FORTIFICATION

in military science, works erected to strengthen a position against attack. Permanent fortifications include lasting forts and troop shelters; they are usually constructed of masonry, concrete, or stone. Field fortifications are those constructed when in contact with an enemy or when contact is imminent. They consist of entrenched positions for personnel, weapon emplacements, cleared fields of fire for weapons, and manufactured obstacles such as mines and barbed wire; and they also include the strengthening of available natural obstacles by utilizing felled trees, rocks, and other materials. There are two chief reasons for fortifications: to obtain the greatest advantage from one's own strength and weapons and to prevent the enemy from using his resources to advantage. The defender is shielded by the protecting fortification, and the attacker is delayed or his impetus minimized by obstacles. The defense of cities and trade centres, usually by high walls, has been important for centuries as a protection for their wealth. Permanent fortifications have also been established at strategic points along routes of invasion. Seacoast fortifications have normally been for protection against naval attack, though from a military standpoint they sometimes included protection from the land side. Field fortifications have been used in varying degrees since the time of the Greeks and the Romans. The citadel was the municipal fortress of the ancient world. It appeared in cities of Egypt, Greece, and the Roman Empire. Obstacles have been utilized throughout history to prevent an enemy from coming to close quarters. The Romans depended upon protective walls and dry ditches in the republican era but later utilized ditches filled with water and spiked tree trunks set in the ground. Obstacles were of little value unless they were tied into the defense system. For instance, the concrete dragon's teeth of the German west wall of World War II were an inconsequential obstacle when no troops or defense guns were nearby. Bulldozers merely pushed dirt over them to create an elevated road, or engineers dynamited a path through them. In ancient days, fortifications hindered the best attacking troops for months and even years. The medieval castle was almost impregnable until gunpowder gave artillery increased battering power. Even against artillery, the fortifications of World War I were able for a time to bear up successfully. In World War II new methods of combined attack made even the strongest permanent fortifications vulnerable. Field fortifications gave some help to the defense by channelizing enemy attacks, though at no time were they impregnable. Historically, both permanent and field fortifications were strong against hand weapons and engines of war but required extensive modification after the arrival of gunpowder. In the age of the tank and airplane, permanent fortifications became inadequate, but field fortifications were able to compel some delay in enemy advances. in military science, any work erected to strengthen a position against attack. Fortifications are usually of two types: permanent and field. Permanent fortifications include elaborate forts and troop shelters and are most often erected in times of peace or upon threat of war. Field fortifications, which are constructed when in contact with an enemy or when contact is imminent, consist of entrenched positions for personnel and crew-served weapons, cleared fields of fire, and obstacles such as explosive mines, barbed-wire entanglements, felled trees, and antitank ditches. Both field and permanent fortifications often take advantage of natural obstacles, such as canals and rivers, and they are usually camouflaged or otherwise concealed. Both types are designed to assist the defender to obtain the greatest advantage from his own strength and weapons while preventing the enemy from using his resources to best advantage. This article discusses military fortification since the introduction of rifled artillery and small arms. For discussions of fortification up to the modern era, see military technology. Additional reading Ian V. Hogg, Fortress: A History of Military Defence (1975); and Christopher Duffy, Fire and Stone: The Science of Fortress Warfare, 16601860 (1975), and Siege Warfare, vol. 1: The Fortress in the Early Modern World, 14941660, and vol. 2: The Fortress in the Age of Vauban and Frederick the Great, 16801789 (197985), treat the development of methods of siege craft and fortification and survey positional warfare. Sbastien Le Prestre de Vauban, A Manual of Siegecraft and Fortification, trans. and ed. by George A. Rothrock (1968; originally published in French, 1740), is the famous text with informative notes, appendixes, and introduction; and Simon Pepper and Nicholas Adams, Firearms & Fortification: Military Architecture and Siege Warfare in Sixteenth-Century Siena (1986), studies the technology and tactics of early modern positional warfare in detail. Horst De la Croix, Military Considerations in City Planning: Fortifications (1972), surveys urban fortifications from the earliest times to the mid-19th century.