Review of fortified doors
Introduction
A ram is a siege weapon originating in ancient times, used to break through gates or fortified walls. In its simplest form, a battering ram is just a large, heavy log, carried by several people and driven forcefully against an obstacle. The momentum of the ram is enough to damage the target. It normally has the head of a ram incorporated into the trunk to take advantage of its antlers curled in the shape of a circle (ariete derives from the Latin aries, ram).
Battering rams proved to be effective weapons of war because at the time wall building materials, such as stone and brick, were weak in stress&action=edit&redlink=1 "Strain (physical) (not yet redacted)") and therefore prone to cracking when struck forcefully. With repeated hits, the cracks would steadily grow until a hole was created. Eventually, a breach would appear in the wall structure, allowing armed attackers to force their way through the breach and engage the citadel's inhabitants.
The introduction in the later Middle Ages of siege cannons, which harnessed the explosive power of gunpowder to propel heavy stones or iron balls against fortified obstacles, spelled the end of battering rams and other traditional siege weapons. Smaller, more portable versions of battering rams are still used by law enforcement officers and military personnel to open locked doors.
A covered battering ram is a battering ram that has a head attachment (usually made of iron or steel and sometimes punning on the head and horns of a ram) to do more damage to a building. It was much more effective at destroying enemy walls and buildings than an uncovered battering ram, but it was heavier to transport.
Classes
In more sophisticated designs, battering rams were powered by a sling (weapon) "Sling (weapon)") and supported by ropes or chains "Chain (object)") within a rolling frame "Frame (furniture)"), so they could be much larger and could also be pivoted more easily against their target. Sometimes the tip of the ram was reinforced with a metal head, and the vulnerable parts of the ram were reinforced with metal bands. Many rams also had protective covers and side walls reinforced with leather or other materials to prevent the ram from being attacked by fire.
Some rams were not propelled by ropes or chains, but were instead supported on beams. This gave the rams a much greater travel, so that they could reach a greater speed before hitting their target, and therefore be more destructive. This type of ram was used by Alexander the Great and described by the writer Vitruvius.