What feature protected the crew in Leonardo da Vinci’s proposed armored vehicle?

Sloped armor protected the crew in Leonardo da Vinci’s proposed armored vehicle.

Leonardo’s fighting-vehicle design used a conical, turtle-like shell made from angled wooden plates reinforced with metal. The sloping surfaces were intended to deflect incoming projectiles and protect the people inside. The vehicle also included openings for weapons around its perimeter.

The machine is often called Leonardo’s tank, but that name is modern. It was not a tank in the later military sense: it had no internal-combustion engine, tracked running gear, or standardized armored-vehicle layout. Leonardo’s drawing shows a manually powered platform with wheels and internal mechanisms.

A famous feature of the design is a claimed gearing problem that would make the vehicle move backward rather than forward if built exactly as drawn. Historians debate whether this was deliberate sabotage, a drafting mistake, or an unfinished design. The protective principle of sloped armor, however, is clearly visible in the concept.