THE MATERIALS INVOLVED IN THE WTC BOMB
As reported in news accounts of the WTC bombing, it appears nitrourea was used as the bomb’s base and cylinders of hydrogen were used to increase the magnitude of the explosion. The following is a brief description of the materials involved.
Nitrourea, a white, crystalline powder, is a Class A explosive. It also is known as m-nitrocarbamide, N-nitrocarbamide, 1-nitrourea, and N-nitrourea. It is a high explosive that presents a severe explosion hazard and is stable until detonated. Although some references say nitrourea is sensitive to heat and shock, the greater likelihood is that it is stable; otherwise, it might be too dangerous to transport by truck (or van).
The power of nitrourea is similar to that of trinitrotoluene (TNT) and picric acid. (TNT and picric acid are used as reference points because TNT is referred to as the “standard” explosive in the United States and picric acid the “standard” explosive in Great Britain.) Nitrourea produces about 90.5 percent of the gas volume of TNT when detonated and has slightly more than three percent more relative power than TNT. It produces about 97.7 percent of the gas volume of picric acid and has three percent less relative power. Its caloric value (power as described by the number of joules of energy per kilogram of weight) is 34 percent greater than TNT’s and 19 percent greater than picric acid’s.
When compared with ammonium nitrate, nitrourea has about 13 percent less gas volume, about 38 percent more relative power, and about 47 percent more caloric value.
Hydrogen is a highly flammable, nontoxic, colorless, odorless, and tasteless gas. Its flammable range is from four to 75 percent, the second widest range of any common flammable gas. With such a wide range, it is easily ignited. The flame from burning hydrogen has a very’ high heat content —its flame temperature is 3,700°F. Hydrogen burns with an almost invisible flame, converting all energy into heat energy.