[Sidebar ([page 6])]:
Napalm: Something New in the Arsenal
Early in 1944, Army Air Corps personnel at Eglin Air Force base near Fort Walton Beach, Florida invented a new weapon. It was a “fire bomb,” first used in combat during the Tinian campaign. The ingredients were diesel oil, gasoline, and a metallic salt from the naptha used in the manufacture of soap. Mixed with petroleum fuels, the salt created an incendiary jelly that clung to any surface and burned with an extremely hot flame. The concoction was called “napalm.” It could be dropped in wing or belly tanks attached to the underside of an aircraft and was fired by an igniter on contact with the ground.
On 19 July, five days before the Tinian landing. Lieutenant Commander Louis W. Wang, USN, arrived at Saipan carrying a small supply of the “napalm” powder and a film made at Eglin demonstrating the potency of the bomb. It showed P-47s making low-level drops after diving from 2,000 feet.
The demonstration film so impressed Admiral Harry Hill and Major General Harry Schmidt that Hill immediately radioed Admiral Chester Nimitz in Hawaii, requesting 8,599 pounds of the powder. They also ordered trial raids on Tinian by P-47 pilots of the Army’s 318th Air Group, using powder and detonators already on hand. These trials were not particularly impressive. Their purpose was to burn off wooded areas that had previously resisted white phosphorous and thermite. The “napalm” scorched the trees but left the foliage only partially burned. One problem was the wood itself—a virtually indestructible type of ironwood. Another was the napalm mixture. Wang had brought with him the wrong formula. “We tried using Jap aviation gasoline,” according to Colonel Lewis M. Sanders, commander of the fighter group, “but that gave too much fire effect. Then we tried Jap motor gas and oil, with the napalm powder, and it was quite successful.”
The P-47 pilots were uncomfortable with napalm missions. They dropped their tanks at extremely low altitudes—50 feet in some cases—and were highly vulnerable to ground fire. They were also unimpressed with the efficiency of these “fire bombs”; much of their incendiary effect was wasted in excessive upward flash. Napalm also had a very short burning time—less than two minutes.
Nevertheless, 147 “fire bombs” were used during the Tinian operation, 91 of them containing the napalm mixture. They were most effective in clearing cane fields. As Major General Clifton B. Cates, the 4th Division commander, later recalled: “The first morning they put it down, I went up to the front line and those planes came in over our heads it seemed to me like about a hundred feet in the air ... [They] let go their napalm bombs right over our heads ... maybe two or three hundred yards in front of us. It was a very devastating thing and particularly to the morale of the Japanese.... I didn’t feel too comfortable sitting up there ... I figured that some of them might drop short.”
Each bomb cleared an area approximately 75 by 200 feet and, in some cases, left behind the charred bodies of Japanese troops. The Marines were impressed. Infantry commanders sought napalm for their flamethrower tanks. It was used widely in 1944 in support of ground troops in the Philippines. On one operation on Luzon, 238 fighters saturated an area with napalm: “The usually stoic [Japanese],” an Air Force historian recorded, “seemingly lost all caution and fled into the open, [becoming] easy targets for other forms of attack.”
Napalm was used effectively in the fire bombing of Japanese cities. It was also used in preinvasion efforts to soften up the defenses of Iwo Jima. Beginning on 31 January 1945, Liberator bombers of the Seventh Air Force began 16 days of daytime sorties against the island in which 602 tons of bombs were dropped and 1,111 drums of napalm were used in an unproductive effort to burn off camouflage from defensive positions and gun emplacements. A Marine intelligence officer is quoted in the official Air Force history of operations over Iwo Jima as saying that “the chief effect of the long bombardment of Iwo was to cause the enemy to build more elaborate underground defenses.”