American Nukes

About the Mark 8 Bomb

Many of the physicists at Los Alamos who developed Little Boy and Fat Man were for the Bomb before they were against it. Oppenheimer was for it, then against it. Szilard was sort of for it, then sort of against it. Klas Fuchs, who gave nuclear secrets to the Soviets, was in his own way against it while at the same time he was for it. Hans Bethe, Isidor Isaac Rabi, Emilio Segrè, Kistiakowsky, all were for it, then all were against it.

One, Joseph Rotblat, coming to the realization that the bomb would actually be used as a bomb rather than used merely as a threat, left the Manhattan Project before Trinity, the only scientist to do so.

Others later became unenthusiastic about the bomb—the fission bomb in all of its forms—only because they wanted a much bigger bomb. Edward Teller and Stanisław Ulam wanted to develop a new technology to create a Super—a bomb far more destructive than anything thought possible at the time.

The famous names, after the war, left the Manhattan Project, moving to universities to pursue their research unfettered by academic and geographic isolation. And to follow the money—the Manhattan Project’s budget fell dramatically immediately after the war and it was not at all clear that the project would continue.

But it did continue and the money began to flow once again as China fell to the Communists in 1949 and as the USSR set off its first nuclear blast that same year, the Korean War starting the next. As the famous scientists left, new scientists came in, drawn by the opportunity to work on difficult and important problems and by the status the projects offered that would enable them to mingle with the big names in their field. One of these newcomers was Ted Taylor, a physicist who had done poorly in graduate school in physics at Berkeley but who, it turned out, was a gifted weapons designer.

The Mark 8 may be one of his creations—the timeline of the development of the Mark 8 and Taylor’s arrival at Los Alamos overlap and he favored small, fission designs. It was a bomb billed as a weapon that (and I quote an informational placard at a museum) “…was for use against hardened or underground targets, such as bunkers, command centers and submarine pens.”

Taylor, years later, said something similar.

He remembers his time working on weapons development not as responding to the demands of the military but in working on interesting ideas, whatever caught his attention, that offered the possibility of clever solutions and then sort of making up, on the spot, practical uses of his ideas:

In terms of the pressure to continue to develop new and more weapons, that pressure came not, certainly in the ‘50s, not from the military, but I think from Los Alamos and from Livermore. Sort of, “Well, gee, if you can do it—all the numbers are so big, if you can make something that can withstand being dropped on concrete and penetrate 300 feet and then go off with a nuclear yield, what might you use that for?“

“Well, knocking out submarine pods and so on,” without giving it much thought. I think, actually, the whole thing is silly, when you begin to look at the whole thing in a lot of detail. But it was enough to get things moving, and then pretty soon the Air Force wanted it to destroy the Soviet navy, the submarine maintenance facilities, and so on.

He designed many weapons. Nuclear bombs, artillery shells, nuclear warheads were all made to his designs. But he changed his mind, saying by the mid-1960s that he was a “nuclear dropout,” warning of nuclear terrorism. He was for nukes before he was against nukes.

The M8 is the first tactical nuclear weapon, the phrase “tactical” denoting a smaller weapon that you might imagine using ahead of your advancing troops or to block the advance of the enemy. These tactical weapons, despite being as powerful and even more powerful as those that struck Hiroshima and Nagasaki, somehow seemed, as the years went by, more potentially usable from a political point of view, and brought with them a corresponding greater potential worry that they would be used.

“Tactical,” “Strategic,” these terms took on their modern meaning decades later with the negotiations on nuclear arms control, nuclear war planers concerned that the use of tactical would lead to the use of strategic and it was the strategic weapons that you had to really worry about, that it was the strategic ones that would invite, even demand, massive nuclear retaliation from the enemy.

It took a long time to realize that a tactical nuclear weapon is only “tactical” to the one launching the attack.

Gallery

Click for details on the photographs

1. The Mark 8 bomb (sometimes called by its nickname, “Elsie”) was unusual in that, despite the use of nuclear fuel-efficient plutonium-based bombs elsewhere in the growing US inventory, it used a Little Boy-like uranium gun design. My assumption is that, due to the intent of this weapon as a ground penetrating bomb where the bomb explodes after impact, not upon impact, the gun design was the more robust choice. Forty Mark 8’s were manufactured in several different versions (with later units modifying earlier units). This use of the still rare uranium caused concern in the other military branches–the Mark 8 was a Navy bomb.
2. Although the bomb had fuzing and other safety devices, on the version meant to be carried externally under an aircraft’s wing, there does not appear to have been any way to insert the nuclear core once in the air. This is especially odd in that the bomb then would been “armed”–in the sense of being ready to explode–while still on the deck of the aircraft carrier.
3. The odd tail design of the Mark 8 was said to be for stability when dropped from high altitude although later versions used a fin design and did away with the ring.

Want to see nuclear weapons for yourself, in person? Check out Where to See Nuclear Weapons in the Resources section.

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 button on the lower right (the brackets on a mobile device) to view each video. Click on the Exit full screen button (the “X” on a mobile device) to return.

No videos available (yet).