View source for Coupure

{{Short description|Structural feature}}
{{For|the prehistoric biological event|Grande Coupure}}
{{distinguish|Flood gate}}
[[File:Diefdijkcoupure.jpg|300px|thumb|right|A coupure where the [[A2 motorway (Netherlands)|A2 motorway]] crosses the Diefdijk ([[Hollandic Water Line]]) in the Netherlands.]]
[[File:Roodehaan - dijkcoupure en schotbalkhuisje.jpg|thumb|right|A coupure with a shed for storing the materials used to close the coupure in [[Het Hogeland]]]]

A '''coupure''' is a means of closing an opening in a wall, [[floodwall]] or [[levee]] (dike). The word comes from the [[French verb]] {{lang|fr|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]] structure.

==Military==
During a [[siege]], 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]].

This was a strategy used many times by defenders of fortifications, for example, by the Irish defenders during the [[Siege of Clonmel]] (April - May 1650).

It can also be a passage through a [[glacis]] to create a [[sally port]], so that the defenders can launch a [[sortie (siege warfare)|sortie]] against the attackers.

==Civil engineering==
When a [[road]] or [[railway]] crosses a floodwall or levee the road or railway can either be laid on a [[Grade (slope)|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]]s. More sophisticated means of closing a coupure consist of   wooden or metal beams or doors. Older coupures are usually brick 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]] 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.

<gallery>
Rheinperle_Deichscharte_s.jpg|A coupure
Rheinperle_Deichscharte_o.jpg|The opening
Rheinperle_Deichscharte_zu_s.jpg|With a floodwall installed
Rheinperle_Deichscharte_zu_o.jpg|The wall from above
</gallery>

==References==
Stephen Francis Wyley ''[https://www.angelfire.com/wy/svenskildbiter/madict.html A Dictionary of Military Architecture Fortification and Fieldworks from the Iron Age to the Eighteenth Century]'', Drawings by Steven Lowe

{{Fortifications}}

[[Category:Dikes]]
[[Category:Flood barriers]]
[[Category:Siege tactics]]
[[Category:Fortification (architectural elements)]]
[[Category:Dams]]


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