This is a slow-motion view of the early stages of the SMOKY fireball and mushroom cloud: www.youtube.com/watch?v=DIji... The spikes emanating from the fireball are the guy wires securing the tower and the top part of the tower vaporizing and turning into superheated plasma—the “rope trick” effect.
The two-stage SMOKY device evolved into the three-stage B41 bomb, the highest-yield thermonuclear weapon ever deployed by the United States (25 Megatons). The B41 weighed 10,500 pounds and had the highest yield-to-weight ratio of any US nuclear weapon. Five hundred were operational from 1960-76.
