Squantos, kindly check my numbers.
Per numbers from the Texas Feed and Fertilizer Control Service, the amount of AN on hand at the West fertilizer facility averaged 54,000 pounds, assuming no loaded railcars [circa 125 tons each per covered hopper/LO car] or contributing oxydizers. Accordingly, about 27 tons on AN.
AN isn't nearly as brisant as TNT, which provides the baseline for figuring an atomic/nuclear detonation, but as a back-of-the-envelope number, it's close enough to 1/40th KT, or .025 KT. The W54 warhead of the Davy Crockett offered a yield of around 22 tons [Little Feller I shot, 07 July 1956] command detonated 3 feet AGL, or 18 tons yield in the following Little Feller II shot 07 July, with a Davy Crockett warhead fored 20-40 feet AGL. So about in the same neighborhood as the West explosion, which appears about the same insofar as effects resulting:
Declassified Little Feller II test shot film
