/ Ie greSSD Brpeoonser 15. The gun-type models, An stockpile now are the Mark 8 (bomb for. subsurface detonatfin) DELETED. and the Mark 9 (280 mm projectile) DELETED Status of Work on Production Models 16. Mark 4 (implosion-type bomb, outside diameter 60 inches, . approximate weight 10,800 pounds). Conversion of Mark 4 bombs to Mark 6 was resumed following a temporary postponement because of difficulty with the new fuze for the Mark 6, Routine functional surveillance of Mark 4 components has been suspended as 42 result of progress in the eonversion program, which is now scheduled for completion in May 1953, rather than June 1953. 17. DOE AECHTERS Mark 6 (Amplosion-type bomb, outside diameter 60 inches, approximate weight 8,500 pounds). The conversion of Merk 6 Mod 0 bombs in stockpile to the Mark 6 Mod 3 has been completed sjry pie. provements, / Several additicnal in- principally changes in the fuzing system, are under development and will be incorporated in stockpiled wearons prior to the advent of the Mark 13 bomb. 18. Merk 5 (implosion-type bomb, outside diemeter 44 inches, approximate weight 3,100 pounds). This weapon is being stockpiled. The cartridge mounting assembly is being modified to permit use both as a bomb component and as a rissile component. 19. ark 7 (implosion-type bomb, epproxinate outside diameter 30 inches, aprproxinate weight 1,600 pounds). ehaaAtratian This wearcr is being