The Cold War was a time of rapidly advancing military technology. Riding the military technology boom of WWII, the coming decades would push technology to its limits, spawning countless attempts at creating the next great piece of military equipment. While many attempts were designed around a logical purpose and were successful, many were not a whole lot more than experiments, meant to prove a concept that didn't fully have a basis in reality.

These vehicles typically would be developed in a shroud of secrecy, keeping their newest developments safe from the glaring eyes of competing military forces. But once the veil of secrecy was dropped, people realized just how strange some of these experiments were. While plenty of classified vehicles that came out of western nations were downright weird, nobody made weird military vehicles better, and in greater numbers than the Soviet Union did.

From gargantuan Aircraft Carrier killing flying boats to tanks built to survive a nuclear bomb, here are 15 of the absolute strangest formerly classified military vehicles the USSR made a reality:

15 Lun Class Ekranoplan

Via Old Machine Press

Flying boats are nothing new, with the type having been in use since its origin in 1910. But the "Ekranoplan" was a radical design that would have re-defined what a flying boat was. Using a cushion of air on top of the water, these monsters used the "Ground Effect" to fly at low altitude across bodies of water, with the intended goal of intercepting incoming aircraft carriers, using its "Moskit" missiles to send them to the depths.

14 Yakolev Yak-36 "Freehand"

Via Wikipedia

While the Ekranoplan failed to revolutionize flying boats, in 1956, the Yak-36 attempted to revolutionize fighter jets, adding vertical take-off and landing (VTOL) capabilities. In reality, it failed and paved the way for several more failed attempts, none of which saw full production.

One particularity terrifying quirk of the Yak-36 was that if one of the two jet engines stalled while hovering, the entire aircraft would immediately flip over and crash. The technology was just too far into the future to become a reality in the '50s.

13 Kalinin K-7

kalinin k7
Via Pinterest

Today, massive airplanes with wingspans of hundreds of feet are common, just look up and you'll probably see an airliner passing overhead that is bigger than the Kalinin K7, but this beast incredibly was made during the early 1930s. With a wingspan of over 170 feet, it was the biggest airplane in the world at the time and could act as a troop transport and heavy bomber. Unfortunately, it was just too advanced, with too many problems for the technology of the day. The program ended when the sole K-7 built crashed during testing.

RELATED: 25 Helicopters And Airplanes That Defy All Logic And Reason

12 Object 279

Via PInterest

From looks alone, this tank is a strange one, but things get weirder when you hear the reasoning for those looks. Designed to be an advanced, all-terrain heavy tank, the odd shape of the Object 279 served a special purpose, to deflect shockwaves from nuclear explosions. Yes, this tank was designed to take a hit from a nuclear bomb and survive. What it didn't survive was the program costs it incurred, being canceled after only one Object 279 was produced.

11 Antanov An-40 "Krylya Tanka"

Via Wikipedia

For those who don't understand Russian, "Krylya Tanka" simply means "Tank Wings," but that's fairly obvious from the picture. The AN-40 was designed to be towed behind a bomber, then released to glide into enemy territory where it would shed its wings and fight as a standard tank. Unsurprisingly, there wasn't much of a point to it, leading to the program's cancellation after just a single test flight.

10 T-55 Progrev-T

Via Reddit

No, that's not some futuristic plasma cannon, or any other crazy sci-fi concept, despite how it looks. That odd piece of machinery replacing the cannon on this T-55 tank is a jet engine from a MIG-15 fighter jet. Instead of destroying other vehicles, it was meant to be pointed at a minefield, where the force and heat of the jet blast would, in theory, clear any mines hidden underground.

9 Tsar Tank "Netopyr"

Via Pinterest

An absurd vehicle that looks like something out of a movie, the Tsar Tank (King Tank) or "Netopyr" (a type of bat) briefly became a reality, albeit not a very useful one. During WWI tanks made their entry onto the battlefield, paving the way for decades of improvements. The Tsar Tank sought to accelerate those improvements, using 30-foot tall wheels to traverse over trenches and any obstacles. In reality, it became stuck in a swamp during testing, where it remained for years until it was torn apart for scrap in 1923.

RELATED: Lend-Lease - 15 American And British Military Vehicles That Fought In The Red Army During WWII

8 Bartini Beriev VVA-14

Via Pr0gramm.com

It seems to be a theme with Soviet experimental vehicles that they end up looking like Sci-Fi machines (or maybe Sci-Fi artists took inspiration from the Soviets?). One of the best examples of this is the Bartini Beriev VVA-14, an odd amphibious aircraft that actually completed successful test flights. Adding to the weirdness, the VVA-14 was capable of hovering over water. But, the 3 prototypes made were scrapped after the program's cancellation.

7 Mikoyan-Gurevich MIG-105

Via Reddit

This is not a fighter jet, this is a space-plane. Meant to be launched like a missile from a high altitude TU-95 bomber, a combination of jet and rocket engines would then carry it into orbit. Numerous tests were conducted in the atmosphere, with the 8th and final test resulting in a hard landing that wrote off the space-plane. In the end, the MIG-105 never made it into space, instead being canceled in favor of the Buran-Energia space shuttle.

6 Ilyushin IL-40 "Brawny"

Via Valka.cz

During WWII, the Ilyushin IL-2 made a legend of itself as a durable and powerful ground attack aircraft. On the outset of the war, with new jet technology gripping the world, it seemed like a natural development to have a jet-powered successor to the famous "Flying Tank." Armed with 6 monstrously powerful 23MM cannons, the IL-40 seemed like a great idea, until those cannons started stalling out the engines when fired, leading to the program's cancellation.

5 ZVM-2901 Shnekokhod

Via Unusual Locomotion

One of the most unique all-terrain vehicles in the world to this day, the ZVM-2901 was built from a UAZ truck as part of a series of screw-propelled vehicles the Soviet Union experimented with. The concept never got off the ground, but they did in fact work as intended. The ZVM-2901, in particular, sat abandoned until a team of Russian engineers restored it to its former glory for all to see.

RELATED: Russian T-14 Armata Battle Tank Heads To Syria For Testing

4 Kamov KA-22 Vintokryl

Via Pinterest

While plenty of Soviet aircraft is downright strange-looking, this behemoth takes the cake in the battle for the weirdest flying machine. Despite the ridiculous looks, it broke several world records in 1960 when it first took to the skies, including rotorcraft top speed and payload capacity.

Unfortunately, the KA-22 was just too complex, and after the prototypes crashed during testing, it was abandoned in favor of the more conventional Mi-6 "Hook" helicopter

3 Project 907 "Triton" Submarine

Via Pinterest

Despite the goofy looks, this mini-submarine is still shrouded in secrecy, with no real confirmation on what exactly it was supposed to do. What we do know is that 32 Project 907 submarines were completed, with each of them carrying a crew of 2 in what essentially is a manned torpedo.

2 Object 934 "Volgograd River Monster"

Via Pinterest

No, this picture isn't the result of someone not paying attention while driving a tank, the Object 934 was designed and built as an amphibious tank. Able to hit 6 MPH when in the water, the Object 934 wasn't successful, with all production orders being canceled. But, the PT-76 amphibious tank fulfilled the same role did achieve success, serving 25 countries faithfully to this day.

1 Sukhoi T-4 "Sotka"

Via Wikipedia

Bearing a striking resemblance to the American XB-70 Valkyrie, the Sukhoi T-4 was a failed attempt at matching the American development of a Mach 3 nuclear bomber. The T-4 isn't a straight rip off though, being shorter, and having a different cockpit design.

But just like the XB-70 Valkyrie, it failed, being too hard to fly, and too expensive for the value it gave in return. Fortunately for aviation enthusiasts, the single prototype T-4 remains on display in the Monino Air Museum to this day.

NEXT: 15 Weirdest Cold War Jets Most People Forget About