Drawing upon Leonardo’s famed notebooks—though many pages remain fragmented—his revolving bridge concept can be summarized as follows:

1. Base Structure on Wheels: A set of wheels atop a simple wooden frame that carries the bridge.
    

2. Bridge Deck on Central Pivot: The bridge plank connects to a central rotating axis or pivot anchored on the frame.
    

3. Manual Operation via Ropes/Pulleys: Armed personnel could pull ropes and turn pulleys to swing the bridge laterally out from the frame and into place over a waterway  
    

4. Stabilizing Features: Likely included side guards, railings, or outriggers once deployed, to balance and secure passage under load.
    

5. Quick Retraction: After crossing, the bridge swings back onto its wheeled base, ready for transport along with the troops.
    

This clever combination of pivoting capability with portability made it a practical innovation based on simple wheel-and-axle mechanisms—emphasizing Leonardo’s genius in applying classical mechanics to field solutions. shutdown123