Constructing A Fuel-Air Car Bomb: A Deadly Guide

Fuel-air car bombs, also known as thermobaric weapons, are a type of explosive device that utilizes a fuel-air mixture to generate a powerful blast. Unlike conventional explosives that rely on a fuel-oxidizer premix, thermobaric weapons use only fuel, making them significantly more energetic for their weight. The basic design involves a container of fuel and two explosive charges. When the munition is deployed, the first charge opens the container, dispersing the fuel as a cloud, which then mixes with atmospheric oxygen. The second charge detonates this cloud, resulting in a massive blast wave that can cause extensive damage to reinforced buildings and fortifications. While fuel-air explosives are challenging to design and deploy, their effectiveness in confined spaces makes them a dangerous weapon with devastating consequences.

Fuel-air explosives are difficult to design

Fuel-air explosives (FAEs) are difficult to design for several reasons. Firstly, they require a precise understanding of the principles of combustion and detonation. FAEs rely on the continual combustion of fuel molecules as they come into contact with the air, generating heat that sustains the detonation. This process is complex and challenging to control.

Secondly, FAEs are typically composed of a single compound as fuel, rather than a mixture of substances, which means that the fuel must be carefully selected and prepared to ensure it ignites and burns effectively. The fuel also needs to be preheated well above its ignition temperature to minimize ignition delay upon mixing with the air.

Another challenge in designing FAEs is ensuring the wide distribution of the aerosol explosive before ignition. This step is crucial for maximizing the explosive's impact, but it can be difficult to achieve, especially in confined spaces or when using a handheld launcher.

Furthermore, designing an FAE requires careful consideration of safety measures. There is a risk of leakage of unreacted toxic fuel, which can pose a significant hazard. Qualified technicians must handle the rendering of FAE munitions safe, and specific procedures must be followed to avoid accidental detonation of the high-explosive content.

Lastly, constructing an FAE device typically involves the use of two separate explosive charges, which adds complexity to the design and assembly process. Overall, the successful creation of a fuel-air explosive requires a high level of technical expertise and a deep understanding of the underlying chemical and physical principles involved.

Gas cylinders can create a flamethrower-like effect

Gas cylinders can be used to create a flamethrower-like effect in a car bomb. This was demonstrated in the 2007 Glasgow airport attack, where the car bomb produced a "flamethrower-like effect", although there was no significant blast. Similarly, the Times Square car bomb in 2010 included propane tanks, which, when ignited, can create a flamethrower effect.

Flamethrowers typically use liquid fuel, such as heated oil or diesel, or gaseous fuels such as propane, which is safer due to its lower mass flow rate and faster dissipation. A flamethrower system consists of two or three cylinders. In a two-cylinder system, one cylinder contains compressed, inert propellant gas (e.g., nitrogen), while the other holds flammable liquid or gas, like propane. The gas propels the flammable substance through a pipe and into the gun element, which includes a reservoir, a valve, and an ignition system. When the trigger is depressed, the valve opens, allowing the flammable substance to flow over the igniter and out of the nozzle, creating a jet of fire.

The use of flamethrowers dates back to ancient times, with the first Chinese use of gunpowder in 919 CE involving the use of "fire oil" to burn a fleet. Modern flamethrowers were first used during World War I, and their use increased in World War II, where they were employed in both vehicle-mounted and man-portable configurations. During this period, the development of napalm, a jellied gasoline mixture, enhanced the effectiveness of flamethrowers, increasing their range and incendiary capabilities.

While the specific design and construction of a car bomb with a flamethrower-like effect may be beyond the scope of this discussion, it is clear that the incorporation of gas cylinders and flammable substances can create a flamethrower-effect, as seen in the Glasgow airport and Times Square incidents.

Fertilizer bombs are used by insurgents in Afghanistan

Insurgents in Afghanistan have used fertilizer bombs, also known as improvised explosive devices (IEDs), for many years. These bombs are made using ammonium nitrate-based fertilizers, which, when combined with a fuel source such as diesel or kerosene, can create a powerful explosion. The gas released from the decomposing fertilizer, along with the energy from the detonation wave, ignites the fuel, leading to a rapid combustion that releases even more gas. This rapid release of a large volume of gas is what causes the pressure waves of the explosion, which can damage nearby structures and harm individuals in the vicinity.

Ammonium nitrate is widely used as a fertilizer in agriculture and is effective at boosting crop yields. However, it has also been a common ingredient in explosives due to its ability to provide both fuel and an oxidizer. In its pure form, ammonium nitrate is not explosive, but when mixed with the right proportions of fuel and a detonator, it can become highly explosive. This dual use has made it challenging to restrict access to ammonium nitrate, as it is essential for food production in many parts of the world.

In Afghanistan, the soil is alkaline with a high pH, and the standard fertilizer used is ammonium nitrate with calcium carbonate. However, efforts have been made to introduce a non-detonable fertilizer in the region. Sandia National Laboratories developed an ammonium nitrate/iron sulfate fertilizer that, when mixed, creates two non-explosive compounds: iron nitrate and ammonium sulfate. This alternative fertilizer can help improve soil conditions in Afghanistan while reducing the availability of ingredients for IEDs.

Despite these efforts, insurgents in Afghanistan continue to use ammonium nitrate fertilizer bombs, taking advantage of their destructive power and the relative ease of access to the necessary materials. The use of these bombs has resulted in numerous casualties and contributed to the ongoing instability in the region. As such, there is an ongoing need to address the security concerns surrounding the availability and use of ammonium nitrate-based fertilizers in Afghanistan and similar contexts.

A fuel-air bomb can be made with a 5 lb. bag of flour and kerosene

Fuel-air bombs, also known as thermobaric weapons, are a type of explosive munition that works by dispersing an aerosol cloud of gas, liquid, or powdered explosive. The fuel is usually a single compound, such as kerosene, rather than a mixture of multiple substances.

To create a fuel-air bomb using a 5 lb. bag of flour and kerosene, you would need to soak the flour with the kerosene and drop it off a tall building or structure. This method may not produce much power, but it can still be dangerous and cause an explosion. It is important to note that attempting to create such a device is highly illegal and unsafe.

The principle behind this type of bomb relies on the combustible nature of flour. Flour is made up mostly of starch, which is a type of carbohydrate or sugar molecule. Sugar molecules burn easily, and when ignited, can cause a rapid combustion or dust explosion. This occurs when the powdered combustible material, in this case, flour, reaches a critical concentration in the air, forming an explosive mixture with the oxygen present.

It is crucial to understand that creating and experimenting with any type of explosive device, including fuel-air bombs, is extremely dangerous and illegal. The potential consequences of attempting to build such a device are severe and can result in serious injuries, death, and legal repercussions. Any discussion on this topic should be limited to academic or theoretical purposes only.

Fuel-air bombs are effective at killing infantry

Fuel-air bombs are highly effective at killing infantry. Fuel-air explosive (FAE) devices consist of a container of fuel and two separate explosive charges. The first charge bursts open the container at a predetermined height, dispersing the fuel in a cloud that mixes with atmospheric oxygen. The cloud of fuel then flows into structures and around objects. The second charge then detonates the cloud, creating a massive blast wave and a large smoke cloud. This blast wave can last significantly longer than that of a conventional explosive.

Fuel-air bombs are considerably more powerful than conventional explosives of equal weight. Their effectiveness is increased when used in enclosed spaces such as tunnels, buildings, and non-hermetically sealed field fortifications. The blast wave can destroy reinforced buildings and is extremely effective at clearing out forests and destroying infantry and weaker ground vehicles.

Fuel-air bombs have been used in guerrilla warfare since the 1983 Beirut barracks bombing in Lebanon, which used a gas-enhanced explosive mechanism that was probably propane, butane, or acetylene. The United States developed the CBU-55 FAE fuel-air cluster bomb for use in the Vietnam War.

The use of fuel-air bombs against military targets is not prohibited by international law. As of March 2024, all attempts to regulate or restrict their use have failed. While fuel-air bombs can provide humanitarian advantages by minimizing collateral damage, their use in populated areas should be minimized due to their wide-area impact.

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