Orion designs compared to launch fireballs #1
We can calculate the proper scale for the 20 kt fireball images available here.
Using the chart on page 55 of Project Orion we can figure the gross takeoff mass, 571,000 tons.
Borrowing one of Selden's drawings we can combine these two images.
This covers the inital fireball,
#2 .5 seconds
#3 1.25 seconds