pipe bomb

pipe bomb, an improvised explosive device that uses a sealed section of pipe as the casing to contain the explosive material. As internal pressure builds, the casing ruptures and scatters fragments outward at high speed, causing widespread injury to those nearby. A pipe bomb can be assembled using components obtained from local hardware stores. The relative ease of concealing and delivering pipe bombs has contributed to their use in terror attacks, episodes of civil unrest, and, in some cases, military operations.

Mechanism

Pipe bombs typically feature a long container filled with explosive materials and some type of fuse or detonator that ignites the bomb. Explosives tend to consist of readily available materials such as black powder, flammable liquid, fireworks, or match heads.

This design is intended to contain heat and gases for as long as possible. By confining the gases, internal pressure is increased far beyond what would occur if the material burned in open air, resulting in an explosion. In some instances, the device may be designed to increase fragmentation and produce additional shrapnel.

Detection and neutralization

Explosive ordnance disposal teams consist of highly trained personnel who safely and methodically dispose of explosive devices.

• Remote robotics: Teams use remote-controlled robots to approach and move devices. This “standoff distance” protects human personnel from the primary blast and fragmentation effects.
• Radiography (X-ray): Experts use portable X-ray systems to look through the pipe bomb’s casing. This allows them to identify the internal layout, specifically the location of the filler and the initiator (fuse or wires).
• Water-jet disruption: To neutralize the device, experts use a disruptor to fire a high-velocity slug of water at the pipe. In some systems the water may travel at speeds exceeding 3,280 feet (1,000 meters) per second, mechanically dismantling the device and separating the ignition source from the filler before a chemical explosion can occur.

Instances of use in terror attacks

• Pipe bomb mailings in the United States: In October 2018 a series of pipe-bomb packages were mailed to prominent public personalities in the United States, including former president Barack Obama, former secretary of state Hillary Clinton, actor and filmmaker Robert De Niro, and other critics of Pres. Donald Trump. Beginning on October 22, the devices were intercepted before detonation, prompting a nationwide investigation that led to the arrest of Cesar Altieri Sayoc, Jr., a Florida man who was ultimately charged with multiple federal offenses related to the illegal mailing of explosives.
• Atlanta Olympics bombing: During the 1996 Summer Olympics in Atlanta, a pipe bomb concealed in a backpack detonated at Centennial Olympic Park, killing one person and injuring many others. The attack was later linked to Eric Rudolph, who pleaded guilty in 2005.
• The Unabomber: Between 1978 and 1995 Ted Kaczynski built and delivered a series of pipe bombs in the United States, beginning with a device sent to an engineering professor at Northwestern University in Evanston, Illinois, which detonated and injured a police officer. He later carried out two major bombings, including an explosion aboard an American Airlines flight in 1979 and another at the home of the president of United Airlines in 1980. These attacks prompted federal investigators to establish the UNABOM (standing for university and airline bombing) task force, and the unidentified suspect became known in the media as “the Unabomber.” Forensic analysis of the fragmentation characteristics (the specific types of wood or metal) of the bombs helped to link Kaczynski to the attacks when he was eventually tracked down.
• Assassination of Robert Vance: In December 1989 Walter Moody carried out a series of mail-bomb attacks in the United States, sending pipe bombs to judicial and civil rights figures. A device delivered to the Alabama home of the federal appeals judge Robert S. Vance detonated on December 16, killing him and seriously injuring his wife, and a similar bomb killed civil rights attorney Robert E. Robinson two days later. Additional pipe bombs sent to a federal courthouse in Atlanta and to the NAACP office in Jacksonville, Florida, were intercepted and defused. Forensic analysis later linked all the devices to Moody, who was convicted in 1991 and executed in 2018.
• The Troubles in Northern Ireland: From about 1968 to 1998, pipe bombs were frequently used during a violent sectarian conflict in Northern Ireland. The conflict involved republican groups, drawn largely from the Roman Catholic community, who sought unification with the Republic of Ireland, and loyalist groups, drawn largely from the Protestant community, who supported continued union with the United Kingdom. Because they could be made from common household plumbing materials, pipe bombs were difficult for authorities to regulate. These devices were often used as antipersonnel weapons in urban neighborhoods.
• “The Mad Bomber” of New York: Between 1940 and 1957, George Metesky planted a series of pipe bombs in New York City. The first device, discovered in 1940 at the Consolidated Edison building, did not detonate, but later bombs, placed at various public locations, resulted in multiple explosions and injuries. The prolonged investigation led to one of the earliest uses of criminal profiling and culminated in Metesky’s arrest in 1957, after which he became known in the media as “the Mad Bomber.”