Largest artificial non-nuclear explosions

Since the invention of high explosives, there have been a number of extremely large explosions, many accidental. This list contains the largest known examples, sorted by date. The weight of the explosive does not directly correlate with the size of the explosion, so an accurate ranking of these explosions is impossible.

2001–present

• 2005 Hertfordshire Oil Storage Terminal fire. On 11 December 2005 there were a series of major explosions at the 60 million gallon (273 million litre) capacity Buncefield oil depot near Hemel Hempstead, Hertfordshire, England. The explosions were heard over 100 miles (160 km) away, as far as the Netherlands and France, and the resulting flames were visible for many miles around the depot. A smoke cloud covered Hemel Hempstead and other nearby towns in west Hertfordshire and Buckinghamshire. There were no fatalities, but there were around 43 injuries (two serious).

• Ryongchon disaster: train explosion in North Korea; officially 54 people were killed and 1,249 were injured on April 22, 2004.

• Seest fireworks disaster. On November 3 2004 about 800 tonnes of fireworks exploded in the Danish town of Kolding. One firefighter was killed, but the mass evacuation of 2,000 people saved many lives. The cost of the damage has been estimated at € 100 million.

• 2001 AZF chemical factory explosion in Toulouse, France. On 21 September 2001 the disaster caused 30 deaths, 2,500 seriously wounded and 8,000 light casualties.

1901–2000

• Enschede fireworks disaster. On May 13 2000 about 177 tons of fireworks exploded in the Dutch town of Enschede. 23 people were killed, and hundreds were injured.

• 1996 Manchester bombing. On Saturday 15 June 1996, the IRA detonated a bomb containing 1500kg (3300 lb) of explosives in Manchester. The bomb was located in a Ford lorry parked two hours earlier in the centre of the city's shopping district. It was the largest IRA bomb ever detonated in Great Britain, and the largest bomb to explode in Great Britain since World War II.

• PEPCON disaster. On May 4 1988 about 8.5 million pounds (3,855 tonnes) of ammonium perchlorate either burned or exploded in a fire and several massive explosions near Henderson, Nevada. Two people were killed, and hundreds were injured. The largest explosion was estimated to be equivalent to a 1 kiloton nuclear air burst¹.

• Minor Scale. Several, if not many, very large deliberate detonations have been carried out in order to simulate the effects of nuclear weapons on vehicles and military material in general. The largest publicly-known was conducted by the United States Defense Nuclear Agency (now part of the Defense Threat Reduction Agency) on 27 June 1985 at the White Sands Missile Range in New Mexico. The Minor Scale test used 4744 short tons of ANFO, with a yield of about 4 kt. Although comparing explosions is difficult, this is probably the largest artificial non-nuclear explosion in history. Similar tests were reportedly carried out in the 1970s in the far north jungles of Queensland, Australia, to test the feasibility of nuclear weapons for clearing forests in the Vietnam War.

• Medeo Dam, near Alma-Ata, Kazakhstan. On October 21 1966 a mudflow protection dam was created by a series of four preliminary explosions of 1,800 tons total and a final explosion of 3600 tonnes of ammonium nitrate based explosive. On April 14 1967 the dam was reinforced by an explosion of 3900 tonnes of ammonium nitrate based explosive.

• Operation Sailor Hat, off Kaho'olawe Island, Hawaii, 1965. A series of tests was performed, using conventional explosives to simulate the shock effects of nuclear blasts on naval vessels. Each test saw the detonation of a 500-ton mass of high explosives.

500 tons of HE awaiting detonation for Operation Sailor Hat.

File:Kn11352.jpg.jpeg

Detonation of explosive during Operation Sailor Hat. Shock front visible moving across the water, shock condensation cloud visible overheard.

• Ripple Rock, Canada. On April 5 1958 an underwater mountain was decapitated by the explosion of 1,375 tonnes of Nitramex 2H (an ammonium nitrate based explosive).

• New London School explosion. On March 18 1937 A natural gas leak caused an explosion, destroying the New London School of the city of New London, Texas. Over 300 students and teachers died.

• The Oppau explosion. On September 21 1921 a silo filled with 4,500 tonnes of fertilizer exploded, killing around 560, largely destroying Oppau, Germany and causing damage more than 30 km away.

World War II era

• Heligoland. On April 18 1947 British engineers attempted to destroy the entire island in what became known as the "British Bang" (or "Big Bang"). Roughly 4000 tons of surplus World War II ammunition were placed in various locations around the island and set off. The island survived, although the extensive fortifications were destroyed. According to , the energy released was 1.3x10²⁰ ergs = 1.3x10¹³ joules, or about 3.2 kilotons of TNT equivalent. The blast is listed in the Guinness Book of World Records under largest single explosive detonation, although Minor Scale would appear to be larger. (The Halifax Explosion was not a detonation.)

• The Texas City Disaster. On April 16 1947, the SS Grandcamp, loaded with 8,500 short tons (7700 tonnes) of ammonium nitrate, exploded in port at Texas City, Texas; this is generally considered the worst industrial accident in United States history. 581 died, over 5,000 injured.

• RAF Fauld Explosion. On November 27 1944 the RAF Ammunition Depot at Fauld, Staffordshire became the site of the largest explosion in the UK, when 3,700 tonnes of bombs stored in underground bunkers covering 17,000 square metres exploded en masse. The explosion was caused by bombs being taken out of store - primed for use and replaced unused, with the detonators still installed. The crater is 30 metres deep and covers 5 hectares. The death toll was approximately 78 including RAF, six Italian POWs, civilian employees and local people. In the similar Port Chicago disaster below, about half the weight of bombs was high explosive. If the same is true of the Fauld Explosion, it would have been equivalent to about 2 kilotons of TNT.

• Port Chicago disaster. On July 17 1944 in Port Chicago, California the SS E. A. Bryan exploded while loading ammunition bound for the Pacific, with an estimated 4,606 short tons (4178 tonnes) of high explosive, incendiary bombs, depth charges, and other ammunition. Another 429 short tons (389 tonnes) were waiting on nearby rail cars, which also exploded. The total explosive content is described as between 1600 and 2136 tons of TNT. 320 were killed instantly, another 390 wounded. The disaster is a cause celebre in the African American community, as most of the casualties were black, and led to a mutiny over working conditions.

• Bombay Docks Explosion. On April 14 1944 the SS Fort Stikine carrying around 1,400 long tons (1422 tonnes) of explosives (among other goods) caught fire and exploded killing around 800 people.

World War I era

• Halifax Explosion. On December 6 1917 two ships collided in the harbour of Halifax, Nova Scotia one carrying 2,653 tonnes of various explosives, mostly picric acid. After the collision the ship caught on fire, drifted into town and eventually exploded. More than 1,900 people were killed and much of downtown Halifax was destroyed. An evaluation of the explosion's force puts it at 2.9 kt of TNT.

• Battle of Messines. On June 7 1917 nineteen (of a planned twenty-one) huge mines — containing over 455 tonnes (1,000,000 lb) of ammonal explosives — were set off beneath German lines on the Messines-Wytschaete ridge. Approximately 10,000 Germans were killed, and the explosion was heard as far away as London and Dublin.

• Silvertown explosion. On 19 January 1917 at 18:52 parts of Silvertown in East London were devastated by a massive TNT explosion at the Brunner-Mond munitions factory. 73 people died and hundreds were injured. The blast was felt across London and Essex, and was heard over 100 miles (160 km) away, with the resulting fires visible for 30 miles (50 km).

• Black Tom explosion. On July 30 1916 1,000 short tons (900 tonnes)of explosives bound for Europe, along with another 50 tons on the Johnson Barge No.17, exploded in Jersey City, New Jersey, a major dock serving New York. There were few deaths, but about 100 injuries; also, the buildings on Ellis Island and the Statue of Liberty were damaged, along with much of Jersey City.

• Lochnagar Mine. On July 1 1916 on the start of Battle of the Somme a charge of 60,000 lbs (27 tonnes) of ammonal explosive was blown at 7.28 am. The explosions constituted what was then the loudest man-made sound in history, and could be heard in London. The mine created a crater 300 feet (90 metres) across and 90 feet (27 metres) deep, with a lip 15 feet (4.6 metres) high. The crater is known as Lochnagar Crater after the trench from where the main tunnel was started.

• Faversham Explosion. On Sunday 2 April 1916, a huge explosion ripped through the gunpowder mill at Uplees, near Faversham, Kent when 200 tons of TNT ignited. 105 people died in the explosion. The munitions factory was next to the Thames estuary, which explains why the explosion was heard across the estuary as far away as Norwich, Great Yarmouth and Southend-on-Sea, where domestic windows were blown out and two large plate-glass shop windows shattered.

• Alum Chine. March 7, 1913. Alum Chine was a Welsh freighter (Cardiff) carrying 343 tons of dynamite for use during construction of the Panama Canal. She was anchored off Hawkins Point, near the entrance to Baltimore Harbor. She exploded, killing over 30, injuring about 60, and destroying a tugboat and two barges. Most accounts describe two distinct explosions.

Before 1900

• The Nanaimo mine explosion. On May 3, 1887, in Nanaimo, British Columbia, Canada killed 150 miners and was the largest man-made explosion in the world until the Halifax Explosion.

• Mobile magazine explosion. On May 25, 1865, in Mobile, Alabama, in the Southern United States, an ordnance depot or "magazine" exploded, killing some 300 persons. This event occurred just after the end of the American Civil War, during the occupation of the city by victorious Federal troops.

• Siege of Multan. On December 30, 1848, in Multan during the Second Anglo-Sikh War, "A shell from a mortar struck a mosque in the city which had been turned into a magazine and stored with 400,000 lbs. of gunpowder. It blew up with a tremendous explosion which shook the earth for many miles round, and darkened the air with smoke and fragments." – from The History of India by John Clark Marshman, Volume III page 340.

• Siege of Almeida. On August 26, 1810, in Almeida, Portugal during the Peninsula War phase of the Napoleonic Wars, the garrison, commanded by Brigadier General William Cox lay under siege from French forces commanded by Marshall André Masséna. A shell made a freak hit on the old castle, which was being used as the main powder magazine. It initially ignited some 4,000 prepared charges, which in turn ignited 150,000 pounds of black powder and 1,000,000 musket cartridges. The ensuing explosion killed 600 defenders and wounded 300 more. The castle was razed to the ground and sections of the defences were damaged. Unable to reply to the French cannonade without gunpowder, Cox was forced to capitulate the following day with the survivors of the blast and 100 cannon. The French lost 58 killed and 320 wounded during the operation.

• Delft Explosion. About 40 tonnes of gunpowder exploded on October 12 1654, destroying much of the city of Delft in the Netherlands. Over a hundred people were killed and thousands wounded.

Comparison with large conventional military ordnances

The most powerful non-nuclear weapons ever designed are the United States' MOAB (standing for Massive Ordnance Air Blast, also nicknamed Mother Of All Bombs, tested in 2003) and the Russian Father of All Bombs (tested in 2007), about 4 times more powerful than the MOAB). The MOAB packs 18,700 lb (8.5 tonnes) of the H6 explosive, which is 1.35 times as powerful as TNT. This gives the bomb an approximate yield of 0.025 kt. As a matter of comparison, it would require 118 MOABs to equate the Halifax Explosion.

Rank Order of largest conventional explosions/detonations by magnitude

These yields are approximated by the amount of the explosive material and its properties. They are rough estimates and are not authoritative.

Event	Approximate yield
Minor Scale	4 kt
Heligoland	3.2 kt
Texas City Disaster	2-4 kt
Halifax Explosion	2.9 kt
Port Chicago disaster	1.6-2.2 kt

See also

List of nuclear tests

List of accidents and disasters by death toll