In 1900, long before the Great War began, and trench warfare created a static Western Front, a German engineer - Richard Fiedler - invented what was perhaps the first terror weapon, the Flammenwerfer (English = Flame-thrower or Liquid fire projector). Adopted in 1906 by the Imperial German Army as a potential infantry support weapon, and developed in secret, this device was formalised as a weapon of war by the creation of a Flammenwerfer regiment: by 1912 there were twelve companies in three battalions. This parent unit was the Guard Reserve Pioneer Regiment, and Flammenwerfer teams were seconded from the component companies to support German infantry assault troops as the need arose.
The original Flammenwerfer apparatus
The prototype was a rudimentary device consisting of a cylindrical steel tank from which ran a metre long length of flexible rubber tubing attached to which was a metal nozzle incorporating a control valve. A leather harness was attached to the cylinder so it could be carried on the back of one of a two-man team. The other team member manipulated the nozzle and the control valve.
The inside of the reservoir tank of the Flammerwerfer was divided into two equally sized compartments that contained, respectively, a pressurised gas (usually nitrogen) and a flammable fluid, such as oil mixed with petrol.
The operator would point the nozzle at an enemy target and open the control valve on the nozzle. As the gas pressure expelled the flammable liquid, the operator would light the fuel using a wick, or taper, and direct the ensuing flame at the enemy.
The flame could be projected for a distance of around 20 metres and for a duration of about two minutes. By skilful use of the operating tap several targets could be attacked in sequence, and the 'life' of the reservoir extended accordingly. Similarly, by means of special cartridges, short bursts of flame could be created and projected to more effectively cover scattered targets.
The deployment of the Flammenwerfer
Given the German Army's predilection for terror weapons and terror tactics, it is somewhat surprising that they did not deploy this weapon until 26th February 1915. The chosen target for the first operational trial was a concentration of French troops in the Verdun Sector.
Apart from the initial surprise element, the Flammenwerfer attack did not have a great impact, and a conventional French counter-attack the following day effectively neutralised the situation.
A much more notable incident occurred at Hooge on the night of the 29th/30th July 1915, during the Second Battle of Ypres. Although only six Flammenwerfers were used on a limited frontage, the effect on the inexperienced troops of Kitchener's British New Army was dramatic, even though there were only few casualties from burns. The Germans captured whole trenches, and a general sense of demoralisation among the British troops was reported by their commanders.
Immediately, the Flammenwerfer was envisaged by all the belligerents as a possible weapon of war with particular application to trench warfare, where it was seen to have great potential against troops in both trenches and dug-outs.
The further development and wider deployment of the Flammenwerfer/Flame-thrower
The French Army had captured examples of the Flammenwerfer during the attack at Verdun and demonstrations were made to the French and British Staff in March 1915. Despite a generally positive appraisal, there were still strong reservations from some British military quarters about its efficacy and applicability as a weapon of war. But, after the Hooge incident, both the French and British began a serious development programme. In the case of the British it was from first principles, whereas both the French and the Americans had already planned prototypes: respectively the J. Herchent and J. Menchen models.
On the British side, the outcome was that a development team of the Trench Warfare Department came up with several prototypes. The first was a one-man knapsack model (The Hay) that was largely based on French patents and had an effective range of about 30 metres (33 yards). It weighed a relatively light 40 kilogrammes (88 pounds) but only had a limited capacity of 30 litres (6.6 Imperial gallons) and an effective operational life of around 20 seconds. It was successfully tested in December 1915.
However, the British High Command could not agree on a coherent modus operandi for the flame-thrower. The machine was produced in some numbers and used on the Western Front in a very limited way to demonstrate to the British troops that an operational one-man model was available should it be needed operationally. But it never went into wide-scale production and deployment. The only notable use of the knapsack sprayer in action was that by the Royal Navy in the Zeebrugge Raid in 1918.
The British produced two other models of flame-thrower, a two-man medium model and a heavyweight version with a crew of eight. The semi-portable, two-man model had an effective range of 50 metres (55 yards) and a flame life of 20 seconds. At 100 kilogrammes (220 pounds) and a capacity of 70 litres (15 Imperial gallons) it presented considerable logistic problems. A batch of 24, 55 litre (12 Imperial gallon) versions of this semi-portable model was taken to France by its British designer, Captain Livens, Royal Engineers, for use in the forthcoming Somme Offensive. It went into action on a limited scale in July and September in 1916.
After nearly a year of development the heavyweight, or battery, version was also ready. It had four 90 litre (20 Imperial gallon) tanks and a combined flame life of 50 seconds. It weighed a tonne and was the size of a small modern car. A flow interrupter device allowed up to 16 'flame balls' to be projected as much as 80 metres (88 yards) over a period of 5 minutes.
Six of the larger Livens battery flame-throwers with 12 tanks (1,100 litres [240 Imperial gallons] of four minutes duration were also taken to France in 1916 for deployment the Somme Offensive. Two machines were dug into the Somme Front and were deployed just before the British troops went over the top. It was claimed that 40 German soldiers were killed by the liquid fire, whilst many others were demoralised.
Evidently, both the two-man and battery flame-throwers produced some effect, but it was not thought to be significantly efficacious in military terms. Further development and deployment by the British Army ceased after 1916.
The introduction on the Western Front in 1915/16 of the highly successful Stokes Mortar, the Livens Oil Can Mortar and, later, the Livens Projector, seemed, at the time, to offer by far the better option. These devices could rapidly rain down on the heads of the entrenched enemy troops large numbers of projectiles containing toxic gas, incendiary bombs and high explosive; all at far less risk to the operators of the British infantry.
The French used their flame-throwers extensively with a portable model - the Schilt - being particularly effective against pillboxes and dugouts. The Schilt carried a useful 15 litres (3.3 Imperial gallons) of fuel with a three burst capacity of 25 metres (27 yards) or a single burst for 100 metres (110 yards).
After the 1915 attacks, the German Flammerwerfer teams were active throughout the war on the Western Front. Particularly favoured were the Grof (Grossflammenwerfer) heavy-duty model, with 35 metres (38 yards) of flame projection, and two portable models, the Klief (Kleinflammenwerfer) and the Wex. The Klief was a two man portable model with a range of 20 metres (22 yards). The one-man Wex, had the distinctive Polo Mint shaped fuel tank - frequently seen in Great War action photographs and ciné film. It had a capacity of 12 litres (2.75 Imperial gallons) and the capability to produce 10 bursts of flame at a range of 30 metres (35 yards) or in a single burst, a projection of flame up to 100 metres (110 yards). Uniquely, the Wex had an automatic ignition system
Perhaps the key development that evaded the designers of the flame-throwers of the Great War was the absence of a fuel thickening agent (e.g. latex rubber). This would turn the fuel into a gel to facilitate its projection and adhesion and reduce the possibility of a blow back on the operators. The efficacy of such a gel was amply demonstrated in the flame-throwers of the Second World War.
Overall, the Flammenwerfer/Flame-thrower was never a great success in the Great War. The operators were singularly vulnerable to small arms and shell and mortar fire: the carrier of the flame-thrower reservoir tank(s) being a particularly obvious target.
Also, the belligerent armies quickly learned to site the defences of their trenches so as to be out of the effective range of the Flammenwerfer/Flame-thrower. The longest effective range ever achieved was around 120 metres (130 yards). The larger models of flame-thrower were difficult to move about and install, and required huge amounts of fuel and gas to keep them working effectively.
Nevertheless, it should be recognised that the British Army totally failed to see the enormous potential that was indicated by the French Army's limited success with the flame-thrower against German strong points. If a thickening agent could have been developed, and an appropriate modus operandi devised, the flame-thrower could well have proved to be a particularly effective weapon against the troublesome and costly strong-points that were encountered during the Allied advance in 1918. This efficacy was clearly demonstrated 30 years later in another World War. And particularly so in the American's Pacific Islands Campaign.
Finally, it is worth noting that the Great War designers got their basic designs right. Although the flame-thrower has been improved over the years, the principle and operating system remain essentially the same.