Mark 17 Bomb
The first Practical thermonuclear bomb
Explosive Power
15 Megatons
Hiroshima Equivalent Factor
1000x
Dimensions
24 feet, 8 inches x 61 inches
Weight
Approx. 42,000 lbs.
Year(s)
1954-1957
Purpose
A much bigger bang.
About THE MARK 17 Bomb
The Mark 17 is a thermonuclear bomb, a fusion bomb, and that, aside from a few experimental and semi-experimental efforts, is different than all of the nuclear bombs that came before. Before the Mark 17, all deployed bombs were various forms of a fission design where atoms were split to release energy. A thermonuclear bomb not only splits atoms but it combines them, a fission bomb wrapped in a fusion bomb wrapped in a fission bomb. They are potentially limitless in their explosive power.
The Mark 17 is a big bomb. Its enormity can only be conveyed by standing next to it. On its support at the museum it is as tall as a man, as long as a mini-bus.
The Mark 17 is a heavy bomb, so heavy that the mass of its 42,000 pounds edges past comprehensibility. What else is that big, what else to compare it to, how does one put such an enormous weight in context? Do I reach for everyday comparisons and say it is equal to ten modern pick-up trucks (thirteen, if you go with the lighter 1954 Ford)? Do I reach for fairy tales and say that you could stack three-hundred and twenty-three king-sized mattresses, stack them two-hundred and fifteen feet high (and wonder if the princess will still feel the pea)?
The mass of this bomb is a semi-abstraction, just beyond any direct human experience.
The Mark 17 is a powerful bomb, more powerful than anything before. The atomic test blasts leading up to its introduction were the most powerful of all of the United States’ nuclear tests, among the most powerful of any such test ever. Bombs before this were measured in kilotons. The explosive power of this bomb is measured in megatons, the metric scale obscuring more than it reveals. The Mark 17, deployed in 1954, was one thousand times more powerful than Little Boy, the bomb that destroyed Hiroshima just nine years before.
What was the military benefit of the Mark 17’s power? What targets would have been on the receiving end of the two hundred of these bombs that were built? What level of destruction did we desire in our war against the Communists? Did we need Moscow reduced to rubble? Did we need the rubble reduced to sand? Did we require the sand to be reduced to dust?
There can be no military reason for such a bomb unless to convince the enemy that you know no bounds, that your reason has turned to unreason, that you are a madman country led by fools bluffing with nowhere to retreat to if your bluff is called other than a civilization-ending war or abject surrender.
So why the Mark 17, why make a 15-megaton weapon? The answer seems obvious. Because a 15-megaton weapon could be built, because the eager scientists and engineers continued their progress, a 15-megaton bomb was built. They took the biggest plane and calculated the biggest bomb it could carry and made a thermonuclear bomb to fit. Not a bomb crafted with any specific targets in mind but a bomb built to the outer limits of what was then possible with the technology available.
The Soviets made their own bomb, in response, of course. They made the Tsar Bomba, half again heavier, almost seven times more powerful, a bomb so powerful that it was unusable at full power, even as a test.
There is no particular reason why even bigger bombs can’t be made.
Edward Teller, one of the most prominent physicists of all time, was the father of the thermonuclear bomb and had pushed the technology even at Los Almos during WWII against all manner of doubters who didn’t think the technology was possible, against all manner of people who didn’t want a thermonuclear bomb to be possible. After the first thermonuclear tests were completed, even after the first thermonuclear bombs had been built, he wanted bigger bombs. He called for bombs not ten times bigger than the Mark 17, not 100 times more powerful, but almost seven hundred times as powerful as the Mark 17, two-thirds of a million times more powerful than Little Boy. The bomb he advocated was a doomsday bomb, a single bomb that would cause second-degree burns from two hundred and fifty miles away, a single bomb that would taint the air across the world with radioactive dust and doing who knows what to the atmosphere above the blast.
Surely Teller was kidding, surely his words only bluster. Surely no one could be that crazy.
Gallery
Nukemap
NUKEMAP is a web-based mapping program that attempts to give the user a sense of the destructive power of nuclear weapons. It was created by Alex Wellerstein, a historian specializing in nuclear weapons (see his book on nuclear secrecy and his blog on nuclear weapons). The screenshot below shows the NUKEMAP output for this particular weapon. Click on the map to customize settings.
Videos
Click on the Play button and then the Full screen brackets on the lower right to view each video. Click on the Exit full screen cross at lower right (the “X” on a mobile device) to return.
Further Reading
- Wikipedia, Wikipedia (Mark 24), Global Security
- If you include test weapons, the first thermonuclear “bomb” appears to have been the Mark 14, an experimental model. Five units were built in 1954 but it was never deployed.
- The Atomic Heritage Foundation has a good, short history of the development of thermonuclear weapons.
- The Mark 17 was so large and heavy that only one Air Force bomber could carry it, the Convair B-36. It was replaced by the B52, which could not carry the Mark 17, and the huge bomb was phased out.
- A Mark 17 was accidentally dropped on Kirkland AFB in an accident that was revealed almost three decades after it occurred. The nuclear fuel “pits” had not been inserted but otherwise it was a fully functional weapon.
- There were several variations of the Mark 17, some intended to detonate mid-air (descending on parachutes to allow the bomber to try and get clear of the blast), while others were designed to explode on ground contact (surely also using parachute to slow the descent). Given the size of the blast I am dubious that an escape by the bomber would be possible, unless the bomb sat on the surface for a period of time.
- The Mark 17 is the most powerful nuclear weapon ever produced by the United States but not the most powerful one ever produced. The Soviets like to one-up the US and built a 100 megaton bomb, which they detonated at half-power.
- To Edward Teller, the great champion of developing thermonuclear weapons, 100 megatons was nothing. Bombs could be, and perhaps should be, made that were much more powerful. Note the sidebar graphic illustrating the relative explosive power of different nuclear weapons.
- The Mark 17 bomb is huge. Its size is hard to convey in photos when it is positioned against large bomber aircraft. If you want a better sense of scale this photo might help.
- This training bomb was found and transported to Kirtland AFB. But they don’t say where it was found.
- There have been 1054 nuclear tests by the United States and among the most famous in popular culture are the ones leading up to the Mark 17, especially the unexpectedly powerful Castle Bravo test (and the radiological disaster that followed) and the unexpectedly powerful Castle Romeo test (the test of the Mark 17 warhead). Romeo was the first detonated from a barge–the thermonuclear tests were so powerful they destroying the military infrastructure on the islands, not to mention the islands themselves.
- These tests, especially Bravo and the horrors of the Daigo Fukuryu Maru, are credited with the inspiration for Godzilla.
- While writing the essay (above) and making the calculations for Teller’s multi-gigaton bomb (and doubting my calculations) I stumbled on Alex Wellerstein’s blog post with the same calculations covering some of the same ground. Well worth reading.