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Tank penetration

Hello dear tankers! In this issue of Entertaining Mechanics, we will talk about such an important aspect of the game as breaking through the armor of a tank. A knowledge of the algorithms of armor penetration is twice necessary for any tanker, on the one hand it will allow you to hit the enemy more efficiently, and on the other it will help to extend the time of your combat vehicle under enemy fire. Therefore, we divided this broad topic into two issues: the security of armored vehicles and the destruction of armored vehicles.

Do not forget that the World of Tanks is a game, not a training simulator, of course, it strives in many respects to comply with the laws of tank battles. But all the same, it has a number of conventions necessary to give the battles proper dynamics.

The processes that occur in reality when a projectile hits a battle are too complicated for miscalculation on the fly, and the scatter of the results is such that the great Belarusian random will seem a model of predictability. For example, a projectile that strikes strictly perpendicular to the armor would have, it would seem, maximum penetration, but when the blank is split from internal stresses at the time of impact, this parameter drops to zero. In the game, he has only a 25% dispersion from the nominal indicated in the description. If, say, your MC1 gun has an armor penetration of 51 mm, then you should expect a spread of 38 to 64 mm. The spread of values ​​for damage is constructed in the same way.

Before we start talking about the geometry and mechanisms of penetration, we explain the terminology that we will use. Take a point on the armor and draw a tangent through it, the normal is the line drawn through the selected point perpendicular to the tangent, in simple terms - this is a normal perpendicular. We also explain that we will consider the angle of entry of the projectile - this is the angle between the normal and the trajectory of the projectile at the point of impact, that is, at 0 degrees the chance of armor penetration will be maximum, and say at 80, most likely, a rebound will occur. It is worth noting that many players define this angle as the angle between the tangent and the trajectory of the projectile, noting, for example, that at angles less than 30 degrees the chance of rebounds is very high. We will adhere to the terminology adopted among the developers of the World of Tanks and in the military-technical literature, and consider the angle from the normal.

Another important concept is reduced armor. A projectile with a large angle of entry into the armor has to penetrate a significantly larger thickness than indicated in the description of the tank. In accordance with the laws of geometry, the final layer or the reduced thickness of the armor to be pierced is calculated as the thickness of the armor to the cosine of the angle of entry. Of course, during the battle no one will sit with a protractor and calculator, and calculate the reduced armor, just remember the intuitive rule: the greater the angle of entry of the projectile, the thicker the armor layer that he needs to penetrate.

In order to make it easier for beginners to understand who and where to break through, a penetration marker was introduced into the game for arcade and sniper sights. If it is green, then when a shell hits the armor normally, you will damage the combat vehicle, if it is orange, then the probability is 50 to 50, if it is red, then it is not worth spending an armor-piercing shell. However, you cannot believe the color of the marker unconditionally, the armor of the tank can be located at the most bizarre angles, in addition, your projectile may deviate from the line of aim and get a little out of the place where you aim. And if you aim at the lower frontal part of the enemy, but he got a diamond, then you can’t always break through it, because even in the tank’s description the armor thickness is 50 mm, then in this case your projectile will have to pierce 60-70-80 mm armor, or even more, however, the color of the marker will not change. But don’t be upset, because the armor in the conditions of real battles behaves exactly the same way and the tank designers made shells for the guns in such a way that when they hit they try to turn to normal at the point of impact and slightly approach the angle of meeting with the armor to 0 degrees. This effect is called normalization of the projectile and since the update 0.8.0 is 4-5 degrees. Thus, we can adjust our formula for reduced armor taking into account the normalization angle. So, in the game, when hit in the armor plate at an angle of 45 degrees, the projectile will turn up to 40 degrees to the normal, and it will be a bit to penetrate the armor, but it's still easier. For example, let's calculate the given armor, taking into account the normalization for two tanks familiar to everyone - the Tiger and the Royal Tiger. For clarity, we, sitting opposite, will shoot at the upper frontal part from a distance of 50 m from guns whose armor penetration is approximately equal to the thickness of the tested armor. For the sake of simplification of calculations, we assume that the projectile flies parallel to the ground, let's start with the Tiger World of Tanks. The thickness of its frontal armor is 100 mm, and it is located with a deviation of the armor of only 9 degrees from the vertical, the angle of entry will be the same, and taking into account normalization we get 4 degrees. We fire from the L40 KVK48 gun with an average armor penetration of 106 mm. We see a lot of penetration of the armor, since the thickness of the reduced armor will be equal to the same 100 mm. Now we invite the Royal Tiger to the stage with a thickness of the upper frontal part of 150 mm, check its durability with a 90 mm M3 gun with 160 mm armor penetration. A sufficiently large number of hits did not cause significant damage to the tank, because the armor has an angle of inclination of 160 degrees, which means that the given armor has an impressive 212 mm, and since the maximum possible armor penetration of our guns with an armor-piercing projectile is only 200 mm, we cannot disturb the royal equanimity by firing at the top frontal part.

Normalization will not help if the angle of entry is more than 70 degrees, since in this case the armor-piercing projectile will simply ricochet. It is very important to remember that it is not worth wasting shells, shooting anyhow, you should at least approximately understand at what angle it will fall into the armor. By the way, after the first rebound, the projectile does not disappear, it can still cause damage, but only within one tank, billiard tricks will not work here, so do not expect that you can masterfully ricochet into another tank. Ricochet when firing armor-piercing or sub-caliber ammunition does not occur if the caliber of the gun exceeds the thickness of the armor. In this case, the projectile tries to penetrate the armor regardless of the angle. When they get into external modules, for example, the undercarriage, a gun or observation devices, the rebound also does not occur regardless of the angle, they generally have a special damage mechanism. Each module has its own reservation and strength points, and the rules for calculating the reduced armor do not apply for them, and it is always necessary to break through a strictly defined thickness. In the event that this happens, the module loses its strength points, and the projectile continues to move and thus may very well damage the hull of the tank. However, in this case, the armor penetration rate of the projectile decreases by the thickness of the armor of the damaged module, and it will be harder for him to break through the main armor. This is the secret of the widely discussed nano-gusli.

The armor of the main machines in games is divided into the main and the so-called screens. The penetration of the main armor removes strength points from the tank, and the screens only weaken the projectile, reducing its armor penetration.

The screens are located at some distance from the main armor and usually have a small thickness, with the exception of screens on the masks of guns. It is very important to remember that when a screen is broken only, the tank does not lose strength points. Why is it important? Because this is one of the main reasons for hitting without damage. Think of the variation in armor penetration values. Even if the shell penetrates the screen, its penetration can be so weakened that it is not enough to break through the main armor.

You probably already know that in the game there are several types of ammunition that affect armor in different ways. Armor-piercing shells - they are subject to the normalization and ricocheting rules in full. World of Tanks sub-caliber shells differ from armor-piercing shells only in increased penetration. High-explosive fragmentation shells do not ricochet, have weak armor penetration, however, they are inflicted even by exploding on armor or close to a combat vehicle. Cumulative shells have increased armor penetration and do not ricochet, however, normalization rules do not apply to them.

Well, it's time to take stock of the theoretical part and demonstrate the mechanism of armor penetration in action. We select the target and shoot, at the point where the projectile meets the armor, there is a screen. What happens in this case?

  1. the server builds the projectile trajectory according to the ballistic formula, determines the point on the screen at which it hit and the velocity vector of the projectile at the time of impact. After that, the angle between the normal to the armor at the point of impact of the projectile and the velocity vector is calculated. If this angle is more than 70 degrees, and the caliber of the projectile does not exceed the thickness of the armor in this place by 3 times, then a rebound occurs.
  2. if the rebound did not occur, and the caliber of the shell exceeds the thickness of the armor by more than 2 times, then in armor-piercing and sub-caliber ammunition, the normalization increases in proportion to the increase in the caliber of the shell to the thickness of the armor according to the following formula. Thus, the larger the caliber of the projectile, the easier it is for him to break through the armor.
  3. the shell penetration value is calculated, it depends on the firing distance. Starting from 100 m, the armor penetration of a projectile also decreases from a random deviation from the deposit, the same plus or minus 25%.
  4. if the projectile pierces the screen, then it flies further, and its armor penetration decreases in proportion to the thickness of the screen. After that, if the projectile meets the main armor, the algorithm repeats. Check for rebound, normalization of the projectile, calculation of the final armor penetration and in case of penetration of the main armor, the tank is dealt damage corresponding to that specified in the description of the gun, taking into account 25% dispersion. It is interesting that in reality a projectile when it hits the armor will change its trajectory under the influence of normalization, but in the game, for simplicity of calculations, it continues to move in a straight line along the initial trajectory. The algorithm is applied sequentially, first for screens or external modules, then for the main armor. In this case, there may be several groups of screens and armor in the path of the projectile, and they break through one after another.

We will talk about the adventures of shells inside the tank, about the features of cumulative shells and the action of high-explosive ordnance in the next issue.

Finally, the time has come for the most entertaining part, namely for stories about tactics that increase the survivability of the tank in battle. Will the theory help us with this, of course! And now we will consider the simplest techniques that logically follow from the knowledge just acquired.

So, reception number 1 - setting the tank with a rhombus or the so-called invulnerability pose: you must position your tank in such a way in relation to the enemy that he had to penetrate the armor of your tank at the least favorable angle. This technique requires a good knowledge of the booking scheme of your combat vehicle. However, with its skillful execution, it will be much more difficult for the enemy to break through your tank. For example, we’ll talk about two well-known vehicles: the IS-7 Soviet heavy tank is armored so that it’s not worth putting a rhombus, because it gets through the worst when it’s standing straight, but the German Tiger, which stands at an angle to the direction of fire begins to reflect shells with its rather thick forehead.

Reception number 2 - exit from around the corner: you need to leave by cutting the corner and not opening the vulnerable side and chassis of the tank for the enemy. You also need to remember the layout of your car and its reservation scheme, trying to expose the least vulnerable part of the tank to attack. Sideways it makes sense to leave only if the enemy has already fired and does not pay attention to you. Recall one of the basic laws of tank building: almost any combat vehicle is armored in the front much better than the side, and on the side, much better than the back and top, so you should always try to turn your forehead, turning to where the most dangerous shells are flying from.

Reception number 3 - horizontal swinging: this is probably the most common technique. It looks like sharp short movements to the left - to the right. These movements make it difficult for the enemy to heal vulnerable zones and prevent him from firing at vertical booking zones. Also, this technique works well on tanks, the front of the tower of which is flat. Rotating the tower to the left - to the right, while the gun is reloading, you seriously complicate the enemy aiming her cheeks.

Reception number 4 - fishing for live bait: this is an element of aerobatics and it is very difficult to execute it in motion. We substitute the enemy’s side, giving him the opportunity to aim and at the moment of his shot we turn the hull. The shell ricochets off the armor without hitting the tank itself. In general, sharp unexpected maneuvers, if you learn not to shoot down your sight, is a very effective technique for a tank duel. But remember that any rotation of the hull of a moving tank reduces its speed.

Reception number 5 - a shootout with the enemy from behind the shelter: for many tanks in the game the tower is better armored than the hull, so you need to hide the lower frontal part behind any shelter. If it’s a wrecked enemy tank, an indestructible obstacle or an earthen hill, wonderful. But you can hide behind one-time obstacles - cars, stone fences, flimsy sheds. One or two shots at you will survive these obstacles. By hiding part of the tank behind an obstacle, you force the enemy to heal less vulnerable parts of the combat vehicle, shoot at the side and track at a very sharp angle and either get a rebound or critical damage to the external module. But at the same time do not lose strength. For a shot, you can turn around or roll back a little, and then, without interfering, return to its original position. The enemy will have to strain very hard, healing the vulnerabilities of your combat vehicle.

Reception number 6 - the use of natural shelters and shooting from unexpected places. The buildings in World of Tanks have windows and doors through which a projectile can fly. In the ruins there may be breaks through which it is convenient to shoot. Fences and strings of stones also allow you to fire at the enemy, showing him only a small part of the tower. Use this, study the cards and memorize such shelters and positions.

That's all. We hope that after watching this issue, you can look at the enemy in the sniper scope much longer, and visits to the hangar will become more rare.

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