Aircraft cavern, a

calque In linguistics, a calque () or loan translation is a word or phrase borrowed from another language by literal word-for-word or root-for-root translation. When used as a verb, "to calque" means to borrow a word or phrase from another language ...

of the

German German(s) may refer to: * Germany (of or related to) **Germania (historical use) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizens of Germany, see also German nationality law **Ge ...

word ''Flugzeugkaverne'', is an

underground hangar An underground hangar is a type of hangar for military aircraft, usually dug into the side of a mountain for protection. It is bigger and more protected than a hardened aircraft shelter (HAS). An underground hangar complex may include tunnels con ...

amongst others used by the

Swiss Air Force The Swiss Air Force (german: Schweizer Luftwaffe; french: Forces aériennes suisses; it, Forze aeree svizzere; rm, Aviatica militara svizra) is the air component of the Swiss Armed Forces, established on 31 July 1914 as a part of the army an ...

Historical

During

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

, the neutral

Swiss Swiss may refer to: * the adjectival form of Switzerland *Swiss people Places * Swiss, Missouri *Swiss, North Carolina * Swiss, West Virginia *Swiss, Wisconsin Other uses * Swiss-system tournament, in various games and sports * Swiss Internation ...

military airfields were for the first time equipped with simple arched concrete U-43 type shelters to protect the aircraft parked underneath. After

, starting in 1947, these open objects became even better protected with steel doors, thus creating the U-68 type shelter. Shortly after World War II and the beginning of the

Cold War The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term '' cold war'' is used because t ...

with the possible escalation between the nuclear superpowers of the Eastern and Western blocks, the

began to develop concepts for defending their neutrality in the case of a conflict. In the 1940s, the Swiss army had already built so-called ''retablierstollen'' (re-equipping caves) at some airfields. These ''retablierstollen'' consisted of 100m long straight tunnels excavated in the rock, making it possible to store and eventually re-arm small Swiss fighter aircraft such as the then used

Messerschmitt Bf 109 The Messerschmitt Bf 109 is a German World War II fighter aircraft that was, along with the Focke-Wulf Fw 190, the backbone of the Luftwaffe's fighter force. The Bf 109 first saw operational service in 1937 during the Spanish Civil War an ...

and the Morane-Saulnier M.S.406. The dimensions of these tunnels are comparable to an

autobahn The (; German plural ) is the federal controlled-access highway system in Germany. The official German term is (abbreviated ''BAB''), which translates as 'federal motorway'. The literal meaning of the word is 'Federal Auto(mobile) Track' ...

tunnel. The airfields chosen were

Alpnach Alpnach is a village in the canton of Obwalden in Switzerland. It comprises the villages of Alpnach Dorf, Alpnachstad and Schoried. History Alpnach is first mentioned about 870 as ''Alpenacho''. Geography Alpnach has an area, , of . Of this are ...

Buochs Buochs is a municipality in the canton of Nidwalden in Switzerland. History Buochs is first mentioned in 1124 as ''Boches''. In 1184, it was mentioned as ''Buoches'', then in 1210 as ''Buches'', and in 1229 as ''Buchs''. Geography Buochs has a ...

Meiringen Meiringen () is a municipality in the Interlaken-Oberhasli administrative district in the canton of Bern in Switzerland. Besides the village of Meiringen, the municipality includes the settlements of Balm, Brünigen, Eisenbolgen, Hausen, Prasti, ...

, St.Stephan and

Saanen Saanen (french: Gessenay; Highest Alemannic: ''Saanä'') is a municipality in the canton of Bern in Switzerland. It is the capital of the Obersimmental-Saanen administrative district. History The village was first mentioned in 1228 as ''Giss ...

, all located in the Alps with a lot of cover in the vicinity of the runway so that the aircraft could be out of sight within minutes after touchdown. In the early 1950s, the first large-scale excavations in rock took place, creating more space in the existing caves. The expanded space created by these excavations was now used to service the aircraft and to execute some minor repairs. The first large-scale constructions inside the caves were at the airfields of

Ambrì Ambrì is a Swiss village in the municipality of Quinto, Leventina District, Canton of Ticino. Geography Ambrì is located in the Leventina Valley, upon the southwestern shore of Ticino river and below the Lepontine Alps, next to the neighbo ...

, Alpnach, Buochs, Meiringen,

Raron Raron (french: Rarogne) is a municipality in the district of Raron in the canton of Valais in Switzerland. History Raron is first mentioned around 1101–1200 as ''Rarogni''. In 1146 it was mentioned as ''Rarun''. A settlement on the Heidnis ...

and Turtmann, starting operations from 1951 to 1954. As the Swiss air force modernized and changed its aircraft during the 1960s, the excavations, now called ''cavernes'', were further modernized and extended. Underground

command Command may refer to: Computing * Command (computing), a statement in a computer language * COMMAND.COM, the default operating system shell and command-line interpreter for DOS * Command key, a modifier key on Apple Macintosh computer keyboards * ...

and

communication Communication (from la, communicare, meaning "to share" or "to be in relation with") is usually defined as the transmission of information. The term may also refer to the message communicated through such transmissions or the field of inqui ...

posts were constructed together with

ammunition Ammunition (informally ammo) is the material fired, scattered, dropped, or detonated from any weapon or weapon system. Ammunition is both expendable weapons (e.g., bombs, missiles, grenades, land mines) and the component parts of other we ...

and

fuel A fuel is any material that can be made to react with other substances so that it releases energy as thermal energy or to be used for work. The concept was originally applied solely to those materials capable of releasing chemical energy b ...

storage facilities, generator and technical rooms to keep the facility running, as well as personnel quarters. The ''cavernes'' have been used to shelter and service the following aircraft types: * de Havilland DH 100 Vampire * de Havilland DH 112 Venom * Hawker Hunter F Mk 58 * Dassault Mirage IIIS / RS * Northrop F-5E Tiger II * McDonnell Douglas F/A-18C Hornet

BAe Hawk The BAE Systems Hawk is a British single-engine, jet-powered advanced trainer aircraft. It was first flown at Dunsfold, Surrey, in 1974 as the Hawker Siddeley Hawk, and subsequently produced by its successor companies, British Aerospace and B ...

aircraft and

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helicopters have only temporarily been stored in ''cavernes'' after being withdrawn from service and then sold to third parties.

Design and construction

A Swiss cavern has space to hold 22 F-5 Tiger aircraft. The outside door usually consists of

composite material A composite material (also called a composition material or shortened to composite, which is the common name) is a material which is produced from two or more constituent materials. These constituent materials have notably dissimilar chemical or ...

, steel with a wooden core. The door is defended by personnel in a hardened bunker covering it with machineguns, making the outside door small arms and hand grenade proof. Past the door is an S-shaped tunnel making it nearly impossible to fire on the main blast doors. The blast doors are made of concrete reinforced steel and as long as they are closed, the aircraft parking area remains fully

CBRN Chemical, biological, radiological and nuclear defence (CBRN defence) are protective measures taken in situations in which chemical, biological, radiological or nuclear warfare (including terrorism) hazards may be present. CBRN defence consi ...

protected. There are two or more tunnels. The first tunnel provides space for eleven aircraft and is equipped to handle major overhauls such as engine replacements. The aircraft are moved by lifting them by cranes. Once they are on the crane, they can be moved through the whole length of the tunnel. There is a linking tunnel to the weapon storage area (WSA) which is extra protected by a sealed door. In case of fire the weapon storage may be filled with inert Halon gas to prevent fire and explosions. The WSA not only holds the munitions needed to re-arm the aircraft (missiles and cannon shells) but also the small arms ammunition for all military working in the caverne. On the opposite side of the WSA is the command facility holding the workshops to service all aircraft systems, the communications cell, briefing room, kitchen, food & water storage, mess, personnel quarters and no-break generators to maintain electrical power under all circumstances. The command facility is also protected by hermetically sealed doors when working under CBRN conditions. Next to the command tunnel is another tunnel with the same dimensions as the first one. This one is also capable of holding eleven aircraft. Fuel storage is located behind all tunnels allowing the cavern to sustain 22 aircraft for about 10 days without re-supplying of electricity, fuel, ammunition etc. from the outside world. 5949 - Meiringen viewed from the Rothorn - Meiringen Air Force Base

5949 - Meiringen viewed from the Rothorn - Meiringen Air Force Base

Operational use

The Swiss air force operates from

Alpnach Air Base The Air Base Alpnach (International Civil Aviation Organization, ICAO code LSMA) is a Swiss Air Force airfield near the town Alpnach in Canton of Obwalden in Switzerland. It has a concrete runway with a length of and a width of , as well as seve ...

, Dübendorf Air Base, Militärflugplatz Emmen, Meiringen air base,

Locarno Airport Locarno Airport, german: Flugplatz Locarno, french: Aéroport de Locarno , mil ICAO code LSMO, also known as Locarno-Magadino Airport, is an airport located near the city of Locarno, Ticino, Switzerland. It is a mixed civilian and military air ...

, Payerne Air Base and

Sion Airport Sion Airport, german: Flughafen Sitten, it, Aeroporto di Sion, rm, Eroport da Sion (Military: LSMS) is the airport of the city of Sion, Switzerland and is located 2.5 km southwest of Sion city in the Rhone Valley. The airport opened i ...

. Meiringen is the only airfield with fully operational cavernes. The caverne at Meiringen was extended and refurbished for about 120 million

Swiss Francs The Swiss franc is the currency and legal tender of Switzerland and Liechtenstein. It is also legal tender in the Italian exclave of Campione d'Italia which is surrounded by Swiss territory. The Swiss National Bank (SNB) issues banknotes and the f ...

to comply to the needs of the current Swiss airforce F/A-18 fighters. Because of the weight of these aircraft hanging them in overhead

cranes Crane or cranes may refer to: Common meanings * Crane (bird), a large, long-necked bird * Crane (machine), industrial machinery for lifting ** Crane (rail), a crane suited for use on railroads People and fictional characters * Crane (surname ...

would be enormously expensive so that was not considered a viable option. Instead an extra tunnel had to be built. The tunnels are connected by some linking tunnels and extra dispersals were added on the opposite walls of each tunnel making it possible to operate 22 F/A-18s. The aircraft are able to roll in and out at the same time without the need of moving parked aircraft. A linking tunnel constructed directly before the main blast doors makes it possible to refuel and rearm an aircraft immediately after its mission without opening the main blast doors. A very important issue when a unit is working under CBRN conditions. The Meiringen caverne ammo storage has an extra tunnel to the outside. The former cavernes at Alpnach,

and Turtmann have been deactivated and closed. The caverne at

Buochs Airport The Buochs Airport, french: Aéroport de Buochs, it, Aeroporto di Buochs ( ICAO code LSZC Mil: LSMU) is a regional airport in the town of Buochs in the Canton of Nidwalden in Switzerland. It has a concrete runway with a length of 2000 meters and ...

has been mothballed but it is estimated that the facility could be reactivated to operate F-5's within two months.

Origin

Originally, the plan for the aircraft cavern started its life as a design for "cavern airfields". High costs and technical difficulties prevented these from realization. The idea of using roads as runways, known as highway strips, was later part of the design demands for the Swiss motorway network.FLUGPLATZKOMMANDO MEIRINGEN
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Other countries

Other countries that have aircraft shelters built inside mountains on their territory include

Albania Albania ( ; sq, Shqipëri or ), or , also or . officially the Republic of Albania ( sq, Republika e Shqipërisë), is a country in Southeastern Europe. It is located on the Adriatic and Ionian Seas within the Mediterranean Sea and share ...

Bosnia and Herzegovina Bosnia and Herzegovina ( sh, / , ), abbreviated BiH () or B&H, sometimes called Bosnia–Herzegovina and often known informally as Bosnia, is a country at the crossroads of south and southeast Europe, located in the Balkans. Bosnia and ...

Croatia , image_flag = Flag of Croatia.svg , image_coat = Coat of arms of Croatia.svg , anthem = " Lijepa naša domovino"("Our Beautiful Homeland") , image_map = , map_caption = , capi ...

, the

People's Republic of China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

Serbia Serbia (, ; Serbian: , , ), officially the Republic of Serbia ( Serbian: , , ), is a landlocked country in Southeastern and Central Europe, situated at the crossroads of the Pannonian Basin and the Balkans. It shares land borders with Hu ...

Montenegro ) , image_map = Europe-Montenegro.svg , map_caption = , image_map2 = , capital = Podgorica , coordinates = , largest_city = capital , official_languages = ...

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of ...

North Korea North Korea, officially the Democratic People's Republic of Korea (DPRK), is a country in East Asia. It constitutes the northern half of the Korean Peninsula and shares borders with China and Russia to the north, at the Yalu (Amnok) and T ...

, and

Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic countries, Nordic c ...

References

Sources and references

* Aeronautica / Flugwehr - und - Technik/ mag.1969. * Brochure 2010 Militärische Denkmäler im Bereich Luftwaffe. * Jubilee book 50 Jahre Flugplatz Meiringen * www.zone-interdite.net/ * Uno Zero Zero – Ein Jahrhundert Schweizer Luftwaffe. Aeropublications, Teufen/ZH 2013, * Book 25 Jahre Fliegerbrigade 32 . Fl Br32 1990.