have been supported by the ship's structure rather than resting on carriages. The inventories of both the Mary Rose and the Tower had changed radically by 1540. There were now the new cast bronze cannons, demi-cannons, culverins and sakers and the wrought iron port pieces (a name that indicated they fired through ports), all of which required carriages, had longer range and were capable of doing serious damage to other ships.

Various types of ammunition could be used for different purposes: plain spherical shot of stone or iron smashed