AEM One-Man Light Tank

France (1930s)
Light Tank – None Built

Arguably the most important tank producer during the First World War alongside the United Kingdom, throughout the 1920 and 1930s, France enjoyed a large armor industry which was composed of a considerable number of different manufacturers and designers. These produced various quantities of prototypes as well as designs that never left the drawing board. One of those was the AEM one-man light tank proposal, a project from a lesser-known manufacturer, which never left the drawing board. This was probably a blessing, as the design for the operation of an entire armored vehicle by one crew member was not at all a viable concept.

An obscure design

The one-man light tank is one of two designs which were found in the archives of the DGA (Direction Générale de l’Armament – ENG: General Armament Direction) in Châtellerault, attributed to an obscure manufacturer known as AEM (Atelier d’Études Mécaniques – ENG: Mechanical Studies Workshop). The other sketch corresponds to another quite odd design, a two-man light tank with a particularly low turret and an articulated track design.

The exact date of these sketches is not known, though they are estimated to be from the 1930s. The AEM one-man tank is known by two profile sketches: one showing the vehicle as it would have looked like from the side, and an internal cutaway showing the internal arrangements. It ought to be noted that the one-man tank proposal is sometimes referred to as the “FT Bis” on the internet. This designation, however, is not at all historical and, while the arrangement of the AEM may look superficially similar to the FT, nothing suggests the one-man light tank was in any meaningful way based on Renault’s WW1 light tank.

External design

The AEM light tank was a vehicle of very limited dimensions. Two measurements are featured on the plans which have survived up to this day: the length of the hull, 2.85 m from the front of the hull to the rear of the tail (which was similar in shape to a trench-crossing tail, but was an integral part of the hull, housing the transmission), and the height of the hull, 1.5 m. From these, the height of the turret can also be extrapolated and should be around 0.615 m without the periscope, and 0.77 m including it, giving a height of 2.115 m without the periscope and 2.27 m with it. Including the barrel, the total length of the vehicle should have been about 3.15 m.

The AEM’s turret had a conical section shape with a relatively rounded top from which a periscope stuck out. This shape meant it would likely have been quite wide for such a small vehicle, though the width of the AEM one-man tank remains unknown. This turret featured a vision port on the left side, and would most likely have had the same feature on the right.

The suspension was composed of 13 tiny road wheels, quite similar to the suspension on the much earlier and much heavier FCM 1A and FCM 2C. Two larger wheels were present at the front and rear of the suspension. The drive sprocket appeared to have been featured at the rear, alongside the transmission, while the front wheel would most likely have been a tender wheel. This suspension would be entirely covered by an armored side skirt.

The thickness of the armor which would have been protecting the vehicle is not known, though it would obviously have been very thin and would have unlikely provided protection from anything bigger than a rifle-caliber round.

Internal arrangement

The AEM tank was to be crewed by a single person. He would sit on a seemingly quite elaborate seat for a tank design, mounted just below the turret in the hull. From there, his feet would reach the clutch pedal while his head would reach in the turret. The steering was, as on most vehicles of the era, assured by two levers.

Almost certainly, the turret was armed with a machine gun. That being said, the weapon featured in the sketches does not match either the new 7.5 mm MAC 31E or the old 8 mm Hotchkiss mle 1914 machine guns. Although most of the barrel is covered by a shroud, the tip does not match with either of those designs, and neither does the pistol grip. The heavier Hotchkiss 13.2 mm mle 1930, which would have been quite ambitious in such a small vehicle, does not match either. It is quite likely the machine gun featured in the sketches was purely representative. In this case, considering the design appears to have been dated from the 1930s, the 7.5 mm MAC 31E would have been the most probable choice.

The turret did feature a sight for the machine gun, installed to its left, a periscope that stuck out from the turret’s top, and vision ports on the sides.

The engine was installed just behind the crewman’s seat. There does not appear to be any bulkhead separating the crew and engine sections of the vehicle, a quite archaic feature already after the FT had shown how much of a drastic improvement this was for crew conditions. The model, power, or fuel of this engine is not known. The transmission was installed at the rear, in what appeared similar in shape to a trench-crossing tail, but was an integral part of the AEM tank’s hull.

Conclusion – a terrible design that didn’t go anywhere

The AEM light tank is only known from two sketches. It appears to have never been seriously considered for production, as indicated by the plans not even being properly numbered. This was likely for the best. The operation of a tank, no matter how small, by a single crewman is generally doomed to fail. The amount of attention required to drive a vehicle, observe from the limited vision available from inside an armored vehicle, and operate a weapon, even a machine gun, is far too much to be the task of just one man. During the campaign of France, even two-man tanks such as the R35/40 and H35/39 proved to absolutely overwork their crews, particularly the commander. Not only that but the suspension designed of the AEM tank, seemingly inspired from WW1-era heavy tanks, would most likely not have been able to provide the tank with an adequate speed, while the tank’s tiny dimensions meant it would most likely have struggled to cross many obstacles despite the trench-crossing tail-shaped rear hull. In practice, the vehicle would have been little more than a mobile machine gun with very thin armor and mediocre mobility, while having a more than 2-meters high profile.

The AEM design would not, however, be the last one-man tank offered to the French military, despite the obvious drawbacks of such a design. As late as 1940, engineer Joseph Francois Raymon Collomp would design a one-man tank tasked with minelaying and demining operations as well as armed with a machine gun, tasked by a single crewman in an incredibly uncomfortable lying position. Thankfully, this design would not go anywhere either.

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AEM one-man light tank specifications
Lenght	2.85m (without barrel), ~ 3.15m (with barrel, estimated
Height	1.5m (hull), ~2.11m (hull + turret without periscope, estimated), ~2.27m (periscope extended, estimated)
Crew	1
Suspension	FCM 2C-inspired, 13 roadwheels, one tender & one sprocket wheel
Armament	One machine-gun of unknown model
Optics	Periscope, vision ports, machine-gun sight

Sources

Tous les blindés de l’armée française 1914-1940 – Francois Vauvillier – Histoire & Collection editions, p.37
Char-français: http://www.chars-francais.net/2015/index.php/engins-blindes/chars?task=view&id=14