the most advanced German flamethrower tank was the Flammpanzer III, seen here as a pair of these vehicles during exercises, source: Worldwarphotos.info with the permission of the operator, edited

From Antiquity to the 1930s

Although the first primitive flamethrowers were demonstrably used by the Byzantines as early as the 7th century AD – and quite possibly by the ancient Greeks and Romans many centuries before that – the modern flamethrower as we understand it today effectively appeared only in the 20th century, with its first wider use in actual combat occurring during the Great War (the First World War). During that conflict, the first experiments with installing a flamethrower in a tracked armoured vehicle also took place. None of the belligerents, however, took a flamethrower tank into production or committed one to combat.

The true development of flamethrower tanks came only with the interwar period, and above all with the Second World War. The Soviet Union devoted considerable energy to this type of fighting vehicle during the 1930s; on the basis of the light T-26 tank alone, at least three distinct flamethrower vehicles were produced there. The first flamethrower tank actually committed to combat was, however, most likely the Italian L3 Lf, during the so-called Abyssinian War of 1935–1936.

The German Approach

Hitler's Germany did not stand aside, but in the second half of the 1930s confined itself to research and experimental trials. The German findings of that period were neatly summarised by Waffenamt official Ing. Olbrich in a paper written in June 1939. The Germans devoted considerable effort to maximising the effective range of the flamethrower. They therefore examined the advantages and disadvantages of pressurising the incendiary mixture using a pump versus compressed gas, the range achievable with nozzles of different diameters and shapes, the effect of the density of the incendiary compound itself, the influence of weather conditions, the effect of nozzle elevation, and a range of other factors. They also analysed the advantages and disadvantages of carrying the fuel directly in the vehicle versus towing it in a trailer.

the PzKpfw B2 (Flamm) was created by converting captured French tanks; the burning incendiary mixture produced enormous quantities of black, choking smoke whose smell helped to drive concealed infantry from their positions, source: Bundesarchiv Bild 101I-708-0293-14, Wikimedia, Creative Commons, edited

On the basis of their findings the Germans came down firmly in favour of carrying the incendiary fuel supply on board the tank itself rather than in a trailer. There were several reasons for this. A trailer significantly reduced the vehicle's mobility and in particular its cross-country performance. It also complicated the already difficult business of reversing a tank. Equally important was the fact that the longer the system of hoses through which the fuel flowed, the more susceptible it was to leaks and pressure loss. It was therefore preferable for the fuel tank to be positioned as close as possible to the projector nozzle – the lance. This naturally argues strongly against drawing the liquid through a long hose from a trailer behind the tank.

The trailer solution had two main advantages, according to its proponents. A trailer could usually carry far more incendiary fuel than could be stowed inside the tank itself. Its second advantage was the theoretically greater safety it offered the crew. If the trailer were hit and caught fire, the crew could immediately detach it by remote control and simply drive away. The Germans consciously chose to sacrifice the first of these advantages. They simply preferred greater vehicle agility and a longer effective range over a larger fuel capacity.

As for crew safety, in their first two flamethrower tank types – the Flammpanzer II and the PzKpfw B2 (Flamm) – the German designers placed the fuel tanks on the exterior of the vehicle (in the first case on the track fenders, in the second on the rear of the hull). For all subsequent types (Flammpanzer III, StuG Flamm and Flammpanzer 38(t)), however, the Germans changed their approach and simply installed the tanks directly inside the fighting compartment. They had come to the conclusion that this arrangement was actually safer overall.

close-up of the flame projector nozzle (lance) of the Flammpanzer II flamethrower tank, source: Flickr.com, edited

The greatest source of danger for a flamethrower tank crew was not, in reality, the fuel tank itself, but the necessity of closing to within a very short distance of the enemy. And this risk had to be taken by the Flammpanzer regardless of whether it carried its fuel in a trailer or in the fighting compartment. The latter option did, however, have the advantage that at the critical moment its fuel tanks were far better protected inside the armoured fighting compartment. Admittedly, sitting inside such a vehicle surrounded by flammable liquid may seem alarming at first glance, but in this respect the Flammpanzer was actually not very different from an ordinary tank, in which soldiers were surrounded by ammunition that was no less dangerous.

The incendiary compound itself also plays an enormous role in the overall effectiveness of a flamethrower. It must not burn too quickly, or it will be consumed before it has done the necessary damage, yet it must burn intensely enough for the burst to have the desired force. It must not be too thin, or it will atomise in flight and drain too quickly from the struck surface on impact, yet it must not be too viscous either, or it will clog the nozzles. The Germans placed their faith in a mixture known as Flammöl (incendiary oil) – a blend of petrol and coal tar. The petrol provided rapid combustion, while the tar gave viscosity and acrid smoke. Igniting such a thick mixture was not always straightforward, especially in frost, and acetylene – which is much more readily ignitable – electric glow plugs, or ignition cartridges known as Zündpatrone were used for the purpose.

German research further showed that for any given nozzle shape there is a pressure and flow velocity beyond which there is no benefit in going further. In other words, you can keep raising the pressure – and with it the muzzle velocity of the fuel stream – indefinitely, but you will reach a point at which air resistance causes the stream to break up rather than remaining cohesive, and the effective range of the flamethrower drops dramatically.

even the Hetzer tank destroyer received a flamethrower version, designated the Flammpanzer 38(t), source: Flickr.com, edited

Wind, naturally, also had a generally negative effect on effective range. The Germans found that while the effect of wind was negligible at ranges up to 30 metres and acceptable up to 50 metres, beyond 50 metres it became quite significant. Another finding was that fuel consumption grows more than linearly with the pursuit of greater range. To deliver an effective flame burst to a distance of 80 metres required 60 to 70 litres of incendiary fuel! Designers therefore had to choose between many shorter bursts and a very limited number of long ones. The Germans generally chose the path of more bursts at shorter range.

Flamethrower Tank Tactics

Flamethrower tanks were generally intended for eliminating or flushing out concealed infantry, particularly from trenches or fortified positions. Their effectiveness in this role came not only from the fire and its heat, but also from the densely acrid and suffocating smoke produced in vast quantities by the burning incendiary mixture. Once the enemy infantry had been driven from cover, the Flammpanzer itself finished the job with its machine gun, or friendly tanks and infantry took care of it. The enormous volumes of smoke revealed a flamethrower tank's position at great distance and attracted unwanted attention from enemy artillery and aircraft. This is why the Germans had very poor experiences with deploying Flammpanzers in the open Russian countryside, where clouds of smoke were visible from literally several kilometres away.

A flamethrower tank was a classic support weapon, intended to help other units overcome a difficult obstacle in the form of fortifications or bunkers. Against enemy tanks and anti-tank guns, however, Flammpanzers were practically defenceless. They therefore needed to be committed ideally in the company of friendly tanks, which provided cover for them. A Flammpanzer could take on an enemy tank only if it managed to approach it undetected and catch it by surprise. In that situation it had a chance of either setting the enemy vehicle directly on fire or at the very least knocking it out of action by destroying its observation devices.

the half-tracked Sd.Kfz. 251/16 was not a flamethrower "tank" as such, but its ability to sow fiery hell was comparable, source: Bundesarchiv Bild 101I-281-1110-03, Wikipedia, Creative Commons, edited

The Road to Oblivion

Although flamethrower tanks were produced and deployed during the Second World War by virtually every belligerent – Germans, Japanese, Americans, British and Soviets alike – their development reached a dead end fairly quickly. The proliferation of cheap hand-held anti-tank weapons with which an ordinary infantryman could destroy even a heavily armoured vehicle at ranges of tens of metres (bazooka, PIAT, Panzerfaust, Panzerschreck…) made the tactical approach of flamethrower tanks literally suicidal. It is therefore unsurprising that after the Second World War this type of armoured vehicle gradually faded into history, superseded by other weapons that deliver incendiary compounds onto a target from greater distances – incendiary bombs, napalm, thermobaric weapons.

ARTICLE
CONTENTS:

A BIT OF HISTORY

THE GERMAN APPROACH

COMBAT TACTICS

THE ROAD TO OBLIVION