Tanks are a staple of ground warfare. Militaries around the world deploy a wide range of tanks, but typically they conform to some basic principals. In nearly all of them, a large turret sits on top of an armored vehicle that moves on treads.
However, this wasn't always the case. In the early 20th century, engineers around the world were scrambling to figure out how exactly to pass uneven terrain and mobilize troops. This period of innovation resulted in today's technologically marvelous tanks, but before that, they had some truly outrageous ideas.
The Tsar Tank
Tank devleopment was in its earliest stages when Tsar Nicholas II ruled Russia in the first decades of the 20th century. The Tsar differed from modern tanks in that it didn't have treads, instead using two massive 27-foot-tall front wheels and a small third wheel, 5 feet in diameter, that trailed behind for steering. Reportedly, when Nicholas II saw a model of the tank roll over a stack of books he was sold on the project, and gave it his blessing.Russian engineers Nikolai Lebedenko, Nikolai Zhukovsky, Boris Stechkin, and Alexander Mikulin developed the Tsar from 1914 to 1915. The vehicle resembled a hanging bat when viewed from above, so it gained the nickname "Netopyr" which translates to "pipistrellus," the genus name for "bats."
The giant, bicycle-style wheels in front of the tank did prove effective for traversing a variety of terrains. But they severely limited the firing range of the 12 water-cooled machine guns situated in between the massive wheels. Thanks to two 250 horsepower Sunbeam engines powering either wheel, the Tsar could reach a respectable speed of up to 10.5 mph.
But mobility eventually doomed the Tsar.When testing began in a forest outside of Moscow, the rear wheel became mired in soft soil. Despite the Russian military's best efforts to free the 60-ton behemoth, it remained in that spot until 1923 when it was sold for scrap.
The Boirault Machine
The French also had their own ideas about what a mobile weapons platform should look like.In 1914, a few months before Britain began work on the "Little Willy" tank that would set the precedent for modern tanks, French engineer Louis Boirault presented the French War Ministry with plans for the Boirault Machine.
Boirault's tank design was 26 feet high, and has been described as a "rhomboid-shaped skeleton tank without armor, with a single overhead track." The machine weighed a whopping 30 tons, and was powered by a single 80 horsepower motor which enabled the craft to move at a leisurely rate of less than 1 mph.
The singular tracked "wheel" that encompassed the Boirault was nearly 80 feet long and had a cumbersome 330 foot turn radius, earning it the nickname "Diplodocus Militarus," after one of the longest and most sluggish dinosaurs of all time.
The Boirault did have success in crossing over trenches and trampling barbed wire. But more conventional tanks were taking shape around Europe by 1915, and the French War Ministry abandoned the project.
The Screw Tank
Before tracked wheels came into prominence as the most efficient way to traverse difficult terrain, there was some exploration into corkscrew-driven machines that could twist and crush their way through ice, snow, and mud. As early as 1899 patents were filed for agricultural machines that utilized auger-like wheels for work in the fields.In the 1920s, the Armstead Snow-Motor kit made waves across the Northern US and Canada as a screw-driven tractor that could haul up to 20 tons through unwelcoming northern conditions.Then, in World War II, the unorthodox inventor Geoffrey Pyke worked with the US military to develope a screw-driven tank to pass over ice and snow in Northern Europe.
The tank made it to a prototype stage, but was never fully realized and died on the drawing board.
Recently, the idea of a screw tank has resurfaced, with the Russians seemingly perfecting the design as illustrated in the video below: