BLU Series Napalm Bombs

Introduction to BLU Series Napalm Bombs

The BLU series napalm bombs (incendiary tanks) are in service with the US Air Force and other NATO countries. While they appear identical, they come in various sizes and calibers. Incendiary tanks of the same caliber have larger geometric dimensions and greater volume, yet weigh less than standard bombs.

Their primary purpose is to target personnel on land and water, easily flammable structures, vulnerable equipment, as well as forests and agricultural crops using an incendiary mixture (napalm). Upon impact and fan-like deployment, a 750 lb incendiary tank creates an intense fire zone spanning up to 4000 m² (an area of 90m by 45m).

Properties and Effects of Napalm

The effectiveness of napalm mixtures is determined by the amount of heat transferred to the ignited material during combustion. Most napalm mixtures have a heat of combustion of approximately 10 kcal/g. Napalm ignites easily but burns slowly, with a duration ranging from 1 to 15 minutes, depending on the formulation, application method, and cluster size.

Napalm’s burning temperature ranges from 800°C to 1100°C, producing a significant amount of carbon dioxide. This gas has a toxic effect on people in shelters. Napalm mercilessly burns its victims and fatally poisons those who do not burn. It also exerts a powerful moral and psychological impact on individuals, suppressing their capacity for active resistance, as all living beings fear fire.

Evolution and Components of BLU Bombs

In 1966, the United States adopted a more viscous incendiary mixture, Napalm-B, which offered superior combat properties. This substance ignites and liquefies easily, adheres to wet surfaces, and is lighter than water. Napalm-B can create a high-temperature focus (up to 1200°C) with a burn duration of 5 to 10 minutes.

Dissolved polystyrene is used as a thickener, known for its high combustible and binding properties. Sometimes, white phosphorus is introduced into the Napalm-B formula, making the mixture even more effective and its effects extremely dangerous.

All BLU series bombs share a similar design, characterized by a cigar-shaped body made of thin, combustible sheet metal. The AN-M23A1 igniter is a metal cylinder measuring 98 mm in diameter and 91 mm in length, rounded at one end and threaded at the opposite end for mounting into the fuze cups located in the bomb’s nose and tail sections.

The igniter’s internal cavity is filled with 0.57 kg of white phosphorus through an opening sealed with a plug. The total weight of the loaded igniter is approximately 1.5 kg. The FMU-7 A/B fuze, an impact-activated fuze with electrical arming, is threaded into the igniter, with an arming delay time ranging from 0.3 to 1.1 seconds.

Tactical Deployment and Historical Impact

Electrical power for arming both the nose and tail fuzes is supplied via flexible cables from a thermal electric battery, integrated into the bomb’s central body section. During the Vietnam War, US aviation employed napalm tanks in low-altitude, high-speed bombing missions (700-900 km/h), utilizing two primary methods.

The first method was skip bombing (ricochet) at very low altitudes, designed to hit exposed personnel and equipment. The approach to the target was made at 60 meters, followed by a descent and precise bombing run from 15 meters. The second method involved bombing from a shallow dive, with a dive angle of 5 to 15 degrees, often accompanied by cannon fire and unguided rocket launches.

The sudden and massive use of napalm tanks by Israeli aviation in the 1967 war against exposed personnel, vehicles, and armored units inflicted significant losses. Up to 75% of the total casualties among Arab troops were attributed to napalm. In South Vietnam, Americans waged a true “napalm war,” with approximately 40% of the bombs dropped on the Democratic Republic of Vietnam loaded with incendiary mixtures.

After studying the experience in Vietnam, the US command concluded that this weapon was most effective when implementing “scorched earth” tactics. This involved massive, concentrated strikes by large groups of aircraft from low altitudes to achieve the complete destruction of troops, structures, and vegetation over extensive areas. Key BLU series bomb types include:

• BLU-1/B: A 750 lb class incendiary bomb, filled with 340-380 liters of napalm.
• BLU-27/B: Externally similar to the BLU-1/B, but filled with the heavier Napalm-B mixture.
• BLU-10/B: A 250 lb class incendiary bomb, filled with 125 liters of napalm.
• BLU-11/B: A 500 lb class incendiary bomb, filled with 245 liters of napalm.
• BLU-23/B: A 500 lb class incendiary bomb, filled with 254 liters of napalm. This bomb was distinct as it could be fitted with a nose fairing and a tail fin kit.
• BLU-32/B: Externally similar to the previous model, but filled with the heavier Napalm-B mixture.