Air raid shelters , also known as bomb 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 (but have been successfully used as defensive structures in such situations). [ quote needed ]
Prior to World War II , in May 1924, an Air Raid Precautions Committee was set up in the United Kingdom . For years, little progress has been made with shelters because of the irreconcilable conflict between the need for the public and the protection of the environment. In February 1936 The Secretary appointed a Technical Committee on Structural Precautions against Air Attack.
By November 1937, there had been slow progress, because of a serious lack of data on which to design recommendations, and the Committee proposed that the Home Office should have its own department for research Work done by the Bombing Test Committee to support the development of bomb design and strategy. This proposal was adopted in January 1939. 
During the Munich crisis , local authorities dug trenches to provide shelter. After the crisis, the British Government has decided to make a permanent feature, with a standard design of precast concrete trench lining. Unfortunately these people are going out to perform very poorly. They also decided to provide the shelter , and to provide them with adequate shelter . 
In World War II
Air raid shelters were built specifically to protect against enemy air raids . HOWEVER, pre-existing buildings designed for other functions, Such As underground stations (gold tube subway 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 shelter shelter would be built in a sheltered air raids. 
Cellars have always been much more important in Continental Europe than in the United Kingdom, and especially in Germany and have been built with cellars. For this reason, air-raid precautions during World War II in Germany could be much more implemented in the UK. All that has been made to ascertain that the cells have been prepared to accommodate the residents of a building; that all 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 other incident; and that means of escape in the case of a real emergency were easily available.
However, the inadequacies of cellars and basements became apparent in the firestorms during the incendiary attacks on the German interior, especially Hamburg and Dresden . The occupants often became trapped in these basement shelters, which had also become overcrowded after the arrival of unsaturated buildings. earlier attacks. Some occupants perished from heat stroke or carbon monoxide poisoning.
Hochbunker (s) , or “high-rise” gold bunkers ( blockhouses ), were a peculiarly German type of construction, designed to relieve the pressure. as pedestrians on the streets during air raids. In contrast to other shelters, these buildings were considered completely bomb-proof. They also had the advantage of being built upward, which was much cheaper than downward excavation. There were no equivalents of hochbunkers in the cities of the Allied countries.
Hochbunkers usually consists of large concrete blocks above ground with 1 m and 1.5 m thick and with huge lintels above doorways and openings. They often had a constant interior temperature of 7 to 10 ° C, which made them perfectly suitable for laboratories, both during and after the war. They are designated to protect people, administrative centers, important archives, and works of art.
Their structures took many forms: usually consisting of square blocks, or low, long rectangular or triangular shapes; straight towers of a square plan rising to great heights, or round tower-like buildings, even pyramidal constructions. Some of the circular towers are located in the walls. Many of these structures can still be seen today. They have been converted into offices, storage space, and hospitals, and have many other peacetime purposes. In Schöneberg , a block of flats was built on 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 to break up one of the six so-called Flak towers of Vienna proved. These towers had anti-aircraft batteries on platforms on their roofs. The attempt to demolish 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 Winkeltürme , named after its designer, Leo Winkel of Duisburg. Winkel patented his design in 1934, and from 1936 on, 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 ranked between 8.4 and 10 meters and the height between 20 and 25 meters. The walls of the towers had a minimum thickness of 0.8 m and 1.5 m for ordinary concrete. The towers were able to shelter between 164 and 500 people, depending on the type. The intention with the Winkeltürme and the other hochbunkerswas to protect workers in rail yards and industrial areas. Because of their shape, the towers 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 bomb did hit the tower in Bremen in October 1944; the bomb exploded through the roof, killing five people inside.
Cellars in the UK, however, have been incorporated into the World War I period , after which they have typically been constructed without barriers. Since the construction of the house has been vastly increased between the wars, the lack of air raid Precautions (ARP) programs 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 demoralizing the population and disrupting supply lines in the UK. Initial recommendations were made under the stairs. Later, Morrison and Anderson shelters .
It has also become available for air raid shelters. Basements under factory premises, schools, hospitals, department stores and other businesses were used. However, these ad hoc shelters could bring additional hazards, as well as insufficient support structures, to the collapse of basements.
When 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 in which they were sheltering .  
Railway arches and subways (underpasses)
Railway arches and subways were also used in the UK for air raid protection at all times during World War II .
Railway arches were deep, curved structures of brick or concrete, set in the vertical sidewalls of railway lines, that had been intended for commercial depots, etc. The arches Were covered usually with wooden or brick screen – gold curtain walls , THUS giving a considerable amount of protection contre air raids – Provided, of course, That railway lines Were not the prime target of the attack at the Particular time and so being white more likely to suffer from direct hits. Each arch could accommodate anything from 60 to 150 or so persons. However, there may be less room for occupants than other occupants. Subways were actual thoroughfaresalso in the shape of the arches, normally allowing passage underneath railway lines.  
London Underground tube stations
Prior to the Beginning of the war, shelter policy HAD beens Determined by Sir John Anderson , Lord Privy Seal and Then, on the declaration of war, Home Secretary and Minister of Home Security. Anderson announced the policy to Parliament on 20 April 1939,  based on a report from a committee chaired by Lord Hailey. This reaffirmed a policy of dispersal and eschewed the use of deep shelters, including the use of tube stations and underground tunnelsas public shelters. Reasons of being unable to live in the city of New York feel safer there than outside the stations.
None of these concerns had been encountered during the bombing raids of the First World War, when Anderson, then chairman of the Air Raid Precautions Committee of Imperial Defense and have ruled out the tube station shelter option in any future conflict.
Following the intensive bombing of London on September 7, 1940 and the overnight raids of 7/8 September, the government stood firm. On 19 September, William Mabane, the Secretary-General of the Ministry of Home Security, urged the public not to leave their Anderson shelterspublic shelters, saying it deprived others of shelter. “We’re going to improve the amenities in existing shelters,” he promised. “We are looking for better lighting and better accommodation for better sanitary arrangements.” The Ministries of Home Security and Transportation Jointly issued an “urgent appeal”, telling the audience “to refrain from using stations as air-raid shelters except in the case of urgent necessity”.
However, the government was then confronted with an episode of mass disobedience. Over the night of 19/20 September, Londoners were taking matters in their own hands. They had flocked to the Tubes for shelter. At some stations, they began to arrive as early as 4pm, with bedding and bags of food to sustain them for the night. By the time the evening rush hour was in progress, they had already staked their “pitches” on the platforms. Police did not intervene. Some station managers, on their own initiatives, provided additional toilet facilities. Transport Minister John Reith, and the chairman of London Transport, Lord Ashfield, inspected Holborn station to see conditions for themselves.
The Government then realized that they could not contain this popular revolt. On September 21, it abruptly changed policy, removing its objections to the use of tube stations. In what it is called, “deep shelter extension policy”, it is a step to close the short section of the Holborn to the Aldwych and turn the tunnel into an air raid shelter. The Aldwych branch of the Piccadilly linewere closed to trains, tracks were concreted over, and reinforced floodgates were installed that could be closed instantly. Seventy-nine stations were fitted with bunks for 22,000 people, and equipped with chemical toilets. 124 canteens opened in all parts of the tube system. Shelter marshals have been appointed to assist in the flooding of tunnels.
Businesses (for example, Plessey Ltd ) were operated by the United States and the United States.
However, tube stations and tunnels were still vulnerable to a
On 16 September 1940, at Marble Arch tube station , 20 people were killed.
On October 14th, 1940, a bomb penetrated the road and tunnel at Balham tube station , blew up the water hands and sewage pipes, and killed 68 people.
At Bank station, a direct hit caused a crash of 120 ft by 100 ft on 11 January 1941, the road collapsed and killed 56 occupants.
However, the highest death toll was caused during an accident at Bethnal Green tube station on March 8, 1943, when 1,500 people entered the station. The crowd suddenly panicked on the sound of an unfamiliar explosion (in fact this was a top-secret anti-aircraft rocket). Someone stumbled on the stairs, and the crowd pushing on, were falling on top of one another, and 173 people were crushed to death in the disaster.
The extent of the disasters and the number of people was not disclosed until after the war.
Nevertheless, the London Underground system is one of the safest ways of protecting a high-density capital. An estimated 170,000 people sheltered in the tunnels and stations during World War II. Although not so much in the capital, it would have been much less secure, but it would have been less secure. 
Artists and photographers such as Henry Moore and Bill Brandt  were employed as war artists in London’s second world war.
Many other types of tunnels were adapted to protect the civilian population, and the military and administrative establishment in the UK during the war. Some had been built many years ago
The Victoria tunnels at Newcastle upon Tyne , for example, completed for 1842, and used for transporting the necklace to the river Tyne, had been closed in 1860 and remained so until 1939. 12 m deep in places, the tunnels , stretching in parts of Newcastle, were converted to air raids with a capacity for 9,000 people. Furthermore, tunnels linked to landing stages built on the Irwell River in Manchester at the end of the 19th century were also used as air-raid shelters.
The broad medieval labyrinth of beneath tunnels Dover Castle had been built originally from the defensive system of the approaches to England, extended over the centuries and further excavated and strengthened during World Wars I and II, until it was capable of accommodating large parts of the secret defense systems protecting the British Isles. On 26 May 1940 it became Vice Admiral Bertram Ramsay of ” Operation Dynamo “, from which the rescue and evacuation of up to 338,000 troops from France was directed.
In Stockport , six miles south of Manchester, four sets of underground tunnels for civilian use were dug into the red sandstone on which the town center stands. Preparation started in September 1938. (Stockport was not bombed until 11 October 1940.) The smallest of the tunnel shelters could accommodate 2,000 people and the largest 3,850 (later expanded to 6,500 people.) The largest of the Stockport Air Raid Shelters  are open to the public as part of the town’s museum service.
In southeast London, residents of the Chislehurst Caves beneath Chislehurst , a 22-mile-long (35 km) network of underground caves which have existed since the Middle Ages for the Minings of Chalk and Flint .
Street communal shelter
In the United Kingdom, it has been recognized that public shelters in open spaces, especially near streets, were urgently needed for pedestrians, drivers and passengers in passing vehicles, etc. The program of building street communal sheltersstarted in March 1940, the government supplying the materials, and being the moving force behind the scheme, and private builders executing the work under the supervision of surveyors. These shelters consisted of 14-inch brick walls and 1-foot-thick (0.30 m) reinforced concrete roofs, similarly to, but much larger than, the private shelters in backyards The communal shelters were usually divided into different sections and were divided into different sections. Sections were normally furnished with six bunks.
The construction work then went on rapidly, until the resources of concrete and bricks were suddenly depleted. Also, the performance of the early street shelters was a serious blow to public confidence. Their walls were shaken down by the earth shock or blast, and the concrete roofs then fell onto the occupying helpless, and this was there for all to see. At around the same time rumors of accidents started to circulate, such as on one occasion people being drowned due to a burst filling the shelter with water. Although much improved designs have been developed, the municipalities have been highly developed, and shortly afterwards have been encouraged to build their homes, or their houses, with materials being supplied by the government.
The Anderson shelter was designed in 1938 by William Paterson and Oscar Carl (Karl) Kerrison in response to a request from the Home Office. It was named after Sir John Anderson , then Lord Privy Seal with Special Responsibility for Preparing Air-raid, immediately prior to the outbreak of World War II, and it was time for the development of the shelter. After evaluation by Dr. David Anderson, Bertram Lawrence Hurst, and Sir Henry Jupp, of the Institution of Civil Engineers , the design was released for production.
Anderson shelters were designed to accommodate up to six people. The main principle of protection is based on curved and straight galvanized corrugated steel panels . Six curved panels were bolted together at the top, so they were one of the four main panels of the United States. A small drainage sumpwas often incorporated into the floor to collect rainwater seeping into the shelter. The shelters were 6 feet (1.8 m) high, 4.5 feet (1.4 m) wide, and 6.5 feet (2.0 m) long. They were buried 4 ft (1.2 m) deep in the soil and then covered with a minimum of 15 inches (38 cm) of soil above the roof. The earth banks could be planted with vegetables and flowers, which could be more appealing and more likely to be the subject of competition in the neighborhood. The internal fitting out of the shelter was left to the owner and was wide variations in comfort. 
Anderson shelters were paid less than £ 5 a week (equivalent to £ 280 in 2016, when adjusted for inflation ). Those with a higher income were charged £ 7 (£ 400 in 2016) for their shelter. One and a half million shelters of this type were distributed between February 1939 and the outbreak of war. During the war a further 2.1 million were erected.  Large numbers were built at John Summers & Sons ironworks at Shotton on Deeside with production peaking at 50,000 units per week. 
The Anderson shelters performed well under blast and ground shock, because they had good connectivity and ductility, which meant that they could absorb a great deal of energy through plastic deformation without falling apart. (This was in contrast to other trench shelters, which were inherently unstable when disturbed by the effects of an explosion – if the roof slab lifted, the walls fell into the However, when the pattern of all night alerts became established, it was realized that in winter Anderson shelters were cold damped in the ground and often flooded in wet weather, and so their occupancy factor would be poor. This led to the development of the indoorMorrison shelter . 
At the end of the war in Europe. Householders who would like to keep their payday loans.
Because of the large number made and their robustness, many Anderson shelters still survive. Many were dug up after the war and converted into storage for use in gardens and allotments . 
A near exact walk-thru replica of an Anderson Air Raid Shelter is displayed at the Tillamook Air Museum , Oregon , United States of America
The Morrison shelter , Officially termed table (Morrison) Indoor Shelter , Had a cage-like structure beneath it. It was designed by John Baker and named after Herbert Morrison , the Minister of Home Security at the time. It was the result of the realization that it was necessary to develop an effective type of indoor shelter. The shelters cam in assembly kits, to be bolted together inside the home. They were approximately 6 ft 6 in (2 m) long, 4 ft (1.2 m) wide and 2 ft 6 in (0.75 m) high, had a solid 1/8 in (3 mm) steel plate “table” top, welded wire mesh sides, and metal lath “mattress” – type floor. Altogether it had 359 parts and had 3 tools supplied with the pack.
The shelter was provided with less than £ 400 per year (equivalent to £ 23,000 in 2016).
When Head of the Engineering Department at Cambridge University , Sir John Baker’s Professor (latterly Baron Baker) presented an undergraduate lecture on the principles of design of the shelter, and an interesting introduction to his theory of plastic design and structures. follows:
It was impractical to produce a design for mass production that could have been a direct hit, and so it was a matter of selecting a suitable design that would save lives in many cases of blast damage to bombed houses. The examination of bombed buildings indicated in many instances, the following is one of the following: a blaze of blast by a nearby blast, and the floor of the first storey . The Morrison shelter is therefore designed to be withstand the upper floor of a typical two-storey house undergoing a partial collapse. The shelter has been designed to absorb this energy by plastic deformation, since it can absorb more energy than elastic deformation. Its design enabled the family to sleep under the shelter of night or during raids, and to use it as a dining table in the daytime, making it a practical item in the house. 
Half a million Morrison shelters had been distributed by the end of 1941, with a further 100,000 being added to 1943 to prepare the population for the German V-1 flying bomb (doodlebug) attacks.
In the examination of 44 severely damaged houses, 13 seriously injured, and 16 injured injured Morrison shelters; thus 120 out of 136 escaped from severely bomb-damaged houses without serious injury. Furthermore, it has been discovered that the fatalities have occurred in a house that have suffered a direct hit, and some of the severely injured were incorrectly sheltered within the houses. 
In July 1950 the Royal Commission on Awards to Inventors made an award of £ 3,000 (£ 94,000) to Baker for his design of the Morrison shelter. 
A shelter segment manufactured by the Stanton Ironworks, Ilkeston, Derbyshire. The shop producing spun-concrete lighting columns, which are manufactured, principally for the air ministry. Reinforced concrete proved an ideal material for air-raid shelters, being strong and resistant to shock with no deterioration with the passing of time. This type of segment has been designed and built for the first time and can be built from the pre-cast steel reinforced concrete segments. The segments were 20 inches wide; a pair of them formed an arch 7 feet high and transverse struts were provided to ensure rigidity. These have been introduced into longitudinal bearers which have been segmented by each segment. Each pair of segments has been bolted together to the apex of the arch and each segment has also been bolted to its neighbor, the joints being sealed with a bituminous compound. The use of these segments has not been possible. Partly buried in the ground, with a suitably screened entrance, this bolted shelter afforded safe protection against blast and splinters. 
Some air-raid shelters were constructed in residential building schemes in anticipation of the Second World War. There is a surviving example at St. Leonard’s Court in East Sheen , southwest London.
Military air-raid shelters included blast pens at airfields for the security of aircrews and aircraft maintenance away from the airbase staff hand buildings.
Few shelters could survive a direct bomb-hit. The German authorities claimed that hochbunkers were totally bomb-proof, but none were targeted for any of the 41 10-ton Grand Slamearthquake bombs dropped by the RAF by the end of World War II. Two of these bombs were dropped on the U-Bootbunkerwerft Valentine’s Day submarine pens near Bremen and these barely penetrated 4 to 7 m (13 to 23 ft) of reinforced concrete, bringing down the roof.
More recently, the penetration by laser-guided “smart bombs” of the Amiriyah shelter during the 1991 Gulf War showed how vulnerable even reinforced concrete shelters are to direct hits from bunker-buster bombs. However, the air-raid shelters are built to protect the civilian population. The most important dangers are the blast and shrapnel. It is unlikely that any military enemy would intentionally target a civilian shelter, even if it were carpet bombing a city. [ quote needed ]
Air raid shelters in modern times
Old air-raid shelters, such as the Anderson , can still be found in back gardens, in which they are commonly used as sheds, or (on the roof which is covered with earth) as vegetable patches. Some are left empty with debris.
Countries that have kept air-raid shelters intact and in ready condition include Switzerland , Spain and Finland .
Many Swiss houses and apartment blocks have structurally reinforced, underground basements, often with a concrete door around 40 cm (16 in) thick. In more modern, post-war times, these shelters are often used as storage, with the footprint of the built-in home. The basement shelters are built to more stringent building codes, as the ceiling should especially protect shelter-seeking people from the collapsing house. Although most Swiss houses provide their own shelters, they are not allowed to provide services.
Barcelona was severely bombed by Italian and German Air Forces during Spanish Civil War , particularly in 1937 and 1938. Underground tunnels were used as shelters at the same time as the population undertakes the building of bomb shelters under the coordination of a committee for civil defense ( Catalan: Defensa Passiva Junta ) providing planning and technical assistance. Hundreds of bomb shelters were built. Most of them are recorded, but only a few are well preserved. Among these stand out the Plaça del Diamant refuge 307 ( Refugi 307 ), today one of the Barcelona City History Museum heritage sites. 
Other cities include Madrid , Guadalajara , Alcalá de Henares , Santander , Jaén , Alcañiz , Alcoy , Valencia and Cartagena . During Spanish Civil War, Cartagena, an important naval base, was one of the main targets for aviation and its allieds. Cartagena suffered between 40 and 117 bombings (sources are mixed about the number of attacks). Most Condon Legionon November 25, 1936. The hugest anti-raid shelter in Cartagena, which could accommodate up to 5.500 persons, is since 2004 a museum site. 
The State of Israel required to access to air-raid shelters from 1951, and all new flats to Merkhav Mugan . All medical and educational facilities are prepared for CRBN attacks (as of 2010); some are built with closed-cycle air systems and are capable of being in addition to all include chemical air filtering systems. The public air-raid shelters are often employed as game rooms in peacetime so that the children will be comfortable to enter the world at a time of need, and will not be frightened.     
Finland has over 40,000 air-raid shelters which can house 3.8 million people (71% of the population). Private homes rarely have, but houses over 600 m 2 (6.500 sq ft) are obliged to build them.  Fire inspectors check the shelters every ten years and be ready for repair. The law requires that the inhabitants of the city should stay in the city for less than 72 hours. Half of the air-raid shelter has to be ready to use in two hours. The types of shelters are:
- K, a small shelter for a small apartment house.
- S1, a usual shelter for apartment house.
- S3, lightweight shelter in solid rock or heavyweight shelter of ferroconcrete.
- S6, large shelters in solid rock that must be able to withstand a 6 bar pressure wave.
All shelters must have:
- an electric and hand-operated air-conditioning system, which can protect from biological and chemical weapons and radioactive particles.
- a radiometer
- dry toilets
- a fixed-line interface
- a spare exit
- water tanks
- a first aid kit
Since 1998, Singapore has required all types of accommodation. The Singapore Civil Defense Force rationalizes building such shelters in high-rise buildings. 
- Air raid precautions
- Blast shelter
- Fallout shelter
- Underground living
- Merkhav Mugan
- Jump up^ Baker 1978, p. [ page needed ].
- Jump up^ Baker 1978, p. [ page needed ].
- Jump up^ “This what railway arches look like” . Urban75.org . Retrieved 2010-06-24 .
- ^ Jump up to:a b “Air Raid Shelters” . Archived from the original on 11 December 2011 . Retrieved 1 Aug 2014 .
- Jump up^ “Hochbunker” . 7grad.org . Retrieved 2010-06-24 .
- Jump up^ Berlin hochbunker, etc. ArchivedMay 5, 2004, at theWayback Machine. 2009-10-24.
- Jump up^ Ladd 2004, p. 393.
- Jump up^ “Wilkinson’s Lemonade Factory” . BBC News. 2003-04-21. Retrieved 2010-06-24 .
- Jump up^ “Account of raid on Wilkinson’s Lemonade factory” . North Shields 173 . Retrieved 17 January 2017 .
- Jump up^ “Railway arches” . Daveh.org.uk. Archived from the original on 2010-03-03 . Retrieved 2010-06-24 .
- Jump up^  ArchivedApril 1, 2004, at theWayback Machine.
- Jump up^ “Shelter policy” . Hansard.millbanksystems.com. 1939-04-20 . Retrieved 17 January 2017 .
- Jump up^  ArchivedApril 3, 2008, at theWayback Machine.
- Jump up^ “HOLNET – London at War 1939-1945 – Shelter” . Lgfl.net. Archived from the original on December 28, 2010 . Retrieved 2010-06-24 .
- Jump up^ “Stockport Air Raid Shelters” . Airraidshelters.org.uk. Archived from the original on 6 August 2010 . Retrieved 2010-06-24 .
- Jump up^ Baker 1978, p. [ page needed ].
- Jump up^ Lawrence James. Warrior Race: A History of the British at War (2003) p. 623.
- Jump up↑ Atlkinson, Keith, John Summers & Sons
- Jump up^ Baker 1978, p. [ page needed ].
- Jump up^ “Development of the Anderson Shelter” . Richmond.edu . Retrieved 17 January 2017 .
- Jump up^ Paul Robertson. “The Baker experiment with a Morrison shelter model” . G.eng.cam.ac.uk. Archived from the original on 20 June 2010 . Retrieved 2010-06-24 .
- Jump up^ “The Morrison shelter design” . Fortunecity.co.uk. Archived from the original on March 6, 2009 . Retrieved 2010-06-24 .
- Jump up^ “Examination of effectiveness of Morrison shelter” . learningcurve.gov.uk. Archived from the original on 2008-08-28 . Retrieved 2010-06-24 .
- Jump up^ Baker 1978, p. [ page needed ].
- Jump up^ The Stanton Ironworks Co. Stanton at War 1939-45. Stanton Air Raid Shelter, page 40. Online bookStanton at War ArchivedMarch 15, 2012, at theWayback Machine.
- Jump up^ “Stanton Shelter at Ashdown Camp” . Ashdowncamp.webs.com. Archived from the original on 2014-02-27 . Retrieved 17 January 2017 .
- Jump up^ “Bomb shelter 307 in Barcelona” .
- Jump up^ “Cartagena Spanish Civil War air raid shelter museum” . Retrieved 6 June 2016 .
- Jump up^ “In the bomb shelter: The brighter side of war” . Broad Street Review . Retrieved 2010-06-24 .
- Jump up^ Home front command, תקנות מוסדות בריאות [[: Category: |]], 2010, p4 section 280 subsection ב [ dead link ]
- Jump up^ Home front command, תקנות מוסדות בריאות [[: Category: |]], 2010, [ dead link ]
- Jump up^ “Shelters in educational institutions” (PDF) . Israeli government . Retrieved 17 January 2017 .
- Jump up^ Home front command, תקנות למוסדות חינוך [[: Category: |]], 2010, [ dead link ]
- Jump up^ “Helsingin Sanomat – International Edition – Home” . Hs.fi. Retrieved 2010-06-24 .
- Jump up^ Singapore Civil Defense Force. “FAQ on CD Shelters” . Scdf.gov.sg. Archived from the original on 28 May 2010 . Retrieved 2010-06-24 .