Let's talk about historical facts first. Who is stronger, Iowa or Yamato?

I saw an article about the strongest warship in World War II earlier. Here, I systematically expressed the battle between the strongest battleships in World War II (Yamato and Iowa), who will win (the firepower and protection of these two battleships were unparalleled during World War II, representing the highest level of human shipbuilding in World War II).

Let's start with the conclusion. Yamato and Iowa have their own strengths. Winning or losing just depends on who is the best. The following are specific reasons:

The performance of World War II battleships mainly depends on four indicators; Three traditional indicators 1: firepower, 2: protection and 3: maneuver. In the middle and late World War II, due to the appearance of radar, a new index was added. Is the fire control system.

The comprehensive performance of these four indicators can reflect the real strength of a bow warship. Let's make a parallel comparison;

One: Firepower

According to the paper data, Yamato's 94-type 45 times caliber 460mm main gun has the longest range and the strongest power in the whole World War II. Its main armor-piercing projectile is 9 1 weight of armor-piercing projectile 1460 kg, with a range of 42,000 meters. It has the ability to penetrate 566 mm vertical armor at a distance of 20000 meters. The MK8 armor-piercing projectile launched by MK7 406mm in the United States weighs 1224.7kg and has a maximum range of 38,700 meters.183,000 meters can penetrate 509mm vertical armor.

Simple paper data show that Yamato's main gun has an overwhelming power advantage to Iowa, but a careful analysis of some other factors will reveal that there is some moisture in it. First of all, let's talk about the US Navy's MK8 overweight projectile. It is much heavier than the ordinary 406mm caliber armor-piercing projectile (1224.7 >: 1000), so its initial velocity is reduced (reduced by 15%), so its trajectory is more curved and it has a horizontal penetration far exceeding that of the ordinary 406mm projectile. At 20000m, the vertical armor-piercing ability only reaches the level of a Nagato 4 10mm3 naval gun.

It is worth noting that the above data are the conclusions of the test firing and ballistic formula calculation of the Japanese Navy and the US Navy respectively. In fact, the U.S. Navy does not recognize Japan's calculation formula, because according to the calculation standards of the U.S. Navy's mathematical model (industrial standards, including the ratio of gun diameter, the amount of propellant, warhead performance, flight state and the difference of armor performance between the United States and Japan), the vertical armor penetration rate of Japan 1 bomb at 20,000 meters is only slightly higher than that of MK8 heavy bomb. On this point, many people inside and outside the United States are controversial, and there is no absolutely authoritative and convincing statement at present. However, it should be pointed out that in 1946, the United States captured Japanese Nobuka by using MK8 heavy bomb bombing, and found that the armor-piercing ability of American armor-piercing bullets was 15% higher than expected, which proved the controversy of the US Navy on the artillery power from the side! Considering the technical gap between the United States and Japan, the difference in armor-piercing power between at least two guns will not be as great as it looks on paper.

In all previous examples of warship bombardment confrontation, most of the cases of sinking injuries came from lateral armor piercing (65% of the results)! —— Especially in the middle and long-range bombing, the effect is more obvious. From the actual war cases and the potential major structural damage to the hull, the vertical breakdown is not as good as the horizontal breakdown. (What needs to be added here is that in the middle and long range, the United States may achieve more efficient horizontal breakdown results. Although this ability will be weakened after entering the middle and short range, it is within a distance of 20,000 meters, whether it is Yamato or Ia. So Yamato's vertical breakdown ability is greatly reduced here! )

In addition, from the first day of service, the Japanese type I bomb has the defect of insufficient strength. When the thickness of the hit armor is greater than 90% of the diameter of the projectile and the falling angle is greater than 25 degrees, it may be broken. The simulated test firing conducted by the US Navy after the war found that its 1 type armor-piercing projectile may not penetrate (more than 55%) when it hits the 4 14mm vertical armor at an angle above 25 degrees. This is one of the shortcomings of Japan's industrial base.

However, the MK8 overweight bullet in the United States is made of the first-class metal processing technology in the United States, and its performance is excellent. The particularly heavy head shell makes it have outstanding armor-piercing performance, and it is not easy to have accidents like those in Japan.

In addition, in order to pursue underwater ballistic performance, Japan adopted a special flat-headed warhead. Moreover, in order to flow out the extra space in the running time after entering the water, the trigger time of the fuze is delayed by 0.4 seconds, which leads to the possible "harmless breakdown". And this is also a problem that will not appear in the United States. However, it has also been pointed out that if the Type I bomb hits the waterline of the opponent underwater, the damage caused is also amazing!

Finally, there is another problem that needs special attention. Due to gun control and the limitation of the weight and volume of loaders and shells, the firing rate of Iowa class in the United States is 20% faster than that of Yamato class, that is, the amount of bombs dropped per unit time is 20% higher, which has opened the gap between the two sides to some extent.

So in general, Yamato's 460mm main gun still has advantages (range and overall power) for Iowa, but this advantage is not overwhelming.

Second: mobility

The theoretical speed of Yamato class is 27 knots, and the maximum speed of sea trial (short time and light load) reaches 28.3 to 28.5 knots, while the theoretical speed of Iowa class is 3 1 knot, and the high speed of sea trial (light load) reaches 32.7 knots.

At this level, Iowa has a great advantage for Yamato, whether it is to seize the shooting position or get rid of the pursuit.

However, because the hull of Yamato is shorter and wider than that of Iowa, the turning diameter of 26 knots reaches 624 meters, and it reaches 589 meters when the rudder is turned at 90 degrees, and the turning coefficient (the ratio of turning diameter to waterline length) is 2.44. Although the hull of the Iowa is slender, it is extremely fast, but the turning speed is not much higher than that of the Yamato. This makes Iowa and Yamato have almost the same tactical mobility in artillery warfare. Considering that the Yamato-class hull is a very stable shooting platform because of its short width, the shooting stability in tactical maneuvers is higher than that of Iowa-class slender hull.

So generally speaking, Yamato maneuver and Iowa maneuver are tied, and each has its own advantages. Only by grasping our own advantages can we create opportunities in naval battles.

Three: Armor protection

The protective ability of Yamato's vertical armor and horizontal armor exceeds that of Iowa, but the gap is not as big as expected. The average thickness of vertical armor, Yamato armor and horizontal armor is 5% more than that of Aihehua, and the gap is much larger, reaching 10% (but considering the excellent ability of crossing armor in the United States, this is not decisive, because both sides can ensure penetration as long as they are within a reliable distance), and the underwater protection ability is great.

However, as described in Firepower, the U.S. Navy is controversial about the armor quality of both sides, arguing that the hardness of U.S. A-class carburized steel is higher than that of VH, which means that the hardness of Japanese steel is only 83.9% of that of American steel. Although it was later considered that the test conditions were too ideal, it was generally believed that the hardness of steel in the United States was higher and the tensile strength was weaker than that in Japan, resulting in the armor thickness not reaching that in Japan (even on the later Montana).

There has been a long debate about which is better in armor thickness and hardness, but it can be considered that even though Japanese armor plates lag behind the US Navy in quality, Yamato is still superior to Iowa in armor.

What needs to be added here is that although the advantage of Japanese armor forced the United States to penetrate at a closer distance (30,000m in Japan and 27,000m in the United States), considering that shooting over 20,000m in World War II largely depended on luck, the longest hit record in World War II was only about 24,000m, and considering that the speed of Yamato was much lower than that of Iowa, it was not so easy for Yamato take advantage of this advantage.

Four: radar shooting control.

This is also the most controversial place. On the one hand, Japan claimed to have the best artillery shooting in the world during World War II, but actually maintained the world record of artillery training in the world, but it should be noted that; This is achieved under the exercise conditions in an ideal environment. The sea is good, no one is fighting back at you, no tactical maneuver is needed, the target is almost stationary, and so on. In 1938 and 1939, the Japanese navy achieved an amazing record of 17.2% and 9% at the distance of 30,400 meters and 30,900 meters respectively, while the US navy's hit rate within 20,000 meters was less than/kloc-0.5% at the same time, thanks to the Japanese navy. But it also benefits from a stable training state.

However, this almost magical shooting record has never been realized under complex battlefield conditions. For example, in the naval battle of samar, Yamato's first volley was 32,000 meters, which formed the cross-shooting of the US escort aircraft carrier, reflecting a very high training level. However, when the American ship released smoke and used artillery to fight back and splash water, Yamato was forced to use torpedoes for tactical maneuvers. After light rain began in the sky, all the artillery of Yamato were not allowed, and the hit rate of 104 406mm artillery was 0. Radar is training hard at Linga anchorage.

In the second night battle north of Guadalcanal on1942+065438+1October 12, Kirishima killed the target South Dakota and fired 356mm shells at 1 17, only hitting two rounds, with a hit rate of less than 65438. After the Washington, hiding behind the United States, recognized the enemy and the enemy again, with the help of MK3 radar, 75 406mm guns poured on the foggy island 7500 meters away in just five minutes, with a hit rate as high as 12% (at least three were not recognized). -

The most direct example is 19441the night battle in Sugaori, Fusang and Shancheng on October 24th, all of which were equipped with the most advanced 22-electric probe in Japan. However, in the face of the complex terrain in the Strait, as well as the destroyers and torpedo boats of the US military, there is almost no force to fight back. Accordingly, Virginia equipped with MK8 radar locked the mountain city at 35,000 meters from the background of the strait. (Some netizens said in my previous post that the hit rate of Sugori in the United States is not high, less than 10%, but considering the performance of Japan, it can be said to be a perfect example of naval gun shooting. )

The MK8 radar equipped in Iowa has a detection range of more than 50 kilometers and a ranging capability of up to 40 kilometers for large targets such as battleships in the main scanning state. When precise scanning is used, the water column of 406mm shells falling into the water from 18500 meters away can be detected, while the later MK 8mod3 (equipped at the beginning of1945) can even detect the water column of 356mm shells falling into the water from 32000 meters away. The ranging accuracy of MK8 at 20km and 30km is +-33.7m and +-43.7m respectively, and the lateral accuracy is +-37.5m and +-56.5m, which not only far exceeds the accuracy of the rangefinder at that time, but also is smaller than the impact point distribution of American warships at the same distance. This means that American warships can even skip the traditional test firing and shoot directly after the artillery battle begins. In fact, many American warships equipped with MK8 radar have indeed achieved the first hit.

On the other hand, Japan's 22-type electric probe claims to be able to detect battleships 25 kilometers away, but its output power is low, its accuracy is low, its ranging error is as high as +-700 meters, its azimuth error is 2.5 times that of similar products in the United States, and its performance is unstable (the electron tube is broken). In the Battle of Sugiwei, Japan tried to use 22 electric probes for artillery guidance, but found that it could hardly work in island clutter, so it was better to use traditional optical night fighting. The gap between the two sides is obvious.

Another extended advantage of American radar is that the highest level of MK38 fire control system was generally installed at that time, which was mainly composed of MK38 shooting director, shooting drawing room, computer, signal transmission and communication equipment.

MK8 ballistic computer receives the target distance and navigation state transmitted by fire control radar, and synthesizes the navigation state, speed, wind direction, atmospheric density, temperature, propellant temperature, barrel wear and other information of ships. The obtained shooting information is transmitted to the servo system of each gun, which can directly control the tilt and rotation of the turret. The gunner can fire as long as he sees the standby light of each main gun on. At the same time, the advanced MK4 1 in the United States constantly sends data to the computer to compensate for the sloshing of the hull, which greatly offsets the advantages of Japanese hull stability. This is a classic remote power operation mode in which the main gun is directly controlled by the central control room (shooting drawing room). The most successful and technologically perfect country in World War II was the United States.

On the contrary, the shooting method of Daiwa in Japan is still the old-fashioned way, using the 98-type azimuth board (shooting director) in the shooting command post to measure the target. The shooting data is transmitted to the main gun, and then the gunner reads it through the instrument, and then manually controls the rotation and pitch of the gun. The gunner stared at Cui Wenyi and fired when it reached the level. Compared with the semi-automatic command system of the United States, Japan's fire control program is complicated, which requires very high human quality, is greatly influenced by human factors, and is prone to mistakes, especially in high-intensity naval battles.

It is conceivable that when the two sides fight, they all cross each other and take tactical maneuvers at the same time. At this time, both sides should recalculate shooting Chu Yuan, reposition and aim at themselves. The United States relies on efficient radar and advanced shooting command to accurately input the data obtained by radar into the ballistic computer, and then the fire control automatically controls the artillery. Compared with Japan, the whole process is less, more efficient and more fault-tolerant.

Therefore, in the contest of fire control system, the United States has completely defeated Japan, especially in complex weather and sea conditions and combat situations (such as night fighting)

General description:

As a traditional battleship, Japan's Yamato has a solid advantage and artillery advantage over the Iowa in the traditional battle, but this advantage is not overwhelming and decisive. The United States can also rely on Japan's mistakes and superb art of directing and shooting, just like Bisman sank Hood. In fact, the performance gap between the two sides is not as big as it seems. Luck and some technical details may just be the decisive factor!