Times of conflict often push countries to the edges of innovation, as armies look for ways to out-power and out-maneuver their enemies. As a result, some truly impressive military vehicles have been created over the past 100 years, stretching the limits of engineering and machinery to lengths, weights, and capabilities previously unthinkable. Below are five of the largest military vehicles ever created.

Typhoon Submarine

Country: Russia

The Typhoon-class subs are the largest military submarines ever built, clocking in at a staggering 515 feet long. Each of the six Typhoon subs built carried a payload of 20 ballistic nuclear missiles and was capable of staying submerged for three solid months at a time. A crew of 160 sailors was required to operate them. Amazingly enough, for a vehicle of its size the Typhoon was remarkably stealthy, thanks to a five-layer hull of sound-dampening plates. The Typhoon subs were first in commission in 1980, by Russia ceased its modernization plan for the Typhoons in 2012 because of great maintenance expense.

USS Enterprise Aircraft Carrier

Country: U.S.A.

With a crew of 4,600 service members, the USS Enterprise was actually the eighth US Naval vessel to bear the name. Launched in 1960, “Big E” shared the same nickname as her WWII predecessor and was the world’s first nuclear-powered aircraft carrier. At 1,123 feet, she was the longest naval vessel ever built, as well as the 12th-heaviest supercarrier, Enterprise was originally meant to be the first of six identical aircraft carriers, but construction costs were so high that the other five were cancelled.  After serving for 51 years, the she was decommissioned in 2013.

Schwerer Gustav Gun

Country: Germany

The largest gun ever built was a German 80 cm railway gun, known as “Heavy Gustaf” or “Great Gustaf.” It was developed in the late 1930s by German industrial conglomerate Krupp as siege artillery for the specific purpose of destroying the main forts of the French Maginot Line, the strongest fortifications then in existence, during WWII. The gun weighed nearly 1,350 tons, required a 500-man crew to maintain and operate, and shot targets up to 29 miles away. The Gustav gun was the largest-caliber rifled weapon ever used in combat, the heaviest mobile artillery piece ever built in terms of overall weight, and it fired the heaviest shells of any artillery piece.

Char 2C Tank

Country: France

The Char 2C, also known as the FCM 2C, was a French super-heavy tank developed during World War I but not deployed until after the war. It was, in physical dimensions, the largest operational tank ever made. 12 men in two separate compartments operated the 69-ton, 40-foot vehicle. It was armed with a 75mm long gun in the world’s first-ever three-man turret, a rear machine gun turret, and three 8 mm machine gun positions at the front. During the French mobilization of 1939, all 10 Char 2cs were activated and put into their own unit, the 51st Bataillon de Chars de Combat. Interestingly, though, the super-heavy tanks were primarily used for propaganda and morale-boosting, often shown in movies climbing and crushing old French forts.

Mil MI-26 Helicopter

Country: U.S.S.R.

As the first helicopter produced with an eight-blade main rotor, the MI-26 is the largest and most-powerful transport helicopter ever created. First flown in 1977, its unmatched lifting power is capable of carrying large-sized cargos weighing as much as 20 tons. 320 Mil Mi-26 helicopters have been built, and are still in use by military and civilian operators. It can carry up to 90 passengers, and holds the world record for the greatest mass lifted to 2,000 meters (it lifted 56,768.8 kg in 1982).

Written by Megan Hammons