Post
by David Lehmann » 30 Jul 2006 21:49
Hello,
I can try to give you elements about the Renault ACG1 light tank.
RENAULT ACG1 (AMC-35)
Studied by Renault already in 1936, the ACG1 (aka AMC Renault Modèle 1935 type ACG1) is a fast full-tracked cavalry combat armored car (light tank). Only 47 have been produced for France. Concerning export, 25 at first and finally only 12 vehicles are ordered by Belgium with the first deliveries in 1937.
The French ACG1 is equipped with the APX2 (2-men turret – 1395mm turret ring) model turret. The Belgian ACG1 has a turret modified by the Belgian industry, the APX2B with a coaxial 13.2mm Hotchkiss HMG instead of the 7.5mm MAC31 MG (therefore the left episcope/diascope had to be moved a bit back). On the Belgian side, 8 Renault ACG1 served in May 1940 in the "Escadron d'auto-blindées du corps de cavalerie. Belgium used also several APX2B turrets in coastal forts in Zeebruge since more turrets than hulls were available.
The Renault ACG1 equipped several small French units like the "Escadron Audigier" and various "Groupes Francs de Cavalerie". One of these units is the "Groupe Franc de Cavalerie n°1" commanded by Capitaine Neuchèze, which e.g. took part to the defense of Saumur on the Loire River with the cadets of the Cavalry school. This "Groupe France" consisted in a motorized infantry company, a mortar platoon, a single 25mm AT gun and three armored platoons: 4 Panhard 178 armored cars, 5 Hotchkiss tanks and 7 Renault ACG1 light tanks.
An other example is the "Groupe Franc de Cavalerie n°4", which was formed on May 25, 1940 under capitaine Huet from elements of the 1e GRDI and consisted of a command platoon, a tank platoon (2 Renault ACG1 light tanks), a motorcycle platoon, an infantry platoon with a mortar, two 25mm AT guns and two 47mm SA37 AT guns. A total strength of 8 officers, 19 NCOs and 150 men for this GFC n°4. It was deployed by general Duffour to cover the crossings at Pont de l'Arche. On the 9th of June, the 25mm AT guns under lieutenant Petit reportedly disabled 16 German tanks. The position however was soon overrrun and the groupe franc withdrew.
Weight : 14.5t
Length : 4.55m
Width : 2.20m
Height : 2.30m
Crew : 3 men
Maximum armor : 25mm (APX-2 turret is made of cast plates bolted together, the hull is RHA bolted armor)
Maximum speed : 42 km/h (Renault M.1936 engine, 4 cylinders, gasoline, water cooled, 180 hp at 1800 rpm, 11080 cm3)
Autonomy : 160 km
Armament : 47mm SA35 L/32 gun + coaxial 7.5mm turret MAC1931. Ammunitions : 120 47mm shells (APC and HE), 5250 7.5mm cartridges (3750 standard = 25 magazines and 1500 armor piercing = 10 magazines).
The maximum armor is 25mm (turret, front and side hull probably).
The rear plate of the hull is 17mm thick, the top is 14mm thick and the bottom is 10mm thick.
The main gun is excellent for 1940, able to destroy the all German tanks at 600-800m (when the hit angle was good enough ... up to 1000m sometimes according to testimonies during the battle of Gembloux for example and probably for the lightest tanks).
47mm SA35 L/32
Used in the Renault ACG1, Renault D2, B1bis (turret gun) and Somua S35 tanks.
Theoretical rate of fire: 15 rpm (about 6 rpm in the APX4 turret of the B1bis in accurate aiming, could drop to 2-4 rpm in combat)
Telescopic sight :
• 4x (L.724 sight, field of view 11.25°, V and later + reticle, range drum up to 1500m for the AP shells and 1600m for the coaxial MG) for the APX1 turret
• 4x (L.762 sight, field of view 11.81°, + reticle, range drum up to 1500m for the AP shells and 1600m for the coaxial MG) for the APX4 turret
• There might be a L.731 sight for the APX1 CE turret (Somua S35) but there is no information about it at the moment.
• There might be a different scope in the APX2 turret (ACG1 light tank) ? But since it is a cavalry tank it may eventually have the same one as for the Somua S35 tank.
Practical AT range : 800-1000m
Ammunition:
Obus de rupture Mle1935 (APC)
Caliber: 47x193R mm
Weight of projectile: 1.620 kg (sometimes 1.625 kg is indicated)
Length of projectile: 145mm (length of the case: 193mm and total length of the shell: 325mm)
V° = 660 m/s (sometimes 680 m/s is indicated)
Penetration: about 40mm/30° at 400m
Obus explosif Mle1932 (HE)
Caliber: 47x193R mm
Weight of projectile: 1.410 kg (142g explosive)
Length of projectile: 183mm
V° = 590 m/s
Accuracy of the 47mm SA35 gun [perhaps a bench rest test ?]:
15 shots at 200m: HxL = 10cm x 20cm
10 shots at 500m: HxL = 55cm x 53cm
Accuracy tested in the APX4 turret (not a bench rest test) [from a 1939 document about the test of the APX4 turret]
30 shots at 200m: HxL = 49cm x 55cm
Like in all the other French tank turrets, the weapons (MG and gun) are "zeroed" at 30 meters but the manual of the APX4 turret indicates that the MG is "zeroed" at 30 meters and the gun at 100 meters. There are indeed 2 different "test cards" that can be used, one at 30 meters and the second one at 100 meters. I don't know if it was the same in the ACG1 cavalry tank.
Regards,
David
, more pictures (espacially of the 75mm AA FRC M36) would also be welcome. 
