Jettisonable fuel tanks ("fire bombs")

General: The "fire bomb" consists of a jettisonable fuel tank filled with gasoline gel (gasoline-Napalm mixture). These bombs have been effective against personnel, wooden piers, inflammable stores, etc., with each bomb covering an area approximately 100 feet by 300 feet.

Various types of jettisonable fuel tanks are available for conversion into fire bombs. A 150-gallon universal or interchangeable tank has been produced. Stabilizers have been designed to give the fire bomb a more stable flight when dropped from a higher altitude. The stabilizers are attached to the present tanks by a harness consisting of four cables which run along the longitudinal axis of the tank and are attached to a ring fitted around the nose. The universal tank has clips welded to the after end, obviating the necessity of the nose ring and cable harness.

Filler: The filler is a gasoline-Napalm mixture. Napalm consists of a mixture of basic aluminum soaps of fatty acids and napthenic acid, which in itself is inert and is used only to congeal the gasoline to the proper consistency. Either 100 octane or 80 octane gaso-line can be used, with 6 percent Napalm by weight added for the mixture. Another pow-der, Marinco, consisting of 50 percent magnesium carbonate and 50 percent calcium car-bonate, is added (7 percent of Napalm by weight) to prevent clogging in the outlet hose.

The Navy has developed the Incendiary Mixers Mk 1 Mod 0 and Mk 1 Mod 1, which mix the gasoline and Napalm in the correct proprotions.

Igniters: The stabilizers are provided with a clamp for attaching an igniter which is in addition to the fuel-tank cap igniter. The Igniters M13, M14, M15, and M16 are used.

Figure 310. Jettisonable Fuel Tanks