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 has been described as a design derivative of the B28 nuclear bomb nuclear warhead design. It was 20 in in diameter and 54 to 58 in long depending on model, weighing 1640 to 1680 lb, and had a design yield of 1.44 megatons.