Military Embedded Systems

In a nuclear war...

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July 28, 2016

Ray Alderman

VITA Standards Organization

WARFARE EVOLUTION BLOG: In this space we have discussed different generations of warfare, potential warfare against countries such as Iran, Russia, China, and North Korea, as well as the war on terror, but there is one are we haven't touched on until now -- nuclear warfare.

Atomic history

On 16 July 1945, at the Alamogordo Bombing Range in New Mexico, a sphere of Plutonium-Gallium alloy, about the size of a softball and weighing 13.6 pounds, was detonated in the first manmade atomic (fission) explosion on earth. The yield had the force of 20 kilotons (20 thousand tons) of TNT. The first atomic bomb used in warfare, Little Boy, was dropped on Hiroshima on 6 August 1945. It contained 140 pounds of enriched Uranium, and the yield was equivalent to 13 kilotons (13 thousand tons) of TNT. The second atomic bomb, Fat Man, was targeted for the city of Kokura, Japan, but the weather was bad over the city that day. So, it was dropped on the secondary target, Nagasaki, on 9 August 1945. It contained 13.6 pounds of Plutonium, and the yield was 21 kilotons (21 thousand tons) of TNT. By 1965, the U.S. had more than 31,000 nuclear weapons. By 1985, the Russians had more than 40,000.

Ten countries have attained the ability to wage nuclear war. South Africa built six nuclear weapons starting in 1979, but dismantled them in 1990 and left the nuclear club. Today, there are nine countries with nuclear weapons. Several sources publish estimates for how many nuclear warheads exist today: SIPRI (Stockholm International Peace Research Institute), ICAN (International Campaign To Abolish Nuclear Weapons), Federation of American Scientists, and Arms Control Association. They are all similar, so we’ll use the basic SIPRI numbers here. The date in parentheses is the year that country gained nuclear weapons. The second number is the estimate of the number of nuclear weapons each country had in 2015. The third number (in parentheses) is the number of nuclear warheads presently mounted on missiles, torpedoes, artillery shells, and bombs (deployed) by those countries. As you can see, only four countries presently have nuclear warheads deployed:

United States (1945) 7,000 (1750)
USSR/Russia (1949) 7,290 (1790)
United Kingdom (1952) 215 (120)
France (1960) 300 (280)
China (1964) 260 (0)
India (1974) 100-120 (0)
Israel (1980’s) 80 (0)
Pakistan (1998) 110-130 (0)
North Korea (2006) <10 (0)

There are about 15,400 nuclear weapons in the world today, a far cry from more than 70,000 during the cold war. Also, there are five European countries that host nuclear weapons on their soil: Belgium, Germany, Italy, Netherlands, and Turkey. You can guess which country owns those weapons. When Belarus, Kazakhstan, and Ukraine became independent, after the collapse of the Soviet Union in December 1991, they inherited nuclear weapons. But, each country returned them to Russia by the mid 1990’s. From this data, we have a general idea of who can wage nuclear war and on what scale.

On 1 November 1952, the U.S. detonated the first hydrogen (fusion) bomb on the Enewetak Atoll in the Pacific: code name "Ivy Mike". A tube 6.67 feet in diameter and 20.33 feet long was filled with liquid deuterium (heavy hydrogen), along with a Uranium explosive compression charge, a Plutonium trigger, and a cryogenic cooling system. The entire device weighed 82 tons. It exploded with a force between 10.5 and 14 megatons (10 to 14 million tons) of TNT. In seven years, scientists had increased the destructive power of a nuclear weapon by a factor of about 700. But this device was way too big to be dropped from an aircraft or mounted on a missile.

To read more Warfare Evolution Blogs by Ray Alderman, click here.

On 1 March 1954, the first dry hydrogen bomb test was conducted at Bikini Atoll in the Marshal Islands: code name “Castle Bravo”. Instead of liquid deuterium, they used about 880 pounds of lithium deuteride. The entire bomb weighed 23,500 pounds, and was 15 feet long and 4.5 feet in diameter, much smaller than Ivy Mike. The nuclear physicists estimated a yield of about 6 megatons (6 million tons) of TNT from the “Shrimp”, their name for the device. What they got was 15 megatons (15 million tons) of TNT, more than twice the estimates. In a bunker named Station 70, with 3 foot thick concrete walls,19 miles away from ground zero, sat six engineers, three Army technicians, and one nuclear scientist, to observe the test. The resulting mushroom cloud was 100 miles across at the top, and 25 miles high.

The bunker started swaying in the shockwave, and the concrete walls began to bulge. Radiation was so intense that the observers had to retreat to the bathroom in the bunker, behind another thick concrete wall. This was the largest explosion ever created by a U.S. nuclear weapon. There’s an excellent detailed account of this hydrogen bomb test in chapter one of Annie Jacobson’s book, “The Pentagon’s Brain” (2015).

The “Shrimp” lived up to its name, compared to what the Russians did on 30 October 1961. They exploded their “Tsar Bomb”, a hydrogen bomb dropped from 34,000 feet by a Tu-95 aircraft at Mityushikha Bay nuclear testing range. The bomb was 26 feet long, 6.9 feet in diameter, and weighed 60,000 pounds. The resulting mushroom cloud was 59 miles across at the top and 40 miles high. The yield on this hydrogen weapon was 50 megatons (50 million tons) of TNT, the largest explosion ever created by man on the face of the earth. Fortunately, both the U.S. and Russia have dismantled their high-yield nuclear weapons. Both countries have nuclear bombs and warheads deployed in the 1.2 to 3 megaton range, while the Chinese still have some 3 megaton warheads, according to my reading. Many of today’s nuclear warheads are low-yield (under 500 kilotons), but today's missiles have multiple warheads for multiple targets (MIRV: multiple independently-targetable reentry vehicle). So, the present nuclear war strategy suggests many smaller nuclear warheads instead of a few large-yield devices. We now have nuclear warheads that fit inside a 155mm (6-inch diameter) artillery shell.

Current times

Today, the U.S. has fission warheads that weigh about twenty pounds or less. We have hydrogen (fusion) warheads that weigh less than 1,000 pounds. In fact, on some of the U.S. nuclear warheads, we have a “dial-a-yield” switch. The technicians can set the yield of the explosion before the weapon is launched or dropped, from 0.3 kilotons to 170 kilotons, depending on the target requirements. The military people in charge of these weapons, being fond of acronyms, call it the “DAY” setting. That’s a nice politically-correct touch by our bomb designers, don’t you think? I’d love to talk to the guy that designed that feature into our nuclear weapons: adjustable yield would not be noticeable to the people in the fireball, or those on the perimeter for that matter.

On 5 January 2016, the North Koreans claim to have tested their first hydrogen bomb. Up to that point, intelligence sources believed that North Korea had only a few fission warheads with yields of less than 10 kilotons of TNT. Seismic sensor data suggested a yield of about 7 kilotons from this explosion, and atmospheric “sniffers” found no evidence of unique Xenon and Argon gas ratios, signatures of a fusion-based nuclear event. According to recent reports, North Korea may have amassed enough Plutonium for 21 traditional nuclear weapons. It is highly unlikely that North Korea has the ability to build a hydrogen warhead.

In the cold war period, the Russians knew that Moscow would be hit by U.S. nuclear warheads early in an attack, wiping-out their command and control systems. How could they retaliate if their leaders were dead and could not issue the order to launch their own nuclear-tipped missiles? So, they came up with the “Dead Hand” system in the late 1960s, better known as the “Doomsday Machine”. Seismic sensors, light-flash detectors, radiation detectors, and pressure sensors would detect a local nuclear explosion and automatically issue the command to release their nuclear-armed ICBMs at U.S. targets. According to top Russian officials, the system was operational in the 1985, but was to be switched-on only in time of crisis, to avoid accidents. Details of this system are covered in David Hoffman’s book, “The Dead Hand” (2009).

On 5 October 1960, the Ballistic Missile Early Warning System (BMEWS) J-site radar in Thule, Greenland, detected thousands of missiles coming over the horizon, heading for the U.S. The nuclear attack alarms went off at NORAD (North American Aerospace Defense Command) at Cheyenne Mountain, from level 3 (possible missiles detected) to level 5 (99.9 percent% probability of nuclear attack underway). NORAD began to alert ICBM and SAC bomber commands to warm-up their weapons. But, Khrushchev was in Washington at the time so an attack made no sense. All U.S. nuclear weapons were put on hold. As it turns out, the BMEWS radar had picked-up the rising moon. There were 20 similar incidents, publicly disclosed, that nearly caused a nuclear war from 1956 to 1995. <http://nuclearfiles.org/menu/key-issues/nuclear-weapons/issues/accidents/20-mishaps-maybe-caused-nuclear-war.htm>

Since 1945, there have been 32 accidents involving U.S. nuclear weapons. These events are called “Broken Arrows”. According to multiple sources, somewhere between 50 and 92 nuclear weapons have been inadvertently lost, when you consider Russian submarine sinkings and crashes of long-range bombers. One of those events was on 24 January 1961 when a B-52 SAC bomber suffered a structural failure near Seymour-Johnson AFB in Goldsboro. The crew jettisoned two MK-39 (3.5 megaton) hydrogen bombs onto farmland before the crash. I was a teenager at the time, living 60 miles away on the coast of North Carolina. Five of the six arming switches on one bomb closed on impact, since the parachute failed to open and it hurtled to earth. If that single remaining $2 arming switch had closed, I would not be here writing this article.

Back in 1965, U.S. Secretary of Defense Robert McNamara asked "Jason," who worked for the Advanced Research Projects Agency (ARPA) -- the precursor to DARPA -- to come-up with a plan to block the Ho Chi Minh trail, from North Vietnam through Laos and Cambodia, that was feeding more than 200 tons of supplies and weapons per day to the Viet Cong and North Vietnamese troops in South Vietnam. They formulated a plan to use low-yield tactical nuclear weapons to close the Mu Gai Pass, a steep mountain road on the North Vietnam-Laotian border. But the plan was abandoned after considering that using nuclear devices in the Vietnam war might irritate both the Russian and Chinese governments.

That brings up ARPA, DARPA, and “Jason”, the topic for our next episode.