W49
The W49 was an American thermonuclear warhead, used on the Thor, Atlas, Jupiter, and Titan I ballistic missile systems. W49 warheads were manufactured starting in 1958 and were in service until 1963, with a few warheads being retained until 1975.
The W49 was listed as the "B28/W49" in a 1987 Congressional report on stockpile reliability suggesting they may be the same weapon. It was in diameter and long depending on model, weighing, and had a design yield of 1.44 megatons.
