Unexploded ordnance (UXO, sometimes abbreviated as UO), unexploded bombs (UXBs), or explosive remnants of war (ERW) are explosive weapons (bombs, shells, grenades, land mines, naval mines, cluster munition, etc.) that did not explode when they were employed and still pose a risk of detonation, sometimes many decades after they were used or discarded.
Around the world
Unexploded ordnance from at least as far back as the American Civil War still poses a hazard worldwide, both in current and former combat areas and on military firing ranges. A major problem with unexploded ordnance is that over the years the detonator and main charge deteriorate, frequently making them more sensitive to disturbance, and therefore more dangerous to handle. There are countless examples of people tampering with unexploded ordnance that is many years old – often with fatal results. Believing it to be harmless they handle the device and it explodes, killing or severely injuring them. For this reason it is universally recommended that unexploded ordnance should not be touched or handled by unqualified persons. Instead, the location should be reported to the local police so that bomb disposal or Explosive Ordnance Disposal (EOD) professionals can render it safe.
Although professional EOD personnel have expert knowledge, skills and equipment, they are not immune to misfortune because of the inherent dangers: in June 2010, construction workers in Göttingen, Germany discovered an Allied 500-kilogram (1,100 lb) bomb dating from World War II buried approximately 7 metres (23 ft) below the ground. German EOD experts were notified and attended the scene. Whilst residents living nearby were being evacuated and the EOD personnel were preparing to disarm the bomb, it detonated, killing three of them and severely injuring 6 others. The dead and injured each had over 20 years of hands-on experience, and had previously rendered safe between 600 and 700 unexploded bombs. The bomb which killed and injured the EOD personnel was of a particularly dangerous type because it was fitted with a delayed-action chemical fuze (with an integral anti-handling device) which had become highly unstable after over 65 years underground. Similarly, in January 2013, a large bomb dropped by an allied aircraft during World War II detonated on a building site in Euskirchen, killing the digger operator, wounding eight others and causing property damage across a wide area. In November 2013, four US Marines were killed by an explosion whilst clearing unexploded ordnance from a firing range at Camp Pendleton.
A dramatic example of MEC (Munitions and explosives of concern) threat is the wreck of the SS Richard Montgomery off the coast of Kent, which still contains 3000 tons of munitions. When a similar World War II wreck, the Polish Kielce exploded in 1967, it produced an earth tremor measuring 4.5 on the Richter scale.
France and Belgium
In the Ardennes region of France, large-scale citizen evacuations were necessary during MEC removal operations in 2001. In the forests of Verdun French government "démineurs" working for the Département du Déminage still hunt for poisonous, volatile, and/or explosive munitions and recover about 900 tons every year. The most feared are corroded artillery shells containing chemical warfare agents such as mustard gas. French and Flemish farmers still find many UXOs when ploughing their fields, the so-called "iron harvest".
In Belgium, Dovo, the country's bomb disposal unit recovers between 150 and 200 tons of unexploded bombs each year. Over 20 members of the unit have been killed since it was formed in 1919.
Thousands of UXOs from the Second World War are still uncovered each year in Germany. The daily average is 15, most of them aerial bombs. Concentration is especially high in Berlin, where many artillery shells and smaller munitions from the Battle of Berlin are uncovered each year. While most cases only make local news, one of the more spectacular finds in recent history was an American 500-pound aerial bomb discovered in Munich on 28 August 2012. As it was deemed too unsafe for transport, it had to be exploded in situ, shattering windows over a wide area of Schwabing and causing structural damage to several homes despite precautions to minimize damage. In 2011, a 1.8-tonne RAF bomb from the Second World War was uncovered in Koblenz on the bottom of the Rhine River after a prolonged drought. It caused the evacuation of 45,000 people from the city and was called "the biggest bomb-related evacuation in Germany's post-war history". On December 20, 2016 another 1.8-tonne RAF bomb was found in the city centre of Augsburg and prompted the evacuation of 54,000 people on December 25. One of the largest individual pieces ever found was an unexploded 'Tallboy' bomb uncovered in the Sorpe Dam in 1958.
Thousands of tons of UXOs remain buried across Japan, particularly in Okinawa, where over 200,000 tons of ordnance were dropped during the final year of the Second World War. From 1945 until the end of the U.S. occupation of the island in 1972, the JSDF and US military disposed of 5,500 tons of UXO. Over 30,000 UXO disposal operations have been conducted on Okinawa by the JSDF since 1972, and it is estimated it could take close to a century to dispose of the remaining UXOs on the islands. No injuries or deaths have been reported as a result of UXO disposal, however. Tokyo and other major cities, including Kobe, Yokohama and Fukuoka, were targeted by several massive air raids during the Second World War, which left behind numerous UXOs. Shells from Imperial Army and Navy guns also continue to be discovered.
On 29 October 2012, an unexploded 250-kilo US bomb with a functioning detonator was discovered near a runway at Sendai Airport during reconstruction following the 2011 Tōhoku earthquake and tsunami, resulting in the airport being closed and all flights cancelled. The airport reopened the next day after the bomb was safely contained, but closed again on 14 November while the bomb was defused and safely removed.
In March 2013, an unexploded Imperial Army anti-aircraft shell measuring 40 cm long was discovered at a construction site in Tokyo's North Ward, close to the Kaminakazato Station on the JR Keihin Tohoku Line. The shell was detonated in place by a JSDGF UXO disposal squad in June, causing 150 scheduled rail and Shinkansen services to be halted for three hours and affecting 90,000 commuters. In July, an unexploded 1000-kilo US bomb from an air raid was discovered near the Akabane Station in the North Ward and defused on site by the JSDGF in November, resulting in the evacuation of 3,000 households nearby and causing several trains to be halted for an hour while the UXO was being defused.
On 13 April 2014, the JSGDF defused an unexploded 250-kilo US oil incendiary bomb discovered at a construction site in Kurume, Fukuoka Prefecture, which required the evacuation of 740 people living nearby.
On 16 March 2015, a 1-ton bomb was found in central Osaka.
Laos has the distinction of being the world's most heavily bombed nation. During the period of the Vietnam War, over half a million American bombing missions dropped more than 2 million tons of ordnance on Laos, most of it anti-personnel cluster bombs. Each cluster bomb shell contained hundreds of individual bomblets, "bombies", about the size of a tennis ball. An estimated 30% of these munitions did not detonate. Ten of the 18 Laotian provinces have been described as "severely contaminated" with artillery and mortar shells, mines, rockets, grenades, and other devices from various countries of origin. These munitions pose a continuing obstacle to agriculture and a special threat to children, who are attracted by the toylike devices.
Some 288 million cluster munitions and about 75 million unexploded bombs were left across Laos after the war ended. From 1996–2009, more than 1 million items of UXO were destroyed, freeing up 23,000 hectares of land. Between 1999 and 2008, there were 2,184 casualties (including 834 deaths) from UXO incidents.
In the aftermath of the 2006 war between Israel and Lebanon, it is estimated that southern Lebanon is littered with one million undetonated cluster bombs – approximately 1.5 bombs per Lebanese inhabitant of the region, dropped by Israeli Defense Forces in the last days of the war.
Buried and abandoned bombs, mortars, artillery shells, and unexploded ordnance from World War II have threatened communities across the islands of the South Pacific. As of 2014 the Office of Weapons Removal and Abatement in the Department of State's Bureau of Political-Military Affairs invested more than $5.6 million in support of conventional weapons destruction programs in the Pacific Islands.
On the battlefield of Peleliu Island in the Republic of Palau UXO removal made the island safe for tourism. At Hell’s Point Guadalcanal Province in the Solomon Islands an explosive ordnance disposal training program was established, which safely disposed of hundreds of items of UXO. It trained police personnel to respond to EOD call-outs in the island’s highly populated areas. On Mili Atoll and Maloelap Atoll in the Marshall Islands removal of UXO has allowed for population expansion into formerly inaccessible areas.
In The Marianas, World War II-era unexploded ordnance is still often found and then later detonated under controlled conditions.
UXO is standard terminology in the UK, although in artillery, especially on practice ranges, an unexploded shell is referred to as a blind, and during the Blitz in World War II an unexploded bomb was referred to as a UXB.
Most current UXO risk is limited to areas, mainly in London and Portsmouth, that were subject to the Blitz and to land used by the military to store ammunition or to train on. According to the Construction Industry Research and Information Association (CIRIA), from 2006 to 2009, over 15,000 items of ordnance were found in construction sites in the UK. Most notably, 1,000 homes were evacuated in Plymouth in April 2009 when a Second World War bomb was discovered, and in June 2008 a 1,000 kg bomb was found in Bow in East London. CIRIA have now published "Unexploded Ordnance (UXO) – a guide for the construction industry" to provide advice on assessing the risk posed by UXO.
The burden of Explosive Ordnance Disposal in the UK is split between Royal Engineers Bomb Disposal Officers, Royal Logistic Corps Ammunition Technicians in the Army, Clearance Divers of the Royal Navy and the Armourers of the Royal Air Force. The Metropolitan Police is the only force not to rely on the Ministry of Defence, although they generally focus on terrorist devices rather than unexploded ordnance and will often call military teams in to deal with larger and historical bombs.
According to the Department of Defence, "millions of acres" may contain UXO, Discarded Military Munitions (DMM) and Munitions Constituents (e.g., TNT or RDX).
According to US Environmental Protection Agency documents released in late 2002, UXO at 16,000 domestic inactive military ranges within the United States pose an "imminent and substantial" public health risk and could require the largest environmental cleanup ever, at a cost of at least US$14 billion. Some individual ranges cover 500 square miles (1,300 km2), and, taken together, the ranges comprise an area the size of Florida.
In addition to the obvious danger of explosion, buried UXO also entails the risk of environmental contamination. In some heavily used military training areas, munitions-related chemicals such as explosives and perchlorate (a component of pyrotechnics and rocket fuel) can enter soil and groundwater. On Joint Base Cape Cod (JBCC) on Cape Cod, Massachusetts, decades of artillery training have contaminated the only drinking water for thousands of surrounding residents. An expensive UXO recovery effort is under way.
UXO on US military bases has caused problems for transferring and restoring Base Realignment and Closure (BRAC) land. The Environmental Protection Agency's efforts to commercialize former munitions testing grounds are complicated by UXO, making investments and development risky.
UXO cleanup in the US involves over 10 million acres (40,000 km2) of land and 1,400 different sites. Estimated cleanup costs are tens of billions of dollars. It costs roughly $1,000 to demolish a UXO on site. Other costs include surveying and mapping, removing vegetation from the site, transportation, and personnel to manually detect UXOs with metal detectors. Searching for UXOs is tedious work and often 100 holes are dug to every 1 UXO found. Other methods of finding UXOs include digital geophysics detection with land and airborne systems.
As recently as December 2007, construction areas outside Orlando, Florida discovered UXO in new development areas and had to halt construction efforts. Other areas nearby, including UXO in the Indian River Lagoon thought to be left from live bombing runs performed during World War II by pilots from nearby DeLand Naval Air Station, have long been avoided by local boaters for fear of accidentally striking UXO as they motor by.
Plum Tree Island National Wildlife Refuge in Poquoson, Virginia was heavily used as a bombing range by pilots from nearby Langley Air Force Base from 1917 through the 1950s. The 3,276-acre former bombing range was transferred to the US Fish and Wildlife Service in 1972. Air Force records show that 300,000 pounds - 150 tons - of various-sized bombs were dropped in just one exercise in December 1938. Because the area is alternately marshy or sandy, many of the bombs didn't explode and instead were partly or completely buried in the mud and sand or lie in the surf just offshore. In 1958 three teenage boys who landed their boat on the island were seriously injured when a 25-pound practice bomb exploded. As of 2007 the US military had not removed a single bomb from the Island. The island is adjacent to the Poquoson Flats, a popular destination for fishermen and recreational boaters and some of the signs placed offshore to warn boaters of the hidden danger posed by the UXO in the surf or buried beneath the idyllic-seeming sand beach and salt marsh have been blown down by storms and haven't been replaced. According to the US Army Corps of Engineers, the cleanup of the UXO on Plumtree Island could take years and cost tens of millions of dollars.
During World War I, the US Chemical Corps was established at American University, based in the University's McKinley Building. After the war, many toxic chemicals and weaponry were buried in or around the Northwest DC community where the university is located. Excavations in the area are ongoing after significant discoveries were made in 2010.
Although comparatively rare, unexploded ordnance from the American Civil War is still occasionally found and is still deadly 150 years later. Union and Confederate troops lobbed an estimated 1.5 million artillery shells and cannonballs at each other from 1861 to 1865. As many as one in five were duds that did not explode. In 1973 during the restoration of Weston Manor, an 18th-century plantation house in Hopewell, Virginia that was shelled by Union gunboats during the Civil War, a live cannonball was found embedded in the dining room ceiling. The ball was disarmed and is shown to visitors to the plantation. In 1999 a Civil War cannonball fell from a large tree in the yard of country music singer Jimmy Dean's home overlooking the James River where it had been lodged since the battle of Chaffin's Bluff.
In late March 2008, a 44-pound, 8-inch mortar shell was uncovered at the Petersburg National Battlefield, the site of an epic 292-day siege. The shell was taken to the city landfill where it was safely detonated by ordnance disposal experts. Also in 2008, Civil War enthusiast Sam White was killed when a 9-inch, 75-pound naval cannonball he was attempting to disarm in the driveway of his home in a Richmond, Virginia suburb exploded. In addition to killing White the powerful explosion sent a chunk of shrapnel crashing into a house a quarter-mile away.
In international law
Protocol V of the Convention on Certain Conventional Weapons requires that when active hostilities has ended the parties must clear the areas under their control from "explosive remnants of war". Land mines are not covered by Protocol V, but Protocol II of the convention requires that mines must be cleared after active hostilities has ended.
In cases of unexploded subsoil ordnance a remote investigation is done by visual interpretation of available historical aerial photographs. Modern techniques can combine geophysical and survey methods with modern electromagnetic and magnetic detectors. This provides digital mapping of UXO contamination with the aim to better target subsequent excavations, reducing the cost of digging on every metallic contact and speeding the clearance process. Magnetometer probes can detect UXO and provide geotechnical data before drilling or piling is carried out.
In the U.S., the Strategic Environmental Research and Development Program (SERDP) and Environmental Security Technology Certification Program (ESTCP) Department of Defense programs fund research into the detection and discrimination of UXO from scrap metal. Much of the cost of UXO removal comes from removing non-explosive items that the metal detectors have identified, so improved discrimination is critical. New techniques such as shape reconstruction from magnetic data and better de-noising techniques will reduce cleanup costs and enhancing recovery. The Interstate Technology & Regulatory Council published a Geophysical Classification for Munitions Response guidance document in August 2015. UXO or UXBs (as they are called in some countries – unexploded bombs) are broadly classified into buried and unburied. The disposal team carries out reconnaissance of the area and determines the location of the ordnance. In case it is unburied it may be dug carefully and disposed. But if the bomb is a buried one then it becomes a huge task. A team is formed to find the location of the bomb using metal detectors and then the earth is dug carefully.
According to the US Army Environmental Command (AEC) UXO has accumulated from military training activities over the years at approximately 1,700 Formerly Used Defense Sites (FUDS), 25 Base Realignment and Closure Commission (BRAC) sites, and a number of active installations covering millions of acres.
By a 2006 presidential executive order the US Armed Forces were mandated to buy "green ammunition" for use at their training ranges. Green ammunition is non-dud producing since they contain no explosives (that is, other than the propellant) and are non-toxic, reducing cleanup costs and environmental risks. Environmentally sound training rounds come in 5.56 caliber and 40 mm high and low-velocity training cartridges for grenade machine guns and under-barrel grenade launchers.
As of 2003 the US army used M918 40 mm cartridges, made to a pyrotechnic design from the 1970s that contains heavy metals in the fuze and potassium perchlorate in the payload. It has a fuze failure rate of 3–8%. The US Army continues to use the M918 and M385 cartridges, favoring a "mixed-belt" approach to reducing duds and toxic leaching; however, the M918 cannot be used in dry weather because of potential range fires.
US defense forces are now testing the 40 mm MK281 cartridge, Non-Dud Producing (NDP) and non-toxic training cartridge for the MK19. In 2006, the US Marine Corps signed a US$61 million 5-year contract with the Rheinmetall Group. The National Training Center in Fort Irwin, California was partially integrating the MK281 into its operations. The U.S. Center for Health Promotion and Preventative Medicine at the Aberdeen Proving Ground, Maryland approved the MK281.
Given that the military used 6–10 million training rounds per year, this leads to a substantial amount of UXO, leading to mandates from the Department of Defense and Environmental Protection Agency to phase out this older training ammunition. This transition has been dependent on the US military-industrial base becoming ready to design and manufacture necessary amounts of green ammunition.
As of 2009, there were no US manufacturers to provide the necessary supply of green ammunition, rendering the Department of Defense's mission to phase out older ammunition at odds with its second mission to buy designs and material from US suppliers. Many small US ammunition manufacturers, many associated with the rapid creation of World War II Army Ammunition Plants, have not invested in green ammunition R&D.
"Green" also refers to the manufacturing process of ammunition. US Army programs at Picatinny Arsenal were researching methods of reducing volatile organic compounds and ozone depleting compounds during the manufacturing process. Attempts are also being made to reduce the amount of hazardous materials in the actual ammunition.