A bastion is a work projecting outward from the main enclosure of a fortification, consisting of two faces and two flanks, and so constructed that it is able to defend the adjacent curtain, or wall which extends from one bastion to another, with a flanking fire. Two adjacent bastions are connected by the curtain, which joins the flank of one with the adjacent flank of the other. The distance between the flanks of a bastion is called the gorge. A lunette is a detached bastion. There have been various forms of bastion through the ages:
A composed bastion is one in which the sides of the interior polygon are very irregular, with the effect of making the gorges also irregular.
A cut bastion is one which has a re-entering angle instead of a point.
A deformed bastion is one in which the irregularity of the lines and angles prevents the structure from having a regular form.
A demi-bastion is a bastion composed of one face only with a single flank and a demi-gorge.
A double bastion is a bastion raised on the plane of another.
A flat bastion is a bastion erected in the middle of a curtain when the latter is too long to be protected by the bastions at its ends.
A hollow bastion is a bastion hollow in the interior, that is between the flanks and the faces of the point.
A regular bastion is one so planned as to possess a true proportion of its faces, flanks and gorges.
In fortifications, a cavalier is an elevation of earth of different shapes, situated ordinarily in the gorge of a bastion, bordered with a parapet, and cut into more or less embrasures, according to the capacity of the cavalier.
Cavaliers are a double defence for the faces of the opposite bastion: they defend the ditch, break the besiegers galleries, command the traverses in dry moats, scour the salient angle of the counterscarp where the besiegers have their counter-batteries, and interfere with the enemies trenches. Cavaliers are likewise very useful in defending the breach, and the retrenchments of the besieged. Research Cavalier
In fortifications a demi-bastion is a half bastion. The term is also applied to that part of a bastion consisting of one face and one flank. Research Demi-bastion
In fortifications an epaule is the shoulder of a bastion, or the place where its face and flank meet and form the angle, called the angle of the shoulder. Research Epaule
Fortification is the science of strengthening positions in such a way that they may be defended by a body of men much inferior in number to those by whom they are attacked; and more particularly, the science of strengthening positions so that they may be held against the assault of troops supported by artillery. Fortifications are usually divided into permanent and temporary. Permanent fortifications are works required to remain effective for any length of time, for the purpose of defending important positions and cities, dockyards, arsenals, etc. Temporary fortifications are such as are designed merely to throw temporary obstacles in the way of the enemy, as field-works, etc.
The former are constructed on the principle that each part must by its fire support and be supported by some other part; that the works must protect the defenders from the enemy's fire as well as possible, and that the fire of the fortress must completely sweep all parts of the ground in front of the fortified lines. The more important details of a classical regular fortification may be briefly described as follows: Around the place to be defended was raised a mound or bank of earth called a rampart, on the upper surface of which, the terre-pleine, the troops and cannon were placed. The terre-pleine was protected from the enemy's fire by a breastwork or parapet, typically about 8 feet high, sometimes pierced at certain intervals with embrasures through which the guns were fired. Beyond the rampart was the ditch, usually about 12 feet in depth, but varying greatly in width. The ditch was sometimes filled with water; in other cases it was dry. The scarp or escarp was the inner wall of the ditch, and it was faced with masonwork or hurdles, sods, etc (the revetement) to retain the earth of the rampart in its place. The counterscarp was the opposite or outer wall of the ditch. From the top of the counterscarp outwards was a space about 30 feet wide (the covered-way, protected by a parapet, tle long superior outward slope of which towards the open ground formed the glacis. The use of the covered-way was to allow the troops to be drawn up on it unseen by the besiegers for the purpose of making a sortie; it also enabled the defenders to keep up a closer fire on the attacking forces. The slope of the glacis was so constructed as to bring the assailants in the direct line of fire from the artillery on the ramparts. At certain intervals there were often bastions or projecting works at salient angles, commanding by their fire the curtain or straight portion of the fortified line between them.
The use of the bastion has given name to what was called the bastionary system of fortification, which in the 19th century largely gave way to what is known as the polygonal or German system, which was considered to have various advantages in relation to the relatively powerful artillery of the time. The polygonal system has also been called the caponier system, from the use of powerful casemated caponiers constructed across the ditches and serving instead of bastions for their defence. The general plan of the works was polygonal, with the ramparts placed on the sides of the polygon. The connecting line of fortifications surrounding a place was called the fortified enceinte, and the works in a regular fortress formed a very complicated whole, including works to which such names as ravelins, demi-lunes, etc, were given. The fortified enceinte immediately surrounding a place was not considered a sufficient defence after the 18th century, on account mainly of the long range of the cannon then developed. Hence it was usual in the late 19th century to surround a fortress with a line of detached forts at some distance from the enceinte, or there may be more than one such line of advanced works. Later fortifications intended to ward off attacks by sea had their sea-faces commonly protected by plates of iron or steel. Scientific fortification may be said to have commenced with the great French engineer Vauban, who served under Louis XIV. He developed the bastioned system, which, as improved by Cormontaigne and others, was still the prevailing type of French fortification as late as 1905.
Field Fortifications varied much according to the time allowed for construction, and during which they may prove useful. Among works of this nature were the redan, which consisted of two parapets, with a ditch in front, forming an angle facing the enemy; the lunette, which was a redan with short flanks; the redoubt, a closed work with a ditch and parapet all round. As none of those works had a flanking fire in itself, they had to be disposed so that they flanked each other within rifle range. To do this effectually, and to strengthen the whole line, the plan generally adopted was to form an intrenched camp by a line of square redoubts, flanking each other, and also a line of simple redans in front of the intervals of the redoubts. When the time was not sufficient to throw up such works, simple forms of intrenchment, such as shelter trenches, were used to shelter troops or oppose the enemy's advance. A very shallow trench, with the earth thrown to the front, so as to afford shelter to one man lying in it, can be made in somewhat less than half an hour; more elaborate forms in about one hour. So that by placing a man at every 4 feet, active troops can make good shelter for themselves in an hour. Shallow trenches are still in use today, after most other traditional fortifications have become obsolete due to the nature of modern warfare. To impede the enemy's advance, traditionally an abattia of felled trees was used and later also wire entanglements, chevaux-de-frise, etc. Today wire entaglements are still used to hinder infantry and steel and concrete obstacles are used to hinder armoured vehicles which have replaced the horses of the past.
Traditional fortifications were found to be obsolete at the start of the Second World War, though conceret emplacements with steel doors were still employed by all sides with varying degrees of success, at best hindering the progress of an enemy and never proving impenetrable. Research Fortification
Fort Erie was a fort in Canada which, during the War of 1812, was abandoned and fired with all its stores on May the 28th, 1813, by orders of General Vincent. The same day the Americans crossed the Niagara and took possession of the ruins. After the Americans had withdrawn from the Canadian shore, the British rebuilt the fort and stationed there 170 men under command of Major Buck. On July the 3rd, 1813, General Jacob Brown, preparatory to an invasion of Canada, invested the fort, and on demand it surrendered. The fort was now strengthened, and made capable of enduring a siege. After the battle of Niagara, the British advanced against the American position. From August the 7th to the 14th the bombardment was almost incessant. At two o'clock on the morning of the fifteenth, the British, 1500 strong, tried to surprise the Americans. Attacks were made upon three points, but one only was successful. The main bastion of the fort was captured and held against all attack. Suddenly its magazine blew up with tremendous force, the attack was renewed and the British retreated, leaving 221 dead, 174 wounded and 186 prisoners. The Americans lost, all told, 137 men. The siege still continued, the attacking works were continually pushed nearer; but on September the 17th General Brown, in charge at the fort, planned a sortie to destroy the British works. An attack in three divisions was arranged and executed under cover of a fog. It was completely successful. The works were captured and destroyed, the British broke camp and gave up the siege, leaving behind over 800 men killed, captured or wounded. When the Americans finally abandoned Canada, Fort Erie was blown up on November the 5th, 1814, and never rebuilt. Research Fort Erie
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Abbreviations
Research Bastion
