W70

Design

Declassified British documents describe the Mod 1 and Mod 2 versions of the weapon have three yields between 0.5 and 50 kilotonnes of TNT (2.1 and 209.2 TJ), while the Mod 3 enhanced radiation version was estimated to have a yield of 1 kilotonne of TNT (4.2 TJ) The Mod 1 reportedly had more yield options than the Mod 2 warheads. The Mod 3 was reportedly 40% fission and 60% fusion, with two yield options. The weapon weighed 270 lb (120 kg), and was 41 inches (100 cm) long and 18 in (46 cm) in diameter.

Mod 1 and 2 weapons were produced from June 1973 to July 1977, while Mod 3 weapons were produced from August 1983 to February 1984. 900 Mod 1 and 2 warheads and 380 Mod 3 warheads were manufactured. The last warheads were retired in September 1992.

The weapon was the successor to the previous proposed Lance warhead, the W63. The weapon used a category D Permissive Action Link and had command disable, but lacked insensitive high explosives and enhanced nuclear detonation safety.

The inventor of the neutron bomb, Samuel Cohen, has criticized the description of the W70 as a "neutron bomb":

the W-70 ... is not even remotely a "neutron bomb." Instead of being the type of weapon that, in the popular mind, "kills people and spares buildings" it is one that both kills and physically destroys on a massive scale. The W-70 is not a discriminate weapon, like the neutron bomb—which, incidentally, should be considered a weapon that "kills enemy personnel while sparing the physical fabric of the attacked populace, and even the populace too."