 Modern variable yield devices would allow a single standardized explosive to be tuned down, configured to a lower yield, automatically.The bombs had to be launched behind the pusher plate with enough velocity to explode beyond it every 1.1 seconds.Numerous proposals were investigated, from multiple guns poking over the edge of the pusher plate to rocket propelled bombs launched from roller coaster tracks, however the final reference design used a simple gas gun to shoot the devices through a hole in the center of the pusher plate.