There are many myths about who first in the world began to develop underground boats and whether they were developed at all, because there are practically no documentaries on this topic.
Thus, according to one of these myths, in 1918, the Russian engineer Peter Rasskazov made the drawings of such a device. But in the same year, he died at the hands of a German agent, who, moreover, also stole all the developments. According to the Americans, the first in the world in the development of the industry began to engage in Thomas Alva Edison. However, according to more reliable information, at the turn of the 20-30 of the last century in the Soviet Union the design of the first underground boat was developed. Its authors were engineers A. Treblev, A. Baskin and A. Kirilov. However, it was assumed that the main purpose of the apparatus will be reduced to the oil industry.

What was taken as the basis for the development of the boat - at the moment it is difficult to say: whether it was a real mole, or the previous achievements of scientists. As a result, a small model was created, equipped with an electric motor, which actuated special devices for its movement and cutting devices. However, the first prototypes were tested in the Ural mines. Of course, it was just a prototype, a smaller copy of the device, and not a full-fledged underground boat. The tests were not successful, and because of the numerous flaws, the very low speed of the vehicle and the unreliability of the engine, all the work on the underground was stopped. And then began the era of repression, and most of those who participated in the development, were shot.
Nevertheless, a few years later, on the eve of the Second World War, the Soviet leadership still remembered this fantastic project. At the beginning of 1940, D. Ustinov, who soon became the People's Commissar of Arms of the Soviet Union, summoned P. Strakhov, a doctor of technical sciences, who was involved in the design of underground tunneling machines. The conversation that took place between them is of interest. Ustinov wondered if the designer had heard about the development of the autonomous underground self-propelled 30-s apparatus conducted by Treblev. Strakhov answered in the affirmative. Then the People's Commissar said that for the designer there is much more important and urgent work related to the creation of self-propelled underground apparatus for the needs of the Soviet army. Strakhov agreed to take part in the project. Unlimited human resources and material resources were allocated to him, and allegedly a year and a half later the prototype was tested. The underground boat created by the designer could work autonomously for about a week, it was during this period that oxygen, water and food were calculated.
Nevertheless, when the war broke out, Strakhov was forced to switch to erecting bunkers, so the designer was not aware of the fate of the underground apparatus he had created. But it can be assumed that the prototype was not accepted by the state commission, and the apparatus itself was sawn into metal, because at that time the army needed aircraft much more, Tanks and submarines.
It is worth noting that similar research and development was done in Nazi Germany. The leadership of the Third Reich needed any super-weapon that would help achieve world domination. According to information that was made public after the end of the war, underground military vehicles were developed in Germany, which were given the names "Subterrine" and "Midgardschlange". The last of these projects was intended as a super-amphibian, which could carry out movement not only on the ground and under the ground, but also under water at a depth of about a hundred meters. Thus, the device was created as a universal combat vehicle, consisting of a large number of interconnected compartments-modules. The module had a length of six meters, a width of about seven meters, and a height of about three and a half meters. The total length of the device was approximately 400-525 meters, depending on what tasks were assigned to this vehicle. Underground cruiser had a displacement of 60 thousand tons. According to some data, the tests of the underground cruiser were conducted in 1939 year. On board it was placed a large number of small shells and mines, underground battle torpedoes “Fafnir”, twin machine guns, reconnaissance shells “Alberich”, transport shuttle “Laurin” for communication with the surface. The crew of the vehicle was left by a 30 man, and inside it was very much like a submarine device. The device could reach ground speed up to 30 kilometers per hour, under water - three kilometers, and in stony ground - up to two kilometers per hour.
The underground boat was an apparatus, in front of which was placed a drilling head with four drills (each was a meter and a half in diameter). The head was set in motion by nine electric motors, the total power of which was about 9 thousands of horsepower. The chassis was made on the tracks, and serviced by 14 electric motors, which had a total power of about 20 thousands of horsepower.
Under the water, the boat moved with the help of 12 pairs of rudders, as well as 12 additional engines, the total power of which was 3 thousands of horsepower.
The explanatory note to the project provided for the construction of 20 of such underground cruisers (each costing about 30 millions of Reichsmarks), which were planned to be used for attacks on strategically important French and Belgian sites, and for mining ports in England.
After the Second World War was over, the Soviet counterintelligence near Koenigsberg discovered galleries of unknown origin and destination, and not far from them - remnants of the structure, presumably - “Midgardschlange”.
In addition, some sources mention another German project, less ambitious, but no less interesting, which was started much earlier - Subterrine or Sea Lion. A patent for its creation was obtained in the 1933 year, and it was issued in the name of the German inventor Horner von Werner. According to the plan of the inventor, his device was supposed to have a speed of about seven kilometers per hour, the crew - 5 people, carry a warhead equal to 300 kilograms. It was assumed that he would be able to move not only underground, but also under water. The invention was immediately classified and transferred to the archive. And if the war had not started, hardly anyone would have thought of this project. However, Count von Stauffenberg, who oversaw some military projects, accidentally stumbled upon him. In addition, in those years, Germany had just developed a military operation called “Sea Lion”, the purpose of which was to invade the British Isles. Therefore, the existence of an underground boat with the same name could be very useful. The idea was as follows: the underground apparatus, on board of which the saboteurs should be, had to cross the English Channel, and then get to the right place underground. However, as evidenced историяThese plans were not destined to be realized, because Hermann Goering was able to convince the Fuhrer that there would be enough bombing for England to surrender, especially since Fau was needed to achieve this goal, and, accordingly, huge material resources. As a result, the Sea Lion operation was canceled, and the project itself was closed, despite the fact that Goering was not able to fulfill its promises.
In the 1945 year, after the victory over Nazi Germany, a confrontation broke out between the former allies for the right to own military secret projects. It so happened that the project "Sea Lion" was in the hands of the Soviet SMERSH. General Abakumov sent it for revision. A group of scientists led by professors G. Babat and G. Pokrovsky studied the possibilities of the project of an underground combat boat. After research, they concluded that the device can be used for military purposes. At about the same time, Soviet engineer M. Tsiferov received a patent for the creation of an underground torpedo - an apparatus that could move underground at a speed of one meter per second. Ideas Tsiferova continued his son, but to solve the problem of maintaining the course of the rocket and failed. In 1950, a patent for the creation of a thermal drill, which was very similar to a rocket, was obtained by A. Kachan and A. Brichkin.

Meanwhile, similar in function machines were developed in England. They are usually denoted by the abbreviation NLE (i.e., naval and land equipment). Their main purpose was to dig aisles through enemy positions. The technicians and infantrymen were supposed to penetrate the enemy’s territory along these aisles and organize unexpected attacks. English development had four names: "Nelly", "Excavator without human intervention", "Cultivator 6" and "White Rabbit". The final version of the English project was a machine with a length of about 23,5 meters, a width of about 2 meters, a height of about 2,5 meters and consisted of two sections. The main compartment was placed on tracked, and very much like a tank. Its weight was one hundred tons. The second compartment, which had a weight of about 30 tons, was intended for digging trenches to a depth of 1,5 meters and a width of up to 2,3 meters. In the English design there were two engines: one set in motion the conveyors and cutters in the front compartment, and the other set in motion the machine itself. The device could reach speeds up to 8 kilometers per hour. After reaching the extreme point of the movement, “Nelly” was supposed to stop, turning into a platform for the exit of equipment.
However, the project was closed after the fall of France. Until that period, was released only five cars. By the end of the Second World War, four of them were dismantled. The fifth car suffered the same fate at the beginning of the 50s.

Meanwhile, N. Khrushchev came to power in the USSR, who had his own political and military trumps during the Cold War. And once again began the development of underground vehicles. Engineers and scientists who were involved in solving this problem proposed a project to build an atomic submarine. Especially for the first pilot production, a secret plant was built as soon as possible (it was ready for 1962 and was located in Ukraine, not far from the village of Hromovka). In 1964, the plant allegedly launched the first Soviet underground nuclear submarine, which was called the “Battle Mole”. It had a diameter of about 4 meters, a length of 35 meters, and a titanium case. The crew of the vehicle consisted of a 5 man, in addition to him on board could also be placed 15 man landing and a ton of explosives. The main task, which was set in front of the boat, was to destroy the underground rocket mines and bunkers of the enemy. There were even plans to deliver these boats to the shores of American California, where earthquakes often occur. The boat could leave a nuclear charge and undermine it, thereby causing an artificial earthquake, and all the consequences attributed to the element.

Tests of the atomic underground boat, according to some sources, began in 1964, during which amazing results were obtained. Further tests were carried out already in the Urals, but during one of them a tragedy occurred, as a result of which the boat exploded and the whole crew died. After the incident, the tests were discontinued. Moreover, when L. Brezhnev came to power, the project was generally closed and classified. And in 1976, with the aim of misinformation, in the press, at the initiative of the head of the Main Directorate for the Protection of State Secrets Antonov, messages began to appear not only about this project, but also about the existence in the Soviet Union of an underground nuclear fleetwhile the remnants of the Battle Mole rusted in the open.

Whether the development of such underground boats is currently underway is unknown. This topic is also a secret, and at the same time mythical, and a country that will have similar devices in its arsenal, of course, will receive a great advantage. If we talk about the scientific value of such devices, it is obvious that only with their help it will be possible to answer the fundamental questions of the structure of the planet.
Materials used:
http://ru.wikipedia.org/wiki/%CF%EE%E4%E7%E5%EC%ED%E0%FF_%EB%EE%E4%EA%E0
http://pandoraopen.ru/2011-12-06/podzemnye-lodki/
http://www.liveinternet.ru/tags/%EF%EE%E4%E7%E5%EC%ED%E0%FF+%EB%EE%E4%EA%E0/
http://oct1000.narod.ru/krot.html
http://poludin.moy.su/news/podzemnye_lodki/2010-08-03-1095