page_title: Flame fougasse
section_title: Safety fougasse
hierarchical_section_title: Flame fougasse / Design variations / Safety fougasse
caption_attribution_description: English: Fougasse charge
context_page_description: A flame fougasse is a type of mine or improvised explosive device which uses an explosive charge to project burning liquid onto a target. The flame fougasse was developed by the Petroleum Warfare Department in Britain as an anti-tank weapon during the invasion crisis of 1940. During that period, about 50,000 flame fougasse barrels were deployed in some 7,000 batteries, mostly in southern England and a little later at 2,000 sites in Scotland. Although never used in combat in Britain, the design saw action later in Greece.
  Later in World War II, Germany and Russia developed flame throwing mines that worked on a somewhat different principle.
  After World War II, flame fougasses similar to the original British design have been used in several conflicts including the Korean and Vietnam Wars where it was improvised from easily available parts. The flame fougasse remains in army field manuals as a battlefield expedient to the present day.
context_section_description: The most common form of the flame fougasse was the safety fougasse. This design allowed the propelling charge to be stored separately until needed. The safety fougasse was constructed as follows: a small section was excavated from the side of a slope, leaving a shallow platform of earth, and a barrel of incendiary mixture was placed horizontally in a low position with one round face pointing towards the target. At the back, a section of stove or drain pipe was placed vertically against the rear face of the barrel. The lower end of the pipe was blocked off with a thin cover and positioned a few inches above the bottom of the barrel. The top of the pipe was fitted with a loose cap to keep water out. This pipe is what makes it a "safety" fougasse because it allows later installation of the propelling charge. Soil was then built up over the weapon until all that could be seen were the front disk of the barrel and top of the pipe.
  The propelling charge was prepared with an electrically triggered detonator in a primer bound with insulating tape to three or four cartridges of ammonal explosive. This assembly was placed in a small, waterproof rubber bag that was, in turn, placed inside a used cocoa tin. Four ounces (110 g) of magnesium alloy turnings were added to ensure ignition of the fuel. The electrical wires were passed through a small hole in the lid of the tin which was then tightly fitted. The propelling charges were kept in storage, only to be deployed when enemy action was imminent. To activate the device, the propelling charge was lowered down the pipe and tamped down with dry soil before being connected to a firing point about 100 yards (91 m) away. Firing required the current delivered by a 120 V battery.
  Private Harold Wimshurst later recalled:
  We had a special job. We had to go all round these villages where there are banks and bends in the road and we had to insert these barrels of inflammable material into the banks. A charge was put behind them with a wire running behind them to the nearest cover. A detonator was put in a pipe down the back of these barrels and the idea was that if the tanks came round on the road, we'd detonate these barrels of flaming liquid over them. 
  A non-safety fougasse could be built by simply burying the propelling charge behind the fuel drum and running leads through the soil. Instructions for several variants of this design were published but this construction increases the hazard because the leads would have to be left exposed on the surface and any electrical current applied could, theoretically, ignite the charge. Also, underground moisture could also easily ruin the charge over an extended period of time.
  The safety fougasse design had the advantage that without the propelling charge the fougasse was sufficiently safe that it did not require a guard. Banks records that installing the charge only when there was clear danger relatively close at hand was a safety feature required to protect the public from accidents. The ammonal used for the main propellant charge is a cheap industrial explosive that is notoriously hygroscopic, becoming less effective when it absorbs moisture. Even though the charge was packed into a rubber bag in a tin and sealed with insulating tape, it would not have been a good idea to store it for long in the damp conditions of a flame fougasse installation.
  Flame fougasses were camouflaged with a covering of light material such as netting – anything heavier would significantly affect the range. They could easily be merged into hedgerows or the banks of a sunken lane within view of a well-hidden firing point. They were placed where a vehicle would be obliged to stop, or at least slow down. The flame fougasse would offer instant and horrific wounds to any unprotected men caught in its fiery maw and would cause a vehicle engine to stop within seven seconds simply because it was deprived of oxygen (although it would easily start again once the fireball subsided, provided nothing was damaged).
  British soldier Fred Lord Hilton MM later recalled:
  On one occasion digg
caption: Fougasse charge diagram.[20]
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