
A coupure is a means of closing an opening in a wall,
floodwall
A flood wall (or floodwall) is a primarily vertical artificial barrier designed to temporarily contain the waters of a river or other waterway which may rise to unusual levels during seasonal or extreme weather events. Flood walls are mainly u ...
or
levee
A levee (), dike (American English), dyke (Commonwealth English), embankment, floodbank, or stop bank is a structure that is usually earthen and that often runs parallel to the course of a river in its floodplain or along low-lying coastl ...
(dike). The word comes from the
French verb ''couper'' which means to cut.
In historic times a coupure was a location where a breach in the city walls or the walls of a fortress was closed. In more modern times a coupure is a way of allowing traffic to pass a
flood protection
Flood control methods are used to reduce or prevent the detrimental effects of flood waters."Flood Control", MSN Encarta, 2008 (see below: Further reading). Flood relief methods are used to reduce the effects of flood waters or high water leve ...
structure.
Military
During a
siege
A siege is a military blockade of a city, or fortress, with the intent of conquering by attrition, or a well-prepared assault. This derives from la, sedere, lit=to sit. Siege warfare is a form of constant, low-intensity conflict characterize ...
, a coupure is a ditch or an earthwork or wooden palisade built behind a breach made by the attacker's guns in the walls of a fortress or a city. Its purpose is to hinder and frustrate an attack made by the
forlorn hope
A forlorn hope is a band of soldiers or other combatants chosen to take the vanguard in a military operation, such as a suicidal assault through the kill zone of a defended position, or the first men to climb a scaling ladder against a defend ...
.
This was a strategy used many times by defenders of fortifications, for example, by the Irish defenders during the
Siege of Clonmel
The Siege of Clonmel, from 27 April to 18 May 1650, took place during the Cromwellian conquest of Ireland, when Clonmel in County Tipperary was besieged by 8,000 men from the New Model Army under Oliver Cromwell. The garrison of 1,500 c ...
(April - May 1650).
It can also be a passage through a
glacis
A glacis (; ) in military engineering is an artificial slope as part of a medieval castle or in early modern fortresses. They may be constructed of earth as a temporary structure or of stone in more permanent structure. More generally, a glaci ...
to create a
sally port
A sally port is a secure, controlled entry way to an enclosure, e.g., a fortification or prison. The entrance is usually protected by some means, such as a fixed wall on the outside, parallel to the door, which must be circumvented to enter an ...
, so that the defenders can launch a
sortie
A sortie (from the French word meaning ''exit'' or from Latin root ''surgere'' meaning to "rise up") is a deployment or dispatch of one military unit, be it an aircraft, ship, or troops, from a strongpoint. The term originated in siege warf ...
against the attackers.
Civil engineering
When a
road
A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation.
There are many types of ...
or
railway
Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in Track (rail transport), tracks. In contrast to road transport, where the ...
crosses a floodwall or levee the road or railway can either be laid on a
grade or through a cut in the floodwall or levee. In case of expected flooding the cut can temporarily be closed. This type of coupure is also known as ''vehicle gate'', ''floodwall gate'' or similar names. The closure can be accomplished by various means.
The most basic means of closing a coupure is with soil or
sandbag
A sandbag or dirtbag is a bag or sack made of hessian (burlap), polypropylene or other sturdy materials that is filled with sand or soil and used for such purposes as flood control, military fortification in trenches and bunkers, shielding gl ...
s. More sophisticated means of closing a coupure consist of wooden or metal beams or doors. Older coupures are usually brick built structures with provisions for placing two stacks of beams between them. Between the stacks of beams, which form two walls,
horse manure or other animal
faeces
Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relati ...
mixed with straw is dumped and compacted. This type of material swells when wet, thus providing additional waterproofing. Modern coupures can consist of only one wall and can be made watertight with the help of rubber flaps or other materials.
Rheinperle_Deichscharte_s.jpg, coupure
Rheinperle_Deichscharte_o.jpg, the opening
Rheinperle_Deichscharte_zu_s.jpg, floodwall installed
Rheinperle_Deichscharte_zu_o.jpg, wall from above
References
Stephen Francis Wyley
A Dictionary of Military Architecture Fortification and Fieldworks from the Iron Age to the Eighteenth Century', Drawings by Steven Lowe
Dikes
Flood barriers
Siege tactics
Fortification (architectural elements)
Dams
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