The system was named after Raymond Adolphe Séré de Rivières, its originator. The system was an ensemble of

fortifications A fortification is a military construction or building designed for the defense of territories in warfare, and is also used to establish rule in a region during peacetime. The term is derived from Latin ''fortis'' ("strong") and ''facere'' ...

built from 1874 along the frontiers and coasts of

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan ar ...

. The fortresses were obsolescent by 1914 but were used during the

First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fig ...

Background

Following the Franco-Prussian War of 1870–1871, France found itself seriously weakened and isolated from the rest of

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located enti ...

, menaced by

Germany Germany, officially the Federal Republic of Germany (FRG),, is a country in Central Europe. It is the most populous member state of the European Union. Germany lies between the Baltic and North Sea to the north and the Alps to the sou ...

and stung by the loss of Alsace-Lorraine. At the same time as the departure of the last German troops, France created the Defence Committee (), which was active between 1872 and 1888, whose mission was to reorganize the defence of the French frontiers and coasts. It was necessary to compensate for the lost territories of the north-east; to modernise old fortifications, which had been shown to be wanting in the last war and to create new fortifications proof against modern weaponry using new and more powerful explosives. The committee was created by a presidential decree on 28 July 1872, with nine members from the Ministry of War and representatives from artillery and

military engineering Military engineering is loosely defined as the art, science, and practice of designing and building military works and maintaining lines of military transport and military communications. Military engineers are also responsible for logistics ...

. General Séré de Rivières, commander of engineering for the Second Army Corps of

Versailles The Palace of Versailles ( ; french: Château de Versailles ) is a former royal residence built by King Louis XIV located in Versailles, about west of Paris, France. The palace is owned by the French Republic and since 1995 has been managed, ...

, was named secretary of the committee in 1873 and on 1 February 1874, he was promoted to Chief of Engineers. Séré de Rivières was re-elected head of the committee several times, with all powers necessary to realize his ideas without opposition. The first works of the new French fortification system were begun in 1874. In 1880, when the work was already quite advanced and after some internal rivalries and political machinations, General Séré de Rivières was removed from the but the work continued.

1874 fortifications

Since the fortifications executed by Vauban in the 17th century, defensive technology had not evolved during the 19th century. During the Franco-Prussian War, their shortcomings became clear and that the "impregnable citadel" could no longer resist assault. It was necessary to rethink strong points and adapt them to the vast increase in the destructiveness of artillery. Gone were citadels surrounding towns. Forts were to be moved some outside cities to keep an opponent beyond artillery range of the city centre. Rings of forts were to be built, spaced to allow them to cover the intervals in between. The new forts abandoned the principle of the

bastion A bastion or bulwark is a structure projecting outward from the curtain wall of a fortification, most commonly angular in shape and positioned at the corners of the fort. The fully developed bastion consists of two faces and two flanks, with fi ...

, which had also been made obsolete by advances in armaments. The outline was a simplified polygon, surrounded by a ditch that was covered by

caponiers A caponier is a type of defensive structure in a fortification. Fire from this point could cover the ditch beyond the curtain wall to deter any attempt to storm the wall. The word originates from the French ', meaning "chicken coop" (a ''capon'' ...

. The forts, built in masonry and shaped stone, were designed to shelter their garrison against bombardment and artillery was laid out on top of the fort in the open. A feature of the new system involved the construction of two defensive curtains, an outer line of forts, backed by an inner ring or line of at vital points of terrain or junctions, along with a great number of coastal batteries. Examples of the first sort may be found at

Verdun Verdun (, , , ; official name before 1970 ''Verdun-sur-Meuse'') is a large city in the Meuse department in Grand Est, northeastern France. It is an arrondissement of the department. Verdun is the biggest city in Meuse, although the capital ...

Toul Toul () is a commune in the Meurthe-et-Moselle department in north-eastern France. It is a sub-prefecture of the department. Geography Toul is between Commercy and Nancy, and the river Moselle and Canal de la Marne au Rhin. Climate Toul ...

Épinal Épinal (; german: Spinal) is a commune in northeastern France and the prefecture of the Vosges department. Geography The commune has a land area of . It is situated on the river Moselle, south of Nancy. Épinal station has rail connecti ...

Belfort Belfort (; archaic german: Beffert/Beffort) is a city in the Bourgogne-Franche-Comté region in Northeastern France, situated between Lyon and Strasbourg, approximately from the France–Switzerland border. It is the prefecture of the Terr ...

in the north-east as well as

Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. ...

and Brest. may be found at Manonviller, (

Meurthe-et-Moselle Meurthe-et-Moselle () is a department in the Grand Est region of France, named after the rivers Meurthe and Moselle. It had a population of 733,760 in 2019.Bourlémont (Vosges).

Explosive shell crisis

From 1883 to 1885, a revolution occurred in artillery, with the introduction of new materials and techniques, notably the introduction of breech-loading, rifled artillery and much more powerful explosives, such as

picric acid Picric acid is an organic compound with the formula (O2N)3C6H2OH. Its IUPAC name is 2,4,6-trinitrophenol (TNP). The name "picric" comes from el, πικρός (''pikros''), meaning "bitter", due to its bitter taste. It is one of the most acidi ...

. The developments multiplied the power of artillery against fortifications. Tests against Fort Malmaison, south of

Laon Laon () is a city in the Aisne department in Hauts-de-France in northern France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territori ...

, in 1886 indicated that masonry forts had little resistance to the new ammunition and that the artillery on their superstructures was extremely vulnerable. High-strength

concrete Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most ...

was more resistant than masonry to explosives. The development of reinforced concrete would make the new fortifications much more resistant to the new explosives. Forts already in use were a large proportion of the system and some of the forts were downgraded and others were covered in concrete which buried vulnerable portions, such as magazines, behind the new material.

New technology

Armor

Advances in the

iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...

and steel industries allowed the new forts to use armour in new ways. In 1875, the Mougin system of laminated armour, using rolled iron, was first used in

casemate A casemate is a fortified gun emplacement or armored structure from which guns are fired, in a fortification, warship, or armoured fighting vehicle.Webster's New Collegiate Dictionary When referring to antiquity, the term "casemate wall" mean ...

s to provide protection against field guns. Rolled iron gave way to

cast iron Cast iron is a class of iron– carbon alloys with a carbon content more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impu ...

, providing protection against heavier siege guns. Mougin also devised the

Mougin turret The Mougin turret is a land-based revolving gun turret that housed some of the heaviest armament in French fortifications of the late 19th and early 20th centuries. While not reliably resistant to the explosive shells of opposing artillery, Moug ...

, a revolving cast iron turret for guns. Cast iron was not altogether suitable for protection against explosive shells and it was superseded in 1882. In 1885, steel was substituted for cast iron. Non-retractable or non-eclipsing turrets could avoid direct-fire damage to their gun embrasures only by facing away from the direction of fire. Eclipsing turrets were developed that were retractable, leaving only their top surfaces exposed. Such turrets were expensive and complex, with serious problems of noise and ventilation but were shown to be effective. Casemated artillery was used as much as possible, due to the lower cost. While heavy armament was being armoured, lighter armament and observers were also protected. A range of armoured machine gun and observation positions were developed and were widely installed.

Organization

The Séré de Rivières system was based on the concepts of the fortified town and the defensive screen. The towns were intended to furnish locations for eventual counter-attack, while the defensive curtain prevented passage by an attacker. The screen was not continuous and was arranged to channel an attack to a secondary line of fortified towns. Other systems were intended to delay the progress of an attack to build up defensive forces. A typical defended point consisted of a circle of forts around a town about from the centre. The forts were able to provide mutual support and could fire on one another to suppress attacks. Smaller works were provided to support the infantry in the intervals between forts, which provided shelter to infantry during bombardment and some contained reserve artillery. A supply network of railways extended behind the lines. Known as the Péchot system; it was first installed at Toul and was generally adopted in 1888.

Forts

Three types of fort were built, stop forts, screening forts and point defence forts; the forts may be further categorized by their state of modernization. Stop forts were intended to be autonomous, capable of functioning if isolated from the rest of the system and assure their own defence. Such forts could fire in all directions. Screening forts were intended to lend mutual support to others of their kind and generally defended on one front. Their artillery focused on specific areas of control.

First generation forts

Prior to modernization, these forts were built entirely of masonry, using large quantities of shaped stone. The forts were provided with a ditch, wide and bounded by the main wall of the fort on one side and a

counterscarp A scarp and a counterscarp are the inner and outer sides, respectively, of a ditch or moat used in fortifications. Attackers (if they have not bridged the ditch) must descend the counterscarp and ascend the scarp. In permanent fortifications t ...

on the opposing side.

Moat A moat is a deep, broad ditch, either dry or filled with water, that is dug and surrounds a castle, fortification, building or town, historically to provide it with a preliminary line of defence. In some places moats evolved into more extensive ...

s were unusual features in the system; most ditches were dry. Some walls were

crenelated A battlement in defensive architecture, such as that of city walls or castles, comprises a parapet (i.e., a defensive low wall between chest-height and head-height), in which gaps or indentations, which are often rectangular, occur at inter ...

for defence and many had

caponier A caponier is a type of defensive structure in a fortification. Fire from this point could cover the ditch beyond the curtain wall to deter any attempt to storm the wall. The word originates from the French ', meaning "chicken coop" (a ''capon'' ...

s at angles to fire along the length of the ditch. Entry was typically by

drawbridge A drawbridge or draw-bridge is a type of moveable bridge typically at the entrance to a castle or tower surrounded by a moat. In some forms of English, including American English, the word ''drawbridge'' commonly refers to all types of moveable ...

. Inside the fort perimeter were multi-story barracks with facades facing interior courtyards. Barracks were typically semi-recessed into the walls and included mess halls, kitchens and cisterns. Powder magazines were buried for protection from artillery, located behind triple-locked double doors and illuminated indirectly from lamp rooms to prevent accidental explosion. The artillery was laid out on top of the ramparts; shelters were provided for ready ammunition. In some cases, artillery was in armoured casemates or Mougin turrets. Special infantry positions were provided for defence of the ditch.

Modernized forts

After the rise of the explosive shell the most important forts were modernised. A covering of concrete was placed over the masonry to protect against the new artillery. In some cases, concrete casemates were built, leaving the stone casemates alone. The most vulnerable locations in the fort were the magazines, which in the modernised forts were dispersed and more deeply buried. Protected paths were created along the ramparts, along with protected sally ports giving on to the ditch and galleries within the counterscarps looking back at the fort. Artillery was removed from the ramparts and placed under shelter of concrete. Fewer new guns was as effective as the former batteries. Eclipsing infantry positions and observation cloches were also provided. The newest forts of this time were given central electrical plants.

Forts after 1885

These forts were built in concrete from the beginning but due to budget cuts were smaller than previous forts.

Wartime improvisation

During the

Battle of Verdun The Battle of Verdun (french: Bataille de Verdun ; german: Schlacht um Verdun ) was fought from 21 February to 18 December 1916 on the Western Front in France. The battle was the longest of the First World War and took place on the hills north ...

the troops, under bombardment and fearing for the concrete fort, excavated new galleries under the fort for shelter and living quarters. Some of these galleries connected neighbouring fortifications, foreshadowing the connected systems of the

Maginot Line The Maginot Line (french: Ligne Maginot, ), named after the French Minister of War André Maginot, is a line of concrete fortifications, obstacles and weapon installations built by France in the 1930s to deter invasion by Germany and force the ...

. The 17 (built in 1917) also foreshadowed this advance.

References

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External links

''Les forts Séré de Rivières''

Index des fortifications Francaises 1874–1914: Inventory of ''Séré de Rivières'' system fortifications

{{DEFAULTSORT:Sere De Rivieres System Architecture in France