Leonardo's studies of a boat's propulsion system operated through man-powered paddle-wheels include this machine. In this design, the men who were to provide the energy required are accommodated below deck. Here they operated the big central drum through a belt which, in turn, meshed with the paddles' axle via a pinwheel, thus propelling the boat. Leonardo was well aware that the system could not have worked exactly as designed - the paddles would have turned in the opposite direction to each other - and that another mechanism was needed.
The model is based on the drawing:
- Codex Atlanticus f. 945 r. (1480-1482)
Milano, Biblioteca Ambrosiana