Drawings by Taccola and others based on his work, served as our model. The support structure and arm were made of wood. The claw was either metal or wood. Its base was a tray in which stones were put so that it would remain on the bottom of the lagoon. The counterweight was also a tray of stones. We constructed our model from Taccola's schematic. We chose to construct the entire machine from wood. Where Taccola might have used iron pins or have lashed the materials together with cords, we have used nails and wood glue. We used the ban saw, drill press, and sanders to shape the claw and cut the supports. We pondered whether there was anyway to reset the mechanism, but due to the lack of writing on the device, we canít be sure if it could be reused. However, in light of the fact that once a hull is pierced the boat sinks, the sinking boat probably landed on the keel breaker, making the issue of resetting moot.
Galluzzi, Paolo. Mechanical marvels: invention in the age of Leonardo. Florence: Instituto e Museo di Storiea della Scienza, 1997.
Prager, Frank D. and Gustina Scaglia. Mariano Taccola and His Book Di Ingeis. Cambridge, MA: MIT Press, 1972.