French tank guns in World War II

I have always wondered about the usefullness of the very short french 37 mm cannons carried by some ofthe French tanks.

To me it seems they were useless against any armoured vehicle, Does anybody know the specs for these guns ?

 

In 1940, when the French tanks saw action against the Germans, French 47mm guns were more powerful than the common German tank gun which was the 37mm. Obviously, later in the war they lost their value, but in the early stages they were relatively quite powerful. Stats would be interesting (I don't have them), but I don't think they'll refute the above.

Welcome to the forum, by the way, Comet fan!

 

Not very useful.

The short SA18( L/18 ) gun had a muzzle velocity of 388m/s(1,273 fps) the much more common SA33 (L/33) gun one of 700m/s(2,300 fps).

For comparison the german 37mm L/45 gun had a muzzle velocity of 745 m/s (2,444fps).

edit: I just remembered Germany relied very much on captured Czechoslovakian tanks in 1940. IIRC the Wehrmacht had at least 300 maybe even 400 Pz.35(t) and 200 Pz.38(t).
The 37mm gun of the Pz.35(t) had the same muzzle velocity as the french SA33, the 37mm of the Pz.38 was equal to the german 37mm L/45 gun.

 

thanks Roel and Markus

Your replies pretty much answered my question.
I can hardly imagine that the SA18 37 mm could be of any use against neither personnel or armoured vehicles.
Personall I would have preferred a 20 MM Machine cannon with a coax 7,5 mm machine gun instead.


By the way

To the best of your knowledge :
Did the French enjoy any successes in tank versus tank during the german invasion ?

 

A bit more information:

The French had an improved loading for the little 37x94R case; the Mle 1935 API, which had a hard steel core in a magnesium sheath (technically an APCR or HVAP round). This had a 600 m/s muzzle velocity and much better penetration. Still no great shakes, though.

The photo below from the Ammo Photo Gallery on my website compares the ammo from the early-war tanks. You can also look at the Ammo Data Tables (link from my sig) which gives the performance of the various ammo types.

From left to right, the rounds are: 37x94R (French 37mm Mle 1916/1918), 37x149R (French 37mm Mle 1938), 37x249R (German 3,7cm), 37x257R (Polish wz 36 - 37mm Bofors), 37x268R (Czech 37mm vz 34/38), 40x304R (British 2pdr), 47x195R (Italian 47mm Mod 37 - Austrian Bohler), 47x193R French 47mm Mle 1935, 47x280R (Belgian AT)

Tony Williams: Military gun and ammunition website and discussion forum

 

Hardly, but not because of bad guns and armour. In fact guns and armour of their tanks were rather superior, but the french tanks had 1-man turrets. So the commander was also the gunner and the loader. This was far too much work for one man and ensured the success of the better lead german tanks.

 

http://www.fun-online.sk/forum/viewtopic.php?t=1076

 

Thought this would be relevant (look at the bottom for French and Checz guns).

Christian

 

Early in WW2 the 37mm anti-tank gun was quite useful against german panzer 1's and 2's , and some armoured vehicles. But with the introduction of the panzer 3 and 4's it was finally useless in tank vs tank action. 8)

 

Not really, since the early versions of the Panzer III and IV had frightfully thin armour and similarly small guns.

 

From the 2367 "modern" French tanks on 10th May 1940, only 515 tanks had a 47mm SA35 and about 300-350 H35/39 and R35 had a 37mm SA38 gun = 815-865 tanks with an excellent (47mm SA35) to good (37mm SA38) anti-tank capacity.
The huge majority of the French tanks are light tanks armed with the 37mm SA18 gun which could be used at 400m against the Panzer I and Panzer II but to knock out a Panzer III Ausf.E/F (the previous models were far less armored and were easier to destroy) or a Panzer IV Ausf.C/D they had to get as close as < 25-100m whereas the enemy could destroy them at about 300m (3.7cm KwK) to 500m (7.5cm KwK).

8mm Hotchkiss Mle1914 MG
- Cartouche Mle1886 D (am) (heavy ball)
- Cartouche de 8mm à balle traceuse (T)
- Cartouche de 8mm à balle perforante (AP)
- Cartouche Mle1932 N (very heavy ball)

7.5mm 'Reibel' MAC Mle1931 MG
- Cartouche Mle1929 C
- Cartouche Mle1929 D (heavy ball)
- Cartouche Mle1929 T (T)
- Cartouche Mle1929 P and TP (AP and APT)
- Cartouche Mle1929 I (Incendiary)

13.2mm Hotchkiss Mle1930 HMG
- Cartouche Mle1935 (heavy ball)
- Cartouche Mle1935 T (T)
- Cartouche Mle1935 PT (APT)
- Cartouche Mle1935 P (AP)

25mm SA35 (L/47.2 or L/60 ?)
- Cartouche de 25mm Mle1934 à balle perforante (charge forte) (AP)
- Cartouche de 25mm Mle1934 à balle traçeuse perforante (APT)

37mm SA18 and SA18 M37 L/21
- Obus de rupture Mle1892/1924 (APHE)
- Boulet de rupture Mle1935 (AP/API)
- Obus de rupture Mle1937 (AP)
- Obus explosif Mle1916 (HE)
- Boîte à balles Mle1908 (canister)
- Boîte à balles Mle1918 (canister)

37mm SA38 L/33
- Obus de rupture Mle1938 (APC)
- Obus explosif Mle1938 (HE)

Note concerning the the APX-R and APX-R1 turret armed with the 37mm SA18 or 37mm SA38 guns :
Elevation of -16° to +20°
Traverse of 5° right and 5° left but it could be blocked to aim only with the turret rotation and so that the coaxial MG was always well aligned with the main gun.

47mm SA34 L/30
- Obus de rupture Mle1892G (APHE)
- Obus explosif Mle1932 (HE)

47mm SA35 L/32
- Obus de rupture Mle1935 (APC)
- Obus explosif Mle1932 (HE)

75mm SA35 L/17.1
- Obus de rupture Mle1910 (APHE)
- Obus explosif Mle1915 (HE)
The 75mm HE shells are able to destroy the armored cars, Panzer I and Panzer II and are very efficient at short range against the tracks and lower parts of the heavier tanks. The HE shell has a penetration of 17mm/30° even at 800m.

On the German side, the only Pzgr.40 (APCR) shells produced in 1940 were for the 3.7cm L/45 KwK36 of the PzIII or the 3.7cm PaK which were equipped with a very small number of APCR shells during the battle of France, probably even only to several Panzer III. The 4.7cm Pak(t) (on the Panzerjäger I mainly) received the APCR shell only in July 1940. The Pz35(t) and Pz38(t) did not have an APCR shell until the Russian campaign started. The 2.0cm Pzgr.40 was introduced in December 1940 or the first months of 1941, the other Pzgr.40 types also until May 1941.
The 7.5cm L/35 KwK37 of the PzIV Ausf.A/B/C/D or the StuG III Ausf.A in France in May/June 1940 could fire the K.Gr.rotPz. (AP) at 385m/s (penetration of 41mm/30° at 100m) but also a HEAT shell (Gr.38 HL/1) at 452m/s which was available in very small numbers but allowed a penetration of 45mm/30° at any range. There was no HEAT shell ready for the campaign in Poland. The Gr.38 HL/1 made the final tests in December 1939 and the shooting of the ballistic tables was finished in March 1940. The shells is listed in the ammo manual of the 7.5 cm KwK from July 1940. HEAT shells use chemical penetration instead of kinetic penetration thus the same amount of armor penetration could be achieved despite striking velocity. HEAT shells also tended to do better with striking armor plates at an angle, but were also easily defeated by employing spaced armor or side skirting. HEAT shells could also be used as a substitute for HE shells. HEAT shells in early WW2 Panzers were not strong enough to penetrate the stronger French tanks, however later revisions (Gr.38 HL/A, HL/B, HL/C) proved more successful on the eastern front.

If we exclude the direct artillery fire and the 8.8cm L/56 Flak, the 4.7cm Pak36(t) L/43.4 mounted on the Panzerjäger I seems to be the most dangerous gun for the French tanks (except the HEAT shell of the 75mm L/24 beyond 500m). The French 47mm L/53 AT gun is the best AT gun before the 5.0cm Pak38 and 7.5cm Pak40.
On the French side, the Laffly W15 TCC (tank destroyer) was really deadly against German tanks with its 47mm L/53 and the Mle1936 APCBC shells, still 72mm/0° at 1000m according to French tests.

The best French tank gun is the 47mm SA35 L/32 which is superior to the German tank guns. The best German tank guns are the 3.7cm L/47.8 (t) of the Panzer 38(t) and the 7.5cm L/35 KwK37 of the PzIV Ausf.A/B/C/D or the StuG III Ausf.A. The French 47mm SA35 gun is better than the German 3.7cm guns with AP shells but it is outclassed by the APCR shells of the 3.7cm L/45 at close range and by the 7.5cm L/24 gun at medium/long range with its HEAT shells. The APCR shells of the 3.7cm L/45 gun are able to penetrate the front armor of a Renault B1bis tank at 100m. The 47mm SA35 L/32 gun APC shells are slower than the AP shells of the 3.7cm L/45 gun (660 versus 745 m/s) but much heavier (1.620 kg versus 0.685 kg) and capped. The French 47mm has a higher KE and a better T/D ratio, leading to a better penetration.


Note about the 37mm and 47mm HE shells :
There were two HE shells for the German 3.7cm guns : the older 3.7cm Sprgr.18 with 26g explosive content and the newer 3.7cm Sprgr.40 with 45g explosive content. Both were produced before the battle of France started.
On the French side the HE shells had 30g (37mm SA18), 60g (37mm SA38) and 142g (47mm SA34 and SA35) explosive content.

Based on penetration values from Jentz (German tests) and calculated, the penetration values at a perfect 0° impact angle and at a range of 100m are about

Main French guns
25mm SA35 L/60 (or 47.2) : about 57mm
37mm SA18 L/21 : about 37mm
37mm SA38 L/33 : about 44mm
47mm SA35 L/32 : about 58mm
47mm SA37 L/53 : about 84mm

Main German guns
3.7cm KwK/PaK L/45 : about 53mm (AP) and 90mm (APCR)
3.7cm KWK L/47.8 : about 55mm
4.7cm PaK(t) : about 78mm
7.5cm KwK/StuK L/2 : about 55mm (APCBC) and 52mm (HEAT)

It gives a good idea of the power of the main guns involved, keeping in mind that the French tanks had a 40-60mm armor and the German tanks had a 13-35mm armor.
In the French tanks and especially the light tanks, there were generally more HE shells than AP shells (3/5th HE shells), illustrating the infantry support role seen as primary task. The French tanks except the 25mm guns and of course the 8mm, 7.5mm and 13.2mm MGs had no tracer shells unlike the German tanks. It was therefore often harder to find the range of a spotted target.


The quality of French tank optics were not at all inferior to the German ones, this is a false statement and an other myth usually spread. In fact they were of similar quality, perhaps a bit more complicated to operate. With the German optics it may have been more easy to determine the range of the target, but only for experienced crew since it was not an easy task. The French optics with their 4x magnification are more suited than German ones to engage targets at long range but the drawback is a smaller field of view which can become an issue during close combat.
In the French tanks, the tank turret gunsight consists of an aiming "v" or "+" and aiming ladders. The telescopic sights have generally a 4x magnification.
The L.762 telescopic sight of the 47mm SA35 gun has a 4x magnification, a 11.81° field of view and consists in a crosshair “+” with three aiming ladders. On the “+” reticle the horizontal line can be adjusted for the elevation. On the horizontal line of the “+” reticle, there are vertical long and short bars. One 2.50m high vehicle covered by a long line is at 500m and the same vehicle covered by a short line is at 1000m range. On the right of the “+” reticle there are two black range ladders : one for the AP shells and one for the HE shells. On the left of the “+” reticle there is one red range ladder for the coaxial MG.
The 75mm SA35 hull gun on the B1bis tank has two L.710 sights (sterescopic telemeter) with a 3.5x magnification, a 11.15° field of view and range ladders (no "v" or "+" reticle). The 75mm SA35 hull gun is a fixed gun with only elevation controls, thus left-right aiming is done via changing the tank's heading with the usual driving system or with the fine-tuned hydrostatic Naeder system.

Another surprising statement is about accuracy of French guns versus German ones. Accuracy is not a matter of nationality, only a matter of ballistics. All the ballistics tests proved that the French guns were very accurate. Some French tankers scored very well, others not so well. This was due to training, 1-man turret etc. but the guns by themselves were totally good ones. About the accuracy of the guns by themselves, here are two examples taken from real 1939-1940 shooting tests with the 47mm SA35 gun (Somua S35 and B1bis turret gun for example) and with the 75mm SA35 gun (B1bis hull gun), both with anti-tank shells :

For the 47mm SA35 :
• 15 shots at 200m : H+L = 10+20 = 30cm
• 10 shots at 500m : H+L = 55+53 = 108cm

For the 75mm SA35 : 10 shots at 400m : H+L = 30+28 = 58cm


Concerning more precisely the 37mm SA18 and SA18 M37 L/21 - in German service : 3.7cm KwK 144(f) - :
Used in the Renault FT17/18C, Renault R35 (APX-R turret), Hotchkiss H35/39 (APX-R turret), FCM-36 (FCM turret), Laffly 50AM, Panhard 165/175 and AMC P16 Mle1929. This gun was in fact intended to support infantry, it was more designed to destroy MG nests than to fight against tanks. Efficient against armored cars and light tanks.
Theoretical rate of fire : 15 rpm
Traverse of 5° right and 5° left (could be blocked to aim only with the turret rotation)
Telescopic sight :
• Renault FT17/18C : 1x (L.??? telescopic sight, with a ?m range drum, field of view 45°, ? reticle)
• Renault R35, Hotchkiss H35/39 and FCM36 : 4x (L.713 telescopic sight, range drum up to 1000m for the AP shells and 1600m for the coaxial MG, field of view 11.25°, V reticle). The L.739 was introduced for the new Mle1935 and Mle1937 AP shells.
• Armored cars : a sight like in the FT17/18 (1x, 45°) or a sight like the L.698 used for the infantry gun (2x, 7.88°)
Practical AT range : 400m

Ammunitions :
Obus de rupture Mle1892/1924 (APHE) - in German service : Pzgr 148(f) -
Caliber : 37x94R mm
Weight of projectile : 0.500 kg (15g explosive)
Length of projectile : 94.5mm
V° = 388 m/s
Penetration : 8mm /30° at 400m
The APHE shell is intended to detonate once the armor has been penetrated. Because of the necessity for a hard point to APHE shells, the fuze is fitted into the base of the projectile. This fuze acts through inertia. As the shell passes up the barrel, either the shock of firing or the rapid rotation removes a safety device and arms the fuze. This fuze contains grossly a weight held by a spring. When the shell hits something hard, momentum throws the weight forward so it strikes the firing element of the fuze and thereby ignites the HE filler of the APHE shell.

Boulet de rupture Mle1935 (AP/API) - in German service : Pzgr 150(f) -
Caliber : 37x94R mm
Weight of projectile : 0.390 kg
Length of projectile : 88mm
V° = 600 m/s
Penetration : 18mm /35° at 400m
The "boulet de rupture Mle1935" consisted of a special solid steel core surrounded by a magnesium sheath that bursts into flame on impact.

Obus de rupture Mle1937 (AP) - in German service : Pzgr 154(f) -
Caliber : 37x94R mm
Weight of projectile : 0.500 kg
Length of projectile : 81mm
V° = 600 m/s
Penetration : 21mm /35° at 400m

German tests with 3.7cm Pzgr 154(f) (source : Jentz) :
100 meters = 25mm /30°
500 meters = 19mm /30°

Obus explosif Mle1916 (HE) - in German service : Sprgr 147(f)
Caliber : 37x94R mm
Weight of projectile : 0.555 kg (30g explosive)
Length of projectile : 109.5mm
V° = 367 m/s

Boîte à balles Mle1908 (canister) - in German service : Ktgr 169(f) -
Calibre : 37x94R mm
Weight of projectile : 0.550 kg (28x14.7mm hardened lead balls)
Length of projectile : 110mm

Boîte à balles Mle1918 (canister) - in German service : Ktgr 168(f) -
Calibre : 37x94R mm
Weight of projectile : 0.705 kg
Length of projectile : 110mm


David