linguistic:paraphrasing, stylistic:style_transfer, information:extraction
The method was applied in four known US programs. First, the " Little Boy " weapon which was detonated over Hiroshima and several additional units of the same design prepared after World War II, in 40 Mark 8 bombs, and their replacement, 40 Mark 11 bombs. Both the Mark 8 and Mark 11 designs were intended for use as earth-penetrating bombs (see nuclear bunker buster), for which the gun-type method was preferred for a time by designers who were less than certain that early implosion-type weapons would successfully detonate following an impact. The second program was a family of 11-inch (280 mm) nuclear artillery shells, the W9 and its derivative W19, plus a repackaged W19 in a 16-inch (406 mm) shell for US Navy battleships, the W23. The third family was an 8-inch (203 mm) artillery shell, the W33.