W41

W41 was the designation of an American nuclear warhead, which was investigated during the late 1950s. Intended for use in the SM-64 Navajo cruise missile, the program was cancelled in 1957. The program was brief, considered at the same time as the TX-29, WX-15-X1 and XW-21 warheads. All were eventually replaced as the proposed Navajo warhead by the 39. The W41 was an adaptation of the B41 (Mk-41) thermonuclear bomb which was produced in large numbers and served in stockpile for 15 years.

History
A warhead version of the B41 thermonuclear bomb, development of the W41 began in November 1956 at Lawrence Livermore National Laboratory. Investigated as a possible warhead for the SM-64 Navajo, a cruise missile then in development, work on the warhead continued through July 1957, when the project was cancelled.

Conspiracy theories
Following the Deepwater Horizon oil spill, conspiracy theories began that claimed a W41 nuclear bomb would be used to seal the oil well, despite the use of a nuclear weapon in the role having been officially rejected.