Ditch (fortification)In military engineering, a ditch is an obstacle designed to slow down or break up an attacking force, while a trench is intended to provide cover to the defenders. In military fortifications the side of a ditch farthest from the enemy and closest to the next line of defence is known as the scarp while the side of a ditch closest to the enemy is known as the counterscarp. In early fortifications, ditches were often used in combination with ramparts to slow down the enemy whilst defensive fire could be brought to bear from the relative protection afforded by the rampart and possibly the palisade.
Siege engineA siege engine is a device that is designed to break or circumvent heavy castle doors, thick city walls and other fortifications in siege warfare. Some are immobile, constructed in place to attack enemy fortifications from a distance, while others have wheels to enable advancing up to the enemy fortification. There are many distinct types, such as siege towers that allow foot soldiers to scale walls and attack the defenders, battering rams that damage walls or gates, and large ranged weapons (such as ballistae, catapults/trebuchets and other similar constructions) that attack from a distance by launching projectiles.
Union ArmyDuring the American Civil War, the United States Army, the land force that fought to preserve the collective Union of the states, was often referred to as the Union Army, the Federal Army or the Northern Army. It proved essential to the restoration and preservation of the United States as a working, viable republic. The Union Army was made up of the permanent regular army of the United States, but further fortified, augmented, and strengthened by the many temporary units of dedicated volunteers, as well as including those who were drafted in to service as conscripts.
Earthworks (engineering)Earthworks are engineering works created through the processing of parts of the earth's surface involving quantities of soil or unformed rock. An incomplete list of possible temporary or permanent geotechnical shoring structures that may be designed and utilised as part of earthworks: Mechanically stabilized earth Earth anchor Cliff stabilization Grout curtain Retaining wall Slurry wall Soil nailing Tieback (geotechnical) Trench shoring Caisson Dam Gabion Ground freezing File:Mechanically stabilized earth diagram.
WehrmachtThe Wehrmacht (ˈveːɐ̯maxt, defence force) were the unified armed forces of Nazi Germany from 1935 to 1945. It consisted of the Heer (army), the Kriegsmarine (navy) and the Luftwaffe (air force). The designation "Wehrmacht" replaced the previously used term Reichswehr and was the manifestation of the Nazi regime's efforts to rearm Germany to a greater extent than the Treaty of Versailles permitted.
Military tacticsMilitary tactics encompasses the art of organizing and employing fighting forces on or near the battlefield. They involve the application of four battlefield functions which are closely related – kinetic or firepower, mobility, protection or security, and shock action. Tactics are a separate function from command and control and logistics. In contemporary military science, tactics are the lowest of three levels of warfighting, the higher levels being the strategic and operational levels.
