What type of vehicle did Leonardo da Vinci design to move using a wound spring rather than a horse?

Leonardo da Vinci designed a self-propelled cart intended to move using wound springs rather than a horse.

The cart was described in Leonardo’s studies of mechanical engineering around the end of the 15th century. Springs stored energy, and a system of gears and controls released that energy to turn the wheels. The vehicle may have been intended for theatrical performances or court entertainment rather than transport over long distances.

The cart is sometimes called Leonardo’s automobile, but that label can suggest a modern engine-powered car. It had no internal-combustion engine, electric motor, or battery. Its movement came from mechanical energy stored before operation, much like a large clockwork mechanism.

A reconstruction made for a 2006 television program demonstrated that the concept could move when built according to Leonardo’s drawings. Because the surviving sketches are incomplete and require interpretation, the exact original configuration remains uncertain. The design is notable as an early attempt at autonomous mechanical motion.