The designers nicknamed the bomb ‘Big Ivan’. The bomb was assembled at Arzamas-16, a secret Soviet nuclear weapons research facility located in the Urals. It weighed 27 tons and was eight meters long. The bomb was a three-stage device originally designed to have a 100 megaton yield. For the test, however, the uranium tamper would be replaced with a lead one, decreasing the yield to 50 megatons but also eliminating much of the radioactive fallout that would be generated by the test. At full yield, Tsar alone would increase the world fission output by 25%. The lead tamper also made the bomb the cleanest device ever made, with 97% of the yield coming from the fusion reaction. Even at the decreased yield, it was approximately 4000 times more powerful then the Little Boy bomb.
A giant 5400 square foot nylon parachute was made for the bomb to slow down its descent to allow the bomber time to escape to a safe distance from the explosion. In the event of a parachute malfunction, the bomber would still be safe because sensors were installed in the bomb to ensure it would only detonate if the plane was a safe distance from the blast.
By October 24th, the final report of the development was published. The development of the bomb, from initial conceptual design to test, took only 16 weeks. The fabrication was rushed, many calculations were skipped, and last minute modifications to the design were made. Facing the tight schedule, bomb assembly began even during design development. Khrushchev had already announced the planned test of a 50 megaton bomb to the world, and a massive testing series began in September 1961. The railroad car the bomb was built on was camouflaged as a regular freight train and the completed bomb was transported to the waiting bomber at Olyena Air Base on the Kola Peninsula.
The Tu-95 bomber that would deploy Tsar had to be specially modified for the test. And entire section of the bottom fuselage had to be removed to make room for the bomb as it was too large to fit in the standard bomb bay compartment. Despite this drastic modification, more then half of it was still hanging outside the plane. A special lift mechanism hoisted the bomb into place and held it till release. The bomber had to be painted with a special white coating to protect it from the immense thermal pulse generated by the colossal explosion.
Massive political propaganda was attached to this test by the USSR; the careers, and possibly lives, of the design team were at stake.
The location for the test was the Sukhoy Nos Peninsula Aerial Nuclear Testing grounds on Novaya Zemlya, also known as Test Site C. Between 1957 to 1962, over 80 nuclear tests were conducted here. The largest man made explosions were detonated over the Sukhoy Now testing grounds. On December 24, 1962 a 24.2 megaton test was conducted at Test Site C, along with a 21.1 megaton test on August 5, 1962 and a 19.1 megaton test on September 25, 1962. These were the 2nd, 3rd, and 4th largest nuclear tests ever conducted, respectively.
The relatively flat terrain of the Sukhoy Nos Peninsula made it a favorable location for nuclear tests. Aerial tests were conducted high above the surface of the Earth to minimize local radioactive fallout. Bombers loaded with atomic and hydrogen bombs would fly out of airbases in the Kola Peninsula from Olyena Air Base and drop their ordinance over Test Site C.
The Tsar drop plane was to be piloted by Major Andrei E. Durnovtsev, who would be made Hero of the Soviet Union following the test. Once there, the bomb would be released at an altitude of 33,600 feet. Barometric sensors inside to bomb were set so that the bomb would explode at an altitude of 13,000 feet. The massive parachute deployed, giving the bomber enough time to reach a safe distance. All crew members put on darkened goggles to protect their eyes from the brilliant flash of light. Six camera crews were assigned to film the explsion, both from the air and from the ground. Major General Nikolai Pavlov, head of the design team and test supervisors, monitored the test 1000 kilometers away at the Olenya base.
One second after detonation, the fireball was over 4 miles wide. Despite the high altitude of the test, the fireball swelled down to the Earth’s surface almost licking the ground. The shockwave of the blast almost killed the crew of the Tu-95 that dropped the plane as the fireball almost reached the height of the release plane. Despite cloudy skies, the flash of light was clearly visible 1,600 miles away. The shockwave destroyed buildings and tore roofs off of homes hundreds of miles from ground zero. Windows in Norway and Finland were shattered. The scientific settelment on the Matochkin Strait called Severney, some 35 miles south of the explosion, was devastated. The thermal pulse of the blast was felt 500 miles from the epicenter. Radio communications were knocked out for an hour and no word of the safety of the Tu-95 and its crew could be reported for some time.
