"Method for sinking a ship. But first they must be affixed together, that is, joined together in such a way that you, on your side, can get detached, at your will, so that when the [other] ship goes to the bottom, it will
not pull yours down along with it. And it is done like this: Pull a weight upward and then drop it, and when it falls, it will give a blow such as one makes on a pile for a castle, and when that falls, it will pull behind it the end
of a beam, which will be an upright pole. And when the upper end of this piece of wood comes, the lower one will go down and break through the bottom of the ship. But make it so that the piece of wood is sharp, so that
as it runs to the point of its blow, the water will not make resistance to it. And above all, make it so that the chains keeping the ships connected together can be cut from your side when you will, so that the adversary ship
will not pull you with him as he submerges"
This is one of the two models of ships with movable bow rams recalling roman vessels, which had rams to hook enemy ships for close distance battling. This craft is equipped with a double ram: the first is inserted into an open well in the hull, positioned beneath the water’s surface and connected by means of cords to the ship’s mast. The second, formed of two paired rams, is fixed directly onto the prow and maneuvered using cords. Leonardo recommended they be of sharpened pieces of wood in order to be able to breach the enemy’s hull and also to be able easily to disengage.
The model is based on the drawing:
- Manuscript B f. 90 v. (1487-1492)
Paris, Institut de France