Ravelin

The revellín (in old Spanish also rebellín) is a triangular fortification located in front of the body of the main fortification —generally on the other side of a moat—, whose objective is to divide an attacking force and protect curtain walls by crossfire. Along with other elements, it is part of the so-called Italian trace design (hence its etymology, since it comes from the Italian rivellino or revellino).

Description

Due to the triangular shape, it differs from the lunette in that it is semicircular, has less thickness than the ravelins and usually lacks artillery equipment, with benches being more common to allow the infantry to fire rifles.

The ravelin may be preceded by a counterguard, which does not have artillery and from which it was normally separated by a moat.

The first built example of ravelin is found in the Italian town of Sarzanello and dates back to the year 1497. The first ravelins were built of brick, although later, throughout the 16th century in the Netherlands, they were made of earth, since which better absorbed the impact of projectiles.

In the fortification system followed by Vauban and in Spain by the engineers of the Royal Academy of Mathematics of Barcelona, the ravelin was built in stone just like the canvas of the wall.

As a general rule, in the ravelins the side of the triangle that is shown inside the fortress is not fortified and sometimes does not even exist, taking its place with stairs and access ramps to the fortification for troops and cannons, as well as in some cases the barracks of the force that is to garrison them. This is done to prevent the enemies from gaining strength in them if they manage to take them. Other constructions attached to the ravelins may be paths covered by two walls that connect a postern in the wall with access to the ravelin to transport reinforcements or supplies to it, protected from enemy fire.

The best preserved set of fortifications of this type in Spain is located in the Castillo de San Fernando de Figueras.