The bomb was designed as a 100 Megaton device, not a 50 Megaton device. This was due to its 3 stage design: fission-fusion-fission. There is fission initiator that when detonated, begins a fusion reaction. Then there is a further fission detonation of a Uranium tamper which boosts the yield by 50 Megatons. For the test, the Tsar had its Uranium tamper replaced with lead to reduce the maximum yield by half (To 50 Megatons).
The blast yield was equal to that of a blast of 57,000,000 Tonnes of TNT....or to put that into context: The weight of 270 Empire State Buildings worth of TNT. This makes the Tsar the most powerful nuclear device ever detonated in history. Think of the destruction at Hiroshima. The Tsar was 3800 times more powerful than Hiroshima.
The bomb's weight was 27 tonnes, and its dimensions were: 8 meters (26ft) in length, and 2 meters (6.5ft) in diameter.
It was air-dropped, from a modified Tupolev Tu-95 Bear, and it used a nylon parachute to slow its decent to give the crew time to escape.
The bomb was dropped from an altitude of 34,500 feet AGL (10,500 meters), and it detonated a little over three minutes later at an altitude of 13,100 feet AGL (4,000 meters). In this time: The Tu-95, travelling at a ground speed of 480kts (552mph, 864kph), travelled into the safe zone (about 45km from ground zero) and was therefore 79km away from the blast.
When the bomb detonated, immediately the temperature directly below and surrounding the detonation would have risen to millions of degrees. The pressure below the blast was 300 pounds per square inch, over three times the pressure in a car tyre. The light energy released was so powerful that it was visible even at 1000km (621 miles), with cloudy skies. The shockwave was powerful enough to break windows at even up to 900 kilometres (560 miles) from the blast. The shockwave was recorded orbiting the earth 3 times. The mushroom cloud rose to an altitude of 64,000 meters (210,000 feet) before levelling out. The thermal energy from the blast was powerful that it could cause 3rd degree burns to a human standing 100 km (62 miles) away from the blast.
The radius of the fireball was 2.3 kilometres (1.4 miles). The blast radius (area in which total destruction ensured) was 13km (8 miles).
The most important thing to note is that this bomb was designed as a 100 Megaton device (Yield equivalent of 0.1 billion tonnes of TNT). If detonated, everything within a 48 kilometer (30 mile) diameter would be vaporised. Everything within a 195 kilometer (120 mile) diameter would be incinerated in a fireball. This would ensure total destruction of a large city like New York, Paris or London, as well as devastation on its outskirts.
about this video
This video shows various important aspects of the bomb, including its development at Arzamas-16, the secret Soviet nuclear weapons research facility and its transportation to the Tu-95 bomber, which was painted white for the test to reflect the heat of the blast. Several different views of the explosion are also shown, including several filmed from the air and ground alike. The last few shots are of the ground zero several days after the test.
