Mark 27 nuclear bomb

The Mark 27 nuclear bomb and closely related W27 warhead were two American nuclear weapon designs from the late 1950s.

The Mark 27 was designed by the University of California Radiation Laboratory (UCRL; now Lawrence Livermore National Laboratory) starting in the mid-1950s. The Mark 27 and W27 were produced from 1958; both were retired by 1965.

The basic design concept was competing with the Los Alamos Scientific Laboratory (LASL; now Los Alamos National Laboratory) design that would become the Mark 28 / B28 nuclear bomb and W28 warhead. The Mark 27 was roughly twice as heavy and had a higher yield of 2 megatons versus the 1 to 1.5 megatons of the Mark/W28 family.

The W27 warhead was 31 inches in diameter by 75 inches long, and weighed 2,800 pounds. 20 W27 warheads were produced for the United States Navy SSM-N-8 Regulus cruise missiles.

The Mark 27 bomb was 30 inches in diameter by 124 to 142 inches long, depending on specific version. The three versions weighed 3,150 to 3,300 pounds. 700 Mark 27 bombs were produced.