The bomb was designed for aerial bombardment and maximum efficiency after being dropped. Therefore, the bomb had a very thin metal sheet as its only cover, as little as 1⁄32 inch (0.79 mm). The bomb is approximately 8 inches (200 mm) in diameter, with a nose the shape of a hemisphere. The M108 bomb fuse at the nose of the bomb detonated the weapon, allowing for the release of the contents inside. The bomb is designed to carry either white phosphorus (WP) or a mustard agent (H). However, the H bomb filler was found to leak from the bomb when loaded, and the M47 and its variant M47A1 were not allowed to be loaded. This was due to the thin steel walls on the weapon. In storage and handling, both corrosion and rough handling were found to cause the bomb to leak. When the bomb is loaded with the chemical filler H, it weighs approximately 93 pounds (42 kg), 73 pounds (33 kg) of which are from H.
The M47 bomb can also be used as an incendiary device as well. A mixture of rubber and gasoline can be used in the field to produce a crude incendiary bomb. A mixture of white phosphorus and jelled gasoline also produces a flammable mixture. Other mixtures include: LA-60 in which crude latex is combined with caustic soda, coconut oil, and water, crepe rubber (CR) in which crude latex reduced to a solid by precipitation and kneading, LA-100 in which crude latex is dried until it is 100% solid, smoked rubber sheets (SR) in which crude latex that has been dried over a fire until it is 100% solid.
When used with these fillers, the bomb uses a 1-pound (0.45 kg) black powder charge to ignite and scatter the incendiary materials. The bomb typically weighs about 85 pounds (39 kg) when the incendiary fillers are used.
The M47A1 was designed to replace the M47. It has a thicker steel cover that is about 1⁄16 inch (1.6 mm) thick and an acid resistant corrosion cover inside.
The M47A2 was designed to fix the leaking problems of the M47 when the agent H was carried. On the inside it was coated with a special oil that protected against corrosion from the agent H.
- BOMB, CHEMICAL, 100-POUND M47 SERIES Archived 2009-01-14 at the Wayback Machine., U.S. Army Corps of Engineers, Fort Worth District, accessed January 3, 2009.
- Morgan, Stephen L. Chemical Warfare: History and Chemistry", University of South Carolina, Department of Chemistry and Biochemistry, accessed January 3, 2009.
- McArthur, Charles W. Operations Analysis in the U.S. Army Eighth Air Force in World War II, (Google Books), American Mathematical Society, 1990, p. 65, (ISBN 0821801589).