A bastion is a projection in a part of a fortification, designed at an angle facing the wall to allow defensive fire from spreading in several directions. It is angular in shape and is usually positioned at the corners. Bastions were dominant for 300 years (from the mid-sixteenth century to mid-nineteenth century). Bastion fortifications replaced the previously used medieval fortifications. The difference between these two forms of fortification is that bastions were flat sided unlike medieval, which were curved.
Importance of Bastion’s Features
The flat nature of bastions helps rule out the dead ground, therefore, making it easier for defenders to fire from any side at the front of the bastion. Bastions cover a more significant piece of land than most towers mainly to ensure that there is enough space for mounting of cannon (mounted guns) and operational activities by the crew. Walls of bastions were thick (made of rubble or hard-packed earth) and would hence allow cannonballs to pass through them but be absorbed. Sometimes bastions could be stormed successfully, and the attackers could do more harm. To stop this, other bastion designs came up, and they would allow trenches to be dug at the rear of the bastion fort hence reducing chances of attack to the main rampart. The distance between the channels and the top of the bastions is broad enough to prevent attackers from scaling up.
Types of Bastions
Various types and designs of bastions have been used over the years. They include solid bastions, flat bastions, composed bastions, void bastions, cut bastions, circular bastions, irregular bastions, double bastions, regular bastions, demi-bastions, and semi-circular bastions. Solid bastions are also known as full bastions. They are filled up and have no vacant space near its center. Flat bastions are built at the center of an enclosed court or curtain when the curtain is too big to be defended by bastions. Both sides of the interior polygon for composed bastions are unequal, while void bastions have a rampart around their faces and flanks, providing a hollow space towards the center that is why they are also known as hollow bastions.
Cut bastions are made at an angle at a particular point, and it could be too acute. Circular bastions (also known as roundels) were an evolution during the fifteenth and early sixteenth century but were slowly replaced by angled bastions. Irregular bastions are also known as deformed bastions and they can either lack one side or have a shorter side of the interior polygon. The double bastion is one built on top of another bastion and the difference in height between them is thirteen feet to twenty feet. Regular bastions have proportional flanks, faces, and gorges. Demi-bastions, on the other hand, have single flank and face; the flank protects the curtain walls and the adjacent bastions. The bastion is fortified with two bastions placed at an angle. Semi-circular bastions were commonly used during the sixteenth century but went out of use since it was difficult to concentrate fire guns around a curve. In general, bastions offered a sufficient amount of protection to the inhabitants.