Leonardo da Vinci proposed wood for the protective shell of his armored vehicle.
The vehicle, designed around 1487–1489, was a conical, covered platform mounted on wheels. Its sloped wooden shell was intended to deflect enemy weapons, while people inside would turn cranks connected to the wheels. The design also included cannon openings around the perimeter.
Leonardo presented the concept as a military machine in his proposals to Ludovico Sforza. Historians have debated whether the drawing contains an intentional flaw: the gear arrangement appears to make the vehicle difficult or impossible to move. Some reconstructions correct the gearing and show that a workable version could be made.
The vehicle is often called Leonardo’s tank, but it was not a modern tank. It had no engine, tracks, turret or enclosed crew compartment in the modern sense. Its wooden armor and hand-powered mechanism place it among Renaissance siege and battlefield concepts.