Thursday, April 4, 2013

Recurring problems of Soviet tank design

In my piece on the T-34 tank I said that postwar Soviet tanks (T-55, T-62, T-72, T-64, T-80) were built on the same principles as the T-34 with unfortunate consequences for the countries that had to use them in combat.

Soviet tanks have performed poorly in WWII, Korea, in the Middle East wars between the Israelis and Arabs and in Gulf War I, in the sense that they have suffered disproportionate losses against tanks that were comparable to them in general characteristics.

It is fascinating to see that the same problems are mentioned in US and Israeli reports separated by decades and referring to different vehicles. From the T-34 in the 1940’s to the T-62 in the Yom Kippur war the same limitations are noted!

Hull size

The T-34 had a huge problem with internal space due to several factors:
1). a large engine that took up roughly half of internal volume

2). its Christie suspension
3). the sloped armor on the sides and back of the vehicle

Postwar tanks did not have these faults but they also suffered from limited internal space since it was a design choice to limit the weight and size of these vehicles.
The result was that all the Soviet tanks were smaller and lighter than their Western contemporaries like the Centurion, M-48 and M-60. This supposedly gave them an advantage in mobility and presented a smaller target at long distances.

However there was a price to pay:
1). The smaller hull affected the performance of the crew and led to fatigue. For example an Israeli evaluation says: ‘As regard to human engineering the best were the Patton tanks (M60/48), then the Centurion and way behind the T-62/55 tanks. The meaning is that the crews of the Patton and Centurion tanks could fight longer periods of time without being exhausted relative to the crews in the T-62/55 tanks.’ [Source: ‘M60 Vs T-62: Cold War Combatants 1956-92’, p39]

2). Compared to Western tanks a smaller number of rounds could be carried. For example the T-34/76 carried 77 rounds but the T-34/85 carried only 56 and 16 of these had to be stored in the turret. In comparison the Pz IV had 87 rounds and the Panther 82.
The Centurion, M-48 and M-60 had about 60 rounds compared to about 40 in the T-55, T-62, T-72. The ability to carry more ammo meant that tanks did not have to leave the battle in order to resupply often. This was noted by the Israelis:

The amount of gun rounds inside the Patton (M60A1, M60, M48) and the Centurion tanks is remarkably higher (about 60 rounds in each) than in the T-62 and T-55 tanks (less than 40 rounds). The meaning is that on average the T-62 and T-55 tanks should leave their active fight and firing positions for refilling of gun ammunition [more often] than the other tanks, which means that on average the percentage of effective tanks in each moment is smaller in T-62 and T-55 units than in the units of the other tank types.’ [Source: ‘M60 Vs T-62: Cold War Combatants 1956-92’, p38]

3). By having ammo and fuel in a small space any penetration of the tank usually led to catastrophic loss of the vehicle and death of the crew. As Zaloga puts it in ‘T-34-85 vs M26 Pershing: Korea 1950’, p23:

Armor data provides only part of the picture of a tank's protection. Other factors in assessing the vulnerability of a tank include the internal arrangement of fuel and ammunition. The T-34-85 is a clear example of the trade-off between the benefits and drawbacks of steeply angled protective armor. Although the T-34's sloped sides reduced the likelihood of the tank being penetrated by enemy projectiles, it also led to a decrease in internal hull volume. In the event that the T-34 was penetrated, the projectile was far more likely to produce catastrophic damage among the fuel and ammunition stored in such a small space. The side sponsors of the T-34's fighting compartment in particular contained fuel cells that if penetrated could lead to fire and the destruction of the tank.

The same problem was identified by the Israelis after the Yom Kippur war. According to ‘M60 Vs T-62: Cold War Combatants 1956-92’, p39:
‘Survivability: The silhouette of the T-62 and T-55 tanks is smaller than [that] of the other tanks and the same is true with the silhouette of their turret. One of the most [sic] disadvantages of T-62/55 tanks is their small internal volume. The meaning is that all the internal systems are too close and when one system is hit after penetration, in most cases another system or systems are also damaged or getting out of action. Because of the small internal volume there is in the T-55 tank a fuel tank combined with gun ammunition stowage in the right front corner of the hull (I am not sure if it is the same in the T-62 tank)[it is]. The meaning is absolute destruction and explosion of the tank in case of a penetration. Analysis based up tests and war analysis showed that the improved Centurion and M60A1 were more or less on the same level survivability. Next came the M48 and Tiran 4/5 and finally the Sherman.

This problem became worse and worse as tank gun calibers grew and more powerful ammo was carried. Zaloga says in ‘M1 Abrams Vs T-72 Ural’, p27 that the T-55 carried 220kg of propellant, the T-62 310kg and the T-72 440 kg.

The result:

 
Turret size

The T-34/76 had a very cramped turret. An evaluation by US personnel noted:

The main weakness is that it is very tight. The Americans couldn't understand how our tankers could fit inside during a winter, when they wear sheepskin jackets

Postwar Soviet tanks had a new hemispherical turret design. This had excellent ballistic protection due to the sloped design but it was very cramped and it seriously affected crew performance and gun depression.

Reload rates
The cramped interior of Soviet tanks limited the speed with which the crew could operate the gun.

The T-34 had a low reload rate of about 4 rounds per minute versus 2-3 times that in German and Western tanks. The same problem was noted in postwar Soviet tanks of the T-55 and T-62 type.

The Soviets tried to solve this problem by installing an autoloader in the T-64, T-72 and T-80 tanks.  This equipment however has a bad reputation due to many cases of malfunction when it was first introduced.


Gun depression
Soviet tanks from the T-34 onwards had poor gun depression which meant they could not fight in hull down position. Western tanks used this tactic with success especially in the Golan front during the Yom Kippur war. From various Osprey books I collected the following statistics:

            Gun elevation
up (+)
down (-)
T-34/76 L-11
30
5
T-34/76 F-34
30
3
T-34/85
25
5
Pz III 50mm
20
10
Pz IV KwK 40
20
8
Panther
18
8
Sherman M3
25
12
Sherman M1
25
10
T-55
18
5
T-62
16
6
T-72
14
6
T-80
15
5
Centurion
20
10
M-48
19
9
M-60
20
10
M1
20
10

An Israeli report noted: ‘The T-62 and T-55 tanks have [limited] depression of their gun, up to about -6 to -7 degrees, whereas all the others have gun depression of about -10 degrees. The meaning is that in many cases the T-62 and the T-55 tanks, while in firing position (behind a fold or a small hill) did not have enough depression and so had to expose themselves more and be more vulnerable to the other side.’ [Source: ‘M60 Vs T-62: Cold War Combatants 1956-92’, p38]

Gun performance
Soviet tank guns of WWII developed lower pressure than Western ones with the result that their accuracy and penetration at long ranges suffered. Did the same problem affect postwar vehicles?

The Israelis found the gun of the T-62 to be quite powerful. However a US test of its accuracy showed that after 1km its ability to hit targets was limited. The M-60’s 105mm was significantly more accurate at long ranges. [Source: ‘M60 Vs T-62: Cold War Combatants 1956-92’, p50-52]

Suspension
The T-34 had poor stability over rough terrain due to its Christie suspension.  Postwar Soviet tanks had torsion bar suspension but the ride continued to be uncomfortable and tiring for the crew.

The dogma of quantity over quality
Why did all the Soviet tanks suffer from the same limitations? The answer is that the Soviet military doctrine emphasized the importance of numbers and the inevitability of heavy casualties. If you expect your tanks to be destroyed quickly then it doesn’t make sense to build expensive ones lavishly equipped with armor and with an emphasis on crew comfort. Instead their goal was to keep weight and size down so they could out produce the West.

The factories of the Eastern bloc churned out thousands of tanks during the cold war and certainly had a big numerical advantage against the West. They also succeeded in building vehicles that were well armed and armored for their time. However their emphasis on production numbers meant that soft flaws (cramped interior, poor gun depression etc) limited their performance in the battlefield.
Western tanks were built on different lines and although they usually had comparable weapons and armor ‘on paper’ in the field of battle they outperformed their Eastern counterparts.

Sources:  various Osprey books including T-34-85 vs M26 Pershing: Korea 1950, Centurion Vs T-55: Yom Kippur War 1973,  M60 Vs T-62: Cold War Combatants 1956-92’, ‘M1 Abrams vs T-72 Ural: Operation Desert Storm 1991’, T-34 Aberdeen evaluation, WWII Myths - T-34 Best Tank of the war

18 comments:

  1. With a decreased emphasis on "private property" (including the self) it was inevitable that the communist system would turn out a larger number of inferior, uncomfortable, death traps.

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    1. It was not about private property but about the value of citizens lives. In the so called "State of workers and peasnats" Communists used workers and peasants to clear minefileds by detonation. That is what you can infer from the own words of Soviet Generals (of course they don't say it as bluntly). And by the way Communists were underrepresented in infantry units (those whose men detonate mines) and overrepresented in artillery units is those who open fire on friendly infantry to make it move.

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  2. Awesome article Christo, Russian tanks are truly overrated death traps, I have a question: You pointed out that the T-55, T-62, T-64, and T-72 all shared the same design principles of the T-34, which resulted in equally horrific losses for these vehicles, so what about the T-80 and T-90 tanks, do think they might also share these flaws?

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    1. The T-90 is just a modernized T-72. They changed the name after the Gulf War showed how poor their weapon systems performed. It has all the flaws of the T-72.

      The T-80 also has the same problems of limited internal space and gun depression.

      They all look the same as they were built with the same design principles.

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    2. Ok, thanks for the response, and again great article, dude, well researched and informative.

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    3. Sorry, but the T-90 renaming is incorrect. It was originally to be designated the T-72BU, but the name was changed late in development due to it being almost unrecognizable from the other later T-72 variants (other than the iconic Soviet low profile of course.)

      Also something you neglect to mention is the fact that Soviet tanks (as well as foreign clones) were designed with a certain military doctrine in mind. And I'm not talking about "quantity over quality" that you have already mentioned. Soviet tanks were designed purely in the offensive role, which is quite different to tank philosophy in the west.

      Also: yes, the Soviets did emphasize quantity over quality, but that had nothing to do with the Soviet view of an individual human life. This concept along with tank design came with the offensive-minded military doctrine that the USSR had at the time. I would be happy to provide more information about how doctrine, not Soviet morals influenced tank design if anyone is interested.

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  3. Mobility.

    Russian tanks were designed for lightning attacks and encirclement movements to wreck havoc behind lines and not to sit at some hill with your great depression and wait for someone to show up, that's what are guided antitank missiles for, just look to what happened to Israeli tank forces against Hezbollah kornets, gun depression or anything else did not helped them merkava tanks. Russian tanks are light, fast and armed with guided missiles besides 125mm, they can cross most bridges and rivers and be on you behind in no time.

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    1. In practice what actually happened was that they had to fight against western tanks that had this capability and that's why the lost.
      The new Russian tank T-14 Armata is built according to Western standards (heavy weight, large size). Why is that?

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    2. The T-14 also doesn't afford the TC the ability to overwatch (ie.look out the top hatch and present a target for snipers). I predict that it will suffer tactically in action.

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  4. I have studied soviet and western tank design for more than 20 years. First, I want to agree that soviet tanks look pretty impressive on paper bad have an abysmal combat performance. What does irritate me however is the fact that the Israelis used them too. For example, Israel captured a number of T-55's, swapped their gun for a 105 mm L7 and pressed them into service. Can you explain why Israel used such an inferior design in its own ranks?

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    1. They were not going up against anything superior when fighting on the Israeli side.

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    2. The Israelis will make do with what they can get. Of course, with their own main weapons, fire control, doctrine, logistics, and training, they achieve results their Russian-supplied opponents don't.

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  5. When a country is fighting for its survival they have to use what is available.

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  6. Hi, nice analysis but seriously flawed in a way that the admittedly existing flaws in the Russian tanks did not prevent western tank designers from committing the same mistakes. Let's take a look:
    1. Sloped armor - if this eats up so much interior space, why do western tanks like the M1, Challenger 2, Leopard 2 have also sloped armor?
    2. Gun depression - if gun depression is so important, why does the Merkava 3 and 4 have only a depression of -7
    3. Overall size - this is more a question of philosophy. On the one side you have a smaller tank with an insignificantly smaller probability of getting hit and on the other side a bigger tank with an insignificantly lower probability of serious damage once penetrated.
    4. Catastrophic explosion - the ammo storage might be debatable in Russian tank, but the incompetence of later western models like the Leclerc to put 18 rounds right next to the driver in the hull or the Leopard 2 to put even 27 rounds next to the driver into the hull is even more debatable.
    5. Performance - so why is the performance record so bad? Crew efficiency! In the Iran-Iraq war Iraqi T72M outperformed Iranian Chieftains. Here equally trained forces faced each other, and the Russian product prevailed.
    6. Number of main gun rounds - don't compare 125mm rounds to 105mm rounds. Stay in the same class. Compare 125mm to 120mm. Here we have T64 - 40; T80 - 45; T90 - 42; compared to Leopard 2 - 42; M1 - 44; Leclerc - 40
    Conclusion: Flawed as these points mentioned in the analysis might be, they were not deemed important enough by western designers to be avoided in their designs, and they did not keep the Israelis from using captured Russian tanks.

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    1. The Israelis might as well use them. They were not going up against Centurions. As for western use of sloping, it is a matter of how extreme one goes in shaping the tank.

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    2. But against Jordanian M48 Pattons in the 6-day-war.

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    3. 1) Fault is NOT having sloped armor, it's the overall design. The Soviets designed to a certain profile and tried to make everything fit, which usually was forced and with mixed results.
      2) Can't fault Israeli mistakes in Merkava 3 and 4. Soviet tanks were designed for their "Deep Operations" doctrine, which means that their tanks were for an offensive role, so a smaller profile is of greater worth to them than ability to hide en defilade and wait for the enemy.
      3) An age-old debate of protection versus mobility. Works that even the more mobile Soviet tanks aren't mobile ENOUGH to escape being hit first.
      4) Western designers screw up too. Maybe that the rounds are in the turret bustle in the Abrams, but behind a sliding blast door, and the compartment has 'blow-out' panels, show that its designers knew that a penetrating hit to where the ordnance is stored is inevitable, and designed so the tank would survive and possibly even DRIVE AWAY.
      5) Equally trained in the Iraq-Iran war in the 80's? Baloney! The Iranians purged their military in the wake of the Islamic revolution, and substituted their willing to go to Muslim 'Heaven' and start making it with the '72 virgins' for sounds tactics and good leadership. The best tanks are no damned good if misused.
      6. Agree about comparing the same classes of rounds. In fact, though I don't agree often with "Blacktail Defense", he criticizes the Abrams a LOT, including that it's 120mm gun wasn't necessary as the 105mm L68 STILL well defeats Soviet tank designs and a lot more 105mm rounds can be carried.

      As for the Israelis, they re-used captured Soviet-made tanks because even a crappy tank is better than NONE. They've stated that they could have swapped their tanks with their opponents and the results wouldn't have changed at all. Doctrine, experience, training, LOGISTICS, and leadership are also huge factors in military successes and/or failures, armored ground combat included. And the Israelis essentially rebuilt their captured T-55 and T-62 tanks into a "Westernized" hybrid, using (usually American) engines, main guns, their MGs (for obvious logistical reasons), and fire-control and communications systems. Or pulled off the turrets and used them as SP howitzers, CEVs, prime movers, and even armored ambulances! Comes from a long-standing necessity of having to make do with what's on hand.

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    4. And they creamed the Jordanians in 1967. A case of being out-fought, even if the equipment is comparable.

      Keep in mind that in the early stages of Barbarossa in 1941, the Soviet tanks were mostly BETTER even without the T-34! More than HALF of the PanzerWaffe had main armaments of 37mm or LESS, and the Panzer I tanks which only had twin MGs were in front-line service! The Germans even pressed whatever British, French, and Polish machines that they could get to run into service, that's how desperate they were for tanks! Even when the T-34s showed up, in many cases they were badly deployed and their crews had little or no training in ANY tank, let alone how to utilize the T-34s strengths. There was even a notorious case of a T-34 being hit 23 times by a 37mm Pak 36 anti-tank gun and finally stopped by a round sticking and jamming the turret! How a tank crew could let themselves get 'pinged' 23 times by a towed (man-handled) pea-shooter and NOT successfully engage it indicates that either the crew is woefully incompetent or the tank has inherent problems in engaging targets, or both.

      At least Zhukov figured this out and had the T-34s held back until their units could be adequately trained. This got good results, both at Mtensk in October 1941 and two months later in the Moscow counter-offensive.

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