In World of Tanks's forum there has been a very interesting debate about Cavalry tanks during early years of World War Two, in concrete during the Battle of France. The discussion has been focused in two tanks: French Somua S.35 and German PzKpfw III.
First of all, I'd like to remember what B.T. White says about these tanks in his book. The German Pz Kpfw III was intended as the basic tank of the Panzer divisions, which was armed with a 3,7 cm. gun and was fairly mobile but armoured only to a maximum of 30 mm. On its hand, the French Somua S.35 had cast armour up to 55 mm., a 47 mm. gun a quite good performance, and was considered one of the best of its class in the world in 1939. French tanks, whose development was to cease after June 1940, had relatively poor suspension systems but in many cases had advanced transmissions and steering and, except for the light cavalry reconnaissance vehicles, were well armoured, much use being made of large castings for hulls and turrets.
The successes of the German Panzer forces in 1939-1941 were attributable to a high degree of training and organization and not just to numbers of tanks or their quality. The French armoured formations were committed piecemeal and apart from slight temporary set-backs such as the attacks of the 1st Army Tank Brigade and de Gaulle’s 4e D.C.R., the Panzer division had it was virtually over in a fortnight.
According to Uranprojekt (WofT member), the S.35 was considered superior, at least by the French, to it's main German counterpart, the Pz. III. It was certainly a better armoured tank and had a better gun whilst having the same top speed.
- Maximum armour (hull/turret): 48 mm/40 mm
- Crew: 3 (driver, commander, gunner)
- Main armament: 47 mm SA 35 gun
- Secondary armament: 7.5 mm Mitrailleuse mle. 1931 MG
- Engine: SOMUA V-8 (190 hp, 9.7 hp/t)
- Top speed (road/off-road): 40.7 km/h (25.3 mph)/32.2 km/h (20 mph)
- Range: 230 km (142 miles)
- Suspension: leaf spring bogies
- Weight: 19.5 t (19.2 long tons)
Somua S.35 [Courtesy from www.wardrawings.be]
Pz. III specs. (Ausf. E and F as those were the models used during the Battle of France):
- Maximum armour (hull/turret): 30 mm/30 mm
- Crew: 5 (driver, radio operator, commander, gunner, loader)
- Main armament: 3.7 cm KwK 36 L/45
- Secondary armament: 7.62 mm MG 34
- Engine: Maybach HL 120 TRM (296 hp, 12 hp/t)
- Top speed (road/off-road): 40 km/h (25.3 mph)/20 km/h (12 mph)
- Range: 155 km (96 miles)
- Suspension: torsion bar
- Weigh: 23.0 tonnes (25.4 short tons)
Panzer III Ausf.F mit 37mm KwK [Courtesy from www.wardrawings.be]
As is evident from the specs, the S.35 was a better armoured and better armed tank. The hull of the S.35 was very rounded and sloped and the 3.7 cm gun mounted on the Pz. III, known as the "door knocker", struggled to penetrate it. The hull of the Pz. III was not rounded or sloped, instead being a rather flat design which the 47 mm on the S35 had little trouble punching through. The S.35 managed the same top speed as the Pz. III. The Maybach engine was more powerful than the SOMUA engine and had a higher horsepower per ton ratio. The only difference was weight, the S.35 was ±4 tons lighter than the Pz. III (S35 weighed about 19 tons, the Pz. III weighed about 23 tons). This minor difference in weight could make up for such a substantial gap in horsepower.
The Pz. III did have a distinct advantage that the S.35 sorely lacked; a radio. Each S.35 built was supposed to have the ER (émeutier-récepteur) 28 short range radio as standard but a shortage of the sets meant that very few S.35s actually got a radio. Generally speaking, the only S.35 in a platoon of 5 S.35s that had a radio was the command tank which had an ER 29 long range radio meant for communicating with HQ. Each Pz. III Ausf. E and F, in contrast, did have a radio with a dedicated crewman to operate it.
It was this lack of radios and poor decision making on the behalf of the French commanders that led to the technically inferior Pz. III winning out over the S.35. The individual tanks in the Panzer divisions that took part in the invasion of France were better able to communicate and coordinate with each other, something the French tanks were largely unable to do. When the French did have the upper hand, such as the early stages of the Battle of Hannut, their commanders were hesitant to use the S.35 for it's intended role and exploit weaknesses that had appeared in the German line. The S.35 was the main French cavalry tank and the French often neglected to use it as such.
In the end, France fell and the surviving S.35s, believed to number as many as 297, out of a total of 430 built were captured by the Germans. These captured S35s entered service with the Germans as training and reserve tanks and were renamed to Pz. 35-S 739 (f). The tank itself remained largely unchanged in German service, the only modification being a new cupola.
Somua S.35 [Courtesy from www.wardrawings.be]
Knot3D (WofT member) tell us, what Steven Zaloga notes about what he calls "Two of the best battle tanks of the 1940 campaign". According to Zaloga, by the usual criteria of tank performance – protection, mobility and firepower – the Somua S.35 should have been a battlefield champion. But wretched ergonomic design of the turret severely undermined actual battlefield performance. The commander was distracted by his role as both commander and gunner, and he lacked situational awareness due to poor turret design. As French tank commanders remarked in their memoirs, once fighting started, they largely lost control of their units. They were too busy operating their own tanks and lacked sufficient radios. As a result, French tank sections and squadrons could not fight as co-ordinated teams.
The Pz.III - already in 1940 - was shaping up to get the ideal balance of combat efficiency in one single unit package, whereas the tanks of other nations might have exceeded individual aspects, but suffered from overall disharmony in the foundation of their hardwired design.
Even in terms of mobility, the Pz. III F already seemed to have the upper hand in real world combat performance over the stats of the Somua S.35.
Interesting to note the Somua was toppling over due to its high center of gravity. Bob Carruthers corroborates the mobility performance of the Pz III as well as the fact,the Maybach engines being equipped with a speed governor.
As Zolaga noted; the S.35 Commander had to pin point an enemy target through one of the periscope's, manually traversing the cupola of that persiscope - and then get back into the turret seat again having to re-orient the turret gun telescoping sight yet again to pin point the target he just sighted. And then, the loader had to duck before each shot, to not get hit by the recoil breach.
The Pz. III commander could do that all in one swift stroke so to say, and he could fully focus on just that. And that's just one of the examples of superior AFV ergonomics ; throat mics in the German tanks being another fantastic innovation - as to avoid tank noise mixing up with internal communications.
In short, I do think most arm chair generals fail to look at what makes an AFV tick ; looking only at armor, gun & shell specs, mobility specs. Whereas, in fact, the so called "soft stats" are just as - if not more so - decisive in real battle.
Sure, the Pz.III F's 37mm gun was not sufficient to pen the S.35 nor the B1 from ranges, but in reality.... all they had to do was incapacitate them ; getting them tracked, jamming turret rings, knocking them so many times that the French crews would abandon their tanks in panic and disarray etc. After France fell, the Pz.III came to maturity until the Ausführung N , eventually limited by its turret ring size.
Panzer III Ausf. E [Courtesy from www.wardrawings.be]