Guadalcanal, Solomon Islands January 15, 1943

On this date in 1943 M1 portable flamethrowers were used success­fully in com­bat for the first time rela­tively late in the six‑month Battle of Guadal­canal (August 7, 1942, to Febru­ary 9, 1943). In one attack by U.S. Marines several 2‑man flame­throwing teams crawled close enough to three Japa­nese bunkers to burn out or suffocate the occupants.

Consisting initially of a single upright 5‑gallon/­19‑liter fuel tank with two com­part­ments (one for pres­surized nitro­gen, the pro­pel­lant, the other for fuel oil) and a hose with a pistol grip and nozzle at the end, all of which was mounted on an infan­try­man’s back, a fully loaded M1 flame­thrower could shoot a stream of burning liquid between 65 ft/­19.8 m (effec­tive range) and 141 ft/­43 m (maxi­mum range) for about 10 seconds of burn time. The 72 lb/­32.6 kg device was normally used to clear out enemy trenches, pill­boxes, and other hardened enclo­sures whose walls were imper­vious to artil­lery bom­bard­ment. An improved ver­sion that con­sisted of three up­right bottles, the M1A1, weighed 7 lb/­3.2 kg less, had three times the range (150 ft/­43 m) with the same fuel tank capa­city, and fired a narrow stream of thickened fuel known as napalm that could reach four times farther into the target struc­ture than the M1. (Napalm is an incen­diary mix­ture of a gelling agent and a vola­tile petro­che­mical, usually gaso­line or diesel fuel.) The first M1A1 infan­try flame­throwers reached the South Pacific in August 1943.

Man-portable flamethrowers posed multiple risks to opera­tors. For one thing, riding on the back of an infan­try­man, the weapon was top-heavy, cumber­some, and its weight impaired his mobil­ity. Secondly, the bulky back­pack wea­pon was plainly visi­ble on the battle­field, turning “flame­tankers” into magnets for enemy fire, espe­cially for sniper bullets. Lastly, the flame­thrower’s effec­tive range was short in com­pari­son to that of other battle­field wea­pons of simi­lar size and weight, meaning that to be effec­tive flame­thrower carriers had to approach their targets up close. The U.S. Army and Marine Corps sought to reduce casual­ties among their flame­thrower teams and increase the kill-ratio by testing the weapons mounted on tanks.

The first combat use of American flamethrower tanks occurred on the neigh­boring Pacific island of Bou­gain­ville in late Janu­ary 1944 as sol­diers and Marines were expanding their beach­head. The tank was the M3A1 Stuart light tank with a modi­fied M1A1 flame gun mounted below its Browning M1919 .30‑cali­ber (7.62mm) bow machine gun. A strong­hold of Japa­nese bunkers dubbed the “Hornet’s Nest” was the objec­tive of these armed men and fire-belching tanks. During the fight the Stuarts used both their 37mm (1.4‑in) guns and M1A1 flame­throwers to elimi­nate Japa­nese defenders. A total of 28 large bunkers were destroyed, of which half were credited to flame­thrower tanks. In all, roughly 80 Japa­nese troops were killed out­side their bunkers, while an esti­mated 120 to 180 Japa­nese were shot, suffocated, or incinerated inside their bunkers.

After capturing the “Hornet’s Nest” senior Army and Marine officers acknow­ledged the urgent need for flame­thrower tanks to dis­pose of the threat posed by hea­vily pro­tected enemy defensive works. In early 1944 new custom-designed E4-5 “auxil­iary” and “primary” flame­throwers entered produc­tion and began to arrive that summer. The Army began adapting the Cana­dian-built Ronson Flame­thrower to the turrets of their M3A1 Stuarts. Nick­named Satans or Zippos, these flame­thrower tanks with their huge 170‑gal­lon fuel tank for maxi­mum burn time saw their com­bat debut on Sai­pan, Tinian, and Guam in mid-1944, about the time Marines began favoring better-armored M4A2 Sher­man medium flame­thrower tanks. Flame­thrower tanks played increas­ingly impor­tant roles in the battles on Iwo Jima and Oki­nawa as well as modest roles in the European Theater in 1944–1945.

World War II Man-Portable and Tank-Mounted Flamethrowers

M1A1 flamethrower being used against a Japanese bunker, Bougainville, March 1944Bunker-busting team with flamethrower

Left: A flamethrower team comprised an operator and an assistant, who turned on the tanks from the rear just before use and, if the device experi­enced an elec­trical spark igni­tion problem, used a ther­mite grenade to ensure that the target emplace­ment “cooked off.” By 1944 the assis­tant also carried a jerry­can of addi­tional fuel. The 5‑gallon fuel tank allowed only 8–10 seconds of fire.

Right: By 1944 many but not all Army and Marine divisions in the Pacific were orga­nizing specially equipped bunker-busting teams of 15–25 men who used “blow­torch and cork­screw” tactics. These teams were formed around two flame­throwers (the blow­torch) who would burn off jungle cover to expose enemy-occupied caves, pill­boxes, and log bunkers. Team mem­bers equipped with rifles, Browning machine guns (BARs), and bazookas (the cork­screw) pro­ceeded to lay down sup­pres­sive fire while the flame­throwers moved forward, directing their narrow streams of liquid fire across and through the enemy’s gun slits, thus forcing the defenders back as demo­li­tion men closed in for the kill. Combi­nations of thrown demo­li­tion charges, bazooka fire, and close-range flame and rifle fire finished the job. (Note: Image is a still from Hell Is for Heroes, a 1962 film.)

M4A3R3 Marine Corps Ronson flamethrower tank during Battle of Iwo JimaM4A1 Sherman Crocodile flamethrower tank, Okinawa, June 25, 1945

Left: Flamethrower tanks carried much more fuel than back­pack-wearing infan­try and fired longer-ranged flame bursts. They were invaluable for rooting out heavy fortifications. As no U.S. tank cannon could pene­trate the thick bunkers and cave warrens created by Japa­nese defenders on islands such as Tarawa or Iwo Jima (shown here), flame-tanks were used instead. Army and Marine infantry provided the necessary security during the tankers deployment.

Right: An M4A1 Sherman flamethrower tank of the U.S. Army’s 713th Tank Bat­talion hoses down a cave entrance in support of the 7th Divi­sion’s advance on southern Oki­nawa, June 25, 1945. Although flame-tanks in the Pacific Theater were widely dispersed in small numbers, the 713th was the only com­plete flame-tank bat­talion and worked closely with the infan­try and regular tank units. In com­bat, flame­throwing tanks were often closest to enemy posi­tions because of the limited range of their firing. Of all the wea­pons directed at them, Japa­nese soldiers were most fear­ful of the fire-belching tanks. Refusing to sur­ren­der and attempting to evade or flee the flames, enemy soldiers were peppered individually or mowed down in mass by U.S. riflemen.

World War II Hand-Held and Tank-Mounted Flamethrowers

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