Tuesday, 29 April 2014

ZiS-5 (3-K)

Aside from the ZiS-5 we know and love, there was another project with this designation, which started in early 1941. The gun was based on the 3-K model 1939 76 mm AA gun, and was noticeably longer than the ZiS-5 that ended up on the KV in late 1941.



"Summary:

Based on trials of the experimental 76 mm tank gun (ZiS-5) in a KV-1 turret, tested over 612 shots and 170 km, ANIOP has come to the following conclusions:
  1. The robustness of the system in general is satisfactory. The factory must increase the robustness of the breech wedge by increasing the quality of the metal, as there was a dent in the lower part of its bearing surface.
  2. The recoil mechanisms of the model 1940 tank gun [F-34] (without a compensator) used in the ZiS-5 system performed satisfactorily, and may be used in this gun system. The factory must improve the return mechanism valve due to its unreliability (when checking pressure, air and fluid can escape through the valve).
  3. The semi-automatic mechanism worked perfectly. There were no breakdowns or deformations. The elevation and trigger mechanisms are reliable, and worked perfectly. The factory must:
    1. Balance the oscillating part of the gun such that the effort required to lower the gun is decreased (effort reached 9-12 kg). 
    2. Turn around the elevation mechanism handle and put it closer to the sight for more convenient work.
    3. Put the firing mechanism lever closer to the elevation mechanism for more convenient work.
  4. The model 900 telescopic sight performed satisfactorily, and can be used with the ZiS-5 gun in the KV-1 turret.
  5. The deviation at 1000 meters is satisfactory:
    1. Shooting with AP shells:
      1. Vertical deviation: 0.17 - 0.24 m
      2. Horizontal deviation: 0.16 - 0.2 m
    2. Shooting with HE shells:
      1. Vertical deviation: 0.29 - 0.34 m
      2. Horizontal deviation: 0.18 - 0.35 m
  6. The gun has insufficient depression (-2 degrees), which is less than required (-5 degrees).
  7. The gun's length does not impede maneuverability. The gun is not afraid of dirt during marches.
  8. Only 44 testing shells were fired. The testing program requires 180 such shells. 120 various special shells that are mentioned in the report body do not give sufficient information about the robustness of the system when firing special shells, as the mount was loaded 14.5% less than required.
    The possibility of using a special shell with this system is doubtful, as the force of resisting recoil reaches 16,000 kg (at the end of the recoil), which is twice as much as calculated. The factory must revise the recoil mechanism in order to make the resistance uniform through the entire path when shooting with a special shell.
Conclusions:
Based on the results of the trials, ANIOP has come to the following conclusions:
  1. The 76 mm ZiS-5 tank gun in the KV-1 turret passed trials. After removing the defects in the report, the gun can begin production.
  2. The feasibility of using special shells is still undetermined. Additional trials must be done using a special charge at a temperature of 40-50 degrees (at a rate of fire of 4-5 RPM), 100-120 shots in total. This can be carried out by the GAU military representative at the factory proving grounds."

Sunday, 27 April 2014

Tigers for Dummies

In January of 1943, the Germans left two Tigers at Worker's Village #5. They left in a hurry, without bringing anything in the tank, including manuals. These manuals promptly fell into the hands of the Red Army.

"Translation from German

Overall short directives of using Tank VI, design H-1
July 14th, 1942

1. Tank hull.

Exit hatches, bottom hatches, and other covers, such as the pistol ports, must be free of sand and dirt used for waterproofing.

2. Engine.

The engine can be cold started by the electric starter. In order to start the engine as quickly as possible, one should use the electric fuel pump for 10-20 seconds. During the winter, it is necessary to let the engine warm up. Turn off the cooling fan while you do this! The engine may only be loaded when the temperature of the coolant water reaches 50 degrees.

With new or refurbished engines, it is necessary to replace the oil after 200, 500, 1000, 2000, and then every 2000 km. At this time, the oil filter should be extracted and cleaned.

3. Radiator.

The radiator should be filled with clean water. Before using the tank, check the level of coolant water. It should be high enough for the mesh bottom of the cap to be moist when the tank is horizontal. In the winter, add anti-freeze. When the tank is in motion, the water temperature should be 85 degrees.

4. Fuel tanks.

The fuel is stored in two tanks, to the left and right of the engine. These tanks are connected to the tanks in the engine compartment. The tanks must constantly be checked to ensure they are not leaking.

5. Drive Shaft.

The drive shaft joints should be oiled every 2000 km with a special high pressure oil injector. The drive shaft is lubricated with oil.

6. Gearbox and main friction clutch.

The selection of the gear and its activation are two independent processes.

  • Starting the engine: push the clutch in, push the starter button, release the clutch, and let the gearbox warm up.
  • Moving: place the gearbox lever into position. Moving forward is possible at any gear. Press down the clutch, push on the gas, and slowly release the clutch.
  • Preliminary selection of the gear: with a lever next to the steering wheel, select the desired gear. You do not need to push the gas. Gear selection can be done in any gear.
  • Stopping: the tank can be stopped in any gear. The gear lever may be enabled or disabled in positions 1-4.
  • Reverse: when in gears 1 through 4, the reverse gear can be selected by pushing on the clutch and moving the selection lever into reverse.
Do not leave your foot on the clutch. Use the clutch only when moving from stationary, stopping, or braking.

7. Steering mechanism and steering column.

When driving on roads, steering is done exclusively with the steering wheel. Two radii are on each side. The size of the radius depends on the gear. The smaller the radius, the lower the gear.

On narrow turns that cannot be achieved on low gears, turn the steering wheel to its limit and push the clutch. The tank will spin in place, with one track in one direction and another in the other. Accelerate by pushing the segmented button near the gearbox and pushing on the gas.

In emergencies, the steering levers may be used. Pushing on one stops a track, and the other track remains in motion with twice the RPM.

When motion is resumed after stopping the tank, ensure that the steering wheel points forward, otherwise the tank will begin rotating as soon as the engine is started.

8. Brakes.

Both tracks can be braked either together, or individually. The brakes are friction disks, and are activated by pushing the brake pedal. They can also be activated using the hand levers.

Steering may be done with the track brakes in emergency situations.

9. Running Gear.

The running gear must be carefully taken care of and kept free of mud, dust, and sand. Regularly oil all running gear components that need oiling with a greaser.

10. Tracks.

Make sure that the track pins are kept in place with a circular stopper. If it is absent, the track pins can be retained by using firm wire bent into the shape of the letter S, slipped through the hole in the end of the track pin.

Broken track links or pins should be immediately removed, and stoppers retained, as they are instrumental for the tank's ability to move.

When tightening the track, it must hang freely and lie on all road wheels except the first. The track is tightened with two screws near the rear idler wheels.

When installing new tracks, make sure they are not placed next to each other, but spaced out through the whole track. If the tracks are worn down, swap the left and right tracks. Replace heavily worn track pins and drive wheels. 

The idler should be movable by 100 mm. If this is not enough to tighten the track, remove one track link.

To repair a partially slipped track, remove a track pin near the idler wheel. By back and forth movement, the track is moved into normal position. Free the idler wheel, fix the lower part of the track, insert the track pin, and replace the track on the idler wheel.

In the event of a fully slipped track, place it flat in front of the vehicle and drive up on it until the rear part of it reaches the idler wheel. Put the front part of the track on top of the idler wheel and slowly spin the idler wheel backwards until the track is stretched. Then insert the track pin.

11. General driving instructions.
  • Do not drive when water coolant temperature is less than 50 degrees.
  • Do not drive when the tachometer hand is in the red zone.
  • Only use the 1st gear to climb and descend from steep hills, trenches, ravines, craters, and difficult to observe terrain. 
  • When going through flat terrain, use the 2nd gear.
  • Only go quickly on well observable terrain. On all terrain with poor visibility and the possible need of overtaking a vehicle, go slowly.
  • During extended marches in the summer, keep the engine below 2400 RPM.
12. Off-road driving.
  • In order to preserve fuel, it is necessary to carefully choose the route. If possible, direct the vehicle across easily traversible terrain (little elevation change, firm ground). 
  • When possible, avoid moist plowed ground, swamps, deep sand. 
  • When knocking over trees, ensure that the vehicle is not lifted by the roots of the tree. The last push on a tree that needs to be felled should be done with only one track.
13. General lubrication directions.
  • Engine
    • It is necessary to measure and refill oil daily. Do not allow excess oil. The tank required domestically produced motor oil.
    • When replacing oil, it is necessary to drain all oil from the engine and replace it with new oil. Make sure the oil is warm when you pour it in. Pour oil in through the oil valve. When changing oil, clean the oil filter.
  • Gearbox
    • The gearbox takes 32 liters of oil through the red cap in the rear. This amount of oil includes reserves for the steering mechanism. The oil levels should be checked in the top right every 500 km. When replacing the oil, clean the oil filter. The oil is replaced by disconnecting any connector below the drive and pumping it out with a hand pump.
  • Steeling mechanism
    • The steering mechanism shares the oil reservoir with the gearbox and does not require special refilling.
  • Final drives
    • The oil reservoirs in the front left and right can be reached through hatches. Approximately 8 liters of oil is required. Two openings are present in the lower part of the final drive, one to drain the oil, the other with a valve that limits the height of the oil.
  • Turret traverse
    • The turret traverse casing has a screw cap in the bottom part for draining oil, and one in the middle for filling oil. This cap can be used to measure the level of the oil. Fill in oil until the level of the cap.
  • Fan
    • The fan drive has an opening for measuring the oil levels. Do not permit the oil to run dry, as each of the 4 separate oil reservoirs must have sufficient oil. Only measure the oil levels when the engine is running.
  • Thick grease
    • When replacing thick grease, ensure that the grease press provides sufficient pressure for the old grease to seep out and create a barrier. That is the only way to ensure that new grease comes in clean with no debris.
  • Lubrication on assembly
    • All bearings, ball joints, mobile shafts and guides must be lightly greased. Immobile shafts, brake pads, and trunnions must be greased with collagen graphite grease.
14. Electrical wiring and its troubleshooting
  1. If the key is in and the lamps do not turn on in positions 0, 1, or 2, turn on the main battery switch.
  2. If the main battery switch is on and the lamps are not, check the fuses. If the fuses are burnt out, replace them.
  3. If the electric fuel pump does not work, examine the appropriate fuses, and replace them if necessary.
  4. The red starter light should only be on when the tank is started. If it remains on, the regulator switch is malfunctioning. Only a specialist should replace the regulator switch.
  5. If the automatic fire extinguisher wiring is faulty, it can be manually activated by pressing a mechanical button.
15. Automatic fire extinguisher

When a fire is detected and the extinguisher goes off, a red signal lamp turns on to notify the driver that the engine has caught fire. In order to remind him of this, the lamp is labelled "Engine fire, immediately idle". 

If the fire is severe and the heat sensors have not cooled off within 7 seconds, the second stage of firefighting begins, in parallel with the first. It can repeat until the extinguishers are empty. The signal lamp will turn off when the firefighting system turns off automatically. One fire extinguisher load weighs about 4 kg, with 2 liters of SV firefighting fluid.

16. Movement underwater

Before proceeding with movement underwater, inspect all hatches, caps, and grilles, to ensure that water cannot come through them into the tank. All hatches must be tightly shut. This is most important for hatches accessible only from the bottom.

Preparations for moving underwater
  1. Test and lock all hatches in accordance to paragraph 2 (Tank hull).
  2. Test the cover between the engine and fighting compartment.
  3. Set the turret to march position.
  4. Cover the gun with the muzzle case.
  5. Cover the slits in the turret using the waterproof strips.
  6. Cover the machineguns.
  7. Open the cover in the rear above the engine deck and extract the intake air hose.
  8. Tightly put together components of the air intake pipes and screw them into the appropriate opening.
  9. Loosen the stopper bolts on the exhaust caps.
  10. Switch the warm air pipes to the engine compartment.
  11. Switch the three-position fuel tank exhaust switch to the engine compartment.
  12. Close the air exhaust device.
  13. Open the cover between the engine and fighting compartment.
  14. Turn on and test the turret traverse.
  15. Turn off the fans immediately before submerging.
Leaving water
  1. Turn on the fans immediately after leaving water.
  2. Prepare the main gun and machineguns for combat.
  3. Remove the watertight strips from the turret slits.
  4. Open the bottom valve and pump out the water that seeped into the tank.
  5. Switch the warm air pipes to the fan compartment.
  6. Switch the exhaust switch to travel mode.
  7. Switch the three-position fuel tank exhaust switch to external.
  8. Demount and put away the air intake pipe.
  9. Tighten the stopper bolts on the exhaust caps."

Next is the labels for the automatic fire extinguisher diagram, but it is not very useful, as the diagram is not in the translated document. 

E-100 Flop

A report from the Combined Intelligence Objective Sub-Committee #19, file XXXII-35 briefly recalls the sad fate of the German super-heavy E-100 tank.


Saturday, 26 April 2014

Donations

I previously mentioned that some people donated money to buy a tank for the Red Army. Here is how much money was donated and how many tanks it bought between 1942 and 1945.


The columns are obviously years, with the final column being the total over the 1942-1945 period. The rows are as follows:
"Total received for tank construction
Additionally, golden rubles (total only)
Additionally, in old (total only)

From workers, factories, and other organizations
From farms of the 65 regions and republics
Personal contributions from soldiers and units
Teachers and students
Churches and churchgoers
The ill, wounded, and hospital staff
Individuals, of those, 47 contributed 100,000 roubles or more

Cost of tanks and SPGs given to armoured units"

Then there is a breakdown of how many tanks were given:
"For national units
a) Polish
b) Czech

For the 1st Ukrainian Front
For the 2nd Ukrainian Front
For the 3rd Ukrainian Front
For the 4th Ukrainian Front
For the 1st Baltic Front
For the 2nd Baltic Front
For the 1st Belorussian Front
For the 2nd Belorussian Front
For the 3rd Belorussian Front
For the 1st Tank Army
For the 2nd Tank Army
For the 3rdTank Army
For the 4th Tank Army
For the 5th Tank Army
For the 6th Tank Army
For Tank Corps
For Mechanized Corps
For various
Total

Note: the amount of tank columns transferred in 1942-1943 is approximate due to a lack of documents"

Note how many vehicles were given in total: over 30,000 tanks and SPGs. 


Defensive KV Line

"To the Secretary of the Leningrad City Council, Kuznetsov for Voroshilov, Zhdanov, Popov, Molotov

The line between the southernmost point of the Krasnogvardeysk fortified region and the Volkhov river south of Luban or Chudovo is about 120 kilometers long. I understand that building a fortified region over that space is difficult. In order to make it easier, I suggest the following plan. Spread out KV tanks through the whole stretch between the southernmost point of the Krasnogvardeysk region and Volkov river, one per kilometer on average (spaced by 2 km or 500 m in places where the terrain needs it). Behind these tanks, place less powerful tanks and armoured cars. After this tank line, place heavy artillery. Infantry divisions are placed directly behind the tanks, using not only their firepower, but armour as cover. This needs 100-120 KVs. I think you can make that amount in 10 days. Stavka can give you 10 days worth of KVs starting on August 29th or 30th. This way, you have a fortress of tanks, artillery, and infantry that can be, at the same time, a division's mobile protection or an offensive wall. If you and the arriving Muscovites approve, I suggest we immediately move from words to actions. The decision to evacuate Putilov and Izhor factories was made yesterday by the Committee of Defense. In connection with the above plan, I delayed the evacuation. If the plan is approved, the Committee can cancel the decision. I await your immediate reply.

#1449/III
Stalin."
RGASPI 558-11-492

Thursday, 24 April 2014

World of Tanks: Today in History: First Tank Battle

On April 24th, 1918, the first tank battle in history happened near a small city called Villers-Bretonneux in the north of France.

The British side was armed with a unit of three MkIV tanks, two "females" with machinegun armament and one "male" with two short barreled 6-pounder guns in its sponsons. The unit was commanded by Captain David Brown, who was in the "male" tank. The tank itself was commanded by Lieutenant Frank Mitchell. 7 medium Whippet tanks also too part in the battle, faster than the MkIVs, but with significantly poorer armour and armament.

Three German A7V tanks opposed the British. These tanks weighed 30 tons, and had decent armour for the time, but were clumsy and could not boast good off-road performance. The A7V was armed with a 57 mm gun in the front, and 6 Maxim machineguns around the perimeter. This monster was crewed by 18 men.

The Germans were advancing towards Amiens. In the early morning of April 24th, Captain Brown returned from a reconnaissance mission and reported that he discovered moving German infantry. Brown did not know that the Germans had tanks. British tanks moved out to the forest clearing in order to attack the infantry. Since the vision of these new tanks was poor, they had a forward observer. At about 9 am, the observer returned, reporting that he discovered a German tank.

Brown left his tank and ran towards the "females" to warn them of the danger (their machineguns could not harm the German tank, but the German tank's gun could knock them out). At the same time, Lieutenant Mitchell ordered to fire on the enemy.

When the MkIVs were turning around to retreat, the Germans spotted them. One of the tanks was hit, but could still move. Mitchell's tank was firing from its right sponson, but could not dial in and hit for some time. The German tank retreated, firing on the move at the British tank, with no results.

Frank Mitchell ordered the tank to stop. This allowed him to aim and hit the German tank three times. The Germans lose three crewmen and suffered damage of the oil system. The wounded A7V managed to retreat two kilometers in reverse, after which the engine stalled.

Mitchell's tank supported his infantry with cannon fire. At the same time, 7 Whippets broke through the barbed wire and suppressed the German soldiers with machinegun fire.

Unfortunately for the British tankers, two more A7Vs were nearby. The Germans destroyed two of the seven tanks like on a firing range. The rest began a hasty retreat. However, in mere seconds, the engine of a third Whippet gave out, and soon after, a fourth broke down. Only three British medium tanks came back out of 7.

Mitchell opened fire at a German tank, but luck was not on his side that day. First, his tank was hit by a British bomb after the pilot confused the tank for a German one, then it hit a mine, severing a track. Mitchell ordered the crew to abandon the tank and retreat.

The first tank battle was not large scale, but it demonstrated the advantage of cannons over machineguns. The presence of a cannon became mandatory for most tanks that were subsequently built in Europe and around the world.

Original article available here.

Pz38(t) Crewman Interrogation

From L.V. Gorchakov's collection.

"To:
Army Armoured and Motorized forces chiefs
Tank brigade commanders
Independent tank battalion commanders
February 28th, 1942

I am forwarding a record of an interrogation of a German prisoner. I propose that you carefully study points 37-60 and consider them in subsequent work when studying the enemy and conducting battle actions against the enemy.

Deputy Chief of the Leningrad Front ABTU, Colonel Salminov
Military Commissar of the Leningrad Front ABTU, Senior Battalion Commissar Lampusov

Protocol of interrogation of a POW, radio operator, 9th company, 21st tank regiment, 20th tank division Emmanuel Schmidt on January 16th, 1942, captured on January 12th, 1942, in the Novoborisovo village.
  1. What unit are you from?
    9th company, 21st tank regiment, 20th tank division.
  2. What is your speciality?
    Tank radio operator.
  3. What type of tank? PzII, PzIII?
    I was in a Czech tank. It is equivalent to the PzII tank, with a turning turret. It is armed with a 37 mm gun and two machineguns. [Pz38(t)]
  4. How many crewmen?
    The crew is 4 men. Driver, radio operator, commander, loader.
  5. Who commands the tank?
    The tank is commander by an officer or unteroffizier.
  6. How many shells are stored in the tank?
    90 37 mm shells.
  7. How many machineguns and bullets?
    There are two machineguns. There are as many as 4-5 thousand bullets, I don't know for sure. If there is a radio, then there is no machinegun, and if there is a machinegun, then there is no radio.
  8. How many tanks in a company?
    17 tanks.
  9. Out of 17 tanks, how many have radio transmitters?
    4 have transmitters. The company commander, and the platoon commanders. The company commander has a spare tank.
  10. How many tanks are left in the 10th company right now, where are they, and what tanks are lacking?
    10 tanks, the rest broke down. They are at Nikolskoye and Novoborisovka.
  11. Who is the commander?
    The company commander is Lieutenant Winter. Before him there was Trier, but he was wounded. The commander of the first company is named Strosser.
  12. What is the radio range?
    3-4 kilometers to receive and up to 4 to transmit.
  13. Is this an ultra-shortwave radio? What frequency does it work on?
    It is an ultra-shortwave radio, it works with a microphone.
  14. Do you encode your communication?
    No, we talk openly, only encode unit numbers.
  15. What party are you a member of?
    I joined the Hitlerjugend at 14 so I could go to school. Now I'm 20.
  16. What is the range of the tank?
    100 kilometers off-road, 150 on a highway.
  17. How many liters of fuel can the tank carry?
    250 liters.
  18. What engine does the Czech tank use?
    There are three companies that make the "Praga" engines, Skoda makes the tanks. The engines are made in Prague, Veirbrach [Beirbach?] sends the engines for German tanks to use.
  19. What is the cooling on the tank?
    The tank is water cooled. In the winter, we use a non-freezing mix called Glizantin.
  20. What is it composed of? How does it smell?
    It is like water, but does not freeze until -30 degrees. I don't know how to make it, we get it pre-made. The driver pours it into the radiator.
  21. Who replaces the driver when he is wounded?
    The radio operator, or anyone that knows how to drive.
  22. What state do you get Glizantin in?
    I don't know, we get it in liquid form, mixed with water. It is slightly thicker than water.
  23. Do you have a powder that you mix with water to make it not freeze?
    No, we only get Glizantin.
  24. Tell the truth, we already know all of this.
    Good, I am telling you all I know.
  25. How thick is the armour of the Skoda tank?
    5 cm in the front, 2 cm on the sides. The tank weighs 10 tons. These are latest tanks, older tanks have 3.5 cm of armour. We only got new ones on October 20th.
  26. What shells do you use against our tanks?
    We use model 1940 shells [PzGr 40] with soft walls but a very hard core.
  27. Do you have thermite shells in your tank?
    We do not have such shells.
  28. When were you drafted into the army?
    I was drafted on October 15th, 1940, in Bromberg. I was in infantry first, then I was moved to a tank unit.
  29. Did you use this book when studying in infantry, or no?
    We used Reiberg's book. I only spent 7 weeks in infantry, as a simple soldier, then was transferred to the 21st tank regiment. The division was located in Turing, the regiment in Stuttgart. I studied for three months to be a radio operator.
  30. When did the division come to Russia, and did it get new men?
    On June 30th, we moved out from our location. On July 22nd, we arrived in Russia. We lost more than 17 tanks.
  31. What is the organization of your regiment?
    Before the war it was divided in there (battalions). Now we have only one, the first and second were combined.
  32. What companies are in your battalion?
    9, 10, 11, 12 companies and the HQ company.
  33. What is in an HQ company?
    There are two tanks for the company commander, a main and a spare.
  34. What tanks are in your company?
    3, 5, 6, 6a, 7, 8, 8a, 10, 14, 15, 16
  35. Do you know an officer called Reichnacht? What about Toma?
    General Toma is the commander of the 20th tank division. I don't know Reichnacht.
  36. Where is your company? The 21st regiment?
    The regiment was in Rusa, since January 5th our company acts independently of the division, regiment, or battalion.
  37. Where is the company and its ten tanks?
    We went from Rusa to Beren, where we spent the night. Then we entered Dudkovo with 6 tanks, 4 were left in Nikolskoye. On January 7th, we attacked Novoborisovo and Vyshgorod with two tanks. Our tank was left to guard Naberezhnaya Sloboda. Two Russian tanks came, and we started retreating to Novoborisovo, met up with 4 tanks, and returned to Vyshgorod. We took it and kept it until 21:00. Then we retreated to Novoborisovo, where we defended until January 12th. From 6 tanks, one broke down, the engine was ruined. Two were sent to repairs for technical reasons.
  38. Were these tanks knocked out in battle?
    No, the Russian tanks did not even shoot shells at us, they only fired machineguns. These tanks broke down. There is no oil, the engines broke, they are very sensitive and always have faults.
  39. What do you do with broken tanks?
    We remove parts, and then tow them to the repair company. The company has 5 tractors, they are now 6 km behind the front line. Usually the company is 10-12 km behind the front line.
  40. Do the tractors tow the tank freely?
    The tank is towed freely. If the suspension is damaged, the tank is put on a special trailer.
  41. Where is your tank?
    I was only in my tank until January 8th. Since then I was in the hospital, I froze my legs. When your infantry captured me on January 12th, I was in a field hospital in Novoborisovo.
  42. How many men in your company?
    There used to be 150, now there is 120.
  43. How do you get food?
    A divisional motorized kitchen comes three times a day. In the morning there is hot coffee, for dinner there is hot soup, for supper also hot [illegible] stock of Christmas presents. For 5 days before being captured, we ate nothing, and constantly smoked, since there was not enough food from the rear.
  44. Did you take food from the local population?
    We did not take food from the locals because we could not leave our tanks.
  45. How did you heat yourselves when the tank was guarding or defending?
    We didn't, which is how I froze my legs. The tank heated me with its engine, but it was still cold.
  46. Does the Skoda tank go through snow well?
    Our tanks cannot pass through snow at all. The tracks do not have traction and they fall through. We only drove on roads.
  47. How do you receive fuel and ammunition?
    After battle, the tanks drive to cars for fuel and ammunition. There is no quota for fuel if there is a lot, you can fuel up as much as you want. If there is not a lot, then there is a quota. There is usually enough fuel, and the tanks were without fuel only once, when there was no fuel at the base at all.
  48. How many cylinders and carburettors does the Praga engine have?
    6 cylinders, one carburettor.
  49. How big is the radio in a Skoda tank?
    The radio is very small.
  50. What schooling did you finish?
    I finished 8 grades of school in 1940.
  51. How many frostbitten men do you have in your company?
    10%. All got frostbite in their tanks.
  52. What fuel does the tank use?
    The tank is fuelled by leaded gasoline.
  53. How do you receive your orders?
    We get our orders over the radio in cleartext. If we are attacking infantry, then there will always be a group of tanks assigned to fight anti-tank guns.
  54. How do you perform small repairs in battle (for example, a broken track)?
    If the track is broken during battle, the crew is obligated to immediately restore it.
  55. If it is not possible to repair the tank, what do you do?
    We wait until the tank company moves forward. After that, we repair the tank. If the tank needs heavy repairs, the crew takes its belongings and we go to get a tractor from the repair company. If the company does not advance and starts retreating, the broken tank is destroyed with a hand grenade. It is thrown into the engine or driver's compartment. Damage from the grenade is insignificant. The crew does not have the right to abandon a tank without damaging it.
  56. What Russian tanks do you know?
    We know T-34, KV, T-40.
  57. What Russian tanks do you like the least?
    The T-34 is a menacing tank. The KV tank is very heavy and brings a lot of damage, but it is not as fast as the T-34. The KV only drives on roads, and does not do well in swamps and off-road. Two KV tanks got stuck in a swamp at Smolensk. The T-34 has an oval form, our shells slide off it.
  58. Would you prefer to fight a T-34 or two KVs?
    I would prefer to fight two KVs. Its gun is stronger, but no matter how much we fight them, they only fire machineguns at us. KVs did not shoot at any German tank. When the T-34 shoots, it is very scary.
  59. How does the T-40 shoot?
    I do not know about this tank, I only saw it once, and not in battle. We are not afraid of Russian tanks, we are afraid of Russian AT guns, they are better than German ones. We are not afraid of tanks because they do not shoot with their guns a lot. There was a KV at Smolensk, it turned its turret back and rammed two of our tanks. It was destroyed by infantry. When we looked at its gun, it was clean, it never shot. Russian tanks did not use their guns, they only shot with machineguns. That is now it was at Novoborisovo, the Russian tanks only used machineguns. 
  60. Why do you not clean up our tanks?
    If we are retreating, we do not clean them up, but if we are advancing, we clean up Russian tanks.
  61. Were you under fire from powerful Russian artillery (Kostikov gun)?
    Yes, at Rusa, it does not penetrate the tank or blow it up. Our top armour is 2 cm.
  62. How many hand grenades are in the tank?
    There is no exact number, we do not need them. Usually 4-5.
  63. What kind of a tank has a bull drawn on it?
    It is the division insignia. Our division has a comb with three tines. Companies have sequential numbers, divisions (battalions) are marked with white paint (1st), red (2nd) or yellow (3rd). All markings go on the turret.
  64. What insignia of other units do you know?
    An infantry division has a green heart.
  65. How do you tell tankers apart from other types of forces?
    Tankers have a skull and crossbones on their collars. The SS has the same symbol, but their uniform is green, and ours is black. All tankers have a government issue sign on their chest, but the SS wear it on their sleeve. Tankers have a pink collar border, communications has green. Communications tanks also have wooden guns.
  66. What about special SS tank units?
    There are SS tank units, but I did not see them. Their uniforms are not different from ours, I think they have a white or blue border. They are in France, they have not been to Russia.
  67. What kind of punishments do you have in the army?
    We have two kinds of arrests, harsh and regular. In a regular one you just sit in a room, but in a harsh one you only get food after three days. In war time, a court-martial can assign either."

Wednesday, 23 April 2014

T-34-85 (D-5T) Trials

Photo #3: T-34 tank with an 85 mm D-5T-85 gun from the front, 0 degrees elevation
Photo #4: T-34 tank with an 85 mm D-5T-85 gun from the left, maximum gun elevation

"Report on gunnery trials of the T-34 tank with widened turret ring

Trial goals:
  1. Determine the convenience and effectiveness of firing on the move, from short stops at immobile targets, and while stationary at moving and immobile targets.
  2. Determine the reliability and robustness of aiming mechanisms, firing mechanisms, gun components, and all installation components.
  3. Determine the rate of fire of the gun in various conditions.
  4. Determine the ability to observe the battlefield by all crewmen, determine the dead zones around the tank, develop a vision diagram.
  5. Determine the comfort of ammunition placement.
  6. Analyze the comfort of all crew member positions.
Between November 20th and 23rd, 1943, the T-34 tank with a widened turret ring, a turret designed by factory #183 and armed with the D-5T-85 85 mm gun was tested at the Gorohovets ANIOP.

Trials were performed with the participation of a commission led by Colonel Kulchitskiy, following the order by NKTP, NKV, and the chiefs of GAU and GABTU.

Brief characteristics of the project

The 85 mm D-5T-85 gun is mounted in an enlarged turret on a T-34 tank produced at factory #183, with the following differences from the production turret:
  1. The turret is an aerodynamic shape with a one piece front part that mounts the D-5T-85 gun on carriers welded to it.
  2. The trunnions are inserted into holes in the carriers and attached with 8 bolts. This kind of attachment [rest of paragraph is worn off]
  3. The hull in the middle of the fighting compartment is modified to increase the size of the fighting compartment and make the crew's work freer and easier. 
  4. The D-5T-85 gun system is installed without additional weights.
  5. The gun stopper is positioned on the left, in the left carrier.
  6. The commander of the tank sits to the left of the gun, behind the gunner. He has a commander's cupola.
  7. The enlarged turret has, aside from the periscope, telescopic sight, and two observation slits in the side of the turret, two prismatic observation devices (similar to the English type) one of which is positioned above the loader and one is placed on top of the commander's cupola. There are also 5 slits in the sides of the cupola.
  8. Pistol ports are present underneath the observation slits on the sides of the turret.
  9. There are three folding seats in the turret.
  10. There is a new turret traverse mechanism. The mechanism is activated using the same handle as the hand traverse.
  11. Ammunition is placed in the turret bustle (12 rounds), next to the loader (5 rounds), and in six metal crates on the bottom of the fighting compartment, forming an immobile floor.
Record of the commission on testing the D-5 85 mm gun in the experimental T-34 with the enlarged turret ring and turret produced by factory #183.

According to orders from NKTP, NKV, GBTU KA, and GAU KA, the commission was composed of:
  • Chair: Guards-Colonel Kulchitskiy
  • Members:
    • From GAU KA: Engineer-Colonel Panchev
    • From GBTU KA: Engineer-Captain Rozengart, Engineer-Captain Konev
    • NKV: comrade Volosatov, comrade Plyplin
    • NKTP: comrade Yurasov, comrade Hlopenko
    • TsAKB: comrade Muravyev
The commission tested the 85 mm D-5 gun installed in a T-34 with an enlarged turret ring from November 19th to November 23rd, 1943.

Conclusions:
  1. The commission is in agreement with the report of the Gorohovets ANIOP on the trials of the D-5 gun in the T-34 tank with an enlarged turret ring.
  2. The commission remarks that the D-5 meets requirements for the armament of a modern medium tank.
  3. The commission remarks that the turret ring, expanded to 1600 mm, allows the use of the 85 mm D-5 gun with a satisfactory rate of fire, significantly increasing the firepower of the T-34 tank.
  4. The commission remarks that aside from replacing the F-34 gun with the D-5 gun, the widened turret ring also allowed for a third crewman (the tank commander), who is provided with a 360 degree observation device, significantly increasing his ability to observe the battlefield and control the fire of the tank.
  5. The commission remarks that the D-5 85 mm gun increases the firepower of the T-34, but due to its thin armour, does not fully solve the issue of improving the T-34's combat qualities compared to the requirements for a modern medium tank.
    The commission deems it necessary to create new medium tanks with powerful armament and thickened armour, rendering them impenetrable to their own guns at a reasonable range.
  6. During the period of designing and ramping up production of these tanks, the commission deems it reasonable to simultaneously produce T-34 tanks with a stock turret ring armed with 76 mm S-54 guns and begin production of T-34 tanks with a widened turret ring and 85 mm D-5 guns.
  7. The commission considers it necessary for the NKTP and NKV to resolve drawbacks in the T-34 tank with widened turret ring noted in the proving grounds report.
  8. The impact of increased weight on the suspension due to the new turret is going to be determined during trials at the NIBT proving grounds."



Tuesday, 22 April 2014

T-34-85 Upgrade

"GOKO decree #4873 from January 1st, 1944 re-arms T-34 tanks with 85 mm model 1944 guns (S-53). Currently, NKV factories produce D-5 and S-53 guns. There are fears that, in the event of insufficient production of S-53 guns, other types of guns will be sent in, which will ruin quotas, as the D-5 and S-53 guns are not interchangeable. This already happened at factory #112. Due to an absence of S-53 guns, the factory was forced to retool to install D-5 guns, and when it received S-53 guns, will be forced to retool again to install S-53 guns, and it will not only be necessary to change the gun mount, but also the turret design.

I ask you to report the plan for supplying factories #112, 183, and Kirov factory with 85 mm tank guns for February, March, and April to G.L. Vershinin, assigned to factories by GOKO decree #5020s on January 23rd, 1944.

Deputy Chief of GBTU TU, Engineer-Colonel Muravich
Acting Chief of the 1st Department of GBTU TU, Engineer-Major Miroshnikov"

The requirement for two turret designs comes up again.

"T-34 tanks built with a 76 mm gun: 540 (18%)
T-34 tanks built with an 85 mm gun: 2449 (82%)

Additionally, it must be remarked that when transferring to an 85 mm gun, factory #112 had to master two types of turrets in 1944, one for a D-5 85 mm gun and one for an S-53 85 mm gun. 

The armour of the tank was increased. The factory began producing tanks with variable armour: front - 90 mm, sides - 75 mm, rear - 52 mm. Only tanks with the thickened turret are being produced as of November 1944."

Monday, 21 April 2014

T-34-85 Identification

Most T-34-85 tanks you will see on photographs are equipped with an 85 mm ZiS-S-53 gun. However, a small amount of these tanks were armed with another gun, the D-5. Here is how one of these rarities looks.


Note the single fan cap in the back, lack of radio antenna in front of the commander's cupola, and forward position of the bolts holding the gun in place. Another interesting point: most of these tanks only had two turret crewmen!

"According to GOKO degree from August 19th, 1943 #3908, and order #7 of the Commander of the Armoured and Mechanized Forces of the Red Army, Marshal of Armoured Forces comrade Fedorenko on January 29th, 1944, the NIIBT proving grounds performed trials of two experimental T-34 tanks from factory #112 from February 5th to February 21st, over the distance of 1000 km. February production tanks #4010163 and #4010171 with engines #E-312513 and E-312579 from factory #76 underwent trials. 

The difference between these tanks and mass production tanks is as follows:
  1. These tanks have 85 mm D-5 guns.
  2. The ammunition rack is reduced to 54 85 mm shells instead of 100 76 mm shells.
  3. The turret ring is 1600 mm instead of 1430 mm. 
  4. The front springs are strengthened (the spring diameter is 32 mm instead of 30 mm).
Tank trials were conducted in accordance with the program confirmed by the Deputy of the Chief of the Armoured Directorate of the Red Army, Lieutenant-General of the Tank Engineering service, comrade Lebedev. All trials were performed in the region of Kubinka station of the Western Railroad."
CAMD RF 38-11355-2358

Well, maybe they forgot. The same document for a T-34-85 with a ZiS-S-53 makes this unlikely, though.

"According to GOKO decree from August 19th, 1943, #3958, the NIIBT proving grounds tested a production T-34 tank from factory #112 from March 8th to March 28th, over 1000 km. 

A tank produced in March of 1944 was used, #G.4020433 with engine #E-402027 from factory #76, and gearbox #7230. The tank has the following differences compared to a stock T-34 tank with a 76 mm gun:
  1. The tank uses an 85 mm ZiS-S-53 gun.
  2. The ammunition rack is reduced to 55 85 mm shells from 100 76 mm shells.
  3. The turret ring diameter is 1600 mm (instead of 1450 mm).
  4. The front springs are strengthened (the spring diameter is 32 mm instead of 30 mm).
  5. The crew is increased to 5."
CAMD RF 38-11355-2364

And, to show the visual differences, another photograph:


Note the double fan cap on the back of the turret, the antenna mount in front of the cupola, and the altered periscope in front of the antenna. The bolts holding the gun in place are now sunken closer to the mantlet. 

Here is another rare tank. A T-34-85 with a D-5-T, and a commander's RSB-F radio! Only 5 were produced.

What looks like an "ordinary" T-34-85 is given away by an additional exhaust pipe on the side, from the generator. 

The rarities never end, as here is a photograph of a T-34-85 with a D-5-T that has a turret mounted radio and 3 turret crewmen. 


Sunday, 20 April 2014

Indirect Fire

A lot of people doubt the effectiveness of indirect fire against tanks, but you can blow up a tank with indirect fire. Even with something like a mortar!


"This act is composed to certify that in battles in [illegible] the Lithuanian SSR, Kluss region, on the night of August 13th, 1944, mortar fire by Guards Senior Sergeant Zinevich's crew aimed at an enemy counterattack set a German tank on fire."

Saturday, 19 April 2014

Lend-Lease for Two

Here are some papers of interest, exchanged between Roosevelt and Churchill just as German tanks were rolling into the USSR. Thankfully, they write in English, so I don't even have to do anything!

NARA 194907

NARA 194988

NARA 194895

NARA 194794

NARA 194891


Friday, 18 April 2014

Lend Lease Impressions: AEC MkII Armoured Car

Armoured cars are usually not my thing, but the review of this one contains many notes about its tank components.

Overall photo of the MK-II (AEC) Armoured Car
Photo #1: 3/4 view from the right
Photo #2: view from the left

"Summary:

  1. The AEC armoured car is built using production tank and automobile parts.
  2. The side of the car does not correspond to its combat ability.
  3. The design of the hull and turret, as well as the thickness of the armour, do not match modern requirements.
  4. The design and combat performance of the AEC is not of interest to us.
Conclusions:
  1. The AEC MkII armoured car is built using production tank and automobile parts.
  2. The engine of the armoured car is a four-stroke AEC engine and does not differ from the one used in English Valentine III tanks.
  3. The armament and turret are used from the English Valentine I and early Churchill tanks.
  4. The transmission and suspension consists of components used in heavy trucks. Parts of this design include the front wheels (drive wheels) constantly being in gear and pneumatic brakes.
  5. Using mass production components makes the design more complicated, and placement difficult (the engine is tilted in two axes), and led to an increase in dimensions, especially height.
  6. The design of the hull is obsolete. The armour plates are horizontal, except in the front.
  7. The mass of the armoured car is 12.2 tons, which is too high for its combat performance. This is explained by its large size and using heavy tank components.
  8. The vehicle is armed with a 57 mm gun MkV and a BESA 7.92 mm machinegun. This assembly has no elevation mechanism. The elevation is changed with the gunner's shoulder. There is a brake for fixing the gun in a certain position.
    The downsides of this design include the lack of balance in the oscillating section of the gun and a poor telescopic sight. It is immobile and has a monotonous scale, which makes aiming difficult.
  9. The ammunition rack is poorly designed. Shells get stuck in their slots and decrease rate of fire.
  10. The armour of the vehicle (maximum 25.4 mm) is insufficient.
  11. The unusual always on front wheels and controllable rear wheels does not decrease maneuverability due to a balance between the axles, but results in more complicated front wheels, as they both turn the car and are drive wheels.
Mobility trials results:
  1. The maximum speed is 78 kph, which is good for a 12.2 ton armoured car.
  2. Medium speeds:
    1. Highway: [illegible] kph
    2. Stone-gravel road: 30 kph
    3. Dirt road: 13 kph
      are satisfactory.
      The relatively low speed across a dirt road is explained by the stiff suspension, as well as that the trials were held on a road previously traversed by tanks. The difference in width and necessity to brake before bumps led to the inability to use the full engine power of the vehicle.
  3. Fuel consumption for 100 km:
    1. Highway: 29 L
    2. Stone-gravel road: 34.7 L
    3. Dirt road: 48.5 L
      is low. These figures demonstrate the the engine is economic and that the gear ratios were picked well.
  4. The range is high:
    1. Highway: 600 km
    2. Stone-gravel road: 500 km
    3. Dirt road: 360 km
      due to the economical engine and relatively large fuel tank (175 L).
  5. Temperature measurement showed that the temperature of the coolant stabilized at 75-80 C and oil pressure at 40-45 psi (3.1-3.2 kg/cm^2).
    The stable temperature shows that the engine power and transmission ratios were chosen well and that the oil and cooling systems work flawlessly.
  6. The vehicle can climb 30 degree slopes, descend on 30 degree slopes, and tilt up to 22 degrees, which is enough for a wheeled vehicle.
  7. The minimum turning radius is 16 meters, and is caused by the large length of the car.
  8. Accelerating the car to 45 kph takes 250 meters. This is a good distance for a 12 ton car and shows that the engine is of good quality.
  9. When driving at 64 kph, it takes 28 meters to brake. This demonstrates that the vehicle has reliable brakes, and is safe to use in a column or in a city.
Gunnery trials results:
  1. The average deviation of the gun at 1000 meters is 0.19 horizontally and 0.18 vertically, and matches norms for the domestic 57 mm ZiS-2 gun (0.18 and 0.20 respectively).
  2. The gun hits targets at 700 meters directly 100% of the time.
  3. The odds of hitting the target from short stops at 400-700 meters decrease to 85%, and further decrease to 8% when shooting on the move.
    The decrease in chance to hit from movement or short stops is explained by large oscillations of the wheels during motion and their slow damping, as well as the poor telescopic sight.
  4. Practical rate of fire:
    1. Stationary: 5.2 RPM
    2. From short stops, including movement between stops: 2.5 RPM
    3. On the move: 4.6 RPM
      Which is insufficient for a 57 mm gun.
      The reasons for low rate of fire include
      1. Poor ammunition rack design with jamming shells.
      2. Poorly balanced oscillating part of the gun.
      3. Poor telescopic sight.
      4. Large and long oscillations of the hull and the high mass of the gun system make aiming difficult.
  5. The gas concentration with a working engine and fans is 0.64 mg/L, and is within acceptable limits."

Thursday, 17 April 2014

Japanese Heavy Tanks



"Note: on Japanese heavy tank cooling systems

The Type 2604 tank has two 12-cylinder liquid cooled BMW engines. The cooling system includes three sections of cooling pipe radiators for each engine, and one section of an oil radiator, cooled with two intake fans that draw their power from the main reductor. The air is sucked in through grilles located above the engine compartment , goes through a section of radiators in the air-tight hull, and is released through a grille in the rear of the tank. For engine maintenance, each of the radiator sections opens upwards if the engine compartment cover is removed.

Advantages of this layout include protection from incendiary fluid. A disadvantage is the inefficient use of space.

The Type 2605 layout differs from the Type 2604. It is 35% smaller, but retains the same type of engine, resulting in a very cramped cooler design. Four radiator blocks are shifted towards the rear, and, along with the separate oil cooler, are cooled with one many-bladed fan, connected to the main reductor by a crankshaft, passing between engines. Air is gathered through vertical grilles in the engine compartment, passes through vertical radiators, and is released behind the tank. If the fan breaks, the air will be partially circulated with exhaust fumes, achieved by a nozzle collector on each engine. 

Advantages of this design include an efficient use of the space available, and the simplicity of design and adjustment of the large (950 mm diameter) fan.  Disadvantages include a lack of air flow over the engine components, leading to overheating of the generator and main reductor, and a small amount of radiator sections (only 4).

The wooden O-I model uses a liquid cooled Daimler-Benz 12-cylinder diesel engine instead of two BMW gasoline engines. The model has two six-section radiators with an air flow achieved by exhaust fumes. The air is gathered by the engine compartment cover. An auxiliary fan helps guides airflow over the engine and helps in clearing out the fighting compartment, driven by the fuel pump motor.

Advantages of this layout include simplicity of design and good ventilation of the tank turret, but only while the engine is running. A disadvantage of this layout is that service of the engine requires removing the airtight radiator sections.

Wednesday, 16 April 2014

Standards

"To the director of Voroshilov factory #174 (Leningrad)

Copy: NKSM Glavspetsmash Chief Engineer

Reply to your letter #4/85-76; 247

No conclusions on the "standards" produced by BBSV-2 will be given by BTU. The "machine gun ammunition rack" and "F-1 hand grenade ammunition rack" are untested and exist nowhere except on paper in BBSV-2. In the future, I deem it sensible to cease such correspondence.

Chief of the BTU 2nd Department, Military Engineer 1st grade, Afonin
Deputy Chief of the 4th Section of the 4th Department, Major Gorohov

February 3rd, 1941"

Tuesday, 15 April 2014

Matilda vs Panther at Tartu

From L.V. Gorchakov's collection.

"Report on the combat actions of the 16th Independent Tank Order of the Red Banner Don Brigade from September 1st, 1944 to September 30th, 1944

1. The enemy, taking heavy losses in battles in the vicinity of Tartu was forced by our advancing forces to retreat North-East and North-West of Tartu, fortifying for a defense with elements of the 11th ID, 96th ID, 32 ID, 185 ID, 37th ID, 46th IR, 20th PD, and the Schmitken tank brigade on the Pyvvatu, Bol, [illegible], Paidla, Tila, and marker 44.6 line, simultaneously counterattacking with up to two regiments of infantry and with support of artillery and up to 50 tanks from the regions of [illegible], Zoraku and Marama, striving to take the city of Tartu.

2. The 2nd tank battalion was equipped with new tanks on August 30th, 1944. The brigade received orders from the commander of the North Combat Sector: by 15:00 on August 30th, march from Unipiha to the North-East outskirts of Tartu in order to deflect potential tank counterattacks in the directions of Anne-Tartu, Vadula-Tartu and [illegible]-Tartu.

At 8:00 on August 30th, the Brigade, composed of 18 Matildas, 2 SU-85, one T-34, an evac unit and an AA battery set out on the route of Unipiha-Tartu. Having completed the 25 km march by 14:00, the brigade reached the North-Eastern outskirts of Tartu, placing its tanks in AT ambushes.

The 1st and 3rd battalions were left in Unipiha without functional vehicles, awaiting evacuation and restoration.

According to the orders, the following was done:
  1. The objective was delivered and explained to all personnel.
  2. Observation of tank ambushes and approaches to enemy lines was performed.
  3. Cooperation with infantry and artillery was outlined.
  4. Anti-tank ambushes were set up on main directions: Kazake, height 62.1, Orova-Tila, Vakhi, and Myuta, composed of three tanks and a unit of mechanized infantry each. Reserves: the commander kept a reserve of 5 tanks and 80 men in the region of the wine factory with the goal of reinforcements of AT ambushes at threatened directions.
  5. Tank ambushes in the regions of Letsi and Varevy were prepared to deflect the enemy's counterattack at the river crossings.
Throughout September 1st and 2nd, the 2nd battalion, infantry, and AA battery securely covered Tartu. The enemy did not show activity, but opened artillery fire in the direction of our units. According to the orders of the 67th Army Armoured and Mechanized Forces commander, 8 tanks were removed from ambushes on the night of September 4th and transferred to Unipiha. Others were left in ambush. At 13:00 on September 4th, the enemy attacked with up to two regiments of infantry and 30 Panther tanks, supported with artillery. Enemy tanks moved out from [illegible], Vazula, Lane, Marama and reached Orova, Tila, and Myuta by 15:00.

9 Matilda tanks from the 2nd battalion deflected the attack from anti-tank positions at Kazake, height 62.1, Tila, Myuta, with support from infantry and artillery. The enemy, at the cost of heavy losses, pushed us back from [illegible], Tila, Vakhi, Myuta, having cut off five out out tanks form infantry at Tila and Vakhi. Further advances of enemy tanks and infantry was prevented by artillery fire. 7 Panther tanks were knocked out, as well as 5 APCs, and up to 200 soldiers and officers were killed.

Our losses: 5 tanks destroyed or disabled, 10 men killed or wounded.

At the same time, the enemy attempted to ferry infantry across lake Vyrtserv. Three tanks in ambush at Verevi opened heavy fire and did not allow the enemy to land. Since a landing was impossible, the enemy turned back, having lost one motorboat, two rowboats. Up to 75 soldiers and officers were killed or drowned.

Due to the developing situation, tanks from Unipiha were transferred over to the anti-tank regions at Radi, Cemetery, and Klaoze with the objective to not let enemy tanks and infantry through to the city. At this time, defenses East, North-East, and North of Tartu were reinforced by elements of the 1047th SPG regiment, 379th Guards SPG regiment, 332nd Guards SPG regiment and 351st Guards SPG regiment transferred over from other parts of the front.

The enemy transferred over two more regiments of infantry and up to 25 Panther tanks from Valga by 18:00 on September 5th, 1944, and with up to two regiments of infantry and 30 Panther tanks and 10 APCs, with artillery support, attacked from Pyvvatu, Tila, Vakhi, and Myuga, with the goal of capturing the city of Tartu.

The 2nd battalion and AA battery opened fire from the anti-tank regions at Kazake, Radi, and Klaoze, along with reinforcing tank units, in cooperation with infantry and artillery. With heavy losses, the enemy was forced to retreat to his starting positions, leaving up to 175 soldiers and officers, 9 tanks, and 5 APCs on the battlefield. From September 6th to 10th, the enemy did not attempt any engagements. limiting himself to periodic artillery fire.

The 2nd battalion and AA battery continued to hold their line at Kazake, height 62.1, Radi, Klaoze and Verevi, carefully observing the enemy.

According to orders from the commander of the North Combat Sector, the tanks still remaining in ambush were removed on the night from September 10th and September 11th and were relocated to Memmatsi by 5:00 on September 11th, 1944."

Monday, 14 April 2014

German Prospects

I showed German production plans before, but those aren't as interesting as the prototypes they had in store.

"Report to the Fuhrer, April 7th, 1944 Top Secret
  1. Planning to deliver trucks for 11 (eleven) motorized units (see attachment).
  2. The Inspector General of the tank forces requested the following armoured vehicle improvements:
    1. Super-heavy anti-tank gun
      1. 15 cm: L/63 (length of barrel in calibers)
      2. 17 cm: L/53
        Penetrating power: 200 mm at 4000 m.
        Shell weight:
        for 17 cm: 72 kg
        for 15 cm: 45 kg
    2. 21 cm SPG: assault gun on the Panther chassis
    3. Modernized PzIV: sloped armour, more powerful engine (fall 1945), 7.5 cm L/70 tank gun.
  3. Bergepanzer III cannot be removed from production and rebuilt as an assault gun (SPG).
    The 240 PzIII tanks currently bring repaired in the rear should be rebuilt as recover vehicles. There is difficulty when converting them into SPGs due to increasing the front armour from 50 mm to 80 mm."

Sunday, 13 April 2014

Guess the Tank

"To the BTU GABTU Chief, military engineer 1st grade, comrade Korobkov

I ask for your conclusions on the description of a Krupp tank, given by a captured soldier from the 11th TD.

Question: What types of tanks exist in your division?
Answer: My division uses the Krupp tank. Weight: 52 tons. Speed: 40-50 kph. Fuel capacity: 500 liters. Fuel efficiency: 60-70 liters for 100 km on the highway, 120-130 off-road. The average range is 420-450 km. The engine power is 300 hp. The tank moves only on tracks. Armament: 1 54 mm gun, 1 7.9 mm machinegun. The crew consists of a commander, driver, loader, and radio operator. The tank is equipped with a radio transmitter and receiver. It can cross a 140-150 cm tall wall, a 5 meter wide trench, or fort a 180 cm deep river. The tank is 5 meters long, 2 meters wide, and 180 cm tall. The turret armour is 5 cm thick. The rest of the armour is 3.7 cm thick.

The tank has a semi-automatic 54 mm gun. The rate of fire is unknown. The machinegun has a caliber of 7.9 mm. The tank holds 75 shells and 1320 bullets. The tank carries spare track parts.

The range of the tank is 420-450 km. A truck can go 350-400, a motorcycle can go 300. On a dirt road, that range is halved.

If swift concentration of forces is required, the division moves quickly, with small breaks for food. Maximum speed is 500 km per day in 14-15 hours.

GABTU HQ Chief Assistant, Lieutenant-Colonel Kudryashov
September 1st, 1941"
CAMD RF 38-11355-117

Friday, 11 April 2014

Tank on Tank Action

Lots of casual visitors to the field of military history look upon "kill ratios" as something that defines the effectiveness of a tank, forgetting that the modern battlefield is populated by things other than tanks, or even anti-tank guns.



Heavy Tanks and Lightening

"To the Deputy People's Commissar of Defense, Lieutenant-General of the Tank Forces, comrade Fedorenko

Report.

On the issue of design and production of experimental heavy tanks, I report that:

The current heavy KV tank fielded by the Red Army demonstrates superiority in battle over fascist tanks with its powerful armour and armament. It can be successfully used to destroy the enemy defences, crushing them with its tracks and gun. The Patriotic war, combining in its nature a positional war with a maneuver war requires much of a heavy tank, and the KV does not fully meet those requirements. The KV lacks mobility for the following reasons:
  1. A low maximum speed limits its ability to move between flanks to counter-attack.
  2. Insufficient visibility from the tank makes orienting on the battlefield difficult.
  3. The tank's mobility is decreased by its number of gears: five forward gears is not enough for a heavy tank.
  4. The force required to shift gears is large. Momentum acquired on lower gears is wasted, and the tank must slowly accelerate in a higher gear.
  5. The brake ribbons are insufficiently reliable and lead to the tank stopping on the battlefield and requiring repairs.
The usage characteristics of the KV are limited by:
  1. The requirement for robust bridges or other means of crossing ravines or water hazards.
  2. The requirement for powerful tractors for rapid evacuation from the battlefield, dragging out of ravines, traps, etc, or the use of more of these expensive vehicles.
  3. The requirement of units to have powerful repair tools.
Based on the above, the government must task the People's Commissariat of Tank Production to order the Kirov factory and factory #183 to produce two experimental prototypes of heavy tanks with the following characteristics"
  1. Combat mass: 30 tons
  2. Crew: 4 (3 in the turret)
  3. Armour:
    1. front and turret: 90 mm
    2. side and rear: 75 mm
    3. roof and bottom: 25 mm
  4. Armament:
    1. 76 mm gun: 1
    2. DT machineguns: 2 (one coaxial and one in the hull)
    3. SMGs: 2 (PPSh)
    4. Flamethrower: 1 (attachable instead of the hull machinegun)
  5. Gun range:
    1. vertical: -5 to +25 degrees
    2. horizontal: 360 degrees
  6. Hull machinegun range:
    1. vertical: -5 to +15 degrees
    2. horizontal: +/- 10 degrees
  7. Ammunition capacity:
    1. Shells: 50
    2. Machinegun rounds: 2520
    3. PPSh rounds: 1000
    4. Flamethrower fluid: 20 shots
  8. Engine: V-2 or V-2K diesel, 500-600 hp
  9. Maximum speed:
    1. Highway: 60 kph
    2. Off-road: 25 kph
  10. Off-road range, non-stop: 10 hours
  11. Transmission: planetary
  12. View: 360 degrees, provided to the commander with an observation hatch in the turret roof, optical sights (with exit eyepiece 10-12 mm and field of vision no less than 60 degrees), and doubled observation devices (in the roof) for the driver.
  13. Communications:
    1. External: quartz radio station
    2. Internal: TPU-3 with throat microphone
  14. The side reductors must be protected by main armour.
  15. The coolant system and air filters should provide 10 hours of uninterrupted movement off-road in 45 degree heat.
  16. The engine must be able to start without external heating at a temperature of -45 degrees.
A tank produced in accordance with the above requirements will be fully equipped for modern war and will be an even more deadly weapon against fascist tanks.

BTU Chief, Major-General of Tank Forces Korobkov
Representing the BTU Military Commissar, Engineer-Lieutenant-Colonel Kovalev
June 1st, 1942"

Seems that the "medium tank with heavy armour" concept surfaced again, two years later. If you look at the characteristics of the A-44, it matches these requirements exactly!

As for the products of Kirov factory and factory #183, those were, of course, the KV-13 and T-43. Neither vehicle ended up in production, but the KV-13 influenced the IS series and the T-43's turret migrated to the T-34-85. 

Thursday, 10 April 2014

Restoring a StuH 42

Not content to fall behind its a rival company's projects, Gaijin (maker of War Thunder) is also funding restorations of WWII vehicles.


It's not as long and detailed as the competitor, and there are no subtitles, but it's short enough to translate.

Edit: turns out there is an English video after all. The video has been updated.

Spare Track Links

"In order to increase the protection of the T-VI (Tiger) tank, the Germans place spare track links in front of the hull, on the vertical armour plate.

In order to check if this is an effective method, in March of 1944, a T-34 upper front hull segment (part number 34.29.304) with track links attached was tested at the NIBT proving grounds.

The shooting was done with an armour piercing 75 mm shell fired from a German gun (PaK 40) with the muzzle velocity of 770 m/s.

Trials showed that the front of the hull protected by track links can be penetrated by the German gun from 800 meters, but not from 900 meters. The unprotected part of the hull can be penetrated from 1000 meters, but not from 1100 meters. Therefore, the tracks increase protection by 200 meters.

I deem it sensible to alter the existing spare track transport method on the T-34 and SU-85. I ask you to order the People's Commissariat of Tank Production to move the spare track link holders to the front of the T-34 and SU-85 hull starting on April 15th, 1944."

CAMD RF 38-11355-2548

Of course, not only the Tigers had such protection. Many vehicles had track links attached to them to the front for extra armour, including tracks from other vehicles.

This StuG, for example, is clearly covered in T-34 track links.


Those that could not find nice and wide T-34 tracks had to make do with less.


As is usually the case, no one waited for orders from the top to improvise. Pictures of T-34s using track links as additional armour way before 1944 are not uncommon. The most common way of using them was tucking them into the infantry rails to protect the turret.

World of Tanks: Today in History: Liberation of Odessa

The goal of the Odessa Offensive Operation that took place between March 26th and April 14th 1944 was to defeat the 6th German and 3rd Romanian armies, liberate Odessa and the North-West coast of the Black Sea, and reach the border between the USSR and Romania.

The preparation of the operation was difficult due to poor conditions of the roads, muddy from spring rains. Supplies could only be delivered by tracked tractors and all terrain vehicles. Furthermore, the planning was done without stopping the offensive, which also caused problems.

The Odessa Operation began on March 27th, when the forces of the 3rd Ukrainian Front widened their footholds on the South Bug. By March 28th, the foodholds deepened to 25 kilometers. In order to continue the success, the mechanized cavalry of General Pliev and 23rd Tank Corps of General Akhmanov were sent in.

The penetration of the defensive lines at the flanks of the German-Romanian group forced them to retreat behind the Dniester river. The mechanized cavalry of the 37th Army cut off their retreat. Some amount of enemy forces broke through in the direction of Tiraspol, but many were encircled.

On April 9th, Soviet forces began advancing, and entered the northern outskirts of Odessa. After a night assault, with the cooperation from resistance and partisans, the city was fully liberated. The Soviet units continued their advance until the Dniestr, where they captured footholds and secured a start of an important offensive against the enemy armies.

Original article available here.

Wednesday, 9 April 2014

Soviet Tanks in the Far East

Here are the tanks the Red Army had available in the Far East for war with Japan as of August 5th, 1945. As you can see, some of these tanks have been there for quite a while, as they are downright antiques. As per Soviet tradition, tanks that require light repairs (repairs that can be completed by the strength of the tank unit) are included in the "functional" column.

Vehicle In possession Functional Med. Repairs Maj. Repairs Irreparable
T-34 1899 1794 32 70 3
M4-A2 250 250 - - -
BT-7 1030 797 41 179 13
T-26 1461 1272 33 122 34
KV 77 47 5 23 2
Valentine 81 78 3 - -
T-60/70 46 14 - 28 4
BT-5 190 101 - 23 66
T-38 325 304 20 1 -
Tankettes 52 52 - - -
IS 19 6 1 12-
T-27 56 56 - - -
T-37 52 52 - - -
M3 light 1 - 1 - -
M3 medium 1 - 1 - -
Various 5 5 - - -
Total tanks 5548 4841 137 455 125
ISU-152 197 188 1 8 -
ISU-122 1 1 - - -
SU-100 262 261 1 - -
SU-76 952 944 9 - -
SU-152 11 - - 11 -
SU-85 6 1 - 5 -
SU-122 6 2 - 3 1
Total SPGs 1422 1393 11 28 1
Total  6980 6234 148 483 126

The small number of IS tanks available casts doubt on the assertion that IS-3 tanks were present in the theater.