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Soviet tactics

1942 Combat Damage Analysis of the T-34 and T-70 tanks

Translation and Analysis of Original 1942 Combat Damage Survey

T-34 Model 1942 medium tank and T-70 light tank knocked out at Kursk, July 1943. Source: https://waralbum.ru/125951/

Introduction

On June 22, 1941, Nazi Germany launched Operation Barbarossa, the invasion of the Soviet Union, conquering over 1500 square kilometers of Soviet territory within 6 months. By November 1941, German forces were within reach of Moscow, but were driven back by a counteroffensive of Soviet reserves, which saved the Soviet capital. The “Great Patriotic War” on the Eastern European Front continued until the fall of Berlin in May 1945, and proved to be the deadliest theatre of World War 2, both in military and civilian casualties. To replace the tens of thousands of tanks lost in the first six months of the war, in 1942, the Soviet tank industry introduced an improved variant of the T-34 medium tank, as well as a new light tank, the T-70, producing around 12,500 T-34 and 4,900 T-70 tanks that year. Although combat losses were less severe than in 1941, the Red Army still lost around 6,600 medium tanks and 7,200 light tanks throughout 1942, a significant fraction of which were T-34 and T-70 tanks.

Thus, in late 1942, the Central Scientific Research Institute No.48 (ЦНИИ 48), specializing in metallurgy and armor characterization, was instructed to evaluate the quality of tank armor through the inspection of disabled tanks recovered from battlefields and undergoing repair. One study was completed on the T-34 medium tank, and another study on the T-70 light tank.

Two engineers were in charge of both studies: Chief Engineer Ardentov and Engineer Schelkanov. The studies were completed in September – November 1942, and the results provide a rare insight into how armored vehicles actually performed under real combat conditions. These reports are translated in the following article as they were written, meaning they occur in the present tense and refer to ‘our’ army et cetera meaning the army of the original authors – the Soviet Red Army. Further analysis within the reports is contained within ‘[ ]’ so as to not detract from their content. Some tables, where data has been duplicated and simply reformatted, have been omitted.

https://youtu.be/oZGXVuAjJfQ

The following Section is a direct translation of reports by the Central Scientific Research Institute No.48 (ЦНИИ 48) in 1942.

Armor layout of a late 1941 T-34 (and T-34-85 below)
Source: http://otvaga2004.ru/tanki/v-boyah/tanki-t34-vov/

T-34 Medium Tank

Tanks play a major role in the ongoing war, so it is important for our army to study their overall survivability, specific vulnerabilities, and major causes of breakdown, ultimately to inform the tank industry. One method is to collect and analyze statistics on disabled tanks undergoing repairs in refurbishment workshops. This data can be used to characterize the advantages and disadvantages of armor, internal mechanisms, and drivetrains currently in use.

The successful armor layout, powerful armament, and adequate mobility of the T-34 have made the tank very popular with the Red Army. Captured German documents reveal that they evaluate the T-34 as a capable enemy tank, requiring new weapons and tactics to counter. At this time, the T-34 has become the most numerous tank in our army, so it is critical to study its vulnerability to battle damage, and the key reasons these tanks are lost in combat.

Statistics were gathered from a sample of 178 tanks which were towed back to repair facilities in Moscow, as well as the repair facility in Factory No.112 [located in Nizhny Novgorod] · 61 tanks were examined at repair facility No.1
· 26 tanks were examined at repair facility No.6
· 91 tanks were examined at the repair facility in Factory No.112

Each tank had a data card filled out, recording:
· Number of projectile impacts on the tank
· Locations of impacts
· Results of impacts and their effect on armor integrity
· Caliber of the projectile – estimated from the impact zone
· Consequences of the impact and reason the tank was disabled

Out of a sub-sample of 69 T-34 tanks examined – these being a subset of tanks at facilities No.1 and No.6:
· 24 tanks (35%) were disabled without armor penetration (i.e. internal mechanical breakdown)
· 45 tanks (65%) were disabled through armor penetration
The remaining 109 tanks were not used for this estimate because they were specifically recovered and towed to these specific repair facilities after suffering armor penetration damage

Out of the aforementioned 24 tanks that were disabled through mechanical breakdown:
· 11 tanks (45.8%) suffered engine failure
· 4 tanks (16.7%) suffered chassis (suspension / wheels / tracks) failure
· 7 tanks (29.2%) suffered both engine and chassis failure
· 2 tanks (8.3%) caught fire
Thus, 18 tanks (75%) required repair of the engine

Out of the full sample of 178 tanks, we subtract out 24 tanks disabled purely through mechanical failure – this leaves 154 tanks that had some sort of armor penetration damage, with a total number of projectile impacts at 534, subdivided as:
· 432 (81%) projectile impacts (penetrations & bounces) on the hulls
· 102 (19%) projectile impacts on the turrets

The 534 projectile impacts are further subdivided into:
· 289 (54%) impacts that did not result in internal damage to the tank and crew
· 245 (46%) impacts that resulted in internal damage

Type Total % Per-Caliber Percentages of the 534 Total Impacts
20 mm 37 mm 42 mm 50 mm 75 mm 88 mm 105 mm No ID
Bounce 289 54.1 % 3.2 % 6.8 % 4.9 % 30.6 % 3.2 % 0.2 % 2.0 % 3.2 %
Penetration 245 45.9 % 1.5 % 3.2 % 2.6 % 23.7 % 6.9 % 3.2 % 0.9 % 3.9 %
Total 534 100 % 4.7 % 10.0 % 7.5 % 54.3 % 10.1 % 3.4 % 2.9 % 7.1 %

Note from Author – It is not clear to what the “42 mm” refers. The Germans technically had the 4.2 cm Pak 41, but this was a squeeze-bore gun, with 42 mm caliber at the breech tapering to 28 mm at the muzzle, and was very rarely used. It is possible, therefore, that the “42 mm” referred to here actually means captured Soviet 45 mm M1937 (53-K) anti-tank guns which were used by the Germans as the ‘4.5 cm Pak 184/1(r)’

Thus, the above tables shows that the dominant anti-tank weapons used against the T-34 are guns 50 mm in caliber or larger, with more than half of all impacts attributed to 50 mm guns alone.

The most effective guns against the T-34 are the 50 mm, 75 mm, and 88 mm, judging from the ratio of penetrations to bounces. The apparent low effectiveness of the 105 mm guns is due to the fact that most impacts attributed to this caliber hit the upper glacis plate at unfavorable angles for penetration.

Average bounces and penetration values per tank / per hull / per turret are recorded as:

Type Tank Hull Turret
Total Per Tank Total Per hull Total Per turret
Bounce 289 1.89 259 1.69 30 0.19
Penetrate 245 1.59 173 1.12 72 0.47
Total 534 3.48 432 2.81 102 0.61

On average, this comes out to 1.6 penetrating impacts to disable a tank.

The sampled tanks had between 1 to 17 impacts each

Impacts 1 2 3 4 5 6 7 8 9 10 11 13 16 17
No. of Tanks 41 33 22 20 7 8 8 2 5 3 2 1 1 1

Breakdown of percentages by location for all impacts and penetrating impacts:
· C1: Percentage of total impacts against the specified surface out of all recorded impacts (penetrating & bouncing)
· C2: Sum totals for tank front / side / rear / turret: percentage of total impacts against specified side out of all recorded impacts
· C3: Percentage of penetrating impacts against specified surface out of all recorded impacts (penetrating & bouncing)
· C4: Percentage of penetrating impacts against specified surface out of all penetrating impacts only
· C5: Sum totals for tank front / side / rear / turret: percentage of penetrating impacts against specified side out of all penetrating impacts only

The sampled tanks had between 1 to 17 impacts each

Location C1 C2 C3 C4 C5
Hull Upper Glacis 20.4 % 22.65 % 3.75 % 8.19 % 9.88 %
Lower Glacis 2.25 % 0.75 % 1.69 %
Lower (Vertical) Side 23.0 % 50.5 % 15.5 % 33.88 % 51.13 %
Upper (Sloped) Side 27.5 % 7.9 % 17.25 %
Upper Rear 3.94 % 7.52 % 1.9 % 4.26 % 9.56 %
Lower Rear 3.58 % 2.45 % 5.3 %
Top Engine Deck 0.19 % 0.19 % 0.19 % 0.41 % 0.41 %
Turret Front & Mantlet 4.86 % 19.14 % 3.19 % 7.39 % 29.02 %
Side 8.61 % 6.56 % 14.28 %
Rear 2.48 % 2.06 % 4.49 %
Roof 1.11 % 0.75 % 1.64 %
Turret Base 0.39 %

In total, 50.5 % of all impacts hit the hull side, 22.65 % hit the hull front, and 19.14 % hit the turret

Breakdown of all impacts by the caliber of the incoming shell

Location Net # Net % Caliber-Specific Percentages of Total Impacts
20 mm 37 mm 42 mm 50 mm 75 mm 88 mm 105 mm No ID
Hull Upper Glacis 109 20.4 % 1.88 % 1.7 % 2.43 % 3.02 % 1.88 % 0.94 % 2.8 % 0.75 %
Lower Glacis 12 2.25 % 0.93 % 0.57 % 0.18 % 0.57 %
Lower Glacis 12 2.25 % 0.93 % 0.57 % 0.18 % 0.57 %
Lower (Vertical) Side 123 23.0 % 0.36 % 1.7 % 1.88 % 16.44 % 0.75 % 0.36 % 0.57 % 0.94 %
Upper (Sloped) Side 147 27.5 % 1.52 % 3.65 % 2.43 % 17.62 % 0.57 % 0.57 % 1.14 %
Upper Rear 21 3.94 % 0.57 % 0.18 % 1.89 % 0.94 % 0.36 %
Lower Rear 19 3.58 % 0.18 % 0.36 % 0.71 % 1.15 % 0.18 %
Top Engine Deck 1 0.18 % 0.18 %
Turret Front & Mantlet 26 4.86 % 0.18 % 2.8 % 1.14 % 0.74 %
Side 46 8.61 % 0.36 % 0.58 % 0.58 % 2.86 % 2.72 % 0.94 % 0.57 %
Rear 13 2.48 % 0.18 % 0.36 % 1.22 % 0.36 % 0.18 % 0.18 %
Roof 6 1.11 % 0.73 % 0.18 % 0.18 %
Gun 9 1.69 % 0.18 % 0.18 % 1.33 %
Turret Base 2 0.39 % 0.39 %

In addition to damage from enemy gunfire, several T-34 tanks were disabled as a result of landmine or incendiary bottle damage. Out of the full population of 178 examined tanks, 9 tanks (5.9 %) suffered landmine detonation. In all cases, this resulted in severe damage to the underside, and in a few cases, the explosion tore off the turret and the upper engine deck armor panels.

Out of the 154 tanks which suffered gunfire damage, 38 tanks (24.6 %) also caught fire and showed evidence of extensive fire damage. Out of these, 31 tanks caught fire as a result of armor penetration, while 7 also had damage from landmine detonation, so it was not possible to determine the root cause of the fire on this small subset.

Summary statistics on all impacts by type of damage and caliber

As seen from the above table, the fraction of total brittle fractures (rupture / fracture / shatter) is quite low – accounting for only 3.9 % of all recorded impacts – indicating that the quality of the armor is sufficiently tough, and not over-hardened. Furthermore, a significant portion of brittle fracture damage came from impacts whose caliber could not be determined, which could include artillery shells and aviation bombs.

Almost 95 % of all impacts with the 88 mm gun resulted in penetration – indicating the T-34’s insufficient armor protection against this caliber gun

In summary:
· Around 35 % of tanks examined in the relevant subset were disabled through internal mechanical failure without any armor damage, primarily through failure of the engine. This indicates a need to improve the quality of engine construction and the design of engines with longer service lives
· The quality of the armor of the T-34 is quite satisfactory as far as its initial design requirement is concerned – to protect against 45 mm armor piercing shells
· The fraction of brittle fractures observed (3.9 %) is not significant enough to be considered a problem
· As examined, the tank components most often shot are the sides (accounting for 50.5 % of all impacts), front (22.65 %), and turret (19.14 %)
· The effectiveness of enemy gunfire is, as expected, strongly dependent on the sloping angle of armor plates: for instance, the upper glacis plate, sloped at 60 degrees off the vertical, saw only 18 % of impacts leading to full penetration
· Meanwhile, the vertical lower side plates suffered full penetration from 67.6 % of impacts, while the upper side plates, sloped 40 degrees off vertical, suffered full penetration from only 28.6 % of impacts. It is logical to assume that increasing the slope would further improve the effectiveness of these plates.
· The most widely used weapon used by the Germans against the T-34 at this time are 50 mm anti-tank guns.
· Based on this analysis, it can be concluded that the Germans do not use large numbers of sub-caliber shells (APDS / APCR) at this time – as these would have a caliber no greater than 37 mm, and the net total number of impacts recorded at 37 mm or below only accounts for 14.7 % of all recorded impacts
· The most effective rounds used against the T-34 are the 88 mm rounds, since around 95 % of all impacts with this caliber led to penetrations. This is not unexpected, since the German 88 mm Flak guns have considerable muzzle velocity.
· The observation that more than half of all impacts are recorded against the sides of the T-34 indicates extensive tactical misuse of these tanks, either through ignorance of overconfidence of their crews and commanders, or due to insufficient visibility of the battlefield from inside the tank.

Thus, two primary recommendations are offered to improve the survivability of T-34 tanks in combat:
1) Improving the reliability and quality of the engine and drivetrain
2) Training crews to use adequate tactics when operating the T-34

Close look: Upper Glacis Plate

Statistics on upper glacis plate impacts across the full set of 154 examined tanks

In total, out of the 109 impacts of the upper glacis, 89 impacts (82 %) were non-penetrating

It can be seen that the most commonly used rounds – 50 mm caliber – have low effectiveness against the T-34 frontal plate, as they accounted for 39.6 % of all impacts, but only 11 % of the unsafe / penetrating impacts

On the upper glacis, which is sloped 60 degrees to the vertical, only 18.1 % of all impacts resulted in penetration or fracture damage, with 81.9 % of recorded impacts bouncing

Close look: Lower Glacis Plate

Statistics on lower glacis plate impacts

In total, out of the 12 impacts of the lower glacis, 8 impacts (66 %) were non-penetrating

Close look: Side Plates (Overview)

In total, 270 impacts against the side plates were recorded (50.5 % of the net total), including the upper (sloped) and lower (vertical) side plates:
· 157 impacts (58 %) recorded on the front half of the tank
· 113 impacts (42 %) recorded on the rear half of the tank

Close look: Side Plates – Lower (Vertical) Side Plates

Statistics on lower (vertical) side plate impacts

This data shows that 50 mm shells were quite effective against the lower (vertical) sides of the tank, with almost 2/3 of all impacts with this caliber leading to penetration.

At the same time, all impacts with 75 mm, 88 mm, and 105 mm shells led to penetration.

Close look: Side Plates – Upper (Sloped) Side Plates

Statistics on upper (sloped) side plate impacts

The effectiveness of sloping (at 40 degrees from the vertical) is evident from comparing this data to the data for the lower (vertical) side plates
· Only around 1/4 of 50 mm impacts lead to penetration on the sloped surface
· Around 28.6 % of recorded impacts were damaging (including 75 mm and 88 mm)

Close look: Rear Plates (Overview)

In total, 40 impacts were recorded against rear armor plates:
· 21 impacts on the upper rear (3.94 % of the net total recorded impacts)
· 19 impacts on the lower rear (3.58 % of the net total)

Only one tank had recorded damage against the upper rear hull plate / engine deck
· Attributed to artillery fire

Close look: Rear Plates – Upper Rear Plates

Statistics on upper rear plate impacts

Close look: Rear Plates – Lower Rear Plates

Statistics on lower rear plate impacts

Close look: Turret Face & Gun Mantlet

Statistics on turret face and gun mantlet impacts

Close look: Turret Side

Statistics on turret side impacts

The following Section is a direct translation of reports by Central Scientific Research Institute No.48 (ЦНИИ 48) in 1942.

Armor layout of a T-70 light tank. Source: http://armor.kiev.ua/Tanks/WWII/T70/1/

T-70 Light Tank

The primary tactical purpose of the T-70 light tank is to engage enemy personnel and suppress machine gun nests. Nevertheless, the relatively strong glacis armor and adequate armament (45 mm gun and machine gun) allow the T-70 to effectively engage enemy anti-tank guns, as well as enemy light tanks, and occasionally enemy medium tanks. Considering the large numbers of T-70 light tanks used in our army at this time, there is significant interest in studying its battlefield vulnerabilities.

Statistics were gathered from a sample of 70 tanks which were towed back to the repair facility at Factory No. 37 in Moscow. Each tank had a data card filled out, recording the number, locations, and results of gunfire impacts and penetrations

Out of the 70 tanks:
· 12 tanks (17.2 %) were disabled without armor penetration (i.e. mechanical breakdown)
· 58 tanks (82.8 %) were disabled through armor penetration
This is a lower overall rate of mechanical failure than was observed with the T-34, but is still too high to be acceptable, and indicates a strong need to improve the quality and reliability of the engine and powertrain.

Out of the aforementioned 12 tanks that were disabled through mechanical breakdown:
· 9 tanks (75 %) suffered engine and/or transmission failure
· 2 tanks (16.5 %) caught fire
· 1 tanks (8.5 %) suffered chassis (suspension / track / wheel) damage
Thus, just as with the T-34, the primary mechanical vulnerability of the T-70 is its engine.

On the remaining 58 tanks with some armor damage observed, a total of 212 projectile impacts were recorded, subdivided into:
· 141 (66.5 %) projectile impacts (penetrations & bounces) on the hulls
· 71 (33.5 %) projectile impacts on the turrets

The 212 projectile impacts are further subdivided into:
· 65 (30.7 %) safe impacts that did not result in internal damage to the tank or crew
· 147 (69.3 %) impacts that resulted in penetration and internal damage
Thus, over 2/3 of all impacts were damaging for the T-70, a much higher fraction than observed with the T-34

The table above shows that the primary class of weapons used against the T-70 are anti-tank guns 50 mm in caliber or below, accounting for 65.9 % of all impacts – out of which, 68.5 % are penetrating

Average quantities of bounces and penetrations per tank / per hull / per turret recorded as

The hulls of T-70 light tanks received a much higher fraction of incoming fire than their turrets, and had a higher risk of penetration.
· 78 % of all impacts against the hull were penetrating
· 52 % of all impacts against the turret were penetrating

The sampled tanks had between 1 to 17 impacts

Of the examined set, 62 % of the tanks were disabled by just 1-3 shots

Breakdown by impact location:
· C1: Percentage of total impacts against the specified surface out of all recorded impacts (penetrating & bouncing)
· C2: Sum totals for tank front / side / rear / turret: percentage of total impacts against specified side out of all recorded impacts
· C3: Percentage of penetrating impacts against specified surface out of all recorded impacts (penetrating & bouncing)
· C4: Percentage of penetrating impacts against specified surface out of all penetrating impacts only
· C5: Sum totals for tank front / side / rear / turret: percentage of penetrating impacts against specified side out of all penetrating impacts only

In total, 43.8 % of all impacts hit the hull side, only 8.5 % hit the hull front, and 33.3 % hit the turret, with the hull sides and turret proving to be the most commonly targeted areas

Out of the full set of 70 examined tanks, 3 tanks exhibited damage from landmines: 2 were also damaged by gunfire, while 1 showed no signs of gunfire damage.

Furthermore, a total of 27 tanks (38.5 % of the net total) showed evidence of fire damage: 25 tanks with fire damage had gunfire damage to their armor, and 2 had no gunfire damage. This high percentage of burned tanks is likely due to the use of flammable gasoline fuel.

Since the significant majority of impacts and penetrations were against the side of the T-70 light tank, it was recommended to improve the armor protection of that surface.

Breakdown by the caliber of the incoming shell

Summary statistics on all impacts by type of damage and caliber

As can be seen from the table above, there is a high fraction of brittle fracture (rupture / fracture), accounting for 25.9 % of all recorded impacts, which indicates low toughness and therefore low quality of the armor used on T-70 light tanks. These are primarily attributed to projectiles over 50 mm in caliber, impacting the side plates.

In summary:
· Around 17.2 % of examined tanks were disabled without gunfire damage, as a result of internal mechanical failure, primarily engine breakdown
· Even though this is lower than the 35 % mechanical breakdown rate observed with T-34 tanks, it is still significant, and shows the engine and drivetrain require reliability improvements
· The largest fraction (40 %) of all impacts were detected on the side plates – which are protected by the least effective armor on the tank, due to its low thickness and lack of slope, and suffer high rates of brittle fracture – this requires a thorough reexamination and redesign of side armor for the T-70
· The other surfaces on the T-70 are protected by more effective armor than the sides, as they are thicker and sloped – these other surfaces are not as brittle, and appear to have adequate toughness
· The most common weapons used against T-70 tanks are anti-tank guns 50 mm in caliber or below, accounting for 65.9 % of all impacts – of which subset, 63.5 % lead to penetrations. The effectiveness of guns over 50 mm in caliber is obviously even higher.
· The observation that more than half of all impacts are recorded against the sides of the T-70 indicates extensive tactical misuse of these tanks, through ignorance of their crews and commanders, or due to insufficient visibility of the battlefield from inside the tank, which leads to delayed or impossible detection and identification of enemy anti-tank guns

Thus, three primary recommendations are offered to improve the survivability of T-70 tanks in combat:
1) Improving the reliability and quality of the engine and drivetrain
2) Strengthening the side armor plates
3) Training crews to use adequate tactics when operating the T-70

Close look: Upper Glacis Plate

Statistics on upper glacis plate impacts

As can be seen, the upper glacis plate effectively stops around 50 % incoming anti-tank shells from achieving penetration [even though it is only 35 mm in thickness]. This can be attributed to the high quality of steel used, as well as the significant slope of the plate, 60 degrees off the vertical.

Close look: Front Midplate & Lower Glacis Plate

Statistics on front midplate and lower glacis plate impacts

Close look: Side Plates

As mentioned earlier, the largest fraction of impacts were against the side plates of the T-70 tanks, which are weakly armored – only 15 mm thick, oriented vertically. It was found that 42.4 % of impacts were against the forward half of the side plates, while 57.6 % of impacts were against the rear half.

Statistics on side plate impacts

As can be clearly seen, the side armor plates fail to provide an acceptable level of protection for the tank, with 8 recorded instances of a penetration through the side even resulting in a penetration or fracture in the armor on the opposite side of the tank

Close look: Air Intake

Statistics on air intake impacts

Close look: Hull Roof Plate

Statistics on hull roof plate impacts

Close look: Rear Plates – Lower Rear Plate

Statistics on lower rear plate impacts

Close look: Rear Plates – Upper Rear Plate

Statistics on upper rear plate impacts

Close look: Turret Face & Gun Mantlet

Statistics on turret face and gun mantlet impacts

The turret likewise does not possess sufficient armor to adequately protect the tank against enemy anti-tank fire, even with calibers 50 mm or below – with 72.9 % of impacts of this caliber leading to penetration

Close look: Turret Side

Statistics on turret side impacts

As can be seen, considerably more impacts were found against the side of the turret – with a much higher proportion of bounces, likely due to the oblique angle of incoming fire coupled with the angling of the turret side armor

Close look: Turret Roof

Statistics on turret roof impacts

Conclusion of translated reports

Early 1942 T-34 knocked out on a village street
The tank shows both penetrations (circled in red) and brittle ruptures (circled in purple), as well as evidence of damage from land mine blast (the missing wheel and damaged track guards)

Analysis – The T-34 in Combat

The following section is not part of the original reports and has been written by the author of the article

The analysis of the T-34 presented here showed that the tank’s armor was performing adequately for its initial design specification. Designed to protect against 45 mm armor piercing shells, primarily from the frontal arc, the data shows that the armor mostly achieved this. To ensure that required level of protection, the hull armor of the T-34 front, rear, and lower side plates was 45 mm thick, while the upper side plates were 40 mm thick, with the upper glacis sloped 60 degrees off the vertical, and the upper sides sloped at 40 degrees. Unfortunately, by the time of Operation Barbarossa, the Wehrmacht was already using large numbers of 75 mm anti-tank guns, as well as 88 mm anti-aircraft guns in the anti-tank role, with significantly better armor penetration. Furthermore, poor crew training and atrocious tactical planning throughout 1941 and 1942 resulted in hundreds of T-34 tanks being ambushed by German anti-tank gun positions, which took advantage of the tank’s more vulnerable side armor – with over 50 % of all shell impacts and over 50 % of all penetrating impacts being recorded against the sides. The unsloped lower side plates proved to be particularly vulnerable, with even 50 mm anti-tank guns penetrating the armor more than 60 % of the time.

The Soviet tank industry made several efforts to improve the armor protection of T-34 tanks. There were several designs of T-34s with additional armor plate ‘screens’ (applique-type armor) welded on, though these did not enter large-scale mass production. A derivative design was also developed, the T-43, which carried much thicker armor with the front thickened to 75 mm, and the sides and rear to 60 mm. Unfortunately, the T-43 suffered from reduced mobility and range, while still remaining vulnerable to German 88 mm guns. Since it did not offer considerable advantages over the existing T-34, and that its production would require a significant delay for factory setup, the decision was made to continue producing T-34 tanks instead. This was an acceptance that the requirements of mass production was more important than a small increase in protection.

Late 1942 T-34 knocked out near Lake Ladoga. A large brittle rupture can be seen at the rear of the turret. Source: https://waralbum.ru/22689/

Thus, from the beginning of 1943 through May 1945, over 36,000 additional T-34 tanks were produced and served with the Red Army, with peak production rates up to 1,500 tanks per month. During the same period, however, around 36,000 medium tanks (primarily T-34’s) were disabled in combat, according to statistics reported by Grigorii Krivosheev in 1993 (although other Russian historians have since pointed out that his calculations are inconsistent, and it is likely that the 36,000 loss figure does not account for tanks that were disabled but later repaired and sent back into service – thus some vehicles may be re-disabled and counted more than once as a ‘loss’).

The decision to keep the T-34 in production without significantly improving its hull armor, even after studies like this, may certainly seem insensitive. However, given the situational context, and the acute need for thousands of tanks to continuously push back the German forces, the consequences of spending valuable time setting up nationwide factory production to produce marginally better protected tanks could have been devastating to the Soviet war effort, and thus, unacceptable. Even if the losses in tanks and tank crews were somewhat reduced with a better design, the overall losses of manpower and territory resulting from a shortage of tanks along the Eastern Front would have far outweighed these small benefits. Thus, the choice was made to focus on improving the reliability, manufacturing speed, and cost-effectiveness of the T-34. As a result, between 1941 and 1945, the labor requirement in man-hours to produce a full T-34 was reduced by a factor of 2.4, while the price per tank was reduced by a factor of 1.9, even though the 1945 variant of the T-34 was a far more capable tank than its 1941 predecessor.

Early 1942 T-34 knocked out in Stalingrad. A prominent penetration can be seen in the front middle of the tank
Source: https://waralbum.ru/community/ww2/23/paged/12/

Analysis – The T-70 in Combat

Unlike the T-34, the armor protection of the T-70 proved to be inferior to its intended design specification. It was also defective in manufacture as it was overhardened, and therefore vulnerable to brittle fracture even if it would not otherwise suffer a penetration. Furthermore, by late 1942, light tanks in general were becoming redundant for the Red Army. Their most critical hour came in late 1941 / early 1942: since the production of light tanks was easier to maintain on surviving factories, and faster to re-establish on factories pulled back deep into the nation, light tanks (primarily the T-60) were produced in large numbers to supply Red Army units with at least some sort of tank, while heavier production lines were being set up in safe zones. However, once mass production of T-34s was resumed in May – July 1942, the need for light tanks diminished, especially in light of the low effectiveness of the T-60. The T-70 was developed as a significant upgrade to the Russian light tank line, to provide a low-cost infantry support tank that would supplement the more expensive though much more capable T-34. It is possible that light tanks remained in production due to their disproportionate apparent effect during the difficult winter of 1941-1942, and a misguided though understandable expectation that they will continue to be effective, though it is also possible that they were simply intended to pad the overall number of fielded tanks, since they still remained an effective weapon against German infantry and lightly armored or soft-skin vehicles.

Unfortunately, the T-70 proved to be generally an ineffective design. It was vulnerable to all types of German anti-tank guns, and significantly disadvantaged when facing German medium tanks and assault guns, like the Pz.Kpfw. III, Pz.Kpfw. IV, and StuG III. However, when used adequately, the T-70 performed well in areas inaccessible to heavier tanks, such as dense forests and boggy ground. It also proved to be unexpectedly effective in villages and urban terrain, since it was a small, difficult target to hit, and was maneuverable on narrow streets. Ultimately, over 8,200 T-70 tanks were produced in 1942 and 1943, complementing the 5,900 T-60 tanks that preceded it, produced in 1941 and 1942. A significant portion of these were also disabled in combat, with G. Krivosheev reporting “losses” of 16,200 light tanks in 1942-1945, while official Red Army statistics list only 1,500 surviving T-70 light tanks in service in January 1946. The fact that Krivosheev’s figure is considerably higher than the production of light tanks in the same period (not even accounting for the surviving tanks in 1946), and cannot adequately be accounted for with surviving Interwar T-26 and BT-5 / BT-7 light tanks, lends credence to the idea that Krivosheev did not account for tanks that were repaired and sent back into action when tallying up losses, and only examined the total numbers of tanks disabled in combat. Nonetheless, the sheer scale of tank losses, including the T-70, makes almost any accurate statistical analysis difficult but does indicate appalling losses in Soviet tanks during this period.

The Red Army finally made the decision to discontinue the T-70 light tank after the Battle of Kursk, realizing that it did not fulfill its intended roles adequately, with the last T-70 tanks rolling off the production line in October 1943. In November, armored units of the Red Army were reorganized, subsequently fielding no tanks lighter than the T-34, though some T-70 tanks that were already produced were used in supplementary roles. Production lines initially used for the T-70 were repurposed to produce the SU-76 light self-propelled gun, based on a stretched T-70 chassis, and armed with the 76.2 mm ZIS-3 field gun. The SU-76 proved to be a far more capable combat asset, ultimately becoming the Soviet Union’s second most numerous armored vehicle of World War 2, with over 14,200 produced between December 1942 and October 1945.

T-70 memorial in Kamensk-Shakhtinsky showing a penetration at the front and brittle rupture on the side plate
Source: https://waralbum.ru/community/armor/76/paged/6/

Overall

These reports, just a few of thousands during the war provide a valuable insight into the chaos being caused by the scale of tank losses for the Soviets, the sacrifices made by the Soviets in repelling the German invasion, and to the combat performance of two of the most famous Soviet vehicles of the era. The T-34 was designed to protect against 45 mm armor-piercing ammunition from the front and its armor reflected this. When the Germans, with larger caliber tank guns and anti-tank weapons as well as improved ammunition, were shooting at it, the quality of the armor was shown to be performing as required. Tied in with good combat tactics, like ambushing and firing at the Soviet tanks from the side and the often terrible tactical use by the Soviets of their own tanks, the reason for the scale of the losses is obvious. It is true that the numbers for tank losses as produced by Krivosheev are likely including some double counting but the production rate had to at least try and keep up with the loss rate to maintain a semblance of combat effectiveness against the Germans. The addition of even a relatively modest amount of additional armor to the T-34 would undoubtedly have improved its protection against German fire but the costs in production were too high in terms of retooling and slowing delivery. The T-34 was simply adequate and good enough to provide the number of tanks needed.

The same is not true of the T-70. It was under-protected and the armor was substandard leading to enormous losses. The real contribution of the T-70 was that it was there when it was needed and was better than nothing but it was simply outclassed, outmatched, and utterly inadequate to the task. The T-34 went on to continue to be developed and upgraded for many years because the underlying design was a solid one, the T-70 was quickly and quite correctly discarded.

However, it must be kept in mind that the analysis carried out in this report is not a full statistical analysis of the global battle damage sustained by these vehicles. The nature of the study meant that only a portion of all the damaged or destroyed Soviet tanks could be analyzed. Tanks which were captured by the Germans or were abandoned on German-held ground could, obviously, not be studied. What is less obvious is the fact that only tanks with certain types of damage made it back to the factories to be repaired and, thus, analyzed. Any tank that was too damaged to be repairable and worth the effort of being recovered was implicitly excluded from the study. Similarly, any tank which received damage that was light and could be repaired in a field repair workshop also never made it back to the factories and was not included in the study.

This means that the study only looked at tanks that received moderate battle damage, severe enough not to be repaired in the field but not catastrophic so as not to be worth the effort of recovering the vehicle. Nonetheless, this study casts a very interesting light on the damage taken by the Soviet tanks during this period and on the fighting that took place on the Eastern Front.

Sources

Ардентов, Щелканов, “Поражаемость Танков Красной Армии и Причины Выхода их из Строя. Выпуск 1: Танк Т-34.” ЦНИИ 48, Московская Группа, 1942
Ardentov, Schelkanov, “Damageability of Red Army Tanks and Reasons for their Breakdown. Issue 1: T-34 Tank.” CNII 48, Moscow Group, 1942

Ардентов, Щелканов, “Поражаемость Танков Красной Армии и Причины Выхода их из Строя. Выпуск 2: Танк Т-70.” ЦНИИ 48, Московская Группа, 1942
Ardentov, Schelkanov, “Damageability of Red Army Tanks and Reasons for their Breakdown. Issue 2: T-70 Tank.” CNII 48, Moscow Group, 1942

Потери Советской Бронетехники в Годы Великой Отечественной Войны
Losses of Soviet Armored Vehicles during the Years of the Great Patriotic War

http://ru.wikipedia.org/wiki/%D0%A2-70

http://ru.wikipedia.org/wiki/%D0%A2-60

http://ru.wikipedia.org/wiki/%D0%A2-34

3 replies on “1942 Combat Damage Analysis of the T-34 and T-70 tanks”

Light tanks are not supposed to be as good as medium tanks. They will always lack armor and firepower. It is application of those tanks in their proper roles which matter. In case of T-70 it was a matter of tooling, machinery and industry. It is a lot harder and more expensive to manufacture heavier vehicles and thus Soviets build those tanks simply because they could. If we consider BT-70 underarmored, BT-7 is even in worse situation just as early Pz.4 and Pz.3 variants. Such analyzes should be taken with a grain of salt.

Article itself states that T-70 had performed in roles where T-34 could not go. This is where light tanks should be going, into difficult terrain like forests. They should not however be viewed as replacements of medium tanks, because light < medium < heavy. This is why we are seeing through history this evolution of nations first going with tankettes then building up to light tanks with mix of medium tanks. Then they figure out the basics that light tanks are inferior in combat to mediums. Then they slowly creep up in weight and become heavy tanks in the name of greatest capabilities.

Each class of vehicles has its own role and each tank is best for customer's needs. For example Switzerland often prioritized light tanks over medium (MBT) tanks of that era, because they have a lot of mountainous territories. Japan always prioritized medium tanks over heavy tanks and MBT, because they lack solid infastructure and soil to support heavy vehicles. Thus for them are best medium tanks like Type 10.

Author of those conclusions should not view T-70 in a light of it being a medium tank like T-34 and thus expecting it to perform just as good. It should rather ask himself, how those tanks were employed and how we should employ them better. Tanks should be held in reserve for tasks like city fighting, forest fighting, swamps, mountains, etc. Some units might have mixed composition while other like mountainous formations might have armored brigades formed entirely of those light tanks.

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