Direct access is acceptable when the scaffold is not more than 14 inches (36 centimeters) horizontally and not more than 24 inches (61centimeters) vertically from the other surfaces. 1926.451(e)(8) The standard prohibits the use of crossbraces as a means of access.
H Bomb. Abbreviation for Hydrogen Bomb. The hydrogen bomb is the big brother of the first nuclear bombs, Fat Man and Little Boy, which were dropped on Nagasaki and Heroshima in 1945. The hydrogen bomb uses a hydrogen neutron, fired at high speed, into an atom of some unstable element, usually uranium.
Confidence votes 2.5K. The short answer is that the hydrogen bomb -- the fusion bomb -- was the natural extension of the relatively simple fission bombs used over Japan in WWII. The very creation of the fission atomic bomb made possible the pressures and temperatures needed to foster a fusion reaction.