The idea of combining two of the deadliest classes of ships into a single whole was born much earlier than one might think. And, in fact, it has largely outlived itself.
From the deck to the sky
Aircraft carriers themselves are a long-standing idea. At the end of the 19th century, the so-called balloon carriers appeared. As the name suggests, these were ships with an observation balloon on board. It is believed that the first time something similar was used in 1849, when the Austrian "Vulcano" launched a balloon to bombard Venice. Due to the direction of the wind, the mission was unsuccessful. In 1910, the American Eugene B. Ely took off for the first time from the deck of a ship in an aircraft that was heavier than air. The aircraft carrier was played by the light cruiser Birmingham, which was equipped with a take-off platform. Two months later, the same tester boarded the armored cruiser Pennsylvania, which also received a special take-off deck.
All this, of course, was very far from practical use in a real war. However, already in 1914, the first "serious" aircraft carrier was adopted: the British ship HMS Ark Royal. He participated in the First World War and carried out the bombing of the positions of the Turkish army. Here, however, it is necessary to clarify that HMS Ark Royal was a seaplane carrier. That is, only flying boats - or seaplanes - were based on board.
Soon, the potential of carrier-based aircraft was fully revealed. During World War II, the American aircraft carriers operating on the Pacific Front played a decisive role in the defeat of Japan, although the Land of the Rising Sun also saw them as the main weapon of victory. In any case, the experts understood that the mighty battleships would never be able to dictate the rules of the game. And the actions of carrier-based aircraft will be of decisive importance.
Hirohito's "strange" boats
Surprisingly, the idea of "crossing" an aircraft carrier surface ship and a submarine also appeared during the First World War. Although then both airplanes and submarines had so many shortcomings that it might seem crazy. For example, German submarines of the U-31 type had a submerged range of only 80 miles (148 kilometers) - at a speed of five knots (9, 26 km / h). And the famous and generally successful for its time British fighter of the times of the First World Sopwith Camel had a maximum flight speed of 199 km / h and a flight range of only 485 kilometers. But the main thing, of course, is the lack of a practical opportunity to create something similar. And even more so - to effectively use this "miracle" in battle.
Nevertheless, Japan, dreaming of building a global empire in the Pacific Ocean, was one of the first to seize this opportunity. If earlier aircraft based on board the submarine were used only for reconnaissance purposes, the Japanese dreamed of bombing distant and inaccessible territories. So the idea was born to supply the "underwater" aircraft with a pair of bombs. Land of the Rising Sun even put the concept to the test. However, first things first.
The first submarine with the ability to transport aircraft was built by the Japanese by 1932. The J-1M project submarine I-5 received a sealed hangar where a small seaplane could fit. Of course, he could not inflict serious damage on the enemy: such an aircraft could be effectively used only for reconnaissance tasks, which, in principle, is important. But much more urgent for Japan were the problems that made themselves felt already in the early stages. Sealing the cracks in the hangar's large hatch proved to be a daunting engineering challenge.The crane that hooked the plane often failed in salty sea water, but none of these difficulties became insurmountable. As with some other submarine aircraft carriers, the submarine did not have a take-off deck. The plane was simply launched into the water using a crane, and then picked up in the same way.
In 1935, the Japanese fleet received another similar boat - I-6 of project J-2. Like her older brother, she carried one seaplane, which also took off from the surface of the ocean. The enlarged hangar made it possible to place the Watanabe E9W seaplane there, which was specially designed for use on board submarines. It was a biplane with two floats, equipped with a 300 horsepower Hitachi Tempu II engine, which rotated a two-blade wooden constant-pitch propeller. The plane could be easily assembled and disassembled right on the deck of the submarine, which was an undoubted advantage. Meanwhile, by the beginning of World War II, it had already become obsolete - and Japan thought about replacing this winged machine.
The shortcomings of boats I-5 and I-6 were all too obvious. Preparing for the launch and the launch itself required a lot of time and effort, which in a war was fraught with the sinking of the submarine. This is how a more successful project of the underwater aircraft carrier J-3 appeared: these boats were no longer produced in single copies, but in a mini-series of two units - I-7 and I-8. The hangar of the submarine already accommodated two aircraft, and a catapult and a springboard were used for their takeoff. Needless to say, how complex engineering problems were solved by Japanese designers. We can say that they had to develop a fundamentally new class of warships.
The empire was in a hurry: boat I-7 was launched in 1939, and a little later I-8 was completed. Shortly before the attack on Pearl Harbor, the Japanese Navy was supplemented by another similar submarine - Project A1 I-9, which included only three submarines, each of which carried one seaplane. The experience gained by the Japanese made it possible to create the first truly massive submarine aircraft carrier in history. In the summer of 1942, the Japanese launched the I-15 submarine of the B1 project: until 1944, they built twenty submarines of this type.
An important distinguishing feature of later Japanese boats was the increased, if I may say so, air potential. The previously mentioned Watanabe E9W has been replaced by the much more modern Yokosuka E14Y seaplane. It is a single-engine monoplane of mixed design with two floats, which could carry small-caliber bombs and was equipped with a defensive machine gun (which, of course, is not enough for a good defense against fighter attacks).
Despite its limited capabilities, in September 1942, a Yokosuka E14Y, delivered by an I-25 Type B1 boat, raided Oregon, dropping two 76 kg incendiary bombs. It was assumed that they would provoke forest fires with subsequent damage to the economy. But this did not happen. But the submarine I-25 went down in history: the Yokosuka E14Y raid was the only case of bombing the continental United States from an aircraft in the entire Second World War. Japan's almost complete absence of heavy bombers deprived the country of the possibility of US carpet bombing, so that aircraft carriers became the only outlet. Such actions could be used for propaganda purposes for their own population, although, of course, they could not seriously affect the course of the war.
Submarine I-25 had a length of 108.7 meters, its total displacement was 3654 tons. The crew of the submarine is 94 people. The boat had six 533 mm bow torpedo tubes, as well as a 140 mm naval gun. On September 3, 1943, I-25 was sunk by an American destroyer off the coast of the New Hebrides.
In general, the boats of the A1 and B1 project can be called relatively successful - by the then Japanese standards. The design of the first formed the basis for the improved AM-type submarine aircraft carrier.At the same time, boats of the B1 type gave rise to the B2 and B3 series, although the submarines of the last series, having hangars, never carried aircraft: by the end of the war they were converted into carriers of suicide torpedoes.
The real mini-revolution was the Japanese submarines of the I-400 type, the first of which were completed in 1944-1945. The boat had a solid full displacement of 5223 tons, and the crew, according to some estimates, reached 195 people, including several dozen officers. The main thing is that each such submarine had a serious air group, including up to four Aichi M6A Seiran bombers. It is an all-metal seaplane that could carry one 800-kilogram torpedo or a 250-kilogram bomb. Its maximum speed was 475 km / h, and its flight range was 1, 2 thousand kilometers. In the stowed state, the aircraft were stored in the hangar, which was in the wheelhouse. The entire plumage of the seaplanes was folded so as not to go beyond the radius of the propeller. To launch them on boats, a launch catapult and launch rails were used.
Despite their shortcomings, the Aichi M6A Seiran bombers appeared unexpectedly, they could sink an American destroyer or frigate, cause serious damage to a cruiser or aircraft carrier. In almost all cases, this would be a one-way flight, since American ships had serious anti-aircraft protection, even without taking into account carrier-based fighters. One way or another, the Japanese were unable to test large submarine aircraft carriers: none of the three built submarines of the I-400 project had time to take part in the conflict. Subsequently, in 1946, they were flooded by the Americans.
By the end of the war, propeller driven fighters could reach speeds at high altitudes up to 700 km / h. Therefore, the "slow-moving" Japanese seaplanes had few chances of salvation; they had to meet with American pilots. Do not forget that in the second half of the conflict, the United States already had dominance in the skies over the Pacific front of hostilities.
On the whole, the scale of the war in the Pacific was such that submarine aircraft carriers probably could not bring victory to the Land of the Rising Sun. Even if they were built in a much larger series. The maximum that could be counted on was a successful aerial reconnaissance.
British M2 and French "Surkuf"
Europeans and Americans, however, could not boast of such achievements. Rather, they probably did not need such submarines. Post-war events really showed that Japanese submarine aircraft carriers were a dead-end branch of evolution, although during the war it still did not seem so unambiguous. Even before World War II, the former "mistress of the seas" was seriously counting on such a weapon. One of the most curious pages of the British submarine fleet is associated with the submarine HMS M2, which was built in 1919. In 1927, she was converted into the first submarine aircraft carrier in the world.
The boat was shipwrecked in the British Lyme Bay, Dorset, in 1932. M2 left its base in Portland on January 26, 1932 and headed towards West Bay for a training exercise. She carried on board the Parnall Peto single-engine reconnaissance seaplane. During the broadcast at 10:11 am, the vessel Titania was announced. Its captain also noted that he saw the stern of a large submarine while submerging, but did not attach any importance to this. The boat was no longer in contact: as it turned out, the crew of 60 people died.
M2 was found on February 3. Further examination revealed that the hangar door was open and the aircraft was still there. The water probably entered through the open door. It is possible that the sailors tried to launch the plane in record time, for which they paid with their lives, although this version was not the only one.
Even more mysterious was the death of a French submarine aircraft carrier. The submarine was launched on October 18, 1929 and entered the fleet in May 1934. She carried a light reconnaissance seaplane Besson MB.411, intended for reconnaissance and artillery fire adjustment.The fact is that the unique submarine received two giant 203-mm guns in a twin installation - it was considered an "artillery submarine". At the time of the German attack on France in 1940, the submarine was being repaired in Brest. With one engine running and a jammed rudder, she managed to cross the English Channel and arrive in Portsmouth, UK. Further service of the boat turned out to be difficult due to a huge number of breakdowns. On February 12, 1942, the Surkuf set out to sea and headed for the Panama Canal to go to the Pacific Ocean: only one engine was working properly on the boat.
Surkuf did not arrive at the destination. The most likely cause of her death was later called a collision with the American bulk carrier Thomson Likes on February 18, 1942. However, until now, the place of death of the submarine has not been found - and the mystery of the French submarine "cruiser" has not yet been solved.
Now there are no submarine aircraft carriers, which, in principle, is not surprising. The dimensions of modern fighters, bombers and reconnaissance aircraft almost completely exclude the possibility of launching them from aboard submarines, even very large ones. However, the rapid development of UAVs makes the idea not so crazy. So, the USA believes in its reality.
Back in 2010, it became known about the development of the Cormorant drone by the Skunk Works design bureau, capable of launching from the Ohio submarine from an underwater position. As a take-off site, it was proposed to use the launchers of ballistic missiles UGM-133A "Trident II" (D5). Cormorant has received stealth technology and can be used for reconnaissance. From the shaft, the UAV will not "shoot" like a rocket, but rather float up. As soon as it is on the surface, the jet engines will turn on, and the device will take off directly from the water. Having completed his task, he will be able to return to the meeting point with the submarine and descend back to the sea surface using a parachute. Then the drone is pulled back using the rope.
Such an apparatus can once again rethink the concept of naval warfare. A huge number of UAVs launched from aboard submarines can become a serious headache for the enemy fleet, especially if they are taught to carry strike weapons. At the same time, the idea looks expensive, risky and technically difficult. By the way, in recent years, there has been almost no new information about the development of Cormorant.
But in the post-Soviet space, they decided to "scare" potential opponents with a giant aircraft carrier boat of Project 941bis, which has a take-off and landing deck and is capable of launching Su-33 aircraft. Alas, this is just a model, a flight of fantasy, although quite serious discussions about the boat are being conducted on the Web. There is even a popular urban legend - about a group of naval officers who did not want to put up with the collapse of the USSR and "continued the fight against capitalism" using such a ship built on their own. Allegedly, this story was even published in The New York Times.
It is noteworthy that in the Soviet years, the project to create a submarine aircraft carrier did exist. However, it was infinitely far from the presented model. In 1937, they developed project 41a, which they planned to equip with the Hydro-1 seaplane. The boat hangar was designed to be 2.5 meters in diameter and 7.5 meters in length. The aircraft could reach speeds of up to 183 km / h, its preparation for the flight should have taken about five minutes. But the project was never implemented.