In attack the lance-flame is usable in all circumstances, inter alia against the personnel, in direct shooting or curve where it can replace the grenades advantageously, would be this only by its prolonged effect. Its ignited liquid penetrating with facility through the least interstice its employment is particularly effective against the motorized machines, the trenches, the shelters and blockhouse, except if the target is hermetically closed.
In defense, it can be effective against the infantry using of the shell holes to progress by successive jumps. But in defense it can also be replaced by traditional association: machine-gun, mortar of small gauge, grenades.
Flame thrower and fortification CORF
The principle of the installation of flame thrower is considered by the CORF, as of the design of the works. But fault of powerful materials and especially taking into account the lack of advantage of the flame thrower in the defense brought closer to the fortification, the weapon is not retained with the profit of the association of FM-JM (tended shootings) and mortars of 50mm (curved shootings) to which are associated grenade throwers.
However, in 1937, the question of the installation of flame thrower in the works returns to the day order, of the material testings are undertaken, analyzed, their results are considered to be - interesting. Only the Mandet flame thrower, handy so much so that it can equip bells GFM, exceeds the stage of the prototype. It will remain however in the paperboards (undoubtedly because of fact that the GFM are already over-equipped).
Mandet flame thrower
Mandet flame thrower
Flyleaf, very ornamented, of the document concerning to the tests of the flame thrower.
Overall picture of the Mandet apparatus tested.
The flame thrower consists of two stations:
- the station of shooting, with the lance adaptable to a standard crenel GFM, been useful by the gunner,
- the station of provisioning, with the engine and flammable liquid tanks, been useful by two providers.
These two stations, more or less distant one from the other, are connected between them by a set of three pipes: one brings the flammable liquid under pressure; the second allows the maintenance of a night light lit at the end of lance; the third is a speaking pipe connecting the two stations.
Description of the lance
Launch Mandet apparatus, view from above right.
Left towards the line:
- with the top of the lance: lever actuating the valve of launching flammable liquid,
- with the lower part of the lance: crank of the magneto (and magneto) being used to ignite the night light of the end of the lance,
- in the center: attachment unit to the crenel of GFM,
- with the far right: burner, night light.
Sight right profile. On this photograph the night light was removed.
Close-up on the night light.
- in the center: gun of exit of the flammable liquid,
- around: night light with eight holes,
- on the left: electric lighter of the night light (connected to the magneto).
Bottles of provisioning.
This station consists of two symmetrical mechanisms alternatively usable and interconnectables.
Each mechanism understands 2 long bottles of air under pressure (propellent) located on both sides of a large bottle (flammable liquid tank) whose contents allow 20 seconds a continuous shooting (that it is advised to replace by a series of 20 one second shootings each one).
When one of the two large flammable liquid bottles is empty, a lever makes it possible the one of the two providers to connect the second bottle to the lance, while the other provider fills the empty bottle. The bottles of compressed air are also interconnectables and last very a life long life (of which we did not find the value exact).
Filling of a bottle.
Restocking in flammable liquid has a strong point: it can be carried out starting from ordinary barrels, of the trade. No pump is necessary because a double pipe makes it possible to put the barrel under light pressure (a strong pressure would make it burst) what drives back the flammable liquid.
Advantages of the system
This system, mobile on carriage, can thus be moved according to the needs. But especially it is autonomous! I.e., that it does not need compressor functioning during the use of the flame thrower nor of pump to reload it. It is an important advantage since it can thus equip the blockhouses deprived of generators.
Handling and performances of the flame thrower
When the apparatus is ready to function the gunner lights the night light, after having opened its circuit, aims and draws, by gust of one duration old jets of 1 second each one.
The pressure of the flammable, variable liquid at will between 500,000 and 1,200,000 Pa, makes it possible to obtain a range ranging between 8 and 30m (less by head wind, as one can suspect it).
As the ignited jet is almost rectilinear until its extinction, if one wishes to carry out curved shootings (for example to reach attackers ravelled in a shell hole), it is enough to launch a jet, extinct night light, then to then ignite the puddle pool produced by a new jet, night light lit.
Weak point: the filling of the flammable liquid tank is not possible in less than 20 seconds (it is necessary some just a little more). However a continuous shooting emptying it in 20 seconds this flame thrower cannot be used uninterrupted more 40s (time of emptying of the 2 tanks). On the other hand, successive short shootings of 1 second can be repeated very a long time because they leave sufficient time to reload the tanks.
Signature of qualification of the flame thrower.
After tests with the Establishment of Technical Experiments of Bourges, on November 15th, 1938, military engineer Principal Cabrit concludes:
The Mandet apparatus appears as of now being able to be subjected to tests in the works strengthened under the normal conditions of employment.
We did not find trace of these tests. Did they take place? Was it noted that they did not bring large-thing to the defense brought closer to the works? Did one judge good not to install an apparatus moreover in already overloaded bells GFM of materials? Always it is that no flame thrower equipped the works in 1940.
SIAM flame thrower
SIAM flame thrower
In 1937, the question of the installation of flame thrower in the strengthened works returns to the day order. The SIAM Establishments produce an apparatus which they present to the Technical Section of the Ministry for National defense and the War on November 17th, 1938. It is a little late, taking into account the fact that the Mandet Establishments already presented a system (different) whose principle was approved.
The SIAM apparatus is much more powerful than its competitor. Indeed, it can launch jets to more than 70 meters, it can be used uninterrupted and its consumption is low (10 liters/second). Moreover it is technically very simple.
Principle of the SIAM apparatus. Cima diagram
The apparatus is technically simple. It is made up: - of a flammable liquid tank whose dimension is not imposed, - of a reserve of accumulation (accumulating) hermetically closed, - of an electrical motor of large power (at least equal to 10 kw) which actuates a pump, - of a pump centrifuges which charges, in flammable liquid, the reserve of accumulation, which increase the pressure of the air in this last, - of a flexible pipe which connects the reserve of accumulation to a lance spray, - of a lance on which a night light is fixed whose lighting is done by magneto.
But the SIAM apparatus has three major disadvantages: its lance is cumbersome, it is not mobile and, especially, it has electric energy requirement, which prevents it from being used in the blockhouses without generating power station. Also on November 30th, 1938 colonel Mouflard, director of the technical section of the Genius, suggests he holding this flame thrower with the rough works and provided that he is installed in the new armourings (thus new blocks) especially studied for this purpose. He proposes a standard armouring particularly bell LG, with retractable mushroom, in order to ensure a shooting on 360°.
Taking into account the fact that the SIAM apparatus was likely to be approved only after the study of new armourings, it is not very probable that an operational prototype was construct. At all events, on our side us did not find traces of them.
Protection of the fortifications
Simulation of attack
Protection against flame thrower
Simulation of attack to the flame thrower
Test of flame thrower in B1 of Laundrette (SF Savoy) April 26th and 27th 1940 (Compare the date of the test with on May 10th, 1940: attacks German).
The French high command having emitted some doubts about the effectiveness of the material of ventilation vis-a-vis the flame throwers whose German army is equipped, of the tests are programmed in the Alps where the Italians did not show quarrelsome acts yet.
April 26th the tests are carried out on a normal air intake (without deoiler nor plate of protection), ventilation moving, of course! A lance-flame projects 10 liters of ignited mixture of oil and gasoline in several successive jets. Then the experiment is renewed.
The results are catastrophic! The filters are immediately clogged and their flow is divided by 3 (It passes from 600m3/h to 200m3/h). Only consolation, they remain tight.
April 27th the tests are taken again with the same protocol, but this time the air intake is protected by a plate from sheet. The results are more satisfactory than the day before since the filling of the filters is then clearly decreased. But it does not remain about it less than after two successive tests the air flow of ventilation passes all the same from 600m3/h to 500m3/h. It does not have what there to dress.
Report of the Permanent Delegation of the Technical Sections during its meeting of May 9th, 1940 (German attack day before):
The tests of flame thrower on the air intakes showed that the filter was rather quickly clogged. The successively tested protective apparatuses (deoiler, plate or hood of protection of the opening of air intake) could not prevent filling.
The problem is immediate unresolved!
Disassembling of filter after experiment.
Effects on the ground
Note, right before the combat of May 1940 (extracted)
Heading of the signed memorandum, on April 30th, 1940, by the GEORGES general, ordering in chief on the North-eastern Face (Document SHAT).
Whatever the mode or the power of the flame throwers those acts by successive jets. In each jet they project during a very short amount of time an significant amount of liquid which is normally ignited with a few meters of the exit of the adjutage. The fluid flush can also not be ignited. In this last case a later jet puts fire at the liquid projected before.
The range of the German machines is not known exactly. One can however admit the following figures: 100m for the tanks flame thrower, 30 with 40m for the portable machines.
The flames act either by direct burn or by rise in temperature (more than 1000°C) making intolerable a zone extended enough to the neighborhoods of the jet. In free ground one cannot approach the jet to less about thirty meters.
During a few moments a fine trellis-work in the manner of a miner's lamp stops the flame but lets pass the liquid. Very quickly the trellis-work is destroyed in consequence of the rise in temperature and the flame which cross-piece again puts fire at the liquid which filtered through netting. On the other hand the least opaque screen in non flammable substance cuts the radiation of heat or stops the jet. The blowpipe flame is accompanied by a great release of smoke which allows with difficulty that which is of object of the attack to see the machine launcher.
Protection in the strengthened works
1 - Works type CORF. No effect is to be feared because of the sealing of the crenels (weapons assembled on kneecap).
[It will be noticed that he does not say anything on the air vents. Note].
2 - Work standard MOM. These works have their embrasures sealed partially either by hoppers or by ground bags.
If the machine flame thrower arrives at range, the flames penetrate inside by the least interstice and act on the personnel . It should however be noted that in the works with several rooms it is rare that the blowpipe flame interests at the same time all the rooms of shooting. In this case of the extinguishers can be implemented by the personnel unfulfilled, and the extinguishers with methyl bromide are very effective, they quickly extinguish the flames without releasing from harmful products. The carbon tetrachloride and foam type fire extinguishers are to be prohibited in an absolute way.
At all events, of the actual position of the things, the most effective answer consists in preventing the machine flame thrower from arriving within reach of jet of the works.
[Without too advances, one can affirm that it is the absolute parade; even against the bombardments, mines and the attack! Note]
Note, during combat of 1940 (extracts)
Heading of the signed memorandum, on June 1st, 1940, by the Renondeau Major general, ordering the 42°CAF ex SF Crusnes (Document SHAT).
After 20 days of German attack:
The action of the flame throwers can be serious only on the crenels of bells of GFM, on the air intakes and the crenels of FM under concrete.
The possible effects of the attacks of the bodies strengthened such as they are briefly above exposed result in prescribing the following instructions relating to defense against the attacks.
All the embrasures must be provided with their lawful equipment, while taking care scrupulously of the normal fixing of this equipment.
[Indeed, it was not useless to recall it because in certain fortifications, the men, tired to be constrained to observe through the ices of épiscopes of GFM, very simple had withdrawn these apparatuses and made their observations with open sky. Note]
Notice, in connection with the absence of flame thrower to the work of Ferté
Certain authors point out that in 1940 if the work of Ferté had been equipped with flame thrower (like, thereafter, German works of the Atlantic Wall) German could perhaps not have approached some and make jump its turret of machine-guns. It is possible. But at the time of the attack, the turret was blocked and unusable, the friendly troops of the vicinity had been withdrawn and one of 3 bells GFM was except service following the bombardments of preparation. With what thus, then, would have resembled the flame throwers of protection? In the case of Ferté, it is a protection by external troops (withdrawn on order) and artillery (deferred for lack of appropriations) which cruelly was lacking, more than any other kind of weapons. (R.Cima)