In 1587 King Philip II of Spain set up the "Royal Administration of the Towers" assigning the task of designing, building and managing a network of forts to defend the Sardinian coasts.

This body, with its headquarters in Cagliari, was headed by the Viceroy who appointed a captain (alcaide), gunners and soldiers to defend the tower (torrieri). Their task was to monitor the sea continuously, to spot enemy vessels and sink them using canons.

These artillery pieces, often given animal names (Falconet, Falcon, Merlin, Culverin, Sagro, Basilisk, Passavolante), required the installation of a specific support called “carriage” (fig. 1). Those supports were in shod timber, with four wheels, where the front wheels could be bigger in size than the rear ones.

Fig. 1 - Passavolante from the Toledo Army Museum (photo by Andrea Carloni https://www.flickr.com/photos/andrea_carloni/sets/72157630194436396/).

In the XV and XVI centuries, the guns bronze or iron, smooth bore and loaded from the mouth. Bullets were spherical iron balls (fig. 2), launched thanks to loads triggered through a hole (focone) in the receiver. Calibres (expressed in pounds, with the weight of the ball) used most in towers were those weighing 8, 6, 4, and 2 pounds (a bronze canon, with a 6 and a half pound calibre, weighed about 500 kg).

Canons equipping the towers had smaller calibres, sizes and weight. Not only was it quite difficult to raise a long, heavy canon on to the place-of-arms, but the tower's vault could not be loaded excessively; what's more, canon size had to be compatible with the small space available on terraces.

Fig. 2 - Iron canon balls in the Sassari Museum (photo M.G. Arru).

The tower's usual equipment included, besides the canons (from two to four), a certain number of canon balls, some barrels of gunpowder (the one used for canons had a greater particle size than the one for mortars and rifles), a mortar  with a few hundred balls, a rifle for each tower soldier with a few hundred bullets (fig. 3); a score of flints for the rifles. There was also everything possibly needed: axes, bill-hooks, tarred rope, water barrels, a copper boiler with tripod, a steelyard balance, earthenware jars.

Fig. 3 - Spingarda (mortar) (from https://it.wikipedia.org/wiki/File:Spingarda-01.jpg).

An 8 pound canon had an average range of about 504 metres, and a maximum of about 3150 metres. The 2 ounce mortar, usually mounted on a tripod, loaded with an ounce of gunpowder had an average range of about 500 metres, and a maximum one of about 2204 metres.

It often happened that the tower had balls of a calibre less than that of the canons supplied; they solved the problem by wrapping the ball in cloths.

Canons and mortars could be operated either directly with a fuse or with a flintlock flint as in rifles.
Tower canons were elevated by inserting wooden wedges under the breech, with an empirical system at the expense of accuracy.

They placed strong planks (madrieri) under the canon's wheels, to protect the floor of the “Place-of-arms”, and after the shot canons were put back in their blocks using levers (fig. 4).

Fig. 4 - Model of a coastal tower: the place-of-arms (Museum of towers of Sardinia).

Each tower was equipped with a pike, a rifle with bayonet and its respective supply of lead balls. In some cases the rifle cartridges were supplied already packed. They used a hoist (ghindazzo) to dismantle and reassemble the canons on the gun carriages.

Along with the canon balls of their respective calibres, some towers were still equipped with chained balls, incendiary devices, the so-called “flasks of fire”.