Saturday, 15 December 2018

New Legs for the Emcha

A reserve for modernization built into a tank's design is one of its most important features, especially in wartime. In this respect, the American Medium Tank M4 is an outstanding example. Thanks to its 1750 mm wide turret ring, it could receive a much larger turret than the one used initially. During production, the tank's protection from the front was improved. Finally, the suspension of the M4 could be improved significantly without changing the rest of the vehicle. The M4A1, M4A2, and M4A3 were major steps for this project. Today let us talk about the peak of evolution for the M4A2 family: the M4A2E8. Although it came late, it managed to make it in time to see battle with the Red Army.

Thursday, 13 December 2018

Lost it on a Horse

"To the Chief of the Financial Department of the North-Western Front
July 19th, 1941

According to existing data, the money box belonging to the finance section of the 11th Army HQ was abandoned along with its contents of 20,000 rubles during the retreat of the forces.

Perform an investigation and hold the guilty responsible. Report to me on the results.

Chief Quartermaster, Major-General of the Intendant Service Hotenko
Chief of the 2nd Department, Major Terpilovkiy"

During the early stages of the war over 41 million Soviet rubles were left in banks that fell into enemy hands and over 44.7 million rubles were burned, buried, or otherwise destroyed before retreating.

Wednesday, 12 December 2018

Bombs vs Artillery

A while ago I posted some data on the effectiveness of high explosive rounds. Recently, a similar infographic came up, but for bombs. I thought it would be interesting to compare the results of the two. The first sequence shows the size of the hole a bomb makes in the ground (the height and radius) and the second shows how far the shockwave travels. 

The smallest of the bunch is the 50 kg bomb, forming a 2.4 meter deep crater 2.2 meters in radius. This is comparable to the effect of a 152 mm HE shell, which creates a wider crater (2.5 meters in radius), but a shallower one (1.8 meters deep). The shockwave from such a bomb would travel for 12 meters. Unfortunately, no fragmentation effect is given for the bomb, nor an explosive effect for the shell, so it's hard to compare. We can compare the appreciable difference between the smallest bomb in the Soviet arsenal and the largest shell at the corps artillery level. 

Via Valeriy Lisyutin.

Tuesday, 11 December 2018

Tank Budgets

"Preparation of materiel

1. Tanks

Unit Cost
Total Cost
T-26 small tank
T-26 infantry carrier
BT fast tank
T-28 medium tank
T-35 large tank
T-75 tank
T-33 and T-41 reconnaissance tanks


Spare parts:
For tank
Total cost
T-33 and T-41
T-27 tankette
Total spare parts

Unfortunately, the source doesn't say what year this budget came from. There are some hints though. The T-33 is a precursor of the T-37A tank. A prototype was built in the spring of 1932, but the tank did not do well in trials and was not accepted for mass production. Presumably, this budget was composed shortly before the decision to not produce the tank was made. The T-41 was also an amphibious reconnaissance tank, which underwent trials in the fall of 1932. The fact that Grotte's TG-1 tank is absent from the list altogether and the T-24 is only listed in the spare part production section agrees with this timeframe. This seems about the right time that something like a superheavy tank that cost twice as much as a T-35 would still be considered viable. 

Monday, 10 December 2018

Servo Controls

"Act #013, composed on May 15th, 1940

The current act is composed by:
  • Bureau "540" researcher comrade I.S. Tomashpolskiy
  • Senior ABTU military representative at the Comintern factory, Captain P.F. Rusakov
  • ABTU military representative at department "500" comrade P.P. Baikov
  • Drivers from plant "530" comrades I.G. Bitenskiy and N.F. Nosik
  • Bureau "520" designer P.P. Vasiliev
to certify that preliminary mechanical trials of mechanical servo devices for control of an A-34 vehicle #311-18-3 were performed from May 12th to May 15th, 1940.

The servo device was designed by bureau 520 designer comrade P.P. Vasiliev and installed in the vehicle based on the author's directions, without installation blueprints.

The proposed servo system eases the effort the driver must apply to levers with the aid of a mechanical system (unlike the earlier pneumatic system), thanks to the actions of the levers and assistance springs. The servo acts when the final drives are disengaged or when the brake ribbons are tightened by the levers. In addition, a change to the return spring on the brake control rods reduced the effort applied to the brake pedal.

During trials between May 12th and May 15th the vehicle travelled 278 km on sand and dirt roads. Within that range turns and figure 8 maneuvers in 1st and 2nd gear were performed on dirt roads and in sand.

No defects in the mechanical servo device were observed during trials. The opinion of all commission members that took part in driving the vehicle, specifically the experienced test drivers, was that the proposed device of the mechanical servo on the A-34 does not require special skills or training to operate, does not cause exhaustion during driving, and does not require special calibration or difficult maintenance.

The effort applied to final drive clutches was measured with a dynamometer as follows:
  1. On hard dirt:
    1. 1st gear 360 degree turn in place: 18-24 kg
    2. 2nd gear 360 degree turn with minimum radius: 16-22 kg
  2. In shallow sand:
    1. 1st gear 360 degree turn in place: 18-30 kg
    2. 2nd gear 360 degree turn with minimum radius: 20-30 kg
Effort applied when turning in 3rd or 4th gear did not exceed 15 kg.

  1. Based on the information obtained during trials, the commission considers it reasonable to introduce the designs proposed by comrade Vasilyev into production for the A-34 instead of the pneumatic system, as it completely satisfies requirements, specifically:
    1. It is simple to produce.
    2. It does not require complex maintenance.
    3. It does not require special skills to operate.
    4. It does not tire the driver during operation.
  2. The commission deems it necessary to equip a trial batch of A-34 vehicles with mechanical servo devices instead of pneumatic.
  3. Bureau 520 must ensure maximum robustness and resistance to wear for components when producing final blueprints.
  4. In addition to the above, the commission considers it necessary for plant #540 to produce one or two sets of servo devices for reliability trials.
May 17th, 1940"

Saturday, 8 December 2018

Anti-Tank Hornet, a.k.a. Rhino

The Ferdinand was unusual among German WWII era SPGs. A number of things, such as the armament and armour, make it exceptional. However, only a small number of these SPGs was built. There were other tank destroyers armed with the same 8.8 cm Pak 43 gun, and the Germans built a whole lot more of them. One was the 8.8 cm PaK 43/1 auf Geschützwagen III/IV (Sf), otherwise known as the Hornisse (Hornet) or Nashorn (Rhino). The Nashorn was often confused for the Ferdinand, which is understandable: the SPG was not a small vehicle.

Thursday, 6 December 2018

Turn up the HEAT

"To the Commander of the Corps Artillery, Commanders of Artillery Units and Formations
April 12th, 1945

Immediately issue a general order to your units to use 122 mm howitzer HEAT rounds. In addition to armoured targets, use HEAT rounds against brick buildings.

Chief of Artillery of the 47th Army, Guards Lieutenant General of Artillery, Govin
Chief of Staff of Artillery of the Army, Guards Lieutenant-Colonel Boriskov"

Wednesday, 5 December 2018


"Concluding Statement on Proving Grounds Trials of the TPU-3M tank intercom device produced by V.I. Lenin factory #197
October 9th, 1940

The commission, consisting of [names and titles] came to the following conclusions after conducting proving grounds trials:
  1. The TPU-3M prototypes meet the tactical-technical requirements set by the US and ABTU.
  2. The TPU-3M intercom device allows very satisfactory communications via radio between KV tanks at expected ranges between KV tanks both while stationary or during movement in 1st, 2nd, or 3rd gear, and satisfactory communication in 4th gear.
  3. No difference could be detected when comparing the legibility of transmissions made through the tank radio directly and those made through the TPU-3M intercom device.
  4. The TPU-3M intercom allows tank crews to communicate with each other in 1st, 2nd, and 3rd gear and is satisfactory in 4th gear (some words had to be repeated).
  5. The TPU-3M intercom meets the requirements for use in tanks in terms of simplicity and reliability. The use of an MA type microphone with an activation button is difficult for the crew, especially the driver.
  6. The commission tested two angled differential throat microphones produced at factory #197 with the TPU-3M. Communication between the commander and radio operator at all speeds was satisfactory. Communication between two tanks, both in motion and stationary, was satisfactory. The commission considers it necessary to use throat microphones with the TPU-3M device.
  7. Acoustic interference in the KV tank make it necessary to connect the commander and the gunner with an intercom, as voice communication between them is difficult. NIST and factory #197 provided a layout that can provide a connection for a fourth member (gunner) to the TPU-3M device, which gave good results both in motion and while stationary. The commission considers it sensible to add the fourth member of the KV tank crew to the intercom.
  1. The commission considers that the TPU-3M tank intercom device produced by factory #197 can be put into production in 1940 after correction of defects.
  2. The commission considers that in 1941 production the TPU-3M intercom device should be equipped with a throat microphone, for which factory #197 must design a new throat microphone based on the samples tested by the commission.

Tuesday, 4 December 2018

SU-100 Review

"March 12th, 1945
Comments on the use of the SU-100 SPG in combat
  1. During the fighting of the Corps from January 14th to March 10th, 1945, SU-100 SPGs were used as tanks, as the Corps fought in operative depth and was almost entirely equipped with SU-100 SPGs.
  2. The off-road mobility of the SU-100 is reduced compared to the T-34 tank, due to the increase in weight and shifting of the center of mass forward due to the longer gun and thickening of the front armour. This adds additional load on the front wheels.
    When crossing obstacles off-road, the gun can strike the ground and then the barrel bursts when firing. The gun mount can shift during sudden turns and driving on uneven terrain. There were cases of a complete breakaway of the elevation mechanism.

Monday, 3 December 2018

Tank Building Progress

"To the People's Commissar of Defense, Marshal of the Soviet Union, comrade Timoshenko

I report to you regarding the progress of carrying out Central Committee of the VKP(b) decrees ## 976-368, 973-366, and 885-330 as of August 1st, 1940.

Item 1, decree #976-368 issued on June 7th, 1940
The decree orders the People's Commissar of Medium Machinebuilding comrade Lihachev to produce 600 T-34 tanks in 1940, of those:
  • 500 at factory #183
  • 100 at the Stalingrad Tractor Factory
Factory #183 must deliver 10 units in June and 20 units in July.

Progress: as of August 1st, 1940, factory #183 produced 10 T-34 tanks instead of 30 ordered by the Decree. The main reason for this shortfall is the slow rate of preparation for production at factory #183 and unfulfilled orders for instruments, devices, stamps, etc. made at GAZ, ZIS, HTZ, STZ, and other factories.
The Stalingrad Tractor Factory is starting to set up T-34 production, but has not produced any tanks. With the help of factory #183 one tank was completed and breaking in is presently in progress.

Item 2, decree #973-366 issued on June 5th, 1940
The decree orders the NKO to supply the Kirov factory with T-28 tanks without need of repairs or modernization for installation of applique armour. Provide 35 vehicles by June 5th, 50 vehicles by June 25th, including 15 vehicles already present at the factory.

Progress: as of August 1st, 1940, the Kirov factory had installed applique armour on 54 vehicles. The shipment of 50 tanks had not arrived, as the Belorussian Special Military District, which was ordered to supply the tanks, did not have enough fully ready tanks in connection with increased rates of use in recent time. Orders were given to the Kiev Special Military District to supply the tanks. The tanks have not yet arrived.

Item 3, decree #885-330 issued on June 28th, 1940
To obtain final approval of blueprints and technical requirements, instruct the People's Commissar of Defense, comrade Timoshenko, and the People's Commissar of Heavy Machinebuilding, comrade Yefremov, to form a commission for trials of a KV tank with a large turret. Trials must be held in Leningrad no later than June 15th, 1940, lasting no less than 1000 km.

Progress: trials were held in Leningrad. The tank travelled 2565 km during trials, 884 on a highway, 656 on a dirt road, and 1025 off-road. trials gave mostly satisfactory results. A number of requests were made of the factory to make improvements and finish the blueprints and technical requirements for approval. An additional report will be supplied.

Assistant Chief of the ABTU, Lieutenant-General of the Tank Forces, Fedorenko"

Saturday, 1 December 2018

The Soviet First

The birth of tank building during WWI did not go unnoticed by the Russian Empire. Pokrovshikov's Vezdekhod tank is often mentioned in this context, but this demonstration vehicle did not bring much value. The Tsar-Tank, aka Netopyr, designed by Lebedenko was equally useless. It was the largest tank in history, but its list of achievements ends there. In practice, the history of Russian tank building seriously began after the October revolution. Its first step was to copy the successful French Renault FT tank.

Thursday, 29 November 2018

Finders Keepers

"To the commander of the 22nd Tank Corps
CC: Commander of the 168th Tank Brigade, commander of the 36th Tank Brigade
June 18th, 1942

In battle at Shevchenkovo, on June 11th, 1942, a T-34 tank with registration number #24-15 belonging to the 168th TBr was knocked out by enemy artillery fire and abandoned by its crew (the commander was Lieutenant Yumashev, who was wounded). An act of the brigade commission consisting of Major Stupakov, Sr. Political Chief Korotyshev, and Lieutenant Sidorin. On June 12th the tank was written off as an irreparable loss as burned up from enemy fire.

Based on the materials I possess, T-34 #24-15 was evacuated from the battlefield by the 36th TBr on June 13th, 1942 with damaged running gear and functional engine (there were no signs of fire). In the nearby forest the tank was brought back into action and drove on its own power to the 36th TBr's repair yard, where it was restored by June 17th, 1942.

Representatives of the 168th TBr, having discovered the tank is battle ready, unlawfully drove the tank from mobile repair base #80 to their own brigade.

In connection with that, I order that:
  1. The commander of the 168th TBr must conduct an investigation into the unlawful writing off of the T-34 tank #24-15, its abandonment on the battlefield, and actions regarding obtaining it from the repair yard.
  2. The commander of the 36th TBr must investigate the specifics of the evacuation of the tank and its repair.
  3. The results of investigations conducted by the commanders of the 36th and 168th Tank Brigades must be delivered to me by the end of June 20th, 1942, with the indication of a guilty party to hold it criminally responsible. 
  4. The commander of the 168th TBr must immediately turn over T-34 #24-15 to the 36th TBr and report by the end of the day of June 18th, 1942.
Deputy Commander of the Armoured and Motorized Forces of the 38th Army, Major General of the Tank Forces Novikov
ABTU Military Commissar, Battalion Commissar Ruzhanskiy"

Wednesday, 28 November 2018

Factory #183 Experiments

"August 1st, 1940

To Chief of the 8th Department of the ABTU
Military Engineer 1st Class, Afonin

Report on experimental work for the month of July at factory #183
  1. Design bureau
    1. Two variants of a T-34 with a flamethrower have been developed. Presently, working blueprints are being composed. The deadlines outlined in the agreement are not being met.
    2. A technical project of a tractor on the T-34 chassis has been completed. Working blueprints of several components have been sent to production. The established deadlines are not being met. Production of blueprints is running 15-20 days late.
  2. Experimental plant #540
    1. Trials of the V-3 engine on an A-5 tank were performed. Trials began on July 17th, but the first outing showed that 250 hp is not enough for an A-5 tank. The engine only reached 1400 RPM in 4th gear on level terrain. After that, the engine was removed and adjusted to 300 hp. Trials resumed on July 24th. The mobility of the vehicle improved with an increase in power. The engine reaches 1800-1900 RPM on level terrain.
      As of July 31st, the engine had worked for 30 hours, after which it broke due to gas penetration.
    2. Assembly of two T-34 tanks with M-250 engines was performed. One tank was completed, and trials will begin on August 1st. The second vehicle is due for completion on August 10th.
    3. Voroshilovets tractor trials with components made with substitutes were performed. The tractor went through 1000 km of high speed trials. Towing trials remain, which will be performed in August.
    4. Two Voroshilovets tractors were assembled for installation of pneumatic controls. Installation of pneumatic controls will begin on August 1st and complete in the first half of August.
Acting regional engineer, Captain Rusakov"

Tuesday, 27 November 2018

Bow Machine Guns

When tanks were used primarily for infantry support, there was no such thing as too many machineguns. Little machinegun cupolas or full on turrets were quite useful. However, as tanks evolved, the bristle of machineguns boiled down to just one in a ball mount in the front hull. Even this feature came under scrutiny, however, as this British document shows.

"As far as is known no useful progress has been made on this and as has been stated on innumerable amount of occasions before, unless the Ordnance agrees to change the shape of the front glacis plate, they are unlikely to attain a satisfactory solution. It is extremely unfortunate that no honest attempt has been made to tackle this design in the past nine months, since the short ranges of Tunisia have shown that the machine gun will come into its own and this bow machine gun with no sight is merely a means of wasting valuable ammunition. Quite recently it was reported from Tunisia that a tank had expended twice its normal complement of S.A.A. Obviously it cannot be wasted hose-piping it from an unsighted gun.

In the absence of any sight, the following alternative solution is offered. As the bow machine gun stands today, it is the weakest point of the tank. That is to say, the strongest part of the front glacis plate of the M.4 will withstand a striking velocity of 2400 f.s. from 3" A.P.C. M.62 ammunition. The bow gun represents only 1300 f.s. S.V. Officers returned from Africa are of the opinion that this bow machine gun, whether provided with a sight or no, is a waste of ammunition, since it cannot be commanded. They would much prefer twin machine guns in the co-axial mount. We continue to press the Armoured Force for this. Meanwhile, it is recommended that the whole question should be reconsidered by D.R.A.C. with the view to agreeing to the elimination of this bow machine gun in tanks as long as no sight is forthcoming."
-British Army Staff (AFV) Situation Report as on 18th July, 1943

KRSTB Radio Trials

"On the execution of factory trials of the KRSTB radio according to order #319 given on December 14th, 1939

Field trials were carried out in Mytishi-Zagorsk in Moscow oblast. Laboratory trials were carried out in laboratories #10 and 17 of NII-20.

1. Items under trial

Testers were given two complete sets of KRSTB radios. A third radio was used to create interference.

2. Goal of trials

The following was tested:
  1. Meeting of tactical-technical characteristics.
  2. Reliability of the equipment.
  3. Main electrical and design characteristics of the equipment.
3. Conditions of trials

Trials were carried out with tanks in motion: A-7 at 45-50 kph, T-26 at 25-30 kph. The air temperature was -31 degrees Celsius. Radio communication reliability was tested by passing short radio messages.

Sunday, 25 November 2018

The Last of the Threes

The issues that the German PzIII medium tank encountered can be tracked by the rate of its production. Only 896 vehicles of this type, including command tanks, were built in 1940. This is a small number, especially considering that German manufacturing shifted to a wartime schedule and up to 7 factories were building this tank simultaneously. To compare, Krupp alone built 290 PzIVs in 1940, and BMM built 370 Pz38(t)s. It was only in the spring of 1941 that the PzIII rose to first place, becoming the most numerous tank built in Germany, a position it held until the end of 1942. The tank remained the most numerous in the German army until mid-1943. Today let us talk about the last variants of this tank: the PzIII Ausf.J through N.

Thursday, 22 November 2018

122 mm HEAT Effectiveness

"October 20th, 1944

Report on the effectiveness of 122 mm howitzer HEAT shells

  1. 122 mm HEAT rounds were fired at a range of 4000-4500 meters using the DT scale and the stock special charge.
    Firing showed that:
    1. Calibration was performed against targets located on a hill pointed towards the battery and a flat horizontal clearing. 90-95% of the shells burst. The explosion is thermite type.
    2. When shooting at targets positioned on reverse slopes, the shells ricochet and do not explode.
    3. Firing at narrow targets from 4000-4500 meters is ineffective due to high dispersion.
      Firing at personnel is also ineffective. Compared to the HE-fragmentation grenade there are a lot fewer fragments, and thus a lot less damage is dealt.
  2. Firing at dugouts, pillboxes, tanks, or armoured cars was not performed.
Conclusions: using HEAT shells fired from a 122 mm howitzer at a range of over 2 km against enemy personnel or MG nests is unreasonable due to low effectiveness.

Chief of Staff, Captain [signature]"

Wednesday, 21 November 2018

T-34 Design Improvements

"Minutes of a meeting with the factory #183 director on August 29th, 1940 on the issue of design changes to the T-34

1. Issue: on the introduction of the F-32 and 45 mm gun on the T-34.

Factory's opinion: in order to prepare production in a timely manner and make the necessary order for armour at the Ilyich factory, it is necessary to install each type of system (L-11, 45 mm, F-32) in the T-34 tank in 1940. Our queries to the BTU remain unanswered.

  1. 200 L-11 systems will be delivered in 1940.
  2. Past that, it will be necessary to install the 45 mm gun in the turret designed for the F-32 with conversion parts.
  3. Factory #183 must investigate the issue of the possibility of installing the 45 mm gun and the F-32 in the L-11 turret by October 1st.

Tuesday, 20 November 2018

Production figures

"Information summary of presence of tanks in the Red Army from January 1st, 1941, to January 1st, 1944

Inventory as of Jan 1st 1941
Produced in the first half of 1941
Produced as of Jul 1st 1941
Produced in the second half of 1941
Produced as of Jan 1st 1942
Produced in 1942
Produced as of Jan 1st 1943
Produced in 1943
Produced as of Jan 1st 1944
























































Chief of the GBTU Tank Directorate, Major-General of the Tank Engineering Service, Afonin"

Via the Ministry of Defense of the Russian Federation.