A flamethrower at the Knob Creek Machine Gun Shoot. Picture: Kristoffer Tripplaar / Alamy

A flamethrower at the Knob Creek Machine Gun Shoot. Picture: Kristoffer Tripplaar / Alamy

Weapons and Kit

Flamethrowers – From The British Ack Pack To The Napalm-Fuelled American M9

A look at one of the most deadly hand-held weapons in history - branded 'inhumane' by military leaders

A flamethrower at the Knob Creek Machine Gun Shoot. Picture: Kristoffer Tripplaar / Alamy

A flamethrower at the Knob Creek Machine Gun Shoot. Picture: Kristoffer Tripplaar / Alamy

Flamethrowers might have been labelled “an inhuman projection of the German scientific mind” by military leaders themselves but the use of one of these most brutal forms of hand-held weaponry has been seen in many conflicts throughout history – with versions dating back to at least 7th Century Greece.

The use of certain incendiary weapons was banned under the 1980 Conventional Weapons Convention, not without good reason, but flamethrowers have long been used in battle and formed part of the arsenal of the First and Second World Wars before going on to be used by American personnel in Vietnam in the 1960s.

What Is The History Of Flamethrowers?

Firing burning fuel at the enemy has been around for centuries with the earliest form of this type of weaponry dating back further than the 7th Century when long tubes packed with some form of inflammable substance such as coal or sulphur would be blown out by the soldier. The soldier would blow down one end like a pea-shooter towards the enemy.

Byzantine armies used a mixture of fuels that sprayed out from narrow brass tubes propelled by the pressure of the burning oil-based liquid to form a flaming jet.

Flamethrowers In Modern Times

It was not until modern times, however, that professional armies took a factory-manufactured flame-throwing weapon into battle.

Germany had refined early experiments in flame-firing weapons into a portable backpack flamethrower by the 1930s.

Flamethrower designs in modern times are based on the early developments of German scientist Richard Fiedler whose man-portable device consisted of a four-foot cyclinder, with pressurised gas in a lower section and a flammable oil in the upper section, connected to a steel nozzle with an ignition wick attached to it.

The first production-standard weapon of this type was issued to German infantry in the First World War.

Primarily used for clearing trenches by firing a flaming spray at enemy soldiers, the Flammenwerfer M16 was taken into battle in the 1900s, with records suggesting the flamethrowers’ first use was in 1915 in the Battle of Verdun, and other reports of its use in the Battle of Argonne – part of the Allies’ final major offensive of World War One along the Western Front.

Wehrmacht Flammenwerfern German flamethrower operator on the Eastern Front early in the Russian campaign in WWII. Picture: Lordprice Collection / Alamy

Wehrmacht Flammenwerfern German flamethrower operator on the Eastern Front early in the Russian campaign in WWII. Picture: Lordprice Collection / Alamy

The Flammenwerfer model was developed further with the advent of the Flammenwerfer 35, or FmW 35, in the 1940s which could fire a jet stream of fuel up to 30 meters from its handler but weighing at some 35kg or more, it was not the most versatile of weapons to carry. At close range, however, it could be deadly – used to blast enemy positions in buildings, or trenches, the weapon gained the somewhat morbid moniker the ‘skin-steal’ due to stripping its targets of skin as they became engulfed in a high-intensity jet of fire.

Outcry Over Flamethrower Deaths

The rise of flamethrowers in warfare was met with growing concern in Britain, where military leaders called them “an inhuman projection of the German scientific mind."

The United Kingdom had already submitted a draft convention to the League of Nations Disarmament Conference by 1933 that suggested a prohibition of the use of incendiary weapons – specifically calling an international end to the use of “projectiles specifically intended to cause fires” and the use of “appliances designed to attack persons by fire.”

Despite the reservations, Britain did push ahead with its own flamethrower weapon – and the use of these incendiary devices was widespread on all sides by the Second World War.

By 1943, Britain had developed the portable No.2 flamethrower, nicknamed ‘lifebouy’ because of the shape of its fuel tank but which more commonly became known as the ‘Ack Pack’.

This largely followed a similar design to Germany’s 1917 Wechselapparat that had been used in the First World War. Containing about 18 litres of fuel in a container shaped a little like a doughnut, this flamethrower was used to clear bunkers and buildings – spraying burning liquid at the enemy.

A typical style of flamethrower. Picture: Jumpstory.

A typical style of flamethrower. Picture: Jumpstory.

The United States also developed flamethrowers during the Second World War.

Its M1 portable incendiary weapon had a range of 15 meters, weighed 72lb and carried about five gallons of fuel. This version was later upgraded into the lighter M1A1, weighing 65lbs.

The M1A1 was a far deadlier weapon – not only did it fire its flame spray up to 45 meters but by this stage, the US had developed its use of napalm, a thicker inflammable agent made from a mixture of petrochemicals and a gelling agent that allowed it to stick to targets. Once ignited, napalm can burn at more than 5,000 degrees Fahrenheit, or 2,760C, making its use in flamethrowers lethal.

The model M2 followed, which was formed by three canisters carried on the soldier’s back containing a mix of fuel and chemicals, with a pistol-like flame-gun carried by hands.

Flamethrowers provided troops with a deadly, and perhaps horrific, method of blasting enemy soldiers as they defended a stronghold position in a bunker or other enclosed space where they could take cover from bullets, even grenades. Flamethrowers tended to fill an enclosed space with a mass of burning napalm or other fuel – and engulfing anyone inside in a ball of flames with little chance of escape.

The downside, however, was that a soldier carrying a flamethrower generally had to come out into the open to fire it – exposing his own position and making him a vulnerable target for snipers who soon realised that if they targeted the canisters, they could cause an explosion, not only killing the soldier carrying the flamethrower but anyone else in the near vicinity.

Other nations had their own versions including Japan, Italy, Poland and the Soviet Union whose 1935 ROKS flamethrower design went some way to solving the problem of users being picked out as prime targets by hiding the fuel tanks as a regular backpack and a nozzle designed to look a little like an ordinary rifle.

Despite increasing unease about the horrors that flamethrowers inflicted on their targets, their use nevertheless continued following the Second World War.

America’s M2 went on to see action in both the Korean and Vietnam wars, while the US developed an even lighter model in the M9, that was also easier to pack and was fuelled by an advanced formula of napalm. The M9 could also reach an effective range of 60 meters at full pressure.

The US used such flamethrowers throughout the Vietnam War but there was growing disquiet over the injuries inflicted on casualties engulfed in flames.

Images from the Vietnam War featuring badly burned bodies galvanised opinion further.

Flamethrowers Not A ‘Mercy Killing’

It was about this time that questions were also being asked internationally, of how painful and inhumane a death was caused by incendiary and immolation devices, specifically on the length of time it took for a casualty to die after being engulfed in a sticky jet of flaming liquid.

The US Chemical Warfare Service (CWS) had initially referred to flamethrower deaths as a ‘mercy killing’ but their early reports, that flamethrowers offered a quick and therefore relatively painless death, had been based largely on eyewitness accounts from the frontline of the Second World War which suggested casualties had been 'silenced' quickly after a flamethrower attack, rather than reliable data and scientific research.

Several years after flamethrowers had been seen in action in major conflicts, the CWS and the US National Defense Research Committee (NRDC) conducted experiments on pigs, dogs and other animals – with the findings revealing that deaths resulted in a combination of factors such as asphyxiation, CO poisoning, extreme high blood pressure, cessation of cardiac function and shock among other causes.

The results clearly suggested to the researchers that flamethrower deaths, even if quick, were unlikely to offer painless, instant or humane deaths.

There were increasing calls for such incendiary weapons to be banned but it was not until 1978 that the United States Department of Defense put an end to the use of the weapon in battle.

The flamethrower has fallen out of favour for a variety of reasons, in part simply because they have been overtaken by more effective battle tactics in modern times, but also as a result of international treaties and the law, and campaigns by human rights groups.

More advanced weapons, such as rocket-propelled grenades (RPG), which can be accurately fired from a distance at a target, have also contributed to the decline in the need for a flame-throwing back-pack of heavy canisters which run the risk of exposing the user to the enemy and can only be fired from a relatively close range to its target.

Have Flamethrowers Been Banned In International Law?

While flamethrowers are not specifically listed as a banned weapon in law, the United Nations Convention on Certain Conventional Weapons (CCW), that was concluded at Geneva on October 10, 1980, and entered into force in December 1983, prohibits or restricts the use of certain conventional weapons which are “considered excessively injurious or whose effects are indiscriminate,” with a raft of restrictions listed in Protocol III of the convention.

Flamethrowers could, technically, still be used in some circumstances, for instance to clear pathways or foliage as part of, say, a military advance, but the CCW includes “any weapon or munitions which is primarily designed to set fire to objects or to cause burn injury to persons through the action of flame, heat, or combination thereof, produced by a chemical reaction of a substance delivered on the target,” and devices of this nature are considered to fall within this category.

Protocol III primarily bans incendiary weapons against civilian targets but its focus, in military terms, prohibits the use of incendiary weapons by air that could indiscriminately kill civilians in the process.

Some form of incendiary weapons are still in the arsenals of some countries, however.

Russia’s TOS-1A Solntsepek, or ‘burning sun’ in English, fires thermobaric missiles from a multiple rocket launcher mounted on a T072 tank chassis – with each missile containing a mix of fuel and air that, when they explode, create a huge ball of heat and pressure. There are reports that suggest such weapons have been used during the recent conflict in Syria.

However, amid a backdrop of public outcry, international law, and the advent of modern battle tactics, and given the limited effective use of flamethrowers in conflict, it seems unlikely that any form of man-portable flamethrower will be seen on the battlefield again.