Today, on the Internet and in various media, you can find a fairly large number of references to underground boat projects, many consider them newspaper ducks and refer to the category of "news from British scientists", but such projects did exist. Many of them remained in the form of paper documents and drawings. Moreover, in Nazi Germany, projects of such mechanisms were even patented before World War II.
In the imagination of engineers and science fiction writers, underground boats were self-propelled mechanisms capable of moving underground, making their own way. Throughout the 20th century, the idea of building an underground boat was addressed in many countries of the world, projects of varying degrees of realism and scale were born, especially notable works in this direction were in the USSR and Germany. At the same time, it should be noted that underground boats did not advance beyond projects and fantastic works of various authors.
Most of the currently known projects and experimental models of "underground boats" were specific versions of a tunnel boring complex (TPK or tunnel shield). Mainly, they were adapted for military use, including waging an underground war, which actively declared itself during the First World War and probably left its mark on the minds of designers and engineers of the first half of the 20th century. Long periods of trench warfare on the Western Front and a high density of troops of the opposing sides led to the fact that the enemy's positions were well protected and prepared in terms of fortifications. Ground attacks of such fortifications turned into a real meat grinder, taking away a huge number of human lives. In these conditions, the idea of an underground war flourished as a variant of breaking into a well-prepared enemy defense. Only the British in 1916 organized 33 separate mine (tunnel) companies with a total number of 25 thousand people to conduct an underground war. An underground war was waged on the Eastern Front, mainly in those areas where the enemy was able to create powerful fortified areas.
Naturally, the experience of the First World War then resulted in a variety of projects in the field of science and technology. Including models of underground boats, however, these projects were almost doomed to failure from the very beginning. Firstly, the Second World War destroyed all ideas about the future conflict that had survived since the First World War, it was a war of motors, rapid breakthroughs and deep encirclement operations, in such a war there were clumsy low-speed mechanisms, and underground boats simply could not be fast. could be used extremely limited. Secondly, the main obstacle in their creation was the problem of providing "boats" with enormous power (tens of MW) and large reserves of energy, which were necessary for the destruction of rocks. And in the future, for example, in the case of installing a nuclear reactor of the required power on an underground boat, another intractable task inevitably arose - its cooling.
Treblev's underground boat project
Perhaps the first who thought of the project of an underground boat was the Russian inventor Pyotr Rasskazov, this happened at the beginning of the 20th century. However, he published his ideas and thoughts in one of the English magazines. What happened to Rasskazov after the 1917 revolution in Russia is unknown, the engineer disappeared along with his developments. The idea of creating a similar apparatus was returned in the Soviet Union even before the start of World War II. A machine capable of moving underground was developed by engineer Alexander Treblev.
Treblev borrowed the principle of operation of his subway from moles. Moreover, the Soviet inventor approached the project very thoroughly. Before starting to create an underground boat, he used X-rays to study the behavior of the animal at the moment when it was digging underground passages. The engineer paid most attention to the movements of the head and paws of the mole. Only after carrying out the appropriate observations, Alexander Treblev began to embody his project in metal.
In its shape, Trebelev's underground boat most of all resembled a capsule, on the bow of which a special drill was located. The plant also had an auger and two pairs of aft jacks. The jacks in the stern of the "boat", according to Treblev's plan, were to serve as the paws of a mole. This unit could be controlled both from the outside and from the inside. The control of the underground submarine from the surface was planned to be carried out using a special cable. Through it, the underground machine was supposed to receive the power supply necessary for operation. The sample developed by Alexander Treblev was quite viable, it could move at a speed of 10 meters per hour, but the project needed a lot of improvements. A significant amount of funds was needed to eliminate them, so the designer ultimately abandoned his development. There is a version that shortly before the start of the war with Nazi Germany, Treblev's project was going to be finalized, focusing directly on the military use of such an underground boat, but the outbreak of war pushed this semi-fantastic project far to the shelf.
The Serpent of Midgard and underground boats for Operation Sea Lion
In parallel with the Soviet Union, the creation of underground boats was puzzled in Germany. For example, the German engineer Horner von Werner patented an underwater vehicle under the designation Subterrine. His car was supposed to move underground at a speed of up to 7 km / h and carry 5 people and up to several hundred kilograms of explosives. The project, patented in 1933, quickly went on the shelf. But he was remembered again already in 1940. The project caught the eye of Count Klaus von Staufenberg, who informed the Wehrmacht command about the unusual machine. At this time, Germany was seriously developing a plan for the invasion of the British Isles - the famous Operation Sea Lion. Her plan was approved on July 16, 1940. According to the developed plan, Hitler's troops were to cross the English Channel, landing between Dover and Portsmouth in 25 (later 40) divisions. The target of the bridgehead attack was London. The date of the start of the operation was constantly postponed, and after the defeat of Germany in the air battle for Britain, on January 9, 1941, Hitler ordered the cancellation of the operation.
It was for this operation that the German military might need underground submarines that could pass under the English Channel and take part in sabotage operations on the territory of Great Britain, striking important defense facilities. Von Werner was even given money for the implementation of his project, but everything stalled at the stage of drawings and laboratory experiments. In addition, the military leadership of Germany counted on victory over Great Britain in an air war, so the von Werner project quickly faded into the background, and then was closed.
Operation Sea Lion Plan
At the same time, von Werner was not the only German who seriously considered the possibility of building an underground boat. Another project belonged to the engineer Ritter, who wanted to bring to life an even more ambitious project - "Midgard Schlange" (Midgard Serpent), the name was a reference to an ancient mythical creature. According to legend, it was a serpent that encircled the entire Earth. The project proposed by Ritter in the summer of 1934 was supposed to be used to destroy the fortifications of the French Maginot Line, as well as attacks on strategic objects in France, Belgium, Great Britain, including ports and naval bases.
Ritter's design assumed decent versatility, except that he could not fly. The car he conceived was supposed to move freely on the ground, as well as underground and under water. The designer hoped that his underground boat would be able to move in hard ground at a speed of up to 2 km / h, in soft ground, black soil - up to 10 km / h. On earth, his creation was supposed to reach a speed of 30 km / h. The dimensions of the device also looked impressive. Ritter dreamed of creating a real underground train with tracked cars. The maximum length reached 500 meters (it could vary depending on the number of used compartments). That is why the project got its name "The Serpent of Midgard". According to the calculations made by the engineer, the weight of his colossus reached several tens of thousands of tons. In theory, a crew of 30 would have to cope with its management.
The movement of the unusual machine under the ground was supposed to be provided by 4 main drills with a diameter of 1.5 meters each. The drills were to be driven by 9 electric motors with a total capacity of 9 thousand hp. The author of the project provided three sets of drills for different types of rocks. The chassis of this vehicle was tracked. The tracks were driven by 14 electric motors with a total power of almost 20 thousand hp. The electric current for the engines was to be generated by 4 diesel electric generators with a capacity of 10 thousand hp. Especially for them, fuel tanks with a capacity of 960 m3 were provided on board.
Since the project was initially considered as a military one, a fairly powerful weapon was envisaged. "Serpent of Midgard" was supposed to carry up to a thousand 250-kg mines, a thousand 10-kg mines and 12 coaxial MG. Also, specifically for the underground boat, specific weapons were designed - underground torpedoes Fafnir 6 meters long (named after the dragon in Scandinavian mythology), special Mjolnir shells (Thor's Hammer) for blasting rocks and facilitating the movement of the "boat" and even a reconnaissance torpedo with microphones and a periscope - Alberich.
In total, Ritter proposed to build up to 20 "underground submarines" worth 30 million marks each. His project "The Serpent of Midgagrda" caused a wave of criticism from experts, since the design justifications for the project were extremely weak. Already on February 28, 1935, it was returned to Ritter for revision, then the fate of his project is lost. The Snake of Midgard project has remained absolutely paper-based. This is not surprising, given the scale of the project and the flight of imagination of its author.
