Mark 12 nuclear bomb
The Mark-12 nuclear bomb was a lightweight nuclear bomb designed and manufactured by the United States of America which was built starting in 1954 and which saw service from then until 1962.
The Mark-12 was notable for being significantly smaller in both size and weight compared to prior implosion-type nuclear weapons. For example, the overall diameter was only 22 inches (56 cm), compared to the immediately prior Mark-7 which had a 30 inches (76 cm) diameter, and the volume of the implosion assembly was only 40% the size of the Mark-7's.
There was a planned W-12 warhead variant which would have been used with the RIM-8 Talos missile, but it was cancelled prior to introduction into service.
The complete Mark-12 bomb was 22 inches (560 mm) in diameter, 155 inches (3.94 m) long, and weighed 1,100 to 1,200 pounds (500 to 540 kg). It had a yield of 12 to 14 kilotonnes of TNT (50 to 59 TJ).
The Mark-12 has been speculated to have been the first deployed nuclear weapon to have used beryllium as a reflector-tamper inside the implosion assembly (see nuclear weapon design). It is believed to have used a spherical implosion assembly, levitated pit, and 92-point detonation.
In popular culture
Though the weapon went out of service in 1962, it resurfaced in a fictional role in Tom Clancy's 1991 book The Sum of All Fears and the 2002 film, where the plot included an Israeli copy of the Mark-12 being lost by accident in 1973 during the Yom Kippur War in southern Syria near the Golan Heights, and then recovered by a terrorist organization.