If-16 Naval Mine

A British naval mine design from the 1940s that was intended to be a high-yield, long-lasting mine, but was ultimately not deployed due to technical issues.

If-17 Armored Vehicle

A Soviet armored vehicle design from the 1940s that was intended to be a fast, lightly armored vehicle, but was ultimately not produced due to design flaws.

If-3 Fighter

A proposed Soviet fighter aircraft design from the 1930s that was ultimately not built due to technical difficulties.

If-4 Bomber

A German bomber aircraft design from the 1940s that was intended to be a long-range strategic bomber, but was never built due to the war’s end.

If-5 Tank

A British tank design from the 1940s that was intended to be a heavy tank, but was ultimately rejected due to cost and complexity.

If-6 Submarine

A Japanese submarine design from the 1940s that was intended to be a large, long-range submarine, but was never built due to material shortages.

If-7 Anti-Aircraft Gun

A German anti-aircraft gun design from the 1940s that was intended to be a high-velocity, long-range gun, but was ultimately not produced due to the war’s end.

Hv-3200

A proposed German tank design that never reached production. It was intended to be an even heavier and more powerful tank than the Hv-3100, but the project was abandoned due to resource constraints and the changing tide of the war.

Hv-3500

A proposed German tank design that would have been equipped with a large-caliber cannon and heavy armor. It was intended to be a formidable opponent to Allied tanks but was never built due to the war’s end.

Hv-3700

A German tank design that incorporated advanced technologies, such as a powerful diesel engine and a more sophisticated suspension system. It was intended to be a highly advanced tank, but the project was abandoned due to the rapidly worsening war situation.