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The history of the IED explained

The last decade, as shown above, has seen a deluge of IED harm, with the vast majority of those killed or injured being civilians. But how did it come to this?  What role have IEDs played in the not-so-recent past?  And what lessons can be learned from their historic use?  In this next section, we seek to look at the history of the IED, in part in an attempt to shine some light on the challenges of the now.

IEDs are clearly not just a modern phenomenon – society has rediscovered the impact and efficacy of IEDs at frequent occasions over the centuries.  They were once the first experiments with explosives to create a means of destruction. This points to a basic truth: that the main difference between the classification of IEDs and manufactured munitions that we see today is essentially a modern phenomenon, and such a distinction historically became possible only when large-scale production of explosive devices became the main means of production.
Series of Developments
Where did, then, explosives first emerge? About a thousand years ago it appears that gunpowder, in an early form, was developed in China. Possibly utilised as simple fireworks, gunpowder was held in a container of paper or bamboo and the effect, when lit, was of a loud crack. Over time, the key mix of saltpeter, sulphur and charcoal (often with other material) evolved, as did the realisation that confining the mix in a strong container – firstly wood and pottery, and later metal, increased the apparent effect of gunpowder. 

It is important to understand that gunpowder is a “low explosive” – the chemical reaction of its components is caused by a burning effect moving through the mix, producing large volumes of gas very rapidly.  This gas, when “confined”, builds in pressure and ruptures the container, projecting fragments by the rapidly expanding cloud of gas over a wide distance. 

The development and refinement of the use of explosives continued – for it was found that not only could gunpowder rupture a container, but the expanding gas could also throw a projectile. So it was that the earliest firearms were invented. From being perhaps only of entertainment value, gunpowder started to be used on the battlefield: making noise, dispersing smoke and causing confusion, as well as creating damage and throwing projectiles.

Knowledge of this remarkable chemical mix and its associated technology spread through the world in fits and starts, firstly to the Arab world and eventually, perhaps in the late 13th century, to Europe. Here, as with any technology, it continued to be refined, improved and new uses were found for the phenomena of rapidly expanding gas. A typical example of an explosive device in this period would have been a pottery container, with a handful of gunpowder tightly packed inside and a fuse lit by the application of fire leading in through a small hole, designed to be thrown at an enemy.  Lighting a burning fuse was also the technique used in one of the early vehicle bombs, used in an attempt to assassinate Napoleon in 1800.

Mechanical developments
For a few centuries, the method of igniting any gunpowder charge involved applying, by hand, a lighted match to gunpowder or a gunpowder-impregnated piece of string which led to the main volume of the charge. Basic European engineering skills also developed “matchlocks”: a spring mechanism which applied an already-burning match to the gunpowder charge. This mechanism could be used to initiate hand-held weapons and cannons but was rarely used in initiating large explosive charges. 

This changed, however, in about 1500 when the “wheel lock” was invented. This small mechanical system enabled energy to be stored indefinitely in a spring. When a trigger was pulled, the spring turned a metal wheel which acted with friction on a substance that caused sparks to fly out. These sparks could then be used to initiate the gunpowder charge. This mechanical step enabled a range of wider applications, removing the need for a human applying a lit match at close proximity.

A typical example of this new device was a 16th-century weapon where the “trigger” of the wheel lock could be pulled at a safe distance to initiate the explosive at a time of choice for the perpetrator. More ingeniously the “pull” on a trigger could, in theory, be caused by a trip line; so it was that the first booby traps using mechanical systems were enabled.  More ambitiously, a trigger could be actuated by a clock, so the first mechanical timed IEDs also became possible.

One of the most significant IEDs in history was such a device; in 1585 an entire ship, the “Hoop”, was filled with a large volume of gunpowder and set to drift against a temporary bridge erected by the invading Spanish army who had laid siege to the city of Antwerp. The charge was initiated by a clockwork timer, and the subsequent explosion killed up to 1,000 people; a devastating weapon for its time and indeed to today.

In the early 1600s, the wheellock, as a system, was superseded by the flintlock which required slightly less engineering skill and was therefore more easily and cheaply manufactured. In a flintlock a piece of flint is held against the action of a spring – when the trigger is pulled the spring acts on a lever which causes the flint to strike a steel pan, in which there is a small amount of gunpowder, igniting the main charge. Used extensively in hand-held firearms, the system was also applicable to improvised explosive devices and was more cost-effective than the wheellock. In the 1800s, the flintlock was superseded by percussion locks which themselves lead to the modern bulleted cartridge. This mechanism, using a fired bullet from a gun, still appeared as an IED initiator well into the 20th century.

An example of the firearm mechanism used on its own to initiate IEDs can be seen in a system developed in the US Civil War. The trigger mechanism was placed under a railway track so that a passing train caused the rail to deflect downwards, pushing on the trigger. A bullet was then fired into a charge of explosives, initiating it. This technique was subsequently used in the Franco-Prussian War, the Boer War and the First World War, there to attack Ottoman railways in Arabia. 

Electrical Initiation
Of course, technical innovation doesn’t occur in strict technological sequences. In parallel with mechanical innovation, other scientific developments became enablers for IEDs. The first electrical initiation of an explosive charge was achieved in laboratory conditions (possibly by Benjamin Franklin) in the latter part of the 1700s. By the mid-1800s, this system had evolved and began to be used by military engineers. Russian defendes against French and British attacks at Sebastopol in the Crimea use electrically initiated explosive charges and similar devices were used in the US Civil War. The poor availability of electrically-initiated detonators and practical batteries, however, did not really cause this method to be used very often in IEDs until the 20th century. 

Chemical Developments.
Over time there were also a series of key technological developments regarding the chemistry of explosives which resulted in “high explosives”. The first high explosives were discovered by alchemists working with exotic precursors in the 1600s, but such discoveries only really became ready for practical use in the 1800s.  The key difference between low and high explosives is that the chemical reaction is not propagated by burning through a material, as in the former, but by a shock wave, as in the latter. 

In general terms, high explosives release more energy at a faster rate than an equivalent amount of low explosives. The first high explosives were extremely sensitive and their successors today are used in very small quantities in detonators (aka blasting caps) to initiate larger volumes of less sensitive explosives.     In the 1800s, a variety of chemical developments resulted in molecular explosives (firstly nitro-glycerine), then a range of others, being used extensively for military and engineering purposes. Molecular explosives are single compounds that react to external stimuli to decompose into gases with a significant amount of energy.  TNT is another example, developed in 1863.  

Explosive mixes were also developed. These were generally an intimate mix of some form of fuel (including powdered metal like aluminium, or simple fuel oil, with an oxidiser such as Ammonium Nitrate); today many IEDs use these mixes of easily available chemicals to create entirely practical high explosives. Their efficacy can be equally deadly – they explode in much the same manner as molecular explosives with pretty much the same effect, depending on the exact mix. 

The evolution of the IED, then, was one driven by a variety of measures; technological discoveries, chemical developments and, as importantly, evidence of impact. In this way, history shows us that IEDs were frequently used by states – or by revolutionaries – in ‘conventional battle’.  It was only, though, when states started to mass-produce arms and explosive devices for their armies, that the distinction between manufactured and IEDs became more salient. 

Encouragement for the use of IEDs by revolutionary politics and war
Political developments in the 1800s were also a key element in the increased utilisation of IEDs. The decade of revolution in the 1840s led to revolutionary politics and the potential of individuals to take violent political activity into their own hands – occurring in parallel with scientific development. There was a synergy between the politics and the technology available to “the people”. 

An example of this was the European anarchist Johann Most, who brought about the concept of “Propaganda of the Deed” – the explosive charge used not only to cause harm but to garner media headlines too. Such propaganda – and the impact one blast could have on an entire society – soon spread the knowledge of IED manufacture and design.  

As social pressures stirred the politics of the latter part of the 1800s and into the 1900s, revolutionary politics and the IED went hand in hand, literally.  A number of wars, not least the US Civil War where there was extensive military use of IEDs, created hundreds of men trained in the use of explosives. Some of them went on to join revolutionary movements across the world, a transference of knowledge that resulted in the widespread use of IEDs in Russia, France, Spain, Italy, the UK, and the US.  

Alongside this, war contributed other pressures. Occupying armies soon became the target of partisans and resistance forces, who were forced to develop their own weapons in whatever improvised means they could. Indeed, the 1890s was dubbed “the decade of the bomb” so often were there assassination attempts by revolutionaries.  IEDs, often called “infernal machines”, were also deployed in a number of wars throughout the 1800s and 1900s, including the Crimean War, the US Civil War and into the world wars of the next century. 

Just as now, there was a widespread concern then about the impact of IED use, its ease of availability and the consequences of such use. Perhaps it is worth contemplating that, in a sense, our concerns today are not new – history does have a habit of repeating itself.

Innovative developments in IED use
The history of IEDs is woven together not just with the military or revolutionary use of explosives, but with a history of human ingenuity.  This ingenuity creates IEDs from unexpected components or applies them to function in clever ways. An early example of this was at the siege of Pskov in 1582 – the besiegers, under Stephen Báthory, sent, via an intermediary, an anonymous “jewelled casket”.  It was a deadly trick – the casket was set to explode when the lid was lifted. Over the centuries there are too many examples to list – but it is axiomatic that many IEDs are ingenious in their design either by design, disguise or application.  

One innovative application that has found, regrettably, much recent use is the suicide IED. Probably the first such event was the assassination of the Tsar in St Petersburg in 1881. Revolutionary terrorists obtained a number of sensitive explosives, and the nature of their plot required them to be present when the Tsar appeared as a target. They were so committed to their cause that they saw the sacrifice of their lives as worthy of that cause, and the concept of “propaganda of the deed” applied absolutely. Today, this concept continues and we have seen this concept applied to other revolutionary causes. 

IEDs continue to be used in the spectrum of military or war operations throughout the 20th century. Not surprisingly, the 20th century saw another rise in the use of IEDs, not only by non-state actors and revolutionary or militia groups as well as the military. 

Within the 20th century, a wider range of IED attack types have been seen, firstly with the use of radio control systems, that allows the perpetrator to physically separate themselves from the device, giving a wider range of tactical opportunities.

More recently, the use of small commercial drone technology for IEDs provides the user with remarkable remote technology to deliver an IED remotely, without risk to themselves, to within an inch of its desired target. A typical IED user now has quite a range of attack methodologies available to him – roadside bombs, initiated by a mix of direct command and sensors, and large vehicle bombs which provide the user with disguise, volume and mobility.  IED technology is also allowing sub-national groups to compete with superpowers on the battlefield and indeed deliver IEDs from great distances. 

So it is that, even though the ‘War on Terror’ has seen a huge number of IEDs being used around the world against militaries and civilians alike, the IED has been with us for centuries, developing in line with technological changes in society, responding to the cultural and political realities of the age, and – in the end – evolving from being the most devastating weapon that states once had in their arsenals, to being the most devastating weapon that their non-state adversaries have today.

This paper was presented at the United Nations General Assembly on the 15th October, 2020, working with UNIDIR and the kind assistance of the French government.

This paper was part of AOAV report on the impact of IEDs today, and through history – and what this means for the future: IEDs: past, present and future.

This is a guest post by Roger Davies, author of