The Somua S35 was one of the most advanced French tank designs of the 1930s, and performed well in 1940 although wasn't available in large enough numbers to make any different to the outcome of the campaign.
The S35 was designed by a subsidiary of the massive Schneider concern, the Société d'Outillage Mécanique et d'Usinage d'Artillerie, for obvious reasons better known as SOMUA.
In the mid 1930s the French cavalry began to receive the Renault AMC 34 and AMC 35 cavalry tanks, but the cavalry wasn't entirely satisfied with the AMC 35, judging it to have too short a range and too thin armour. In June 1934 a new specification was draw up, calling for a vehicle with a more powerful gun (47mm or 25mm), higher top speed and thicker armour (40mm) and a crew of three.
Somua originally submitted a half-track for the Cavarly's AMC fighting tank role but this was rejected in favour of the Renault AMC 34. The Army still wanted Somua to produce a design, in case Renault was unable to produce enough tanks, and the design of the S35 was submitted in October 1934. The prototype of the S35 was produced in 1935. It was a very advanced design for the period. Both the hull and turret were produced from large cast components at a time when most tanks were riveted together. The cast armour was unusually thick for the period, ranging from 20-55mm.
It was armed with a 47mm SA 35 gun, a very powerful tank gun for 1935 and still very potent well into the Second World War. It could also fire effective armour piercing and high explosive shells, something that British tank guns couldn't manage until late in the war. The APX 1CE turret used on production vehicles was electrically traversed. A similar APX 4 turret was used on the Char B1 bis and the Char D2. In French service the turret had a fully rotating domed cupola on top.
It also had a radio as standard equipment, very rare at the time. It was powered by a 190hp V-8 engine, giving it a better power-to-weight ratio than the contemporary Renault R35 light tank. Steering was provided by a mechanically operated double overlapping differential system.
The S35 had nine road wheels on each side, with combined coiled and semi-elliptic leaf springs. Eight of the road wheels were carried in pairs on articulated arms with semi-elliptic leaf springs, with two pairs carried together on a single assembly. The ninth wheel was mounted on a coil spring. The suspension was protected by skirts. The suspension was designed by Eugène Brillié, who had also designed the first French tank, the First World War Schneider CA1. At the same time he developed a very similar system that was used on the Skoda LT vz.35, known in German service as the PzKpfw 35(t).
It did have two design flaws. The first was that it only carried a crew of three - driver, radio operator and commander/ gunner/ loader. As a result the commander was overwhelmed in combat, making the tank less effective than it should have been (although the radio operator could also operate as a loader in the APX 1CE turret). The second was that the hull was produced in upper and lower halves, which were then bolted together. Direct hits on the join could split the tank in two.
The prototype S35 was put through trials in August 1935 and quickly ordered into production as the Automitrailleuse de Combat modele 1935 SOMUA (quickly renamed as the Char de Cavalerie 1935 S), although it is generally known as the SOMUA S35. It was also known as the Char 1935-S.
On 7 September 1936 General Gamelin’s four-year rearmament plan was accepted. This included the creation of three light tank divisions (divisions legers mécaniques), to be armed with the SOMUA S35 and Hotchkiss H35.
On 1 September 1939 the French Army had ordered 500 S35s. 270 had been completed, 248 delivered and 191 were in service.
By May 1940 only 400 had been produced, and 250 were at the front. The S35s were concentrated in the three light armoured divisions in the cavalry (1st, 2nd and 3rd DLM), which had a total of 272 tanks fairly equally divided between the three divisions. Another 35 were in use with the newly formed 4th DCR (the infantry's armoured divisions).
The three cavalry armoured divisions (DLM) advanced into Belgium with the northern wing of the French army. The 1st DLM, with the 1st Army, ended up getting caught up in the disastrous fighting that ended with the evacuation from Dunkirk. 2nd and 3rd DLM ended up clashing with the 16th Panzer Division in Belgium. The S35 performed well here, but a comparative handful of tanks couldn't make up for failings elsewhere.
Those with the 4th DCR, commanded by Charles de Gaulle, took part in his bold counterattacks, although again these had little impact on the course of the battle.
After the fall of France the Germans took the S35 into service as the PzKpfw 35-S 739(f). Some were still in use in 1944 and were used against the Allies after the D-Day landings.
Vichy France was also allowed to keep some SOMUA tanks. After the failed Allied attack on Dakar in 1940 Vichy was allowed to move 22 SOMUA tanks to West Africa. Another unit was moved to Tunisia in 1941, and clashed with American tanks during Operation Torch. In one clash on 9 November four S35s were lost in a clash with seven M5 light tanks near Port Lyautey in Morocco
Any S35s captured intact from the Germans after the D-Day landings of 1944 were then given to the Free French, who used them against the isolated German garrisons of the Atlantic ports.
In 1940 a modified version of the tank, the Somua S40, was just entering production. It had a 220hp diesel engine and modified suspension, but only a handful were completed before the fall of France.
The S35 was also used as the basis of a self propelled gun, the Char Automoteur Somua S Au 40 This carried a 75mm gun mounted on one side of the hull, with the driver on the other side. The prototype also carried an unarmed turret.
AMC Somua, type AC2
Automitrailleuse de Combat modele 1935 SOMUA (official title)
AMC modele 1935 SOMUA
SOMUA S35 (popular name)
Length: 5.38m/ 17.65ft (AFV and Weapons WWII)
Width: 2.12m/ 6.95ft (AFV and Weapons WWII)
Height: 2.63m/ 8.62ft
Crew: 3 (commander/ gunner, driver, wireless operator)
Weight: 19.5 tons
Engine: 190bhp at 2,000rpm frin Somua V-8 liquid cooled gasoline engne
Max Speed: 40kph/ 24.8mph
Max Range: 260km/ 161 miles radius of action
Armament: 47mm SA 35 main gun, co-axial 7.5mm Reibel machine gun
Hull front and side: 40mm
Hull top and floor: 20mm
Turret sides: 56mm
Turret top: 30mm