Sherman vs Tiger

In 1914 engineer N. Lebedenko, working in the private laboratory over the order of military department at the constructing of the device for bombs throwing, projected the battle machine of weight about 40 tons, as an increased gun-carriage, with a diameter of running wheels of 9 m.
N. Zhukovskiy and his nephews, B. Stechkin and A. Mikulin, the workers of the laboratory also took part in this work.

It was supposed that this machine (the designers named it as "Netopir" - noctule) will easily overcome any barrier or an obstacle but the two engines " Maybach " (with the capacity 240 h.p. at 2500 rev/min each ), one is for each wheel, will provide the speed of up to 17 km/h.

The rim of a wheel, calculated by Zhukovskiy, had a T-shaped section. A wooden overlay was fastened to the shelf of a T-beam. Two automobile wheels were pressed to the overlays, by means of a railway spring. Rotating in meeting direction, they transferred the moment from the shaft of the engine to a running wheel. In case of an overload driving wheels slipped and protected the engine from breakage. It was planned to deliver the machine to the front in parts and to collect there with bolts.

After finishing all calculations, the diminished wooden copy (diameter of a wheel - 30 sm) with a drive from a gramophone spring, was made. This model was shown to Sovereign Nikolay the second by Lebedenko. Fascinated with the toy that easily got over thick book volumes, the Sovereign ordered to open the account for financing the project. The total sum of expenses made 210000 rubles.

At the end of July, 1915, when the parts of the hull were made, they begun the assembly. In 60 kilometers from Moscow, the assembly was begun the way it had been planned to be done at the front. The weight of the machine exceeded the calculated 1,5 times. That was caused by use of a thicker metal. In August, at the presence of a high commission, the tests began. Moving over a firm platform with confidence, the machine, by breaking a tree, went away on to a soft ground and, by getting into a ditch with its rear wheel, stuck. The capacity of engines was not enough for a relatively small rare wheel's releasing.

In 1916 Mikulin and Stechkin were developing more powerful engines, but the machine was too vulnerable for guns and the financing for tsar-tank was stopped.

Nevertheless, it was the largest of all working prototypes, for all the history of tank construction. After standing up to 1923, "tsar-tank" was disassembled and turned into scrap metal.