Air raid shelter


Air raid shelters are structures for the protection of non-combatants as well as combatants against enemy attacks from the air. They are similar to bunkers in many regards, although they are not designed to defend against ground attack.

History

Pre-WWII

Prior to World War II, in 1924, an Air Raid Precautions Committee was set up in the United Kingdom. For years, little progress was made with shelters because of the apparently irreconcilable conflict between the need to send the public underground for shelter and the need to keep them above ground for protection against gas attacks. In 1935, every city in the country was given a document to prepare air raid shelters. In February 1936 the Home Secretary appointed a technical Committee on Structural Precautions against Air Attack.
By November 1937, there had only been slow progress, because of a serious lack of data on which to base any design recommendations and the Committee proposed that the Home Office should have its own department for research into structural precautions, rather than relying on research work done by the Bombing Test Committee to support the development of bomb design and strategy. This proposal was eventually implemented in January 1939.
During the Munich crisis, local authorities dug trenches to provide shelter. After the crisis, the British Government decided to make these a permanent feature, with a standard design of precast concrete trench lining. Unfortunately these turned out to perform very poorly. They also decided to issue free to poorer households the Anderson shelter, and to provide steel props to create shelters in suitable basements.

World War II

During World War II, many types of structures were used as air raid shelters, such as cellars, Hochbunker, basements, and underpasses. Bombing raids during World War I led the UK to build 80 specially adapted London Underground stations as shelters. However, during World War II, the government initially ruled out using these as shelters. After Londoners flooded into underground stations during The Blitz, the government reversed its policy. The UK began building street communal shelters as air raid shelters in 1940. Anderson shelters, designed in 1938 and built to hold up to six people, were in common use in the UK. Indoor shelters known as [|Morrison] shelters were introduced as well.
Air raid shelters are still in use to some extent in various nations such as Spain, Switzerland, Israel, Singapore and Taiwan.
Air raid shelters were built to serve as protection against enemy air raids. Existing edifices designed for other functions, such as underground stations, tunnels, cellars in houses or basements in larger establishments and railway arches, above ground, were suitable for safeguarding people during air raids. A commonly used home shelter known as the Anderson shelter would be built in a garden and equipped with beds as a refuge from air raids.

Types

Trenches

Air raid trenches are forms of trenches that began to be constructed for defensive purposes around the world after the creation of bomber aircraft. They were especially prevalent during World War II, but have also been used in other wars.

Cellars

Cellars have always been much more important in Continental Europe than in the United Kingdom and especially in Germany almost all houses and apartment blocks have been and still are built with cellars. Air-raid precautions during World War II in Germany could be much more readily implemented by the authorities than was possible in the UK. All that was necessary was to ascertain that cellars were being prepared to accommodate all the residents of a building; that all the cellar hatch and window protections were in place; that access to the cellars was safe in the event of an air raid; that once inside, the occupants were secure for any incidents other than direct hits during the air raid and that means of escape was available.
The inadequacies of cellars and basements became apparent in the firestorms during the incendiary attacks on the larger German inner cities, especially Hamburg and Dresden. When burning buildings and apartment blocks above them collapsed in the raging winds, the occupants often became trapped in these basement shelters, which had also become overcrowded after the arrival of inhabitants from other buildings rendered unsafe in earlier attacks. Some occupants perished from heat stroke or carbon monoxide poisoning.

Hochbunker

Hochbunker, were a type of construction designed to relieve the pressure Nazi German authorities were facing to accommodate additional numbers of the population in high-density housing areas, as well as pedestrians on the streets during air raids. In contrast to other shelters, these buildings were considered completely bomb-proof. They had the advantage of being built upward, which was much cheaper than downward excavation. Hochbunker usually consisted of large concrete blocks above ground with walls between thick and with huge lintels above doorways and openings. They often had a constant interior temperature of, which made them perfectly suitable for laboratories, both during and after the war. They were used to protect people, administrative centres, important archives and works of art.
Their structures took many forms: usually consisting of square blocks or of low, long rectangular or triangular shapes; straight towers of a square plan rising to great heights, or round tower-like edifices, even pyramidal constructions. Some of the circular towers contained helical floors that gradually curved their way upward within the circular walls. Many of these structures may still be seen. They have been converted into offices, storage space; some have even been adapted for hotels, hospitals and schools, as well as many other peacetime purposes. In Schöneberg, a block of flats was built over the Pallasstrasse air-raid shelter after World War II. During the Cold War, NATO used the shelter for food storage.
The cost of demolishing these edifices after the war would have been enormous, as the attempts at breaking up one of the six so-called Flak towers of Vienna proved. The attempted demolition caused no more than a crack in one of the walls of the tower, after which efforts were abandoned. Only the Zoo Tower in Berlin was successfully demolished.
One particular variant of the Hochbunker was the Winkelturm, named after its designer, Leo Winkel of Duisburg. Winkel patented his design in 1934, and from 1936 onward, Germany built 98 Winkeltürme of five different types. The towers had a conical shape with walls that curved downward to a reinforced base. The dimensions of the towers varied. Diameters ranged between and the height between. The walls of the towers had a minimum thickness for reinforced concrete of and for ordinary concrete. The towers were able to shelter between 164 and 500 people, depending on the type. The intent with the Winkeltürme and the other Hochbunker was to protect workers in rail yards and industrial areas. Because of their shape, the towers became known colloquially as "cigar stubs" or "sugar beets".
The theory behind the Winkeltürme was that the curved walls would deflect any bomb hitting the tower, directing it down towards the base. The towers had a small footprint, which was probably a greater protection. A US bomb did hit one tower in Bremen in October 1944; the bomb exploded through the roof, killing five people inside.

Israel

Miklat Is a type of air raid shelters found in Israel inside homes, near residential areas and in other places across the country.
These places are also called Merkhav Mugan. They are reinforced security rooms required in all new buildings by Israeli law.

Types

  • Miklat Tzibury –, a partly underground facility, installed in residential areas. They are commonly used for community needs. Maintained by the local governance and Home Front. They are located in streets and near public facilities.
  • Miklat BeBayit Meshutaf – in a condominium, a facility built into a building which has been declared as a condominium it includes all the facilities that a public shelter has, but is maintained by the building residents.
  • Merkhav Mugan Dirati – installed in residential apartments and private houses.
  • Merkhav Mugan Komati – common floor space in apartment buildings in which there is no Merkhav Mugan Dirati in every apartment and in other multi-storey buildings.
  • Merkhav Mugan Mosadi – installed in every public structure.

    United Kingdom

Cellars

Cellars in the UK, were mainly included only in larger houses, and in houses built up to the period of World War I, after which detached and semi-detached properties were constructed without cellars, usually to avoid the higher building costs entailed. Since house building had increased vastly between the wars, the lack of cellars in more recent housing became a major problem in the Air Raid Precautions programmes in the UK during World War II.
Alternatives had to be found speedily once it became clear that Germany was contemplating air raids as a means of demoralising the population and disrupting supply lines in the UK. Initial recommendations were that householders should shelter under the stairs. Later, authorities supplied materials to households to construct communal street shelters and Morrison and Anderson shelters.

Basements

s also became available for the use of air raid shelters. Basements under factory premises, schools, hospitals, department stores and other businesses were utilised. However, these ad hoc shelters could bring additional dangers, as heavy machinery and materials or water storage facilities above the shelter, and insufficient support structures threatened to cause the collapse of basements.
When the Wilkinson's Lemonade factory in North Shields received a direct hit on Saturday, 3 May 1941 during a German attack on the north-east coast of England, 107 occupants lost their lives when heavy machinery fell through the ceiling of the basement in which they were sheltering.