On July 1961, the Soviet leadership under Premier Nikita Khrushchev decided to break a de facto moratorium with the U.S. that had existed since the conclusion of the last test series on both sides in 1958 (with even some intentions to formal limitations on nuclear testing). At the meeting with his nuclear weapons scientists he spoke in an unmistakably way:
“Khrushchev simply began the meeting with a speech declaring that tests would resume in the fall to ‘show the imperialists what we could do’, a decision that came as a surprise to the scientists present.”
Even though it is not clear whose idea it was, but not much time went by until the idea came up to build and explode a device as big as never before.
The idea of a 100 megaton weapon was born.
After a rushing development time of only 16 weeks (inluding skipping mathematically analysis which lead to last minute design modifications) the bomb was dropped by a Tu-95 bomber about 55 km north of the Severny settlement and 250 km north of the headquarters at Belushya, from where it was observed by the State Commission.
The bomb was so heavy that special constructions on the delivery plane were necessary to carry the 27 tons bomb which was dropped with a parachute to give the crew of the plane enough time to gain some distance.
Senior weapon designer Sakharov decided to test a reduced version of the device with a yield of 50 megatons. An important decision as it is explained on the website of nuclearweaponarchive:
“This three stage weapon was actually a 100 megaton bomb design, but the uranium fusion stage tamper of the tertiary (and possibly the secondary) stage(s) was replaced by one(s) made of lead. This reduced the yield by 50% by eliminating the fast fissioning of the uranium tamper by the fusion neutrons, and eliminated 97% of the fallout (1.5 megatons of fission, instead of about 51.5 Mt), yet still proved the full yield design.”
On 30 Octobre 1961 11:32 AM the biggest detonation human species ever set off blasted. The tremendous fireball reached the earthly ground despite the burst height of 4’000m and the flash of light was visible at a distance of 1’oookm! Windowpanes were partially broken to distances of 900 km, all buildungs at a distance of 55km were completely destroyed, radio communication was interrupted for almost one hour.
“The atmospheric disturbance generated by the explosion orbited the earth three times. A gigantic mushroom cloud rose as high as 64 kilometers (20’000ft).”
One assumes that the test device was never build for other purpose than propaganda effect because of its mere weight and the fact that it was even to big for most U.S. cities..