Operation Big Bang or British Bang was the explosive destruction of bunkers and other military installations on the island of

Heligoland Heligoland (; , ; Heligolandic Frisian: , , Mooring Frisian: , ) is a small archipelago in the North Sea. The islands were historically possessions of Denmark, then became possessions of the United Kingdom from 1807 to 1890. Since 1890, the ...

. The explosion used 7400 tons (6700

metric ton The tonne ( or ; symbol: t) is a unit of mass equal to 1,000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton in the United States to distinguish it from the non-metric units of the sh ...

s) of surplus World War II ammunition, which was placed in various locations around the island and detonated at 1 p.m. on 18 April 1947 by the

Royal Navy The Royal Navy (RN) is the naval warfare force of the United Kingdom. It is a component of His Majesty's Naval Service, and its officers hold their commissions from the King of the United Kingdom, King. Although warships were used by Kingdom ...

. The energy released was 13

terajoule The joule ( , or ; symbol: J) is the unit of energy in the International System of Units (SI). In terms of SI base units, one joule corresponds to one kilogram- metre squared per second squared One joule is equal to the amount of work done ...

, or about 3.2 kilotons of

TNT equivalent TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. A ton of TNT equivalent is a unit of energy defined by convention to be (). It is the approximate energy released in the de ...

making it the largest artificial non-nuclear explosion at that time. The objective of the blast was to destroy the bunkers and military installations on the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

island of Heligoland, but due to the enormous amount of explosives it was foreseen that the entire island might be destroyed. The porous sandstone that makes up the island allowed the blast wave to escape so only the southern tip of the island was destroyed, but there was considerable damage to the northern tip.

Background

The German Navy in the Second World War HU104923

Because of its location in the centre of the

German Bight The German Bight ( ; ; ); ; ; sometimes also the German Bay) is the southeastern bight of the North Sea bounded by the Netherlands and Germany to the south, and Denmark and Germany to the east (the Jutland peninsula). To the north and west i ...

, near the mouths of the

Weser The Weser () is a river of Lower Saxony in north-west Germany. It begins at Hannoversch Münden through the confluence of the Werra and Fulda. It passes through the Hanseatic city of Bremen. Its mouth is further north against the ports o ...

, the

Elbe The Elbe ( ; ; or ''Elv''; Upper Sorbian, Upper and , ) is one of the major rivers of Central Europe. It rises in the Giant Mountains of the northern Czech Republic before traversing much of Bohemia (western half of the Czech Republic), then Ge ...

, and the

Kiel Canal The Kiel Canal (, until 1948 called in German the ) is a fresh water canal that links the North Sea () to the Baltic Sea (). It runs through the Germany, German states of Germany, state of Schleswig-Holstein, from Brunsbüttel to the Holtenau di ...

, the waters around the island of Heligoland were the scene of four

naval battles Naval warfare is combat in and on the sea, the ocean, or any other battlespace involving a major body of water such as a large lake or wide river. The armed forces branch designated for naval warfare is a navy. Naval operations can be broadly d ...

1849 Events January–March * January 1 – France begins issue of the Ceres series (France), Ceres series, the nation's first postage stamps. * January 5 – Hungarian Revolution of 1848: The Austrian army, led by Alfred I, Prince of Windisc ...

1864 Events January * January 13 – American songwriter Stephen Foster ("Oh! Susanna", "Old Folks at Home") dies aged 37 in New York City, leaving a scrap of paper reading "Dear friends and gentle hearts". His parlor song "Beautiful Dream ...

1914 This year saw the beginning of what became known as the First World War, after Archduke Franz Ferdinand of Austria, heir to the Austrian throne was Assassination of Archduke Franz Ferdinand, assassinated by Serbian nationalist Gavrilo Princip ...

, and

1917 Events Below, the events of World War I have the "WWI" prefix. January * January 9 – WWI – Battle of Rafa: The last substantial Ottoman Army garrison on the Sinai Peninsula is captured by the Egyptian Expeditionary Force's ...

. In 1807, the United Kingdom occupied the island, which had previously belonged to Denmark. In 1890, in the so-called Heligoland-Zanzibar Treaty, the

German Empire The German Empire (),; ; World Book, Inc. ''The World Book dictionary, Volume 1''. World Book, Inc., 2003. p. 572. States that Deutsches Reich translates as "German Realm" and was a former official name of Germany. also referred to as Imperia ...

exchanged German territorial claims in Africa for the island of Heligoland in order to develop it into a naval fortress and later a

naval base A naval base, navy base, or military port is a military base, where warships and naval ships are docked when they have no mission at sea or need to restock. Ships may also undergo repairs. Some naval bases are temporary homes to aircraft that usu ...

. According to the provisions of the

Treaty of Versailles The Treaty of Versailles was a peace treaty signed on 28 June 1919. As the most important treaty of World War I, it ended the state of war between Germany and most of the Allies of World War I, Allied Powers. It was signed in the Palace ...

, Article 115, the fortress was to be destroyed after the First World War. The work lasted from 1920 to 1922, but was not as thorough as originally envisaged; the basic structure was preserved. During the Nazi period (1938), the never-completed " Project Lobster Claw" (Projekt Hummerschere) was started to make the island a military counterweight to the British naval base in

Scapa Flow Scapa Flow (; ) is a body of water in the Orkney Islands, Scotland, sheltered by the islands of Mainland, Graemsay, Burray,S. C. George, ''Jutland to Junkyard'', 1973. South Ronaldsay and Hoy. Its sheltered waters have played an impor ...

. After the end of World War II, the island was in the

British occupation zone in Germany The British occupation zone in Germany (German: ''Britische Besatzungszone Deutschlands'') was one of the Allied-occupied areas in Germany after World War II. The United Kingdom, along with the Commonwealth, was one of the three major Allied po ...

and served as a blasting and training ground between 1945 and 1952.

Explosion

In April 1945, after a

Royal Air Force The Royal Air Force (RAF) is the Air force, air and space force of the United Kingdom, British Overseas Territories and Crown Dependencies. It was formed towards the end of the World War I, First World War on 1 April 1918, on the merger of t ...

bombing raid on Heligoland with about 1,000 bombers occurred on 18 April, the approximately 2,500 inhabitants were evacuated by the ''

Wehrmacht The ''Wehrmacht'' (, ) were the unified armed forces of Nazi Germany from 1935 to 1945. It consisted of the German Army (1935–1945), ''Heer'' (army), the ''Kriegsmarine'' (navy) and the ''Luftwaffe'' (air force). The designation "''Wehrmac ...

'' garrison. On 11 May 1945 the island was occupied by British forces. In order to deny the uninhabited islands to the Germans as a potential naval base, the British began preparations to blow up the bunkers and military installations on Heligoland in 1947. They filled the Nordsee III submarine bunker in the southern harbour and the tunnel labyrinths with leftover munitions from the world wars. Since the preparations took longer than planned, the original deadline of 31 March could not be met. On 18 April 1947, exactly two years after the bombing raid, the

detonated the bomb. Stacked were about 4,000 torpedo heads, nearly 9,000

depth charge A depth charge is an anti-submarine warfare (ASW) weapon designed to destroy submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited ...

s and over 91,000 shells of various calibres. The blast was set off by British engineers aboard HMS ''Lasso'' from a distance of about 17 kilometres. The British staged this blast for the German public; there was a separate brochure about it. Almost 20 journalists watched directly from the steamer ''Danzig''. A smaller explosion was used to scare away the birds. The main explosion occurred a few minutes later. A huge jet of fire and tons of rock shot into the sky. The tremors could be felt in

Cuxhaven Cuxhaven (; ) is a town and seat of the Cuxhaven district, in Lower Saxony, Germany. The town includes the northernmost point of Lower Saxony. It is situated on the shore of the North Sea at the mouth of the Elbe River. Cuxhaven has a footprint o ...

, 70 kilometres away. The mushroom cloud rose about nine kilometres (according to other sources, one kilometre) into the air. The explosion shook the island base to a depth of several kilometres.

Results

The island survived the blast, but the southern tip of the island, the rubble of which makes up today's , was blown away. Parts of the cliff also collapsed, and many craters were created. The harbour facilities and coastal protection walls remained intact, and the surviving civil air raid shelters today attract up to 10,000 tourists annually. The only building to survive the blast was the flak tower, today's Heligoland Lighthouse. The detonation could be registered seismographically in Germany and used to study the

Earth's crust Earth's crust is its thick outer shell of rock, referring to less than one percent of the planet's radius and volume. It is the top component of the lithosphere, a solidified division of Earth's layers that includes the crust and the upper ...

.G. A. Schulze: Anfänge der Krustenseismik In 1952, after protests by the residents, the people of Heligoland were allowed to repopulate the island. Today, on the anniversary of the demolition, a memorial service is held in the civil defence bunker.

References

External links

* 'Heligoland Goes Up: Destroying Hitler's Sea Base' (1947), British Pathé, * 'Festung, Seebad, Labor', Regina Kusch and Andreas Beckmann, 18 April 2007
German radio transcript
{{DEFAULTSORT:Big Bang 1947 1947 in Germany 1947 in military history Explosions in 1947 20th century in Schleswig-Holstein Allied occupation of Germany Aftermath of World War II in Germany British forces in Germany Building bombings in Germany Attacks on military installations in Germany Attacks on military installations in the 1940s April 1947 in Europe Heligoland Military history of Schleswig-Holstein Naval bombing operations and battles 20th-century history of the Royal Navy Non-combat military operations involving the United Kingdom