Flames on Treads: The Untold Story of the Experimental M2 Medium Tank Flamethrower, 1940

In the tense twilight before America’s full entry into World War II, engineers and military thinkers feverishly sought new ways to break the deadlock of modern warfare. Among their many experiments, one blazed with both ingenuity and danger: the fitting of a flamethrower to replace the main gun on an M2 medium tank—a fire-breathing dragon made of steel, designed to terrify and obliterate foes behind even the stoutest defenses.

The M2 Medium Tank: America’s Early Armored Hope

The M2 medium tank was, in many ways, a child of its era. Conceived in the late 1930s as a stepping stone toward a robust armored force, it sported riveted armor, multiple machine guns, and a stubby 37mm cannon in its primary role. When it was introduced, it seemed formidable—until German blitzkrieg tactics and tanks like the Panzer III and IV in Europe revealed just how rapidly armored warfare was evolving.

While the M2 itself was quickly overshadowed by later designs, it became a crucial test-bed for innovation. America’s war planners, observing the carnage from campaign after campaign in Europe and Asia, realized their tanks and tactics had to adapt—fast.

The Rise of the Flamethrower in War

No weapon of the early 20th century inspired such a mix of awe and horror as the flamethrower. Long before tanks rolled into battle, the first crude hand-held flamethrowers sowed panic among enemy troops, clearing trenches and bunkers with searing jets of liquid fire.

But by the late 1930s and early ’40s, military engineers around the world began experimenting with mounting flamethrowers on armored vehicles. The results, particularly in the brutal jungle fighting of the Pacific and the mine-strewn hedgerows of Europe, would eventually become iconic. Yet few realize that some of the earliest steps in transforming tanks into mobile infernos occurred in the United States, with the humble, ungainly M2 serving as an unlikely pioneer.

The Experimental Conversion

In 1940, American designers and the Army’s Ordnance Department initiated a series of tests to explore new methods of assaulting fortified positions—like pillboxes and bunkers—which standard tank guns and infantry struggled to crack.

The experiment was dramatic and radical: remove the M2’s 37mm main gun and install, in its place, an armored flamethrower unit. This transformed the tank into a short-ranged but terrifying weapon, capable of spraying almost unbroken sheets of flame hundreds of feet ahead. Instead of bullets and shells, this tank projected a weapon straight from the worst nightmares of those on the receiving end.

Photos from this era, grainy and often labeled “Secret,” show M2 tanks with stubby flame projectors jutting from their turrets or hulls, hoses snaking to large, armored fuel tanks mounted internally or in the rear compartment. The conversion required significant internal modification to accommodate pumps, fuel presses, and fire suppression equipment—since one stray shot could now set the whole machine ablaze.

Testing Fire: Trials and Tribulations

The test grounds of Aberdeen Proving Ground and other military installations became the arena for this new breed of tank to show its worth. Engineers in heavy leather aprons and anxious officers looked on as the first prototype rolled over chewed-up earth, the hum of its engine replaced by a guttural roar as the flamethrower spat arcs of fire across test targets.

Eyewitness accounts described the psychological effect as much as the destructive power: targets burst into flames almost instantly, and the scent of burning fuel and scorched earth filled the air. Training dummies that represented enemy troops or bunkers fared no better—they were rapidly engulfed and rendered unusable, demonstrating the terrifying potential of this approach.

But there were problems, too. Early flame units lacked reliable range and accuracy. The complexity of the plumbing and the volatility of the fuel mix were constant hazards. A tank forced to retreat with a ruptured fuel tank would quickly become a death trap for its crew. Firefighting methods were primitive, relying largely on quick escape and good fortune.

Legacy and Impact

Ultimately, the M2 flamethrower tank never saw combat. Its armor was thin, its silhouette outdated, and its speed and mobility not up to the demands of 1940s warfare. However, it was a vital stepping stone. Lessons learned from these experiments provided crucial insights for the development of more effective flame tanks—like the M4 “Sherman” Crocodile in later years, and the specialist tanks that proved decisive in Pacific island battles against deeply entrenched Japanese defenders.

Most importantly, the concept—that tanks could be more than gun platforms, that they could reshape the battlefield through psychological shock as much as sheer destruction—endured. American and Allied troops would go on to use flame-throwing tanks to flush out snipers, clear caves, and neutralize bunkers in North Africa, Normandy, and Iwo Jima.

The Human Element: Steel, Fire, and Fear

For the crews tasked with operating these experimental tanks, the risks were immense. While the M2’s armor might narrowly deflect rifle bullets or shrapnel, the knowledge that a single armor-piercing round could ignite the onboard fuel weighed heavily on their minds. Training emphasized not just mechanical proficiency, but nerve, discipline, and teamwork.

One former test crewman, interviewed decades later, recalled: “We knew what we were playing with. It wasn’t just a weapon; it was a message. Fire changes a man’s thinking. The tank could break a line, but with a flamethrower… nobody wanted to face that.”

The presence of flamethrower tanks—even in small numbers—had an outsized psychological effect on the enemy, often prompting surrender from dug-in positions that would have cost hundreds of lives to take by conventional means.

Lessons for the Future

The little-remembered M2 flamethrower tank never gained the fame of its more successful successors, but its ashes mark a turning point in armored warfare doctrine. Out of its experiments grew a new generation of specialized combat vehicles and tactics, fueled by both technological possibility and the urgent demands of total war.

Today, only a few images—and fewer still, fragments—of these pioneering flame tanks survive. Yet their story is a testament to the creative, sometimes desperate ingenuity of those who strove to equip American forces for the firestorms of 20th-century battlefields.

As the world moved toward a future of ever-more advanced armored vehicles, the M2 flamethrower tank flickered briefly—a fleeting, fearsome idea, illuminating a path from the old world to the mechanized wars that would define a century.