Why has Japan’s proud spear become so useless? Revealing the secret of Type 93 oxygen torpedo

In the history of World War II, Japan’s Type 93 oxygen torpedo was fearfully called a Spear torpedo by the U.S. Navy. This torpedo was powerful and had a long range. It was one of the most advanced torpedoes at the time. Japan is full of confidence in this weapon and calls it a "winning weapon". However, in actual combat, this weapon is not only useless, but also sinks its own warship. Why has this winning weapon become so useless? 1 , Japan and torpedoes After Japan's Meiji Restoration, Japan began to transition into a modern country. It not only wanted to "rich the country and strengthen its military", but also introduced a large number of foreign advanced weapons and military technologies. Torpedoes were a weapon that aroused great interest among the Japanese. In 1966, British engineer Robert Whitehead developed a weapon that uses a compressed air engine to drive a single propeller and controls the depth of the torpedo through a hydraulic valve to control the horizontal rudder at the tail. So it was called a torpedo. However, the speed of the torpedo at that time was only 11 kilometers per hour, and the direction of the torpedo was not controllable. However, in the Russian-Turkish War of 1877-1878, the Russian Navy used torpedoes to sink Turkish warships. Countries have realized the value of torpedoes. Compared with the past, which could only be bombarded by naval guns, torpedoes are a very convenient weapon that can sink enemy warships in an instant. In order to improve the performance of the weapon, various countries began to study torpedoes crazily. During this process, torpedoes experienced two major technological leaps. The first time was in 1899, when a gyroscope was installed on the torpedo in order to use the gyroscope to orient the torpedo. Direct navigation, thereby greatly improving the accuracy of torpedoes. The second time was in 1904, when the American E.W. Bliss invented the "thermodynamic torpedo" that mixed air and fuel to generate power propulsion. The speed was increased by 65 kilometers per hour and the range was 2,740 meters. At this time, Japan also invested in the research and development of torpedoes, and Japan had an unusual interest in this small and powerful weapon during the Russo-Japanese War. In the Battle of Tsushima, Japan concentrated its destroyers and torpedo boats to launch a night attack on Russia, which sank three Russian battleships. Since then, the Japanese have defined this lightning strike tactic as the foundation of their navy and used it as a way to reverse the situation. ""Decisive weapon. ” At the 1922 Washington Naval Conference, the Japanese Navy was in a dilemma because its naval tonnage was far inferior to that of the U.S. Navy according to the treaty. Although the U.S. Navy was a two-ocean fleet, once the war started, the Japanese Navy had fewer battleships and battlecruisers. The admiral is far inferior to the United States. Faced with this dilemma, Japan once again turned its attention to torpedoes, hoping to use torpedoes to make the two sides evenly matched. This is how the Japanese Type 93 torpedoes were developed. The development of the Oxygen Torpedo Type 93 torpedo began in 1928, under the supervision of Major General Kishimoto Kakoharu and Colonel Toshihide Asakuma. At that time, the biggest potential enemy of the Japanese Navy was the U.S. Navy's Pacific Fleet. The U.S. Navy's combat plan expected that the Japanese army would invade. The Philippines, a member of the American League of Nations, therefore set its operational policy to invade the Pacific, aid or recapture the Philippines, and destroy the Japanese fleet. Since the number of Japanese warships was smaller than that of the U.S. Navy, the Japanese army planned to use light cruisers, destroyers and submarines as the main force. A series of small-scale battles at night gradually weakened the U.S. Navy. When the two sides were numerically evenly matched, or when the Japanese had a certain advantage, they would then invest the main fleet. This was the Japanese Navy's so-called "nine-stage gradually reducing attack tactics". "The Japanese Navy invested a lot of resources in this regard and planned to develop a large, heavy and long-range torpedo, the Type 93 torpedo. The reason why it spent a lot of money to develop torpedoes is that torpedoes are one of the few small ships such as destroyers. One of the naval weapons that damaged battleships. The Japanese Navy focused on the use of compressed oxygen as the oxidizer in the torpedo propulsion system instead of compressed air, which burned methanol or ethanol. Compressed air only contains 21% oxygen. Using high-concentration oxygen can accommodate about 5 times the oxidizer under the same volume pressure, increasing the range of the torpedo.

In addition, due to the use of compressed oxygen to eliminate inactive nitrogen, the combustion products of the engine are only water-soluble carbon dioxide and water vapor, resulting in a reduced bubble trajectory of the torpedo, making the torpedo more difficult to detect. However, compressed oxygen is dangerous to handle, so the Japanese army must invest a lot of time in researching and developing related technologies and training torpedo soldiers to ensure the safe use of these torpedoes in combat. Later, weapons development engineers of the Imperial Japanese Navy discovered that if they first used normal compressed air to start the engine and then gradually switched to high-concentration oxygen, they could avoid the accidental explosion problem of these torpedoes in the past. In order to prevent the crew and the enemy from knowing that the torpedo uses high-concentration oxygen, compressed oxygen is called ""special air"" or ""second air". This kind of torpedo was also put into mass production in 1937 for Japan. Used by the Navy. The Type 93 torpedo is equipped with a 490-kilometer high-explosive warhead and has a maximum range of 40 kilometers when traveling at 38 knots (70 kilometers per hour). Its long range, high speed, and heavy warhead make it suitable for surface combat. It has considerable lethality and is fired from 610mm torpedo tubes on the decks of destroyers and cruisers of the Imperial Japanese Navy. Due to the relaxation of the weight limit by the London Naval Convention in 1930, Japanese destroyers previously in service could not be equipped with Type 93 torpedoes. (Such as the Fubuki Special Type). Some Japanese destroyers are different from destroyers of other countries in that they have torpedo tubes installed in the turret. The turret can protect the torpedoes from fragments and is also equipped with a torpedo tube loading device. Almost every ship of the Imperial Japanese Navy. Cruisers were equipped with Type 93 torpedoes. In the early surface battles of 1942-1943, Japanese destroyers and cruisers were able to launch torpedoes from about 20km away to attack Allied warships trying to enter the bombardment range. The torpedoes used by the other side were not launched at a distance greater than 10km, which was the Allied torpedo range. After many battles, the Allied warships suffered multiple torpedo strikes, leading their officers to believe that these torpedoes were launched in conjunction with Japanese surface ships. During the attack, the Type 93 torpedoes launched by undetected Japanese submarines continued to advance and hit Allied ships much farther than the intended target. They thought that their ships triggered mines. Most of the Allied forces did not understand the performance of the Type 93 torpedo until they captured the complete Type 93 torpedo in 1943. 3. The torpedo was not easy to use. Type 3 torpedoes are not easy to use. In addition to the fact that naval battles have changed from battleship duels to aircraft carrier duels, one of the biggest flaws of this type of torpedo is also due to this. This kind of torpedo is more susceptible to shock detonation than the compressed air torpedoes of the allies, and the heavy warhead it uses is usually enough to sink the destroyer carrying it, or seriously damage the cruiser carrying it, so in actual combat, once the destroyer or cruiser is attacked. When an Allied air attack occurs, the captain must make a decision whether to abandon these torpedoes to prevent them from being detonated during the attack. A typical example is the Japanese heavy cruiser Chokai in the Battle of Samar Island. At that time, the Chokai was attacked by the United States. The Navy was hit by a 127mm artillery shell, and was severely damaged. Logically speaking, as a heavy cruiser, it should not be so vulnerable, but because the shell detonated the torpedo, causing its rudder and engine to lose function, it had no choice but to do so on the second day. The sky sank. The unreliability of the fuze was also a problem. The Type 93 torpedo used a trigger fuze, but the fuze made by Japan was too sensitive. After launch, the torpedo was easily triggered by waves or the wake of the warship, resulting in serious accidents. The torpedo detonated before it hit the target. As a result, the Type 93 torpedo often failed to achieve results and could only explode into waves in the sea. At the same time, there is also a problem with the gyroscope of this torpedo. According to its speed, the rotation speed of the gyroscope should be 20,000 revolutions per minute. However, the actual rotation speed of the Type 93 torpedo is only 8,000 rpm. This makes it very easy to lose control after the torpedo is launched, and the hit rate is greatly reduced. Although Japan tried to modify it late in the war, it was not completed until the end of the war. During the night battle on Guadalcanal, the Japanese heavy cruisers Takao and Atago fired torpedoes at the American battleship South Dakota.

However, due to the instability of the fuse of the Type 93 torpedoes, most of the torpedoes exploded prematurely before approaching the South Dakota. The Japanese not only failed to sink the battleship South Dakota, but also allowed the battleship Washington to seize the opportunity to counterattack. With the help of new radar positioning, it severely damaged the Japanese ship and turned the tide of the war. The most deadly thing is its excessively long range, which often causes huge trouble in actual combat. Because once the torpedo misses its target and is not detonated by the waves, who knows where it will fly. Although in actual combat, U.S. warships were sunk due to accidental hits and collisions, they often also hit their own warships. During the Battle of Surabaya on March 1, 1942, the Japanese Navy heavy cruiser Mogami fired a round of torpedoes at the US heavy cruiser USS Houston at 1:27 in the morning. However, because the set depth was too high, the six torpedoes crossed the bottom of the target ship and headed straight ahead. While the Battle of Surabaya was going on, the Japanese Army was also conducting a landing on Java Island, and these torpedoes headed straight for the Army's ships. Eight minutes later, a Japanese Army minesweeper was the first to be blown to pieces. Three minutes later, the Japanese Army's hospital ship "Horai Maru" and transport ships "Sakura Maru" and "Tatsuno Maru" and the landing ship "Shenzhou Maru" were successively sunk by Japanese Navy torpedoes. Of course, this matter during the Surabaya Naval Battle was definitely problematic. If the depth was really too deep, then the torpedoes should not be able to destroy these Japanese Army ships. , obviously the USS Houston heavy cruiser escaped the torpedo, but the Japanese Army could only suffer a loss. After all, what could they do to the Japanese Navy? Of course, the Type 93 torpedoes were produced in smaller quantities, or they were inferior. Difficulty in maintenance, etc., there are countless. In short, this weapon is of little use in actual combat. If it is really useful, then it is probably just accelerating the demise of its own warships. Conclusion It can be imagined that what the Japanese Navy did. The Type 93 oxygen torpedo, which had high hopes, has basically become useless in actual use. Although it has achieved results, the overall result is not that great. The so-called "definitive weapon" developed with great effort has become a weapon from the beginning. A joke. It must be said that this is also a common problem in the development of Japanese weapons. References: "Japanese Navy Illustrated Book" "Japanese Navy Shipborne Weapons Large Illustrated Book" "The Rise and Fall of the Imperial Japanese Navy"