Weapons of War: Louis Renault’s FT, the Little Tank That Could

An FT-17 Tank at the Glade of the Armistice,  Compiègne

By James Patton

After the frenetic activity of the first six months of the First World War, the Allies saw that the Germans were building very strong fortifications in their lines. These featured extensive use of reinforced concrete and the construction of Stellung, or strong points, that could repel frontal assaults. In due time, the idea arose that the way to break through these defenses might be to employ a swarm of mobile mini-forts to lead the attack. 

Born into a wealthy family, Louis Renault (1877–1944) and his brothers Marcel (1873–1903) and Fernande (1864–1909) founded the firm Renault Frères  in 1899, which quickly became the largest automobile manufacturer in France, specializing in taxi cabs, of which they were also the largest manufacturer in the world. Renault taxi cabs became famous due to their use in the “Miracle of the Marne” transfer of troops from the Paris garrison to attack the German flank in September, 1914. 

Louis was the designer and engineer, the brains of the business, as Fernande was a salesman and Marcel a bookkeeper. In 1909, Louis became the sole owner as well, and the firm was incorporated as Les  Société des Automobiles Renault.

In 1915 the Renault firm was solicited to produce one of the new combat vehicles that the British had code-named "tanks"; the armaments and steel giant Schneider-Creusot had already signed on board. But what the generals wanted Louis deemed impossible. The desired tank would carry artillery and bristle with machine guns, requiring a large crew. Louis knew that the available engines weren’t powerful enough. He determined that the horsepower to metric ton ratio (HP/MT) should be at least 7 to 1, and the designs being developed were far lower than that. Louis felt that under-powered tanks would move too slowly and break down too often, so he passed on the procurement.

Louis Renault at the Turn of the Century

Eventually he was persuaded to take another look. The heavy tanks had performed pretty much the way he thought they would, and had thus far failed to play a significant role. However, tactical thinking was changing after the disastrous failure of frontal assaults, and there were now proponents of infiltration attacks that would probe for weakness rather than try to crack the Stellungs head-on. This was an application of cavalry tactics, replacing the horse with a relatively fast and maneuverable vehicle that, unlike a horse, was impervious to machine gun bullets and shrapnel.

Louis was interested in building this "tank." What he and his chief designer Rodolphe Ernst-Metzmaier (1887–1985) came up with was called the FT, later also the FT-17. It weighed 6.4 MT, much less than the  heavies (the British Mark IV weighed 28 MT) and with the 4 cylinder 39 hp automotive engine, the HP/MT ratio was  6.1 to 1, not quite Louis’s ideal ratio, but much better than the Mark IV’s 3.5 to 1. The U.S.-built model, called the M-1917, had an American-built 42 hp industrial engine and  Louis’s ratio improved to 6.4 to 1, so it was 2.8 km/hr faster. Both models had a short combat range of 56 km, which was typical of all tanks at that time. Unlike the heavies, the FTs were light enough to be transported about on heavy trucks or towed trailers.

The FT’s  engine was behind the crew. The internal ventilation was effective, as the radiator fan drew air through the crew area, so the tank was mostly free of fumes. With its Zenith carburetor the FT could operate on a 45-degree slant and with the asymmetric tracks the FT could climb steep embankments, yet it was small enough to go through a fortification rather than having to go over it. In addition to the main clutch, the driver had separate clutches for each track. Since a major problem of the heavies was thrown tracks, Renault designed self-adjusting tension maintainers which significantly alleviated this problem on the FT.

The armament was either one 8mm Hotchkiss machine gun or one Puteaux 37mm short-barreled gun, and either one was mounted in a turret that could be hand-cranked around on a ball-bearing race to rotate a full 360 degrees—no other tank at that time had this capability. The crew was two men (driver and gunner) while the heavies typically had a crew of eight, sometimes more. And, because the combined weight of the engine, crew and armament was so much less, Renault was able to give the FT 22mm of front armor (the American M-1917 model had only 15.25mm), thicker than that of any of the heavies. 

Drawbacks were: the front track wheel suspension was exposed and easily damaged by anti-tank gun fire, changing damaged rear track wheels was a labor-intensive job, and the radiator fan sometimes threw the fan belt.  

The French Army initially ordered 3,530 FTs. The first examples came out in 1917, but they weren’t used in combat until 31 May 1918. The early examples had a cast steel turret, which couldn’t be produced fast enough, so a fabricated steel unit had to be used instead. 

A French Tank Column on the Western Front

By the date of the Armistice, 2,697 had been delivered.  Renault’s firm made 1,850 of these (Schneider-Creusot made 600 of the rest). Overall,  around 7,830 were produced.  About 200 were supplied to the American Expeditionary Force (AEF), who had also ordered 4,440 of the M-1917 from three different American firms, 950 of which were delivered before the Armistice, although none of these saw combat with the AEF. 

The AEF was eager to exploit the offensive potential of the FT, and on 12 September 1918,  Lt. Col. George S. Patton Jr. led a battalion of FTs from his 1st Provisional Tank Brigade in the St. Mihiel Offensive, the first cavalry-style tank attack, which gained significant chunks of territory. At times Patton actually walked in front of his lead tank to guide the column through difficult places.  Two weeks later, Patton again led 144 tanks from two battalions in the Meuse-Argonne Offensive, until he was wounded at Cheppy. Once again, he wasn’t in his tank and, somewhat embarrassingly, he was hit in the butt.

Fast forward to WWII, where the Wehrmacht captured over 1,700 FTs in campaigns during 1939–42 and re-used them, primarily for patrol and police duty in occupation zones. The FT and M-1917 tanks were ultimately used by 28 different military forces in at least 18 conflicts over the period from 1917 to 2007. 

American Tankers with Their French FT-17s

Because of its manueverability, speed and reliability, the FT was so successful that it was copied almost immediately and indeed, spawned a whole generation of small armored vehicles. The first copy was the Italian Fiat-3000, which dates from May of 1919 and was that country’s first mass-produced tank. In the 1920s, the Soviets reverse-engineered some derelict FTs abandoned by the White Russians, and in 1928 introduced the T-18 (also known as the MS-1), a slightly up-gunned copy with a different suspension that saw combat in the Sino-Soviet War (1929–32), but short-range tanks weren’t very useful to the Soviet way of war. Britain, Czechosolvakia, Germany, and Japan also produced light tanks and even "tankettes" (turret-less) in the interwar period.  

There are about 70 FTs  still extant. Eight are in the U.S., including one found and brought back from Afghanistan. Also among these is the damaged specimen at the National WWI Museum in Kansas City, Missouri. Les  Musée des Blindés in Saumur, France has seven, three of which are in running condition, including one  with a modern machine gun, which was captured by French Commandement des opérations spéciales (COS) soldiers operating in Afghanistan in 2007. 

National Guard Renault Tanks Securing San Francisco's Embarcadero During the 1934 General Strike

Over the years I’ve viewed several FTs, at sites in western Europe, the U.S. and even Serbia. For a long time I thought that I saw an FT serving as a "gate guard" to a military base in Iquitos, Peru, but now I’m sure that it was a Czech LT-38 instead (saw one of those in Serbia too). The LT-38 was one of the various postwar models derived from the FT, and the type was used in Peru from 1939 until 1988.

Sources include Tank-Hunter.com, The Tank Museum (Bovington, UK) and Les  Musée des Blindés