The bizarre "Tsar-tank" was built in 1915. It was probably the largest (40 tons) tank ever made anywhere.he idea was based on a simple fact: it is easier to hold the line than to attack. An attacking side needs protection. There were armored vehicles invented for that purpose, but they were useless on bad roads. The pass-ability of a wheel directly depends on its diameter, so engineers decided to make huge wheels for armored vehicles. This idea first occurred to Captain Nikolay Lebedenko, the head of the Moscow military and technical laboratory.Nikolay Lebedenko suggested the project of a very unusual military vehicle in May of 1915. It was an armored vehicle with huge wheels, which looked like a gun-carriage. Engineers Boris Stechkin and Alexander Mikulin (they later became famous Russian academicians) started working on the project.Mikulin remembers: Nikolay Lebedenko invited me to come to his office, he locked the door and whispered to my ear: "Professor Nikolay Zhukovsky referred you as a skillful engineer. Do you agree to work on the project of the machine that I invented? Such machines will help to break through the whole German front just within one night, and Russia will win the war."It is worth mentioning that Lebedenko was not the only person, who suggested a project of an armored vehicle with huge wheels. However, it was Nikolay Lebedenko, who managed to realize his project in real life. The wheels of his vehicle were nine meters in diameter. The machine weighed about 40 tons, it was nine meters high, 17 meters long and 12 meters wide. Yet, the machine was not equipped with guns, for the Central Artillery Department provided guns only for the projects, that were considered ready for practical usage.The machine was tested in August of 1917. It moved, broke an old big birch-tree on its way and got stuck in the ground with its rear roller. Another test took place in 1918, but it was not a success either. Nikolay Lebedenko's further fate is not known. Like a lot of other people, he vanished in the turmoil of post-revolutionary events in Russia. Academician Boris Stechkin thinks that Lebedenko probably died. Lebedenko's machine was called the Tsar-Tank. It did not take an honorable place next to the Tsar-Bell or the Tsar-Cannon. The Tsar-Tank rusted in the woods, until it was dismantled in 1923. That was the end of the inglorious history of the first Russian self-propelled armored vehicle.Such unlucky inventors as Nikolay Lebedenky became a real disaster for Russian military men in the beginning of the 20th century. There were too many projects of wonder arms. For example, an engineer offered to use boiler metal for producing rolls of six meters in diameter, which would be tens of meters long. As an inventor thought, soldiers could roll those rollers in front of them. Rollers were also supposed to be outfitted with machine-guns at its ends. The inventor wrote all that in a letter, which was completed with a touchy request  "Please, let me know, if there anything else that I can invent to fight the enemy." However, the engineer did not specify the way, how soldiers were supposed to turn those huge rollers or roll them up on hills.Those so-called inventors could not boast of their engineering knowledge, although experienced engineers suggested unreal monsters sometimes too. For instance, there was an interesting project of an "upgraded tortoise," which was suggested by engineer Navrotsky. The machine was supposed to weigh 192 tons, to move with the help of three rolls and to have an unimaginable complex of ordnance  16 guns and ten machine-guns.European engineers also dreamed of designing such movable fortresses. Major of the Royal Naval Aviation Service Hetterington projected a "land cruiser" in the beginning of 1915. The British defense monster was supposed to have three wheels of 12 meters in diameter, six guns and 12 machine-guns. The project was considered at the committee for land cruisers: the mass of the giant cruiser made up one thousand tons. The director of the ship-building department refused from building such a monster.A certain time later, British designers liked the caterpillar ordnance idea, which pushed huge wheels into the background, and resulted in the invention of a caterpillar tank. Winston Churchill was one of proponents of the novelty. A new model of an English tank was named after him during WWII. However, the invention of caterpillar tanks did not stop Russian engineers from designing something new and extraordinary. In 1928, a Russian engineer recommended the Russian military command to subdue the enemy with the help of a self-propelled two-wheeled vehicle. The diameter of its wheels was 12 meters. Yet, the whole project was briefly described on several sheets of paper, which did not allow to get to essence of it.