While
the United States and Russia/Soviet Union have signed several agreements that
limit the number of nuclear weapons in each nation's stockpile, recent
modernization of the U.S. nuclear forces have increased the killing power of
the existing American ballistic missile forces. A
recent analysis by Hans Kristensen, Matthew McKinzie and Theodore Postol on the Bulletin of the Atomic
Scientists website looks at how this new technology is undermining the concept
of strategic nuclear stability between the United States and Russia.
Since
2009, a device called the "super-fuze" (officially known as the
MC7400 AF&F system) has been incorporated into the U.S. Navy's W76-1/Mk4A
warhead used by America's submarine-borne nuclear forces. The adoption of
the super-fuze was part of a Life Extension Program (LEP) designed to extend the life of the W76-1/Mk4A warheads to roughly 60 years from 20 years. Before the adaptation of this new
technology, it was quite likely that the most accurate ballistic missile
warheads might not detonate close enough to their targets to destroy hardened
targets. The new super-fuze is designed to detonate above and around the
target, resulting in a much higher destroy-ratio. What this means is that
the U.S. submarine force has a much greater possibility of destroying hardened
targets like Russian ICMB silos with far fewer missiles than it did in the past. The authors of
the study note that 10 years ago, only 20 percent of nuclear warheads carried
by U.S. submarines had the super-fuze technology; they now estimate that all of
the nuclear warheads carried by U.S. submarines in both the Atlantic and
Pacific Oceans now have the capability to destroy hardened targets as shown on
this graph:
How
does the super-fuze work? Let's start with a picture of the super-fuze:
The
super-fuze is also known as the arming, fuzing and firing (AF&F) system which consists
of a fuze, an arming subsystem which includes radar, a firing subsystem and a
thermal battery to power the entire system (i.e. the detonator to laypersons).
The arming, fuzing and firing system is located in tip of the cone-shaped
renters body above the nuclear explosive package.
Back
in 1994, the Defense and Energy Departments studied equipping the W76 warhead
with a new fuze. At the time, the W76/Mk4 warheads were equipped with a
fixed height-of-burst fuze; this meant that the fuze could not adjust its
detonation at a more optimal location if it were falling long or short of a
target. As a result, most submarine-based nuclear weapons were aimed at soft targets like military bases. The Defense/Energy study found that
a Mk4A equipped with a fuze that had an adjustable height-of-burst as it
arrived at its target would result in far greater damage to hardened targets.
This means that a smaller number of Mk4 nuclear warheads could do far
greater damage to Russia's military infrastructure than those equipped with the
traditional fuze.
Let's
look at an example. First, let's define the circular error probable
(CEP), the technical name for a weapon's miss distance. The CEP is
defined as the radius of a circle around the aim point within which half of the
warheads aimed at a target are expected to impact. For the study, the
authors assumed a 100-kiloton nuclear blast which generates 10,000 pounds per
square inch or more of blast pressure and a circular error probable (CEP) of
100 metres, a miss distance that is comparable to the CEP of the Trident II sea-launched ballistic missile. Here is a diagram showing the detonation
spread for a conventional ballistic missile fuze with the horizontal axis
showing the ground circular error probable and the dome-shaped volume showing
the "lethal volume" within which a 100 kiloton nuclear explosion will
general 10,000 psi or more of blast pressure on the ground:
As
you can see, missiles with the traditional fixed height-of-burst fuze can
easily overshoot or undershoot the "lethal volume", making them less
effective.
The
super-fuze is designed to measure its altitude before it arrives near the
target at an altitude of between 60 to 80 kilometres above the surface of the
earth. If the warhead's altitude as measured by the super-fuze at a given
time during its flight is exactly equal to the altitude expected for the
intended trajectory, the missile is on target. If the altitude is lower than expected, the warhead would likely hit short of its intended target
and vice versa. The super-fuze can shift the down-range aim point,
resulting in a very high percentage of missiles that detonate in the
"lethal volume", resulting in a much higher destroy-ratio.
Here
is a graph showing the probability that warheads will detonate close enough to
a ground-target that is hardened to withstand 10,000 psi of blast overpressure
for both the conventional fuze and the super-fuze:
The
probability of destroying a Russian hardened missile silo with a super-fuze
equipped ballistic missile is roughly 86 percent compared to 50 percent
for a traditional fuze. The 86 percent probability is similar to the
probability that three traditionally fuzed ballistic missiles would destroy the
same target. This means that the super-fuze essentially triples the
killing force of the W76/Mk4A warhead. For a target that can only
withstand 2000 pounds of blast overpressure, the probability of a kill rises to
99 percent compared to 83 percent for three warheads.
How
would this play out during wartime? Currently, there are approximately
890 nuclear warheads on U.S. ballistic missile submarines of which 506 are of
the W-76-1/Mk4A type. Russia has 136 silo-based ICBMs; this means that
all Russian ICBMs could be destroyed by using 272 warheads (two warheads to
each silo). This would consume only 46 percent of the inventory of W76-1
warheads, leaving a total of 234 free to target other Russian installations.
Let's
close this posting with a quote from the article:
"The capability upgrade has happened outside the attention of most government officials, who have been preoccupied with reducing nuclear warhead numbers. The result is a nuclear arsenal that is being transformed into a force that has the unambiguous characteristics of being optimized for surprise attacks against Russia and for fighting and wining nuclear wars...We estimate that the realist sof arms reductions with the increase in U.S. nuclear capacity means that the U.S. military can now destroy all of Russia's ICBM silos using only about 20 percent of the warhead deployed on U.S. land- and sea-based ballistic missiles.
We cannot foresee a situation in which a competent and properly informed U.S. president would order a surprise first strike against Russia or China. But, our conclusion makes the increase se-base offensive and defensive capabilities we have described seem all the more bizarre as a strategy for reducing the changes of nuclear war with either Russia or China..." (my bold)
It's certainly starting to feel like the Cold War all over again.
So now the Russian will develop the Super, Super fuse who will be twice as good.
ReplyDeleteLMAO
Probably Russian Superfuse is more precise and reliable than those made in USA and indeed no more made in USA today, better let China made those superfuse for the US
ReplyDeleteU guys are both idiot trolls, US is about innovation and determination. We could wipe u off the map b4 u knew u were dead.....hahaha keep trolling
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