Bunker: Difference between revisions

In the [[First World War]] the [[belligerents]] built underground shelters, called [[Dugout (military)|dugouts]] in [[English language|English]], while the Germans used the term ''Bunker''.<ref>Harry Horstmann, ''Der Soldat: In Sprache und Tradition'' (2010), p. 153.</ref><ref>{{cite web |url=https://www.dwds.de/wb/Bunker |title=DWDS – Bunker |access-date=2016-11-16 |url-status=live |archive-url=https://web.archive.org/web/20161116103616/https://www.dwds.de/wb/Bunker |archive-date=16 November 2016}} Das Wortauskunftssystem zur deutschen Sprache in Geschichte und Gegenwart</ref> By the [[Second World War]] the term came to be used by the Germans to describe permanent structures both large ([[blockhouse]]s), and small ([[Pillbox (military)|pillboxpillboxe]]s), and bombproof shelters both above ground (as in ''[[Hochbunker]]'') and below ground (such as the ''[[Führerbunker]]'').<ref>"The German term Bunker was used to denote a type of shelter which was of permanent construction. It can be distinguished from the improvised type built in cellars or by reinforcing ordinary buildings. Bunkers were of two types: underground and tower" ({{cite book|author=Morale Division|year=1945|title=The effect of bombing on health and medical care in Germany| volume=65 |series=Reports: European war, United States Strategic Bombing Survey |edition=2 |publisher=United States War Department|page=189 (footnote "*")}})</ref>

{{see also|pillboxPillbox (military)}}

This type of bunker is a small concrete structure, partly dug into the ground, which is usually a part of a trench system. Such bunkers give the defending soldiers better protection than the open [[Trench (military)|trench]] and also include top protection against aerial attack. They also provide shelter against the weather. Some bunkers may have partially open tops to allow weapons to be discharged with the muzzle pointing upwards (e.g., mortars and anti-aircraft weapons).<ref name="Queen's">''[http://archives.queensu.ca/wwi/warfare.html An archival look at World War I] {{webarchive |url=https://web.archive.org/web/20081219002104/http://archives.queensu.ca/wwi/warfare.html |date=19 December 2008 }}'' from the [[Queen's University at Kingston|Queen's University]] Archives, Kingston, Ontario, Canada. Accessed 2008-02-10</ref>

Typical industrial bunkers include mining sites, food storage areas, dumps for materials, data storage, and sometimes living quarters. They were built mainly by nations like Germany during World War II to protect important industries from [[bombingBombardment|aerial bombardment]]. Industrial bunkers are also built for control rooms of dangerous activities, such as tests of rocket engines or explosive experiments. They are also built in order to perform dangerous experiments in them or to store radioactive or explosive goods. Such bunkers also exist on non-military facilities.

When a house is purpose-built with a bunker, the normal location is a reinforced below-ground bathroom with large cabinets.{{Citation needed|date=March 2011}} One common design approach uses [[fibre-reinforced plastic]] shells. Compressive protection may be provided by inexpensive earth arching.{{Citation needed|date=March 2011}} The overburden is designed to shield from radiation.{{Citation needed|date=March 2011}} To prevent the shelter from floating to the surface in high groundwater, some designs have a skirt held- down with the overburden.<ref name=Kearny>{{cite book |last=Kearny |first=Cresson H |url=http://www.oism.org/nwss/ |access-date=2008-06-19 |title=Nuclear War Survival Skills |year=1987 |isbn=0-942487-01-X |publisher=Oak Ridge National Laboratory }} '''NOTE''': Kearny recommends stockpiling materials for a blast or [[fallout shelter]] and constructing it only if war appears very likely.</ref> It may also serve the purpose of a [[safe room]].{{Citation needed|date=March 2011}}

Munitions storage bunkers are designed to securely store [[explosive]] [[Shell (projectile)|ordnance]], and contain any internal explosions. The most common configuration for [[high explosives]] storage is the [[igloo]] shaped bunker.{{Citation needed|date=February 2019}} They are often built into a hillside in order to provide additional containment mass.

A specialized version of the munitions bunker called a [[Gravel Gertie]] is designed to contain [[radioactive]] debris from an explosive accident while assembling or disassembling [[nuclear warhead]]s. They are installed at all facilities in the United States and United Kingdom which do warhead assembly and disassembly, the largest being the [[Pantex]] plant in [[Amarillo, Texas]], which has 12 Gravel Gerties.<ref>{{CitationCite web needed|date=February5 2019March 2022|title=Bunker: What is it, types and all you need to know |url=http://www.news9live.com/knowledge/bunker-what-is-it-types-and-all-you-need-to-know-157289 |access-date=4 September 2023|website=News9live |language=en-US}}</ref>

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File:Objekt 17 5001 toegangsdeur 02.JPG|Object 17/5001 Prenden, Germany

The basic plan is to provide a structure that is very strong in [[compression (physical)|physical compression]]. The most common purpose-built structure is a buried, steel [[reinforced concrete]] [[Vault (architecture)|vault]] or [[arch]]. Most expedient blast shelters are civil engineering structures that contain large, buried tubes or pipes such as sewage or rapid transit tunnels. Improvised purpose-built blast shelters normally use earthen arches or vaults. To form these, a narrow, {{convert|1|-|2|m|ft|round=0.5|adj=on}}, flexible tent of thin wood is placed in a deep trench, and then covered with cloth or plastic, and then covered with {{convert|1|-|2|m|ft|round=0.5|abbr=in}} of tamped earth.

Nuclear bunkers must also cope with the underpressure that lasts for several seconds after the [[shock wave]] passes, and block [[radiation]]. Usually, these features are easy to provide. The overburden ([[soil]]) and structure provide substantial radiation shielding, and the negative pressure is usually only {{frac|1|3}} of the overpressure.<ref>The Survival Option: Guide to Living Through Nuclear War, Ivan Tyrrell. Publisher: Jonathan Cape Ltd; 1st Edition (1982), Language: English, Hardcover: 256 pages, {{ISBN|0224020595}}</ref>

The doors must be at least as strong as the walls. The usual design is now starting to incorporate [[Vault door|vault doors]]. To reduce the weight, the door is normally constructed of steel, with a fitted steel lintel and frame. Very thick wood also serves, and is more resistant to heat because it chars rather than melts.{{Citation needed|date=December 2008}} If the door is on the surface and will be exposed to the blast wave, the edge of the door is normally counter-sunk in the frame so that the blast wave or a reflection cannot lift the edge. A bunker should have two doors. Door shafts may double as ventilation shafts to reduce digging.

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