1961 ... a lot of fun at parties!

... B-41 Hydrogen Bomb - yield 25 megatons - 500 built - largest weapon ever fielded by the the USA.


Otto Didact said...

As one who spent 5 wonderful years assigned to a SAC base with Titan II missiles and having spent 3 years in Titan II comm, I can tell you what I was told about thermonuclear warfare and why the B-41 was the largest yield bomb the U.S. ever made.

First off, you must understand that an explosive device's destructive power does not increase in a linear manner. A 10 megaton bomb is not twice as powerful as a 5 megaton bomb. Actually it is only a touch more than 40% more destuctive. This is because the energy expands in a sphere and thus follows what is known as "square law" meaning that the destructiveness goes up as the SQUARE ROOT of the change in power. Since 10 is only 2 times 5 the change is the square root of 2 or 1.414. If you want to double the destructiveness of a bomb your increase must square. The square of 5 is 25 thus to double the destructive power of a 5 megaton bomb the power of the bomb must be 5 square megatons or 25 megatons. To double a 25 megaton bomb's destructiveness would require 625 megatons - something nobody ever dreamed of making.

To be maximally effective (i.e. to be the most destructive) a nuclear or thermonuclear device's fireball must remain spherical as long as possible. For maximum destructiveness then you need to detonate the bomb in the air otherwise all you do is make a big hole and sent up tons of radioactive material into the atmosphere to fall eventually onto YOUR territory. The longer the fireball stays spherical, the better. I was taught that when you get more than a tiny bit bigger than 25 megatons, the fireball ceases to be spherical far too soon as it either hits the ground or the top of the atmosphere. Since even a 50 megaton would only provide a theoretical 40% increase in destructive power and since the fireball would run out of space to be spherical very quickly, the U.S. decided early on to limit the size of their weapons to 25 megatons. In practical use the largest bomb we were prepared to use was the 5 megaton thermonuclear device in the payload of the Titan II.

For reference, even a 5 megaton device is hellishly destructive. A 5 megaton air burst at 10,000 feet (3,000 meters) would theoretically destroy commercial structures for FIFTEEN (15) MILES (24 kilometers) in EVERY DIRECTION! I once heard Titan II described as "America's largest mobile phallic symbol" and it would be used to F**K an entire county!

Anonymous said...

The above photo is of a Mk-53/B-53 Thermonuclear gravity bomb. The bomb shared a 'physics package' with the LGM-25C "Titan II" ICBM, designated W-53. The estimated yield was about 9 megatons.