzzle brake. This is no ordinary SU-100, but a SU-122P, a SU-100 with a D-25 gun.

The sack was there for a very good reason.

"Fig. 2. The 122 mm SPG D25-SU-122P hits the ground with its barrel when descending from a bump with the gun elevated at 12 degrees."

Thursday 24 July 2014

Diesel for T-37

"From Tukhachevskiy
To comrade Stalin
June 28th, 1934

Currently, the construction of the Ufa Motor Factory is being completed, which will produce automobile and tractor engines of various types from 40 to 175 hp. The factory will have a diesel plant, which will produce 10,000 engines for heavy fuel per year. The diesel engine plant and its support plants are almost complete. 

The main task right now is supplying them with equipment. If this is done, diesel motors may start production in 1935. The issue of equipment at this factory was raised a number of times at the NKTP, but never received a positive answer, since it was explored only from the point of view of car and tractor engines. The Ufa factory has the potential to become a production base for modern tank engines.

The T-37 scout tank should be converted to a diesel motor. This motor, which is compatible with the T-37, is currently undergoing trials in Moscow in a truck. This is a Perkins motor, 50 hp, with the same size as the Ford motor, but only 100 kg heavier. 

If such a motor is installed on a T-37 tank, the higher power will result in much higher tactical qualities of the vehicle. 

The diesel plant of the Ufa factory can produce 500 motors of this type in 1935, if it is supplied with 110 units of domestic equipment and 45 units of imported equipment (costing 300,000 rubles).

The factory is not equipped at this time, and delays in solving this issue may result in no motors being produced in 1935. I ask that you listen to the issue of preparing the Ufa Motor Factory at the Defense Commission.

Deputy People's Commissar of Defense, Tukhachevskiy"
RGASPI 558-2-113

Wednesday 23 July 2014

Another Raseiniai

Here is an interesting scenario, very similar to the Battle of Raseiniai just over a year earlier: a KV tank stuck with no support turns back a vastly numerically superior German force. However, Raseiniai was reconstructed entirely from German documents, whereas this award order was composed after investigating the area and questioning nearby villages.

"Award Order
  • Name: Konovalov, Semen Vasilyevich
  • Rank: Lieutenant
  • Position and unit: KV tank commander, 1st company, 1st tank battalion of the 15th Tank Brigade
  • Year of birth: 1920
  • Nationality: Russian
  • Service in the Red Army since: 1930
  • Party membership: VLKSM
  • Wars fought in: Patriotic War
  • Wounds or concussions: none
  • Previous awards: none
  • Recruited at: Tenkov recruitment office, Tatar ASSR
On July 13th, 1942, near the N-Mityatinskoye region, Lieutenant Konovalov's KV tank was immobilized by a breakdown. The crew was repairing the tank. At this time, two German armoured cars were spotted. Comrade Konovalov opened fire, and burned up one armoured car, the other got away. A column of tanks followed the armoured car, first 35, then 40 more. The enemy was moving towards the village. Lieutenant Konovalov, using his position in a camouflaged tank, decided to face the enemy in battle. At 500-600 meters, the tank opened fire. 4 tanks were destroyed. The enemy did not engage, and retreated. Shortly after, the column repositioned, and attacked the village with 55 tanks. Lieutenant Konovalov decided to continue fighting the enemy vehicles, despite their numeric superiority. The crew torched 6 more enemy tanks, forcing them to retreat. The enemy attempted a third attack, but the heroic tankers decide to fight to the last shell. They destroyed 6 more enemy tanks, 1 amoured car, and 8 vehicles carrying enemy soldiers and officers. The Soviet fortress fell silent. The enemy opens fire from a 105 mm gun from a range of 75 meters. The heroic crew, along with Lieutenant Konovalov fell in this uneven fight. Protecting our Motherland, Lieutenant Konovalov demonstrated heroism worthy of a posthumous award of the title "Hero of the Soviet Union", with the Gold Star and Order of Lenin.

1st tank battalion commander, Senior Lieutenant Vasiliyev"

There is also another difference between this and Raseiniai: the crew did not all die. Three crewmen (including Konovalov) managed to leave the KV through the "hatch of heroes", wander around the enemy rear until they "found" a tank, and drove it back to their lines.

Tuesday 22 July 2014

SU-85 and SU-57

I wrote about some of these light TDs before, but here is a document describing them in more detail.

"Report of results of a trip to the Molotov GAZ factory in the city of Gorkiy

Experimental work is being done on the following vehicles:
  • SU-85: an 85 mm D-5S-85A gun on the SU-76 chassis
  • SU-57: a 57 mm ZiS-2 gun on the SU-76 chassis
  • KSP-76: a 76 mm ZiS-3 gun on the GAZ-63 chassis
  • Automobile mount of a 76 mm ZiS-3 gun on a GAZ-AA chassis
1. SU-85 on a SU-76 chassis: Consists of an 85 mm D-5S-85A gun on a production SU-76 chassis. It differs in the following ways:
  1. An 85 mm gun is mounted.
  2. The engines are turbocharged to 85 hp.
  3. Planetary final drives are used.
  4. Shock absorbers are installed in the front and rear.
  5. The rear armour hinges downwards.
  6. The return idlers are removed, and replaced with a runner.
  7. The size of the porthole is increased.
The tactical-technical characteristics of the vehicle are as follows:
  1. Mass: 12 tons
  2. Crew: 3
  3. Length with gun: 5500 mm
  4. Maximum speed: 35 kph
  5. Average speed on dirt road: 20 kph
  6. Average speed on highway: 28 kph
  7. Ground pressure: 0.54 kg/cm^2
  8. Effective hp/ton: 14.2
  1. Gun: D-5S-85A
  2. PPSh: 2
  3. 85 mm shells: 40
  4. Maximum gun depression: -5 degrees
  5. Maximum gun elevation: +15 degrees
  6. Horizontal traverse: +/-12 degrees
  7. Bore axis height: 1670 mm
  8. Periscopic sight: Hertz panorama
  9. Telescopic sight: TSh-15
  1. Type: GAZ-203F
  2. Maximum hp: 2x85/3600
  3. Gearbox: ZiS-5 type with reinforced roller
  4. Final drive: 2-stage cylindrical pair with a planetary mechanism, ratio 1:7.8
  1. Tracks: T-70 type
  2. Number of teeth on drive sprocket: 16
  3. Type: Torsion bar, with additional shock absorbers on rear and front.
The other parameters of the SU-85 are identical to the SU-76. A prototype was manufactured and underwent trials. Trials were satisfactory. Assembly of a second prototype is in progress and will be delivered to trials on June 25th, 1944. In case of successfully completed trials, the factory can begin mass producing the vehicle without much difficulty in 0.5-1 month.

2. SU-57 on the SU-76 chassis: The prototype has been built. The electric firing mechanism has not been tested. The factory has scheduled gunnery trials."

Monday 21 July 2014

Super BT

Tactical-Technical requirements for armour screens of BT-5 and BT-7 tanks
July 4th, 1941

Overall requirements

In order to increase the armour of existing BT-5 and BT-7 tanks, it is necessary to attach armour screens. The main requirements of armour screens are as follows:
  1. The armour must be attachable at repair bases, repair factories, and at factories when the tank undergoes major repairs.
  2. Screens can be attached directly against the armour, as well as up to 25 mm away from the armour.
  3. The reliability of armour screens should withstand driving the vehicle and being hit by machinegun bullets and shells.
  4. In all cases, the armour cannot sustain brittle damage (cracking and shattering).
  5. Experimental screens are produced in two variants:
    1. the first variant, equipping the BT-5 with armoured screens:
      1. Front of the hull: 35 mm thick
      2. Upper side hull: 30 mm
      3. Turret: 35 mm
      4. Rear: 20 mm
    2. the second variant, equipping the BT-7 with armoured screens:
      1. Front of the hull: 35 mm thick
      2. Upper side hull: 30 mm
      3. Turret: 35 mm
      4. Rear: 20 mm
        Note: factory #183 is allowed to increase the thickness of these screens with the condition that the total weight of the plates does not exceed 3000 kg.
  6. The changes to the mobility characteristics of the BT-7 and BT-5 will be evaluated during trials.
  7. Two BT-5 and two BT-7 tanks will be built.
  8. The screens should be compatible with both cylindrical and conical turrets, with the condition that the turrets still need to rotate 360 degrees.
  9. While designing the screen configuration, factory #183 should resolve the following issues:
    1. a) Technological process of screen production
    2. b) An original method for the attachment of screens.
    3. c) Instructions for installation and removal of tank components with the screens mounted.

Chief of the 3rd Department of the BTU, Military Engineer 1st grade, Afonin
Chief of the 3rd Section of the 3rd Department of the BTU, Military Engineer 2nd grade Vurtsev"

Sunday 20 July 2014

World of Tanks: Today in History: First Russian Tank

On July 20th, 1915, a Russian engineer named A.A. Porokhshikov arranged for the first demonstration of the "Vezdekhod" vehicle, which is now considered one of the first prototypes of a Russian tank.

As all tank projects of the early 20th century, the Vezdekhod had little in common with modern vehicles. It was a small tankette with an aerodynamic shape, which propelled itself with the aid of a wide strip of rubberized fabric stretched over rotating drums. The engine power was only 10 hp, but due to the vehicle's small mass (3.5 tons), it could reach speeds of up to 25 kph.

The July 20th trials showed that the vehicle did not measure up to Porokhovshikov's calculations. The fabric strip tore and slipped off its drums, the turning mechanisms were so weak that the driver needed to push off with a pole to maneuver, and the low cabin was too small for even one person. 

As the fabric strip proved unusable, Porokhovshikov abandoned it, and used a wheel and track design. The suspension was novel as well. The Vezdekhov would travel on roads using its front wheels and the rear sprockets of the tracks. To clear obstacles, the tank could "lie down" on the tracks entirely.

The tank's drawbacks were never fully resolved, and the vehicle did not make it to mass production. Nevertheless, the Vezdekhod was a novel design for its time. It was the first to use friction clutch turning mechanisms, a convertible drive (if in an unusual form), and armament in a rotating turret.

Original article available here

Valentine Spurs

You see a lot of mentions of spurs for Lend-Lease vehicles in memoirs, but not a lot of details. Here is a detailed description of that these spurs would look like.

"Brief description of removable NIBT designed spurs

Eight spurs are attached per track. The foundation of the spur (fig. 1) is composed of ribbon steel. Its edges are bend, and have openings for a track pin. A spine is welded to the top of the ribbon, which improves traction.

The spur is connected to the tracks with an oversized track pin. The pin is affixed with a spring ring.

Fig. 1: Overall view of the spur and connecting track pin.

Fig. 2. Components of the spur and the connecting pin."

The NIBT solution wasn't the only one.

"According to an order from the Chief of the Tank Directorate of the GBTU of the Red Army, Major General of the Tank Forces, Afonin, the NIBT proving grounds familiarized itself with track spurs proposed for the MkIII tank by comrade Zaharenkov.

It was established that:
  1. The spurs are made from bent iron with a wave shape, which will be difficult to produce by the tank units themselves.
  2. The spurs are welded to the tracks, and are impossible to remove on good quality roads.
NIBT developed two types of spurs in 1942, two rectangular plates welded to the track, and removable ones (see photo #1 in the attachment). 

Both spurs were trialled on the tank in winter, and showed good results in terms of performance and reliability. 

Spurs proposed by comrade Zaharenkov are a repeat of already tried designs, but are more difficult to produce.

The removable spurs are more convenient to use, as they can only be used on poor roads, which will prevent the destruction of good roads, as well as excess shaking, lower speed, and higher fuel consumption. 

The NIBT proving grounds recommends the spurs developed here as those that best solve the issue of increasing off-road performance, are easy to produce, and have been tested."

"Conclusions on the spurs for the MkIII tank produced by GBTU NI proving grounds
  1. Valentine tank tracks are sufficiently modern, and there were no complaints (especially in the summer) about their grip. However, proving grounds trials showed that in winter, Valentine III and Valentine VII tanks have insufficient grip on snow (especially packed) when tilted (10-12 degrees).
  2. The removable spurs developed and trialled at the NI proving grounds increase the maximum tilt (24-25 degrees).
  3. The spurs are simple to produce and install, and can be produced in the field. I consider it reasonable to recommend units to produce these spurs and use them depending on road conditions.
  4. The design of the spurs proposed by comrade Zaharenkov is unusable, as they demand more time and resources, make the track significantly heavier, and reduce the performance characteristics of the tank.
December 24th, 1943"

Saturday 19 July 2014

Penetration, Part 6: Field Artillery Edition

While knowing how well your tank guns perform against enemy tanks is very important, sometimes things don't go as planned, and instead of the predicted location, tanks show up right in front of your face. In that case, it's important to know how well all of your artillery works, not just tank guns. These trials examined the performance of divisional level guns and up against armour. The answer may surprise you! That is, unless you read Penetration Part 3, in which case it will not, as many of the guns tested show up there as well.

"Report on the composition of tables of penetration for 122, 152, and 203 mm concrete piercing shells for A-19, ML-20, and B-4 systems

Assignment #7773

From April 17th to May 15th, 1941, ANIOP composed theoretical calculations for penetration of 122, 152, and 203 mm shells, and then tested them by shooting at the expected velocities. Work was done according to a program composed by ANIOP and confirmed by Deputy People's Commissar of Defense, Marshal of the Soviet Union, comrade Kulik on December 19th, 1940.

Process steps:
  1. Processing of experimental data from ANIOP records.
  2. Performance of trial shooting at 500, 1000, 2000, and 3000 equivalent velocities at plates 30 degrees from normal.
  3. Processing of data and composition of data tables.
  4. Processing of experimental data to determine the penetration of 152 mm, 122 mm, 107 mm, and 76 HE shells, and composing penetration tables for HE shells.
Tables for 122 and 152 mm shells were not composed due to a lack of trials material at ANIOP."

Then we have a short section on how the De Marre equation works, which I am sure you are all familiar with. To the practical tests!

"Firing at provided velocities.

Firing the 122 mm corps gun model 1931 (A-19) and 152 mm gun-howitzer model 1937 (ML-20) was done at the 8.5 kilometer position. Firing from the 203 mm howitzer model 1931 was done at the NIMAP main battery. The plates at 8.5 km were hung on metal frames and held on at the corners with bolts. The plate at NIMAP was attached to a large stump using rivets. 

Shells used were: stock concrete penetrating 122 mm 2-02819, 152 mm 2-04834, and 203 mm 2-1763, with sulfur charges and blank detonators. 

The propellant was reduced, with the following gunpowder types:
  1. 122 mm gun: NF 17/1 26/39 P
  2. 152 mm gun-howitzer: 15/7 TsA 18/39 Shuf 
  3. 230 mm howitzer: 17/7 sb.21/40 Shuf
Material on the HE action of 76 and 107 mm shells was taken from ANIOP reports.

Results on shooting concrete piercing shells is attached in table #1. Detailed results are in attachments. Graphs of calculated and experimental penetration are in the attachment. After firing, the shells and plates were photographed, the photographs are in the attachment."

Sadly, I do not have the attachments, nor the next few pages. I do have the conclusions though.

"Summary and Conclusions

Inspection of table #1 and the graphs concludes:
  1. Results are significantly lower than calculated. Shooting at 500 meters, the penetration is 102 mm with 203 mm concrete piercing shells (calculated: 154), 100 mm from 950 meters with the 122 mm gun (calculated 138 mm) and 90 mm at point blank with the 152 mm gun-howitzer (calculated 132 mm). HE shells penetrate 40 mm (107 mm gun model 1910/30) at point blank and 30 mm at 500 meters with the 76 mm L/40 divisional gun model 1902/30.
  2. The best penetration was achieved by the 122 mm concrete piercing 2-02819 shells. These shells can penetrate 5-6 mm more than 203 mm shells. 
  3. When penetrating armour, both HE and concrete piercing shells shatter into fragments. The breach in the armour with the caliber of the shell counted as the penetration. In this case, the damage beyond the shell would be dealt by the fragments of the shell and the armour.
  4. Most experimental data points lie in the vicinity of a 2200 resistance factor armour plate, which is what was used in calculations."