I said up front that the NNSS remains in use for several different purposes,
although the level of activity today is not nearly as high as it once was. To
my best ability to remember the numbers, I think we were told that during the
period of active testing the staff compliment was about 13,000. Today there are
about 8,000 personnel that work at the site, between the various contractors
and subcontractors. This is as good a time as any to elaborate a bit on the
organizational structure of the NNSS.
One of the interesting things about the nuclear weapons complex is the
extremely high level of at least semi-privatization. While the NNSA is either
the largest or second largest component of the Department of Energy by budget
(it depends a bit on exactly how you break down the DoE's various buckets of
funding), it makes up well less than a quarter of the DoE staff. This enigma
results from contracting: considered as the NNSA, the nuclear weapons complex
is more than 50,000 people. Only about 2,500 are federal employees. The rest
are employees of a dizzying network of contractors that range from well-known
defense entities (Lockheed-Martin) to the small and surprising (San Ildefonso
Services, a fully owned enterprise of the sovereign government of the Pueblo of
San Ildefonso, comprising about 600 enrolled members and northwest of Santa
Very few people civilians involved in nuclear weapons are actually federal
employees, and they're limited mostly to the NNSA offices that exist to
coordinate and supervise these many contracts.
This staffing analysis admittedly excludes the sizable military component of
the nuclear weapons program, as each military branch has an organization
dedicated to the handling and deployment of nuclear weapons as well as the
personnel in the field that are actually responsible for it. For historic
reasons rooted in the genesis of the Manhattan Project, though, nuclear weapons
are viewed as being more a civilian matter than a military one. Although the
separation has decayed over decades, it has always been the gist of the
situation that the Department of Energy owns nuclear weapons, and the military
is allowed to borrow them. The military, of course, has its own extensive
contracting operation, and many military organizations related to nuclear
weapons are extensively staffed by contractor employees.
While privatization of defense functions is mostly a newer trend, it is deeply
rooted in the world of nuclear weapons. Since the very beginning, the Manhattan
Project relied heavily on the work of various outside organizations, first
among them universities. A substantial portion of the Manhattan Project,
including most of the operations at Los Alamos, were actually performed by the
University of California. Los Alamos Scientific Laboratory and later Los Alamos
National Laboratory continued to be managed as a subsidiary of UC until 2005
when both UC and DoE initiated a series of changes that saw LANL transferred
first to Los Alamos National Security (LANS), and then just over a decade later
again to Triad National Security. UC remains one third of Triad, along with the
Battelle Institute (a nonprofit heavily involved in federal research and
development) and Texas A&M.
Sandia National Laboratories, originally a division of LANL and thus UC, was
transferred to Western Electric in 1949 and remained a concern of AT&T and Bell
Laboratories until until 1993, when it was transferred to Lockheed-Martin.
AT&T's involvement in nuclear weapons is not limited to telecom or even
communications R&D; AT&T was in fact a major component of the weapons
enterprise for decades. Today, Sandia is operated by Honeywell, as are several
other components including the Kansas City National Security Campus.
The split between LANL, operated by universities, and Sandia, operated by
engineering organizations, reflects the history and culture of the
laboratories. While both conduct extensive basic research and there is plenty
of overlap in functions, the broad division is that LANL is responsible for the
design of the nuclear device itself (an issue at the cutting edge of physics)
while Sandia is responsible for a way to deliver downrange (a matter of
ballistics and mechanical engineering). Even the locations reflect this divide:
LANL hidden high on a mesa, and Sandia in the desert scrub of a ballistics
research range dating back to World War One and the New Mexico School of Mines'
(my alma mater, under its present name of New Mexico Tech) work on proximity
These early examples of full-service federal contracting were major precedents
in the creation of the "GOCO" or Government Owned, Contractor Operated model.
While nuclear weapons facilities are owned by the federal government, they
are almost all operated by either a private company or a public institution
(or perhaps a coalition of some combination of the two). The operator, often
called an Operations and Maintenance or O&M contractor, is paid a "management
fee" to perform this function. A related concept is that of the FFRDC or
Federally Funded Research and Development Center, an umbrella category that was
created to somewhat standardize the legal nature of nuclear weapons
laboratories as well as several other government-owned R&D organizations such
as the DoD's Aerospace Corporation and Rand Corporation.
While FFRDCs are not necessarily related to nuclear weapons (some having been
born entirely in the military or department of commerce), a large portion of
them and most of the larger FFRDCs fall under the auspices of some component of
the Department of Energy. Most of the DoE FFRDCs, arguably all, are either
historically or currently involved in nuclear weapons. Only three, Sandia, Los
Alamos, and Lawrence Livermore are directly considered nuclear weapons
laboratories (these are sometimes referred to as the tri-labs). Nuclear weapons
as a broad state function have many aspects beyond the design and testing of
weapons, though. Savannah River National Laboratory, for example, located at
the site of a former uranium refinery in Tennessee, is primarily involved in
researching environmental remediation and hazmat handling methods. Expressed as
a quip, Savannah River National Laboratories exists to try to find a way to
clean itself up.
This is all a long preamble to explain that there are a lot of distinct
organizations involved in nuclear weapons and it can be difficult to keep track
of them. Names like EG&G, SAIC, and UC ought to be as closely connected to
nuclear war as the Manhattan Project.
In the case of the NNSS, the name to know is Mission Support and Test Services
or MSTS LLC. MSTS is a coalition of Honeywell, Jacobs Engineering (builder of
nuclear reactors), and Stoller Newport News Nuclear (builder of aircraft
carriers). More subcontractors than can be easily listed perform various
functions on the behalf of MSTS, including the amusingly named "Securing Our
Country" which provides the private paramilitary security force at several
nuclear weapons sites. Apparently embarassed at the somewhat cringy name, they
now tend to insist that it's "SOC" and it doesn't stand for anything.
The NNSS staff today is made up of the employees of all of these contractors,
and most of the staff are involved in maintenance and cleanup activities. This
is a common theme in the world of nuclear weapons: managing the legacy of
environmental contamination and hazardous waste is just as big of a job as, and
sometimes bigger than, actually designing and building weapons. Even
maintaining roads becomes a substantial operation at the scale of the NNSS.
Two major facilities at the NNSS speak to this point. The Radioactive Waste
Management Facility, which was pointed out to us in the distance, receives
low-level mixed waste from other DoE and DoD sites that needs to be removed and
disposed of elsewhere (instead of being permanently disposed of on-site, which
is typically the preferred option to avoid the political controversy around
transporting nuclear waste). This type of waste is made up basically of the
contents of trash cans in laboratories that handle nuclear materials. Gloves,
aprons, instrumental apparatus, storage containers, etc that were exposed to
nuclear material and thus remain slightly radioactive due mostly to particulate
contamination. There are even building materials from demolition of
contaminated labs, animal carcasses from medical testing, and low-level
radiation sources removed from medical equipment.
This waste is inspected, packaged, and then buried in a series of shallow
trenches engineered to prevent any leakage or wind dispersion. Ongoing
monitoring will be performed, essentially into perpetuity, to ensure that the
containment mechanisms are effective. The RWMF benefits greatly from its
remote, arid location: it is far above the water table and far away from
populated areas, granting a significant safety margin.
It also benefits from its location well inside of a secured federal
reservation. The RWMF is able to accept classified waste, such as components of
classified designs, for burial. This capability is uncommon enough that NNSS is
the final resting place of some classified objects that are not radioactive or
hazardous at all, simply impractical to destroy. I have previously mentioned on
this blog that the NSA lists "permanent burial" as an acceptable method of
destruction of classified matter. Here it is, out in the Nevada desert.
Elsewhere in the NNSS, some low-level waste has been buried inside of the
subsidence craters resulting from underground tests. This method is convenient
and permitted for certain types of lower risk waste, much of it brought in from
the nearby Tonopah Test Range. As in most federal facilities, disposal of
hazardous materials is restricted by state law, and so all of these waste
handling activities are conducted under permits from the Nevada Division of
Environmental Protection. The state and federal governments coordinate a
variety of precautions and restrictions on the transportation and handling of
waste, which include a prohibition of transportation of waste on certain busy
freeways and highways and selection of routes based on weather conditions.
As part of its efforts to mitigate transportation risk, the NNSS grants
substantial funding to nearby fire and emergency management departments to
support their general operations and specifically radiological response
This is not to say that NNSS activities today are all about cleanup. Another
facility pointed out to us in passing, near the U1a complex, is the Device
Assembly Facility. The DAF was constructed as a new consolidated building for
the safe handling of nuclear weapons components, including both nuclear
material and high explosives. It consists of a series of isolated underground
cells, each designed for the safe containment of a huge explosion. These are
accessed by a fortress-like concrete portal cut into the ground, flanked by
guard towers and surrounded by multiple layers of fencing and intrusion
detection. Because it can contain a substantial quantity of "special nuclear
material" (in other words, weapons-grade plutonium and uranium), the DAF is
likely the most security-sensitive facility on the site and is guarded 24/7 by
a paramilitary force and numerous technical security measures.
The disconnect between public perception of security at defense facilities and
the actual reality can be stupifyingly large. Media depictions give many the
idea that a typical military installation is defended by laser perimeters, dog
patrols, and a heavily armed response force. Of course, most military
installations are actually protected by nineteen-year-old enlistees running
more on Red Bull than tactical training, and response to even the most obvious
security violations is more likely to take 30 minutes than 30 seconds.
The weapons complex tends to run on the more secure end of government
operations, but as a group of nuns memorably demonstrated even some of the most
sensitive nuclear sites are vulnerable to wirecutters and determination. The
NNSS, like many military and weapons installations, both benefits and suffers
from its immense size. Hard perimeter security of over 1,000 square miles
simply isn't practical, and a daring person could probably walk right into the
NNSS and remain unnoticed for quite some time. There may not even be a fence
for much of the perimeter. Harder protective measures are found at individual
security-sensitive sites. On the upside, the many miles of barren desert
between actual facilities and the perimeter make it very difficult to escape
undetected after triggering any sort of alarm.
Still, the DoE faces the same budget pressure as the military, and security
measures have certainly decreased since the days of the Manhattan project. Los
Alamos personnel in the 1940s were trained on a "badge challenge" procedure:
when a guard trained a gun on them, they would set their ID on the ground, turn
the other direction, and walk ten paces to wait until instructed otherwise.
Although I hear this has changed in recent years, when I was in Los Alamos they
were indecisive on whether or not it was worthwhile (or perhaps more
truthfully, within their budget) to check badges in person at all. Throughout
the weapons complex there are many visible remnants of security measures that
once were, replaced by dwindling patrol forces that, admittedly, remain very
well-trained---particularly by the lax standards of US law enforcement.
This came to my mind contemplating the guard towers of the DAF, some of the
only guard towers that can be found anywhere in a nuclear weapons installation.
In my career I have worked in one environment that I would call extremely
secure. It was not a weapons or military installation. It was a Federal Reserve
Bank. In employee orientation, a sergeant of the Federal Reserve Police told us
proudly that there has never been a successful heist on the Fed, although it's
been depicted fictionally several times in films. 82-year-old Megan Rice got to
the Y-12 enriched uranium storage complex to commit principled vandalism... by
her description and the admission of Y-12 security forces, basically by walking
After the end of testing, with device assembly no longer a major activity, the
DAF was converted to the National Criticality Experiments Research Center
operated by LANL. Here, researchers directly handle complete nuclear weapon
pits and other quantities and forms of special nuclear material that are
capable of prompt criticality. The DAF serves not only to protect these
materials from theft but, perhaps more importantly, to protect the outside
world from the effects of a criticality accident.
On the matter of response times, as we drove through the complex we passed by
another fire station. Our guide explained that the NNSS fire department had a
target of a 30-minute fire or medical response to any part of the range that
was in use. While the two stations put most of the NNSS within 30 minutes, when
the Pahute Mesa, in the far northwest of the NNSS, is in use it's necessary to
stage an ambulance and fire engine at the "midway" point between the second
station and the mesa, about 30 minutes from each. Despite the seeming danger of
the NNSS, most of the fire department's time, he said, was spent on mutual aid
to the rural departments around the area. There are a lot of one-ambulance
towns in Nye County, and the NNSS's EMTs regularly meet up with those
ambulances to take their patients into Las Vegas, allowing the rural ambulances
to return to duty a couple hours sooner.
As with most nuclear installations, the NNSS has an on-site medical clinic
which is both equipped to handle radiological emergencies and a great
convenience to the staff. NNSS is one of the DoE sites which enthusiastically
holds a "VPP Star," a distinction awarded by OSHA for effective implementation
of a Voluntary Protection Program. VPPs are occupational safety programs that
go beyond the legal requirements, and to hold a VPP Star an employer must
maintain below-average injury and illness rates. Some nuclear sites such as
LANL have developed something of a reputation for a troubled safety culture,
but others excel in implementing their safety programs. Surprisingly, working
with nuclear weapons can be one of the safest career options many craftspeople
Leaving the underground testing area, our coach briefly descended into the
subsidence crater left from an underground test, the driver somewhat nervously
navigating the steep road rutted by recent rainstorms. The odd thing about
underground testing is just how underwhelming ground zero is. While the crater
was about as deep as our coach was tall, perhaps 12-15 feet, it was only about
a thousand feet across, and the bottom much smaller. At the center, a wide,
rusted metal column jutted out of the ground at an odd angle, cut-off cables
hanging out the top and birds nesting in an aperture in the side. This was the
top of the casing of the shaft, and the only direct indication of the actual
Parked for a moment at the bottom of the crater, I contemplated how we were
ourselves displaced downwards as a latent effect of a nuclear explosion. We
tend to imagine the result of nuclear weapons in terms of Hiroshima and
Nagasaki, but in the world of industrialized testing that same power is neatly
managed and contained. Even the radiation effects are quite minimal. Near the
center of the crater was a ring of fencing with radiation hazard signs. Our
guide explained that the radiation in the crater had never measured
significantly higher than background, but as part of a groundwater monitoring
project a water well had been drilled from the crater down to near the
detonation point. Years ago, water had been pumped from the well into a tank
and then sampled to monitor contamination. Some of the water had leaked from
the fittings, and so even though no radiation had been found, as a matter of
policy the area where the water pooled was considered a danger and required
radiological protection for entry.
Much of the safety and security of these sites comes from this type of pedantic
compliance with broad precautions. I am reminded of the story of the top secret
orange. The story goes that a laboratory at Los Alamos which handled metal
models of weapon pits (which were of a classified design) found that the guards
sometimes weren't sure whether or not a given object was a model pit and thus
classified. To resolve the issue, they adopted a policy that all spherical
objects within the lab must be kept in safes when not attended. Perhaps you can
guess the punchline: a laboratory worker was written up for a security
violation after leaving an orange on his desk. Sometimes strong systematic
security requires treating fruit as presumptively classified .
On the way around the crater our guide mentioned that you could see a USPS
truck at the rim of the crater. Not as the result of any experiment on the
nuclear survivability of letter carriers, but just because it was a government
surplus item that made a convenient enclosure for some monitoring equipment.
Unfortunately it had disappeared: "it was just there two weeks ago!" our guide
insisted. Like beige paint and breezeblocks, odd bits of government property
that disappear as quickly (and mysteriously) as they appeared are part of the
aesthetic landscape of the nuclear weapons complex.
A limited budget, an oddly strong sense of thrift, and a close relationship to
the military result in extensive use of the cast-offs of other federal
agencies. Federal spending is always a bit of an enigma this way. For every
billion dollars spent on F-35s there are at least fifty enlisted personnel
emptying trash cans under roof leaks. The DOD plunges into a multi-year,
multi-billion boondoggle to replace HEMTTs while National Science Foundation
grantees repurpose retired units to move their building supplies.
A remarkable example of this phenomenon is our tour's next stop.
One of the better-known historical sites at the NNSS is the "gun turret." It
is not a gun at all, although it once held one. Collecting data from nuclear
tests has always been a challenge, and even for atmospheric tests it was
difficult to place instruments close enough to ground zero to collect data
without taking damage from the shockwave. Somehow, the details of which seem
lost to history, someone at the NNSS implemented a clever solution: a turret,
borrowed from a scrapped Navy cruiser, was stripped of its three 8" guns and
shipped to the Nevada desert.
A somewhat improvised gun emplacement was built on a mesa at the NNSS and the
turret installed in it. In place of the guns, a single "barrel" made of lead
wrapped in sheet metal was installed on the front. For a series of several
atmospheric tests, measurement instruments were placed in the barrel and the
turret was aimed squarely at ground zero. Because the lead barrel blocked both
light and background radiation coming from off-axis sources, this allowed for
accurate measurements of light, x-ray, and gamma output that were used in
verifying performance calculations. Since the turret could be re-aimed at
various test positions and was cabled to permanent underground recording
equipment bunkers nearby, it allowed for a lot of saved money compared to the
conventional approach of trenching long cables from recording bunkers to
instruments near the device that would not survive the explosion.
As I mentioned, the history of the gun turret was not well documented.
Fortunately, as our guide tells us, an NNSS employee spent some spare time
carefully examining it and was eventually able to find a serial number on an
original component. Research aided by a naval museum determined the origin to
be the USS Louisville, which during World War II suffered strikes by Kamikaze
pilots twice. The Louisville was repaired and returned to service both times,
and participated in end-of-war activities including the evacuation of prisoners
of war before being sold. The turret in question was damaged in one of the
Kamikaze strikes and swapped for a spare. By the time repairs were completed
the war had ended---and so it sat as surplus in a Navy yard for a decade before
being picked up for use at the NNSS. Due to the enormous size and weight of the
turret, its delivery to the NNSS was itself a complicated operation. It was
shipped over sea by the Navy to Port Hueneme, and then trucked nearly 400 miles
over land by a heavy hauling contractor.
There is an obvious symbolism to the gun turret's new home in the desert. Like
the USS Desert Ship, a pseudo-vessel apparently run badly aground in White
Sands Missile Range for testing of missile systems, the gun turret is a
curiosity: a ship out of water. It is also a weapon repurposed for science...
but for the science of developing better weapons. Swords may be beaten to
plowshares but plowshares are not always entirely innocent. Plowshares will
return, in a dramatic fashion.
At least as far as I can keep my timeline straight, the Gun Turret was our last
stop before lunch, and that's a good time for a break. Keep an eye out for Part
 I write this story the way I do because I am honestly not sure if it is
true. I believe I originally heard it at LANL where it was told in the way of
an urban legend, but it has also occasionally appeared in reputable sources.
Anyone who has been through LANL's employee safety training, and has
experienced the instructional video on the requirement to use handrails when
climbing stairs, probably finds it credible.
After our time milling around the Mercury cafeteria, it was back aboard the
coach to enter the test site proper. As our guide explained, the NNSS can be
divided into work areas such as Mercury and the range itself. On the days
that tests were scheduled, everyone other than personnel for that specific test
was prohibited from entering the range area for safety reasons. Considering
weather delays and technical issues, this sometimes meant a full day of lost
work as the entire staff huddled in Mercury awaiting news that they could once
again head out to test sites.
The first point on the tour after Mercury, then, and perhaps the first truly
related to nuclear testing, was Checkpoint Pass. Here, where the road passes
over a low ridge, there is still a wide part of the road with a row of
floodlights where guards would check if each person was on the staff list for
the test of the day. This is one of many places where the history of nuclear
testing seems remarkably well preserved, even ready to be returned to use.
There are reasons for this, as we will discuss later.
Shortly after Checkpoint Pass our guide points towards Control Point. This is
the building from which underground tests were actually performed. Like the
operations control center, it is a largely unremarkable low concrete building.
What stands out is the rack of microwave antennas spanning the side of the
building facing the valley. Presumably a great deal of microwave communications
were used for control and monitoring, probably in the later era of testing
based on the use of delay-lens antennas. Microwave communications were widely
deployed by telcos in the 1950s but the equipment and antennas were
exceptionally large and heavy. I am not sure if this early microwave equipment
would have been used in the frequently-reconfigured testing environment. By the
'80s microwave would have become an inexpensive and fast to deploy network
The microwave infrastructure here was clearly substantial. Looking down the
ridge into the valley several passive repeaters (billboard-like structures that
act as mirrors for directional microwave links) can be seen, their aim
suggesting that they allowed antennas at Control Point to reach sites on the
other side of a hill to the building's west. Passive microwave repeaters have
always been a minor fascination of mine. They are only really practical for the
very short wavelengths of GHz microwave systems, and the high attenuation of a
passive reflector combined with the ever lower cost and maintenance burden of
active repeaters makes them rare today. Passive repeaters can sometimes still
be found in use by rural telcos to reach AT&T or MCI sites outside of direct
view of their exchange facilities, but perhaps the best places to hunt for them
are dams. Likely a majority of the hydroelectric dams of the southwest, often
being in deep canyons, used passive repeaters set on the canyon rim to get
telephone and industrial control signals to the powerhouse.
I should avoid dallying too long on the details of the telecom equipment, but
this will not be the only example I find interesting. The communications
infrastructure at these types of national security sites is a revealing example
of the very close relationship between national defense and the
telecommunications industry---especially AT&T, which at the NNSS as in other
places is practically an arm of the government.
Just past control point, our guide calls out two sets of wooden benches, one
at each side of the road. These were the spectator stands for atmospheric tests,
set far enough away for safety but with a clear view. Anyone not wearing safety
goggles was required to face away for one minute around detonation, protecting
them from vision damage due to the intensely bright light. One set of benches,
closer to the road, was for government officials and other VIPs. The other,
somewhat further away, was for the scientists and engineers who had planned
the test. And just a bit ahead of the benches, a rocky outcropping is known
as News Nob due to its use by media crews invited to report on nuclear tests.
Despite the commonplace nature of worn wooden benches and a rock face, this is
one of the more emotionally impactful sites on the tour. From 1951 to 1963, the
NNSS detonated nuclear devices above ground, typically on short metal towers.
These tests were not just sources of data but spectator events. On this topic,
our tour guide, who had seen underground tests but started decades too late to
see any above ground, seemed practically wistful. "Imagine what it would be
like to see that," he said. I cannot be sure if this is reality or an
embellishment by my own memory, but I could swear that he then echoed the words
of Oppenheimer and the Bhagavad Gita: "to see the radiance."
This is one of those things about nuclear weapons that is difficult to capture
in language without resorting to poetry. As much as we might hope for
disarmament, and as much as we might celebrate the end of atmospheric testing
and the end of all testing some decades later, I am quite sure that we all want
to see it, just once. Lot's wife, as we usually understand it, turned back to
see the cities. I have always thought, though, that it is a better explanation
that she turned back to see the destruction. Who wouldn't be curious about
the physical manifestation of God's power? A surprising number of people,
sitting on those benches and equipped with protective eyewear, saw just that.
They looked down on Frenchman Flat, toward all the land of the plain, and saw
dense smoke rising from the land, like smoke from a furnace (Gen. 19:28 NIV).
Lucky that Oppenheimer had developed a fascination with Hinduism; had he been
a Christian, he, too, might have been turned to salt. Then again, he might not
have been labeled a Communist and stripped of his clearance. Oppenheimer had a
difficult time with more than one higher power.
As our coach carried on towards Sodom and Gomorrah, the guide pointed out
the two matching sets of utility poles, one on each side of the road. During
testing, utility crews would relocated the electrical lines to whichever side
of the road was opposite the current test site. This way, cranes and other
tall vehicles could be moved more easily and safely. Likely from later
testing, there is also a tremendous amount of buried conduit throughout the
valley. At seemingly random locations, but probably corresponding to various
tests, rusting electrical panels popped up by the side of the road with
disconnects and pin-sleeve connectors. Small signs marked the route of high
voltage raceways, and numbers on the panels hinted at a probably rather
hairy stack of maps and diagrams.
For quite some distance along this road a hefty bundle of telephone cables runs
along its own poles. One branch of it heads uphill to a microwave site atop a
small peak, south of control point. It continues some way into the valley but
likely drops into underground conduit before too far.
I wondered, of course, who installed and maintained the telephone
infrastructure. While I cannot provide an in-depth discussion of this topic
(at least not yet), the existence of an AT&T special toll area tariff for the
Nevada Test Site suggests that AT&T provides the service, and the tariff
includes detailed rates for certain services which were or are presumably in
use. This includes a Dimension 2000 PBX (nearly $10,000 per month after a
$75,000 installation charge), a 225 kW diesel generator, and dedicated
emergency lines. The Dimension 2000 is capable of up to 2000 lines and 14
attendant consoles. This equipment was probably installed somewhere in Mercury
in an NNSS-provided building, and maintained by appropriately cleared AT&T
The microwave site near Checkpoint Pass has been licensed, at various recent
times, to WCS Microwave Services and Verizon Select Services. Neither company
is easy to find much information about, but both seem to bid on various
government contracts for connectivity. WCS is a subsidiary of Williams
Communications and VSS is, of course, a subsidiary of Verizon Communications. I
would hazard to speculate that the NNSS turned to these vendors to provide
their backhaul (and based on license locations some internal connectivity)
after the breakup of AT&T introduced a great deal more competition in that
market. It's interesting that Williams Communications specializes in cable
television systems, inviting one to wonder if they specifically provided
services related to the many video cameras that were used to observe and record
As we drove further into the valley, several towers started to loom on the
horizon. One of them was our next destination: the Icecap site. Icecap was an
underground nuclear test planned to be 20-150 KT and buried 1,550 feet
underground. It was scheduled for Spring 1993, just months after the official
issuance of a moratorium on all nuclear testing. As a result the site, nearly
ready for the test, was abandoned in place. It now serves as an excellent
historical example of the preparations for an underground test.
There are several prominent features at the site, but at the core is a 157 foot
tall modular metal tower. After drilling of the test shaft was completed (at
3-5 feet across with very tight linearity tolerances this was no small feat), a
metal cover was installed over the shaft for safety and a set of sea
container-like modules stacked above it to form a temporary tower. Inside of
that tower, the tall cylindrical "canister" or "rack" was assembled. The
canister is suspended from the top of the tower by cables. Round walkways
throughout the height of the tower, reached by stairs and a small lift on the
side, provided technicians with relatively easy access to different points
throughout the canister.
The size and mass (300,000 pounds) of the canister are surprising, while the
fact that large portions of it seem to have been sealed up with duct tape is a
reassuring bit of normalcy. Nuclear testing is just about as complicated as the
design of the weapons themselves. While the canister contained the "nuclear
device" (not called a weapon because it is not equipped with delivery or fuzing
equipment), most of it is taken up by a dizzying number of instruments that
measure physical force, radiation, and other properties of the detonation.
These measurements are the actual outcome of the test, and can be compared
against calculations to determine the performance of the device.
There is a problem: nuclear detonations are a hostile environment for precision
instruments. This is the central challenge of underground testing. In
atmospheric testing, instruments can be located far enough away from ground
zero to survive the detonation (we will see an example of this later). For
underground tests, the radius of destruction is relatively small, but it
contains far too much soil and rock for remote instruments to be useful.
Instead, most of the measurements must be taken from the same shaft as the
To resolve this conundrum, engineers had to dance very closely with the
destruction. It is simply the nature of underground nuclear testing that the
measurement instruments will be destroyed almost instantly. They must collect
their data and report it before the blast reaches them. Every underground test
was a remarkable race: as the blast propagated through the canister, each
instrument produced a signal which traveled through cables to safety just ahead
of the advancing shockwave. Cables were turned to vapor just behind the
messages they carried.
The canister, then, looks something like a diving bell. From the top, dozens
of coaxial cables and just a few fiber optic bundles ('92 was still an early
era for small-scale fiber optic systems) hang back down the tower and then
out a small hatch at ground level, where they are lined up on a series of
zigzagging wheeled racks that allow them to be unfolded as the canister is
The primary motivation for underground testing is containment of contamination.
In a properly performed underground test, almost no radioactive particles
escape to the surface. This is achieved simply through the tremendous mass of a
thousand feet of earth. There is a problem, though: the shaft itself.
Once preparation of the canister is completed, the tower is disassembled and
the canister is transferred to a crane. Due to the limited length of the
crane's hoist cables, the canister is lowered into the shaft in a series of
steps. After each step, it is transferred to hang off of anchors around the
shaft while long rods are added on so that the crane can retract its cables,
attach to the top of the rods, and then lower the canister another step. Once
this slow descent is completed, the shaft is backfilled with materials
carefully chosen to prevent the blast pushing them out. A certain amount of
the backfill and suspension rods will be vaporized in the detonation, as will
The greater challenge is small leaks: because the cables have multiple layers
of jacketing that are easily destroyed, they can provide narrow paths to the
surface through which the immense pressure in the blast cavity will force
fallout. To prevent this, the cables are periodically interrupted by "packings"
where various mineral and artificial materials are sealed around the cable.
These materials are designed to flow and fuse under heat and pressure, sealing
off the cable path.
About ten meters from the top of the shaft, our guide points out a metal
pipe sticking out of the ground. This is the casing of a second shaft,
drilled to comply with mutual verification provisions in treaties with
Russia. The Russian government has the option of installing their own
instruments in this small second shaft, if they so choose, allowing
them to independently measure the yield of the device. Our guide explains
that this was rarely done in the late years of testing, as remote sensing
and seismic methods had improved to the degree that Russia could collect
the same information without the need to arrange a site visit. Nonetheless,
the option was always made available.
A surprisingly short distance away from ground zero are the trailers. These are
the endpoint of the cable's suicide mission, and contain a variety of recorders
and control equipment that are used to both prepare the canister for the test
and collect the resulting data. Even at their close range (around 200 meters)
they are safe from any immediate effects of the blast, but within the blink of
an eye after detonation the ground under them will be lifted slightly upwards
before falling back down. At their position this movement is small but still
extremely fast, creating enough G-force to damage equipment. To protect the
recorders (some of which were likely still electromechanical even in these late
tests), the trailers were installed on frames that sat on piers supported by
stacks of honeycomb-like blocks of corrugated aluminum. These collapsed under
the force of the shockwave and cushioned the trailers.
There are not just a few trailers. Some have been removed from the Icecap site
but there are still almost 20 left, each one numbered to keep track of them as
they were moved from test to test. Some are just enclosures for racks of
equipment, others are frames with electrical switchgear and communications
equipment. One wonders if any of the engineers who designed these trailers went
on to contribute to today's modular data center systems. Sandia's involvement
in mobile data terminals and control systems for the military suggests so.
As we drove away from the Icecap site (and passed a couple of other towers
remaining from planned tests that were canceled at earlier stages of
development), our guide explained the problem of the craters.
The whole underground testing area of the NNSS is littered with small craters,
often packed in a surprisingly tight grid. These craters are not the result of
soil thrown away by the detonation, which occurred far below them. Rather,
they are subsidence craters. The heat of the detonation compacted, melted, and
fused the materials near the device, leaving an underground cavern lined with a
glass-like material. At some point after the detonation, the walls of this
cavern would fail, causing a column of soil above the cavity to fall downwards.
The resulting crater is not very big or deep and the test planners became
adept at predicting the size of the craters, allowing them to place the trailers
just outside. What proved far more difficult was predicting when this collapse
As we drove onwards, our tour guide took advantage of the coach's entertainment
system and played a short film which he called "zero time to collapse." This
video consisted of footage of a series of different tests, cut together so
quickly that the effect was somewhat dizzying. Over and over, we saw footage
from a helicopter circling a bit of desert as a voice counts down. At "zero" a
chirping alarm sounds as a shockwave whips through the scrub---curiously, the
wrong direction. Our guide explained this perceptual oddity: the lifting of the
surface by the shockwave occurs too quickly to be caught on video or even
really to be perceived by the eye. What you see instead is the soil falling
back down to its original position with the acceleration of gravity, which of
course settles to a stop first further away from ground zero where it was
displaced by less.
Then, there is a cut, which skips over a period of minutes to hours (in some
cases, we were told, as long as 48 hours). A voice, working off of seismic
instruments that monitor for the failure of the cavern walls, says "collapse
imminent" and within seconds the ground simply falls away, leaving a crater.
And then it repeats. Over, and over, and over, showing perhaps 20 tests. By the
end it almost becomes boring, a highly accelerated introduction to the
mundanity of evil. Not even the wonder of tens of kilotons equivalent creating
an impossible cavern endures the about 900 underground detonations performed at
Some of the tests are slightly different from others. In one, the video of the
collapse is from a low angle and not very clear. Our guide explains that the
helicopter had had to land for fuel while waiting for the collapse and so
missed filming it. In another, the collapse is less a crater than a sinkhole,
with neatly vertical walls. Our guide says that this result is an oddity and
something of a mystery; it only happened in one test and presumably results
from some detail of the geology that still hasn't been determined. In just one
test, the voice counting down is a woman's, reminding you of the gender
disparity that remains to this day in the defense industry. The nuclear weapons
complex has its own deep history of sexism, homophobia, hysterical
anti-communism, etc., but that is a topic for another time.
We are by this point many miles deep in the NNSS and have more miles to cover
to reach our next stop. On the way, our guide points out some support
facilities. The Big Explosives Experimental Facility or BEEF is a range
equipped to test huge quantities of high explosives. As a whimsical anecdote,
our guide explains that BEEF's cow-shaped steel sign had been stolen some time
earlier, perhaps as a prank by military personnel. NNSS craft workers made a new,
larger sign and then buried its base under a ton of gravel. That ought to
discourage any future larceny.
Driving along the main road, we passed the U1a complex, or as our guide allows
himself to joke once, the "A-hole." This deep shaft complete with mine-type
hoist headworks, along with a neighbor, connects to a complex of underground
tunnels where subcritical experiments are conducted. In these tests, weapon
pits a little shy of heavy enough to achieve criticality are subjected to the
high-explosive implosion mechanism used inside weapons. After the test the
deformed pit can be measured to calculate the implosion forces. An addition to
the U1a complex currently underway is a linear accelerator that will be used
to image the internal density of the pits, giving more data about the accuracy
of the implosion. In a moment my husband found especially amusing, our guide
said that office space in the underground complex has become very limited but,
due to the time involved in taking the hoist up and down, the scientists were
reticent to regularly come to the surface. The office trailers at the top
of the shafts are being renovated in an effort to lure the staff above ground
and free up space. "The scientists have dug in," my husband quips, "and are
refusing to come up. They say they want more plutonium."
This, too far into the series to explicitly touch on this important topic, is a
good time to finally say something about stockpile stewardship. This is the
greatest challenge of the nuclear weapons complex today and, by budget, the
main activity of the Department of Energy.
The United States has not detonated a nuclear weapon in thirty years.
This raises a troubling question: do they still work?
Every year, the National Nuclear Security Administration (the component of the
Department of Energy that oversees the weapons program) and directors of the
three nuclear weapons laboratories (Los Alamos, Lawrence Livermore, and Sandia)
prepare a report to the President of the United States. This report says that
the Department of Energy is confident that the United States' nuclear arsenal
is not only safe, but also functional. Some years ago I heard Dr. Jill Hruby,
at the time the director of Sandia National Laboratories and now the
Undersecretary of Energy over the NNSA, say that she considers developing the
confidence to sign this report to be the most important function of the weapons
Because the only designs that have been subject to "real" quality control
testing (by detonation of sample units) are more than 30 years old and thus
have undergone radioactive decay, mechanical wear, maintenance and
refurbishment activities, etc., and an increasing portion of the stockpile
consists of designs that have never been tested, this assurance must make the
directors a bit nervous. Our confidence in the nuclear stockpile today rests on
subcritical testing, testing of individual components, and increasingly,
computational modeling. It is exactly because of the challenge of stockpile
assurance that a surprising portion of the world's most powerful computers are
owned and operated by the Department of Energy.
A tremendous amount of effort has been put just into understanding how
weapons-grade plutonium and uranium change (or don't) when left in storage for
decades, and how to refurbish weapon pits. The same problems exist for the high
explosives, neutron generators used to force prompt criticality, specialized
thermal batteries that power electrical systems in nuclear weapons, and even
simple mechanical components.
An enormous staff of people (probably 30,000 across the complex) and billions
of dollars in budget go, essentially, to doing everything anyone can think of
other than actual testing to determine whether or not nuclear weapons even
work. Every year the degree of separation between tested designs and the
current stockpile increases, and so this confidence becomes based on greater
levels of abstraction. In a way, it adds a fascinating new aspect to the fear
of nuclear apocalypse: the outcome of a nuclear war has perhaps become even
harder to predict as the possibility increases that some portion of our nuclear
arsenal (and, for the same reasons, that of other major nuclear powers) will
just not work.
It is because of nervousness about this possibility that there have been some
calls to resume nuclear testing in the United States. I will not go into
analysis of this decision, although I personally am strongly opposed. It is a
closer possibility, though, than you might imagine. At several points our tour
guide gave the context that the NNSS remains under standing orders to be ready
to pick up where it left off. While testing has not been performed for so long
that mastery of all the steps involved is now somewhat questionable, the NNSS
retains an inventory of ready-to-go boreholes, drilling equipment, tower
modules and components. In theory, should the order come, the NNSS could
perform an underground nuclear test within 24 to 36 months.
Subjectively, the NNSS does not feel abandoned so much as it feels like it is
in waiting. And administratively, it is.
We are, at this point, probably only a few hours into the 8 or so hours of the tour.
I will return with Part 3, once again probably quite soon.
I promised a travelogue, and here we go. I'm not exactly a travel writer, but I
was recently able to visit a place that's fairly difficult to get to, so I
think it's worth sharing my observations. I started writing this because I
thought there should be more on the internet about the NNSS tour program and
the site and tour as a subjective experience. Personally I absolutely love
tours, not just to see things but because I think the tour guide and the design
of the tour are often just as interesting as the site itself. When you take a
guided tour you are sort of seeing a place through the eyes of its own public
affairs department, and when it comes to the national security state that is an
especially interesting thing to behold.
So this is, in part, a dry recounting of the NNSS tour and how it works. It is
also, probably in larger part, my thoughts and observations on the historical
and modern cultural role of the NNSS. As the location of the vast majority of
US nuclear detonations, it is perhaps the most profound artifact of nuclear
weapons. At the same time, it is seldom seen and, well, there's not that much
in it to see.
The Trinity Site, with its twice-yearly open houses, is something of a mecca
for everything from anti-war activists to the most hawkish cold-war
enthusiasts. On repeated trips to the Trinity Site I have seen brash Texans and
Buddhist monks, both in awe, but both in very different ways. The Trinity Site
seems to encourage visitors to engage at a more philosophical level, perhaps
due to the widespread knowledge of Oppenheimer's quotation of the Bhagavad
Gita, perhaps simply because there is honestly not very much to see there. You
visit the Trinity site, at least if you know what it's like, to find out what
it feels like to stand in the shadow of the "radiance of a thousand suns."
There is no tour to speak of.
The NNSS, though, despite having a public tour program, receives far less
attention. There is, you will find, a lot more to look at there. As a result,
the NNSS visitor experience feels less emotional and more technical. At the
same time, every feature the guide points out is imbued with that same
radiance. The Trinity site is where a force of incredible destruction was first
unleashed. The NNSS is where that same force was industrialized, refined, and
One of the first things you learn about the national security state is its
penchant for renaming things. This is prominently true in the military, but you
also see it in the Department of Energy. And so, the Nevada Test Site, having
once been the Nevada Proving Grounds, is now the Nevada National Security Site.
The verbosity of "National Security Site" is awkward but well in line with the
"Kansas City National Security Campus" and "Y-12 National Security Complex,"
down to being frustratingly inconsistent.
That's all a preamble to explain that I will be referring to it as the NNSS,
although during the time period I will mostly be covering it was not known by
I don't intend to write a proper history here, but not that many people are
familiar with the NNSS (at least by name), so I will give the general
background. The NNSS was established in 1951 in response to the need for a
long-term proving ground for nuclear weapons. In the days of the Manhattan
Project proper, testing had been rather scattered: the Trinity test, the first
and most famous test of a nuclear device, was conducted in a barren part of
central New Mexico, near the north end of the White Sands Missile Range and
often described as near Socorro although a better (but much smaller) town to
relate it to is San Antonio.
To many viewers this might seem like an ideal test site, considering the
enormous size of the White Sands military reservation. That itself was a
problem, though, as the Army made quite a bit of use of White Sands to the
extent that the Trinity test camp was accidentally hit by pilots practicing
bombing runs---not once, but twice. Moreover, fallout from the test reached the
Chupadera Mesa where it injured cattle and potentially ranchers. The extent of
the radiological contamination of the Chupadera Mesa is the subject of ongoing
For these reasons, subsequent nuclear testing was mostly performed in the
Pacific Ocean. In 1946, two weapons were detonated at Bikini Atoll in the
Marshall Islands. These tests badly contaminated Bikini Atoll and the region,
as well as Hunter's Point Navy Shipyard in San Francisco and potentially
other sites at which Navy support vessels were decontaminated post-test.
In 1948, three additional tests were conducted at the nearby Enewetak Atoll;
contaminated topsoil from the atoll was interred under a concrete dome on
Runit Island which is now in danger of failure due to tidal incursion.
According to Los Alamos's curious tradition of naming things after places
it destroyed, Bikini Atoll and Enewetak Atoll are both streets in LANL's
main office complex, TA-3.
These Marshall Islands tests were followed by a brief reprieve, lasting until
1951. A curious thing about the Manhattan project is how quickly it ended:
after the conclusion of World War II, there was a brief period in which nuclear
weapons didn't seem especially important. The weapons program almost shut down
during this period, and there was no effort towards stockpiling. It briefly
seemed like the whole thing might have been a bit of a one-off, not a major
ongoing function of a nuclear state. It did not last.
In my eyes, 1951 marked the beginning of a real, organized nuclear testing
program in the US. Prior to that had been scattershot experiments coordinated
somewhat haphazardly. From 1951 onward, nuclear testing was operated as an
ongoing business function, using an established process and permanent
infrastructure. While testing would continue at the Marshall Islands for about
a decade further, mostly to accommodate larger-yield tests, the cost of
performing them so far overseas was tremendous. For the testing program to be
cost-effective it needed to be domestic. Ongoing domestic testing required an
area even more remote than southeastern Socorro County: southeastern Nye
Over 1,000 nuclear detonations occurred within the ~1300 square miles of the
NNSS. While the vast majority were underground, 100 were conducted above
ground. The mushroom clouds were visible from the Las Vegas Strip. Fallout
from these above-ground tests headed mostly away from civilization until Utah,
where it almost certainly resulted in excess fatalities due to cancer. The
underground tests left little evidence other than a vast valley of small
craters, each the result of soil falling in on the glass-lined underground
cavern created in milliseconds by the buried weapon.
The NNSS is still in use today, although nuclear testing ended in 1992
following to the Comprehensive Test Ban Treaty. Perhaps the most dramatic
activity today is subcritical testing, in which the pits and high-explosive
components of nuclear weapons are tested under real detonation conditions---but
with too little radioactive material to achieve criticality. Because of the
involvement of both nuclear material and a lot of explosives the process must
be treated much like an actual nuclear test. The site is also used for
long-term disposal of low-level nuclear waste from the weapons program,
counter-terrorism testing and training, and the National Criticality
Experiments Research Center, one of only a few sites capable of conducting
experiments with quantities of nuclear material that could become critical.
It is an odd happenstance that the NNSS is both exceptionally remote and only
about an hour from Las Vegas. This makes it something of a tourist destination.
In the days of atmospheric testing (the '50s to early '60s), tourists used to
visit Las Vegas during announced tests in hope of seeing the flash and cloud.
Today, it is possible to take a tour, although not especially easy. Public
tours are held nominally once a month and have a capacity of about 20 people.
They're usually full up well in advance. Some years ago I had set up a script
that would check the webpage on tours for changes and notify me, so that I
could apply for a tour as soon as the next batch of dates were announced
(usually about six months at a time). I succeeded in reserving space for myself
and my husband on a tour in early summer 2020.
You might remember some things about early summer 2020.
By the time our tour date came around, all tours had been canceled indefinitely
due to COVID. I was somewhat skeptical that the tours would ever come back,
given the small scale of the operation and the presumable complexity of its
security plan. But fortunately, several months ago I got an email from the tour
coordinator that they were picking tours back up. She was offering the upcoming
dates to the people they'd canceled on. I was able to snag a tour date in
mid-August, which largely by coincidence ended up matching up neatly with a
period of "funemployment" before I started a new job .
I had planned to hike Tikaboo Peak (viewpoint to Area 51) and visit some other
national security sites that week but, owing to Nevada summer weather and my
own desire to put in as little effort as possible, ended up spending most of
the week luxuriating in the clingy embrace of Caesar's Rewards while riding
every form of transportation I could. While I do indeed have videos of both
monorail (Bombardier Mark VI, of course) and APM (Doppelmayr Cable Liner), I am
doing my best to avoid dancing off the cliff and becoming a train vlogger.
Instead, I am going to tell you what it's like to take a public tour of the
Nevada National Security Site.
First: if you would like to do the same, you can learn about it
According to that website tours are booked through June 2023. I would recommend
that you watch that website carefully and submit your badging form as soon as
more dates are announced; I would anticipate that H2 2023 tours will fill very
quickly. There are also administrative details: tours depart from the National
Atomic Test Museum in Las Vegas near the strip. Cameras, phones, binoculars,
and bags are prohibited. The tour leaves in the morning and takes the full day.
Much of this is because of the distances involved: it is about an hour drive
from Las Vegas to the site, and about another hour from one end of the site
to the other. I believe we were told the tour covers about 270 miles.
Fortunately we were on a comfortable coach with a gregarious tour guide,
former public affairs manager Darwin Morgan.
I will discuss the tour stops in no particular order, mostly because I'm not
sure that I remember the order correctly. I'll also give the caveat that the
NNSS staff seem to be actively working to both improve the tour and accommodate
activity at the site, and so the itinerary will likely change with time.
The first item of interest in the tour comes as you approach the entrance to
the NNSS, on Highway 95, a generous four-lane highway improved to its large
size to accommodate the huge number of people that commuted between the site
and Las Vegas during the days of active testing. Today it is mostly empty,
particularly since it spends most of the distance near Las Vegas either in or
adjacent to the various military reservations that make up the broader Nevada
Test and Training Range (NTTR). It's important to understand that an enormous
portion of the state of Nevada is reserved by the Federal Government for
various defense uses. The NNSS is just one part of this sprawling complex.
Area 51, for example, is not especially far from the NNSS but is not part of
it. The NNSS is also not the Department of Energy's only secretive operation in
southern Nevada, as the Tonopah Test Range of the NTTR is operated by Sandia
National Laboratories. It is also known as Area 52 and is near its more famous
Driving out highway 95 you pass by Creech Air Force Base, a surprisingly small
but densely packed Air Force installation used by UAV pilots. Our guide
promised that you can almost always spot UAVs on approach or departure, and
indeed it only took a moment to spot an MQ-9 Reaper performing touch-and-gos.
It is reassuring that some of the military's most sophisticated aviation
technology still relies on such conventional training techniques. One wonders
if somewhere in a nearby building an instructor was nagging "too high, where's
the needle?" Of course the airfield is less of the main feature than the many
small buildings around it, as most of the pilots of Creech AFB are flying
aircraft over a very different desert.
At around this point our tour guide explains a bit about the oddity of the
NNSS's long commute. Most nuclear weapons installations of the era provided
staff housing, but NNSS employees have long faced a rather tedious drive, and a
dangerous one given the drinking culture of the time. There had been a plan to
build an "atomic town" on the edge of the site for its personnel, but the
extremely low water table and budget limitations prevented any serious efforts.
The closest town is Indian Springs, directly across from Creech AFB, which had
at the time been somewhat eschewed due to its poverty (much of the town has the
feeling of a trailer park facing hard times). Of course, the large staff of
Creech AFB has brought a change in fortunes and Indian Springs is now seeing
quite a building boom.
A bit closer to the NNSS is Cactus Springs, which had consisted largely of a
gas station and bar which was apparently popular with NNSS staff. With the end
of nuclear testing came the end of the bar, and today Cactus Springs is home to
the Temple of Goddess Spirituality, constructed just after the end of testing
in 1993 and tended to by spiritualist Genevieve Vaughan as a shrine to the
Egyptian god Sekhmet. This situation is a bit hard to parse but reminds you
that the desert is full of strange and wonderful things.
On the approach to the NNSS gate, our guide points out the Desert Rock
airstrip. Desert Rock was, at its peak in the '60s, a fairly large Army camp
built to support operations at the NNSS---particularly the testing of nuclear
effects on Army equipment and personnel. Yes, "personnel." If you have heard
the stories of only partly-witting Army soldiers taking shelter from nuclear
blasts in trenches only to emerge from those trenches and march for ground
zero, you have heard of the Desert Rock exercises. As it turns out, the
radiation exposure from these experiments was generally kept within the 3 rem
safety limit established for the program. Epidemiological research has found
an increase in leukemia in participants in these tests, although not one so
significant that it is clearly related (there being known confounding factors,
such as the very high rate of smoking in the military at the time).
Today, little is left of Desert Rock besides a field of concrete pads (from
tents and temporary buildings) and an airstrip. Our guide explains that, as the
closest airstrip to the NNSS, it is still maintained to some degree for
emergency use. Desert Rock is more interesting to me because of my peripheral
knowledge that it is the subject of conspiracy theories: Desert Rock receives
very few aircraft and has nearly no support facilities, but for a time was
visited somewhat regularly by a set of business jets owned by known CIA fronts.
The resulting accusation that NNSS hosted some sort of black site have never
been confirmed and are not, to my mind, very credible. A bit of imagination
will develop more likely motivations for CIA activity at the site.
Just as the bus pulls off the highway, we pass a set of signs warning off
wanderers. Our guide explains that the bold white line painted across the
road here is the boundary of the reservation, and that during the era of more
active anti-nuclear protest the Nye County Sheriff's Office was on hand to
arrest the crowds of demonstrators that would regularly march over it. These
activists were held in a set of chain-link pens just by the road while the
sheriff's deputies wrote citations and were then sent back over the line to
public land. This symbolic criminality, civil disobedience in perhaps the most
pure form, happened regularly for many years.
Today, the specter of nuclear war is largely forgotten, and along with it the
large-scale, organized anti-nuclear movement. Very few demonstrators bother
to visit the NNSS, as is the case with other nuclear weapons complex sites
where even major traditional protest dates like the anniversary of the bombing
of Hiroshima turn out only a few people... people old enough that they had
lived through the Cold War. It has always felt to me that the nuclear weapons
program attained its current state of acceptance not through any actual change
in public opinion but simply by attrition. Nuclear weapons have been around
long enough, and with little enough impact on the world, that few can be
bothered to care.
The tour enters the NNSS, as essentially everything does, at Mercury. The
security checkpoint is some distance past the reservation line (this seems
common at this type of installation, I suspect so that it gives errant drivers
time to discover their mistake and gate runners very few excuses), and the town
of Mercury is just past it. Mercury is nominally a town, and has a post
office to bolster that claim, but it has no population and serves instead as
the main post for the NNSS. Our guide points out the fire station, the post
office, and an imposing concrete building that houses the Operations Control
Center from which the whole site is run.
As we passed through Mercury our attention was called to a set of newer
buildings. Our guide explained that the NNSS was having a hard time hiring
and retaining staff and that the Cold War-era work environment was thought
to be part of the problem. A building program had been started to transform
Mercury into a more "campus-like" installation that would appeal to young
We stop for coffee and a bathroom at the Mercury cafeteria. I commented here to
my husband that I find the "campus-like" construction effort to be a real
shame. The history of the nuclear weapons program, having grown so abruptly to
massive scale in the '50s and '60s, has given it a curiously consistent
aesthetic. Simple rectangular buildings with cast concrete segment roofs and
breeze-block screens over plate glass windows. Heavy wood paneling in an effort
to add aesthetic interest. Suspended fluorescent lights with sheet metal
baffles, at least a third of them dead or dying. Everything, everywhere,
painted the same shade of tan.
This is, of course, a description of anything built by the army in the
mid-century on a tight budget and even tighter schedule. Both in conceptual and
historical terms, it is one step nicer than a row of Quonset huts. But it is a
consistent look, and as a result your average Department of Energy installation
looks more harmonious than a university campus with a 300-page architectural
master plan. More significantly, I think it maintains a certain important
spiritual connection between the weapons complex today and the Cold War.
Philosophically, it might be important for the staff there now to remember that
they are operating a legacy of a foregone time. Efforts to modernize the
buildings, like efforts to modernize the weapons themselves, come with a
degree of danger.
After our brief visit to the cafeteria, we re-boarded our bus and continued over
a low ridge into the test site itself. And that's a good cliffhanger, so hold
on for Part II. I'm currently in Fort Worth for a long conference, so I have
quite a bit of free time and not a lot else to do. That means posting!
 I'm now with GitLab in professional services. That's right, if you spend
enough money on GitLab, I might come with it! Opinions are mine and not those
of my employer, except for the bad ones, which are the opinions of someone else
that I've never met before and certainly did not arrive here with.
Programming note: Sorry for the infrequent posts lately, I have been traveling
and starting a new job. Probably the next thing I post will be a report on some
of that travel, which you will hopefully find interesting.
Previously on Deep Space Nine, we discussed the landscape of common retail
EAS systems: electromagnetic, acousto-magnetic, and RFID. I now want to
extend on this by discussing some peripheral systems that serve as part of the
larger retail loss prevention technology stack. I will follow up on that by
saying a bit about why none of these approaches seem to end up working that
Shopping carts are fairly expensive, running around $200 to replace. Since
shopping carts are attractive for moving stuff, they have a tendency to "go for
a walk" and require frequent replacement. The first type of "smart cart"
technology to make a widespread appearance is "cart retention" or cart
anti-theft. Most Americans have probably encountered these by now, although
they remain fairly uncommon in New Mexico.
While there are a number of vendors and systems, most are based around a fairly
simple concept. A special wheel or wheel housing contains low-power electronics
which observe for an RF tone. When the tone is detected, some type of locking
mechanism activates that prevents the wheel from rotating. The wheel usually
remains locked until commanded to unlock via an RF or IR device.
To form a cart perimeter, a cable is buried around the perimeter of the parking
lot that acts as an antenna. The emitted power is quite low, so carts only lock
when passing fairly close to the cable. In some systems, a second cable buried
a bit inside of the outer emits a separate tone that commands the wheels to
unlock. This makes it possible for a customer to reset a cart by dragging it a
short distance back towards the store, potentially saving employee effort.
Most cart retention systems operate at low frequencies, below 9 KHz in the case
of the Gatekeeper Systems offering. These low frequencies are fairly efficient
with the very long antenna cables used, penetrate materials well, and best of
all are below allocated spectrum... so there is no licensing required.
You can probably imagine that the "locking cart wheel" technology can be
applied to a few different problems. A common form of retail loss, and one that
tends to involve fairly large dollar amounts, is "push-out theft." A push-out
thief loads up a cart with products and simply walks out. With well-chosen
items like powdered laundry detergent it can be difficult to detect this type
One approach is aggressive traffic management in the store, using one-way gates
and barriers to prevent customers exiting without passing through the
checkstands. This kind of highly visible security is becoming more common but
it's not completely effective... for one, having a large number of
self-checkout machines tends to make it pretty easy to get through the
checkstands without paying or being noticed.
A somewhat more sophisticated, and annoying, solution is the installation of a
pushout prevention system like Gatekeeper's Purchek. While there can be more
complexity to these systems, the basic idea is that each cart is temporarily
"enabled" when a customer completes a purchase, and stays enabled for a time
period like 30 minutes. Outside of that time period, any attempt to leave the
store with a cart will cause that cart to lock. This should prevent anyone
leaving with a cart of unpaid items.
You can probably think of a few ways to implement this, and they've probably
all been done by at least one company, even the bad ones. In the case of
Gatekeeper's older generation Purchek system, each checkstand seems to contain
a unit that transmits a signal which starts the exit timer in the cart wheel.
When the cart is pushed through the exit, a tone transmitted by a floor antenna
causes it to check the exit permission timer and lock up if it is not still
There are variations with appreciably more complex configurations though, and
Gatekeeper Systems holds a patent on a cart-to-cart and cart-to-access-point
mesh networking system that can be used to apply particularly complex logic
to make lock-on-exit decisions. It's not clear to me how much of the patented
material is actually implemented in their commercial products right now, but
certainly some of it is.
Many grocery stores now feature a panel antenna mounted near the exits facing
the area approaching the doors. This panel antenna is used by the Gatekeeper
door controller to communicate with the cart wheels, and it's hard to suss out
the exact logical architecture of the system but it seems that the door
controller can query the cart wheels for a recent historical average rotational
speed and can use the history of detection of that cart wheel to determine the
location history of the cart. These can be factored into the exit permission
I have heard complaints of Kroger configuring the time window during which exit
is enabled after paying to be as short as 60 seconds, short enough that walking
slowly toward the exit (e.g. due to a disability) will consistently result in
the cart locking at the doors. There is a substantial accessibility issue with
many of these loss prevention technologies and vendors seldom address it in
their marketing material.
Networked communication with cart wheels can also be used for various
convenience use cases, like automatically counting carts in the parking lot to
determine when carts need to be rounded up, and allowing a parking lot
attendant to unlock all carts in a corral area at once. Nonetheless, Kroger
consistently struggles to have any carts available at the entrances, but that
comes down to staffing... which we'll get to in a bit.
One long-running source of loss prevention frustration is that deck at the
bottom of the cart between the wheels, often called the bottom-of-basket or
BOB. The way most checkstands are configured, the cashier cannot directly see
this area... but it's often used for relatively expensive item like 24-packs of
beer. It presents a significant opportunity for both accidental failure to ring
up an item and intentional theft.
A friend who once worked in a grocery store told me that his chain had a
general practice of cashiers making some comment about a fictional coworker or
relative named "Bob" to warn another cashier that a customer had something on
the bottom of their cart. For decades, checkstand manufacturers have offered a
low-tech BOB solution consisting of a "periscope" configuration that allowed
the cashier to see the foot-level area by looking in a mirror mounted under a
hood near the weighscale/barcode scanner. Many stores just placed an adhesive
parabolic mirror on the side of the next checkstand over that served the same
purpose more simply.
These solutions are simple and effective, so of course there are options which
are complex and, well, questionably effective? The Lanehawk from Datalogic is a
camera and illuminator which mounts in the space most checkstands have for the
lower periscope mirror. It uses machine vision to detect items in the BOB and
identify them, giving the cashier a prompt that rings them up in one button
press. I have seen LaneHawk installed at several stores and I have never
actually seen it work. It's hard to tell if this is because of poor reliability
or because of retailers starting deployment and never finishing it due to
training or configuration issues, which seems to be oddly common with this type
Queue and customer volume management
Customers get irritated if they have to wait too long to check out, but idle
cashiers waste money. Stores have to try to strike a balance between short
wait times and high utilization rate for open checkstands.
There are two basic ways that technology can, in theory, help: first, counting
queues at the checkstand can allow for a fast automatic call for more cashiers
when lines start to grow. There are various systems that can do this including
Gatekeeper based on counting the number of cart wheels apparently in queue for
A second and more interesting approach is predictive queue counting. By
knowing how many people entered the store and when, it's possible to predict
the likely number of people who will queue to check out some time in the
future. Several grocery chains have invested in Irisys's system, which uses
distributed "people counting" units to track the arrival rate of customers.
This data, along with potentially data on customer location in the store based
on other vendor's systems, drives television screens mounted near the
checkstands that display the current number of open checkstands and the number
that will be required to maintain a queue depth target in 15 and 30 minutes.
For some odd reason these three numbers are labeled "Lanes Open," "Action Now,"
and "30 Minutes," the first and third of which are inconsistent but logical and
the middle of which is just bizarre. Besides this real-time feedback it also
collects historical data to make long-term projections, which can be used for
scheduling cashier shifts.
For some reason Irisys's marketing material repeatedly mentions the use of a
"VGA display." It's unclear to me if the copy is from the '90s or just the
attitude of the person who wrote it. The use of consumer televisions should
reassure us that it is at least WXGA.
The data for these systems can come from many, diverse sources. Kroger
stores in my area are equipped with machine-vision based people counting using
multi-lens 360 degree cameras as well as Bluetooth and WiFi-sniffing people
counting systems. Some machine vision is infrared, but some is visual. Some
people-counters use simple multi-spot passive IR methods (somewhat like typical
burglar alarm motion detectors) while others use proper imaging.
If data collection on customer volume can be gathered automatically, what about
data on stocking levels? There are products on the market that monitor shelf
stocking using machine vision, but I have not personally seen them widely
deployed. The principle is fairly simple, just pointing a camera at a shelf
(often using fisheye optics for wide coverage) and using obvious methods to
see if items are present where they should be.
Shelf stocking information can also be gathered by robots that travel the store
floor observing shelves. This has been shown at a number of trade shows but I'm
not sure if it's actually being done on any large scale. I tend to think that
it would end up being more expensive overall than fixed cameras, considering
the more complex maintenance situation.
Staff and Equipment
Given the amount of technology apparently being thrown at the problem, why is
it that retail loss prevention (at least in my market) mostly seems like a
I'm not an industry insider or anything, so I can only speculate. But it seems
clear that insufficient staffing is the single greatest issue at the moment,
and I think that's been the case since prior to COVID. Basically al of these
systems are dependent on having enough staff to attend to them, and grocery
stores frequently fail on this front. Kroger spent a good chunk of money
installing guard podiums at the entrance of all their stores with monitors
showing surveillance video, but I still haven't actually seen one staffed,
presumably since it would prevent the single guard actually walking the
The issue has become more acute as retailers have made increasing use of
two particularly labor-intensive approaches: separate, dedicated cashier
stands for high-theft areas, and locking displays.
In the former system, the liquor and cosmetics sections are isolated (perhaps
by awkwardly installed screen walls) and have a dedicated cashier. This cashier
is presumably more able to monitor for shoplifting since they have a small
assigned area, and it prevents unpurchased items from those sections
circulating to parts of the store where they would be much easier to conceal.
Kroger rolled out this system over the last two years in my area and has had
significant practical problems. The thing that has most stood out to me is that
they have consistently laid out these areas with the expectation that the
cashier stand with their back to the products. This obviously limits how
vigilant the cashier can be, and moreover poses a safety concern to the staff
since it reduces their situational awareness and provides an easy covert
approach to potential thieves. There is news reporting that, in some areas,
these checkstands have been modified in response to union complaints related
to employee safety.
There are other issues yet. The checkstand obviously needs to be staffed for
this system to be effective. Early on Kroger tended to leave it unstaffed most
of the time, but the switch to self-checkout stands seems to have enabled more
consistently posting a cashier. Second, it creates a situation in which
purchased merchandise circulates around the store. This is significant, since
it means that it is now fairly normal for a customer to check out and only pay
for some of the items they are taking with them. This makes "theft by
omission," already common at the self-checkout stands, difficult to impossible
to detect. The use of "paid" stickers and stapling bags shut mitigates the
issue somewhat but not entirely, since the realities of a busy retail store
make it very hard to consistently adhere to and enforce these mechanisms.
In a particularly interesting gaffe (or perhaps partially implemented change in
policy), Kroger stores in my region have not installed an EAS tag deactivator
at the cosmetics checkstand. Cosmetics items are relatively commonly tagged, and
Kroger tags many items post-manufacturing with an anti-tamper tape overlay. Due
to the lack of a deactivator, though, these items now set off the EAS portal
every single time they are purchased. The guard now responds to all EAS alarms by
resetting them with no further investigation. Brilliant.
Nonetheless, there is obvious potential to reduce theft. I tried to find some
sort of data on the efficacy of this measure but either there's little to be
found or, perhaps more likely, I don't know the right terms to search for.
The other common staffing approach seen today is locking up certain items in
their displays, and then requiring customers to find a staff member to have
them unlocked. The staff member might walk the item to a checkstand instead of
trusting the customer with it, once unlocked . This method has been around for
decades and is becoming increasingly common, from Walgreens (just about
everything) to The Home Depot (cordless tools, certain consumables like diamond
blades). The theft advantages are obvious, but the big problem is that there
have to be enough employees around for a customer to reasonably be able to find
someone. I am always very curious about how much sales drop when this system is
introduced; I have basically stopped buying cosmetics at Walgreens because of
the difficulty of getting an employee to show up.
Where does this whole thing leave us? Despite a lot of development retail loss
prevention is still an unsolved problem in many ways. The greatest problem
remains the trade-off between loss prevention and staffing costs: loss
prevention technologies have to be cost effective, and that usually rules out
the most effective designs (ubiquitous use of RFID).
Amazon Go has demonstrated the strong potential of machine vision and other
machine learning technologies. This kind of ubiquitous tracking requires
extensive infrastructure support, though, and major retail chains often seem to
struggle with much more basic equipment installations. No doubt the management
model of these companies, including franchising in some cases, is part of the
difficulty, but it's also what has allowed these chains to grow to such large
To some extent the increase in online shopping has obviated loss prevention
technology, and there are no signs of this trend stopping. Future stores will
probably lean more and more into showroom-type design, but in many cases their
loss prevention efforts will lead to higher and higher friction to actually
making a purchase. This seems unwise as a strategy to compete with Amazon but,
well, does anyone have a good plan to compete with Amazon?
 An interesting factoid is that Walgreens uses expensive Medeco cylinders on
the plexiglass display cases that you can force open by hand. I assume this is
just to allow same-keying with other more secure enclosures, but one wonders at
how much extra money these expensive cylinders have cost across the enterprise.
Long time no post, or at least it feels that way! I have returned from a long
vacation in a strange foreign country where the money is made of plastic, and
I am slowly recovering from the tactile disturbance this caused. As tends to
happen I ended up thinking a lot about the small details of international
interoperation, and the issue of currency is an interesting one. I think my
next post will be a bit about the mechanics of the relatively seamless ability
to spend US funds in Canada or Mexico today. But first, a post that I started
before I left and didn't finish until now...
You know how sometimes when you leave the grocery store, an alarm goes off
which is either completely ignored or immediately reset by staff? What's up
with that? Well, I can only really offer a satisfying explanation of the how,
as the why is a topic of some complexity.
The whole world of tag-detection-based anti-theft technology can be broadly
referred to as Electronic Article Surveillance, or EAS. One of the tricky
things about understanding EAS is that, much like with proximity key systems,
several significantly different technologies are in use simultaneously. There
are a lot of "urban truths" about EAS that are often correct insofar as they
apply to one particular EAS technology, but often not even one of the more
widely used ones. The different practical and security properties of EAS
systems are interesting from an evolution of technology perspective, and the
cutting edge of EAS gets into some interesting areas of RF engineering.
The general principle of EAS is fairly simple: article tags are affixed to,
or placed in, products that might be stolen. At the exits of a retailer, a
"portal" system is installed that detects the tags. When an item is sold to
a customer, a cashier uses some mechanism to either remove or deactivate the
tag so that the customer can exit without causing the portal to alarm. What's
less simple is the number of different ways of achieving this.
EAS systems are commonly, but mostly incorrectly, referred to as RFID. In fact,
the most commonly deployed EAS use a technology which is quite dissimilar to
RFID and relies on magnetic, rather than electric, field coupling. This makes
it all the more interesting that EAS started out on the path to RFID, before
taking rather substantial detours into the world of magnetics.
There seems to be some confusion in common sources about the nature of the
first EAS, although it's agreed to have been invented by Arthur Minasy in the
mid '60s. It's actually not at all difficult to find the original patent
granted to Minasy in 1966, in between Minasy's many other forays (he was the
type of "serial inventor" which is rarely seen today). The original Minasy
design, commercialized by a company he founded called Knogo, is a simple
passive circuit that receives RF energy via an antenna, rectifies it to DC, and
uses that to power an oscillator that emits RF at a different frequency. This
is, of course, substantially similar to the RFID concept and I find it likely
that Minasy would be listed today as among the significant contributors to RFID
were it not for the fact that this original technology was quickly abandoned by
Knogo and is little known today. This is true to such an extent that articles
about the history of EAS, if they go into any real detail on early systems,
tend to describe the replacement of the Minasy system as Minasy's original
There is a fundamental problem with both Minasy's early design and modern RFID
in EAS applications: it requires electronic components, and electronic
components are expensive. This was true in Minasy's day when individual
transistors were a meaningful impact on the BOM cost, and it remains true today
when EAS tags are made in tremendous volumes and fractions of a cent make a
The Minasy system, often called "RF tags" or "resonant tags," are still in use
today. The relatively high cost of the tags tends to limit them to applications
where they can be reused, mostly in the form of "hard tags" attached to
clothing and removed on sale using a special tool. That said, it is possible
to "deactivate" resonant tags. LC tags can be manufactured with an intentional
susceptibility to failure when exposed to an excessively strong RF field, for
example by using a capacitor which will overheat and allow the plates to short
together. The tags can then be placed on a device which emits the same
frequency as the detectors but at a much higher power level, resulting in
intentional failure of the tag.
A more recent (but not very recent) innovation is thinner and cheaper RF tags
operating at a higher frequency---typically 8.2MHz, while the original Minasy
system had been tuned for 2MHz with very low precision. These 8.2MHz tags
look like rectangular thin paper stickers, and when peeled up the metal foil
antenna is visible underneath. They operate on the same principle as Minasy's
system but are almost always deactivated by RF field rather than removed. Their
thin size makes them well suited to printed materials, but they can also be
applied to boxes and other packaging.
Far more common today than RF tags are a later development, the magnetic EAS
tag. Magnetic tags exist in two major variants, the first having been developed
by 3M in 1970. The 3M technology, commonly known by its 3M brand name "Tattle
Tape," can more generically be called electromagnetic or EM EAS. EM tags rely
on an interesting property of magnetic fields, or rather their interaction with
Magnetic materials such as iron can be "magnetized" by exposing them to a
magnetic field, causing an alignment of the magnetic dipoles of the material's
molecules. During this process some of the energy of the field is consumed.
Magnetic materials also have a "saturation value," which is a measure of their
greatest potential to become magnetized, or the point at which no further
improvement in the magnetization of the material can be achieved. For most
magnetic materials, the saturation value is quite high. It is possible, though,
to design materials that are magnetizable but have a very low saturation value.
The most common in EAS applications is an alloy called "metglas," so called
because it has a non-crystalline structure more similar to glass than metal.
When a quantity of metglas is placed in a magnetic field, it absorbs some of
the energy of the field in order to become magnetized. It quickly reaches
saturation and stops interacting with the field. This behavior is quite useful
as it can be detected by magnetic means.
So, an EM EAS system relies on a portal with two antennas, typically
placed on the two sides of the door (in multi-door situations it is common to
have multiple towers which alternate receiving and transmitting). The
transmitting antenna emits a magnetic field. The receiving antenna on the other
side of the portal observes this field. When metglas is introduced into the
field, it briefly absorbs energy and then stops when it reaches saturation.
This can be observed as a brief dip in field strength at the receiving antenna.
By rapidly alternating the field emitted by the transmitting antenna (essentially
using it as an AC electromagnet), this effect can be checked for many times a
Even better, the nonlinear behavior of metglas in a magnetic field causes a
number of effects in a rapidly alternating magnetic field including harmonic
frequencies resulting from the repeated magnetization and demagnetization of
the metglas. Modern EM EAS systems use complex DSP techniques to observe for
multiple different effects caused by the low-saturation-value material, making
them less susceptible to false positives. In fact, false positives in the
detection of metglas are quite rare (although EAS are usually quite prone to
false positives, they come from other causes which we will discuss later).
Because materials with a very low saturation value are exceptionally rare in
nature, the presence of rapid magnetic saturation behavior is a very strong
indication of the presence of a tag.
Magnetic EAS technology becomes even more interesting when you consider the
issue of deactivation. EM tags are typically manufactured with a strip of a
normal ferromagnetic material placed alongside the metglas strip. If this
material is magnetized, it keeps the metglas strip constantly saturated,
preventing it interacting with external fields. Thus an EM tag "deactivator"
simply emits a strong enough field to magnetize the ferromagnetic strip. Even
better, an "activator" can emit a rapidly alternating magnetic field which will
effectively "scramble" the magnetic orientations of the underlying magnetic
elements in the magnetic strip, causing it to lose its magnetic field. The
metglas strip will no longer be held in constant saturation and will be
detected as usual.
This ability to activate and deactivate EM tags at will is unique to EM tags
and is the cause of their ongoing popularity in libraries. Libraries install
tattle tape permanently, usually adhering it to a middle page near the spine
where it is difficult to notice. The circulation desk deactivates tags when
books are checked out and activates them when books are checked in, usually
using a device that just has an "activate/deactivate" switch to select between
a fixed and alternating magnetic field.
If this neat property of EM tags seems a little too good to be true, well, it
does have caveats. First, the ferromagnetic element in EM tags is of relatively
low coercivity (e.g. magnetically "soft") to allow for easy activation and
deactivation. That also makes it prone to being affected by various
environmental magnetic fields, and as a direct result EM tags have a tendency
to "self-activate" over time. If you have ever renewed a library book a few
times and then set off the door portal when returning it, this is due to the
ferromagnetic element simply losing its magnetization over weeks of exposure to
electrical equipment and other ferromagnetic materials.
Second, the only aspect of EM tags that can be detected is the presence of an
active one. There is no way to differentiate EM tags from each other. This can
be a practical problem in circulation environments like libraries. In my city,
the county library has ended use of EM tags in favor of an RFID system, but
much of their inventory is still "tattle taped." The tags in these older books
are now almost all active due to environmental demagnetization, and so it is
more or less guaranteed that carrying a county library book into the university
library will set off the portal system... on the way in and out. This kind of
nuisance alarm behavior will very quickly cause staff to disregard the EAS
system, and so the county library's upgrade to RFID has no doubt significantly
reduced the effectiveness of the university library's system.
EM tags are most often seen in the form of "tattle tape," whether made by 3M or
a competitor. These tags are long, narrow strips that are usually self-adhesive.
They are thin enough to sit inconspicuously in the pages of a book, but large
enough that they would be tricky to get onto the packaging of smaller products.
You don't see them very often, mostly because in their most common application of
library books they're placed either in the spine or on a page very close to it,
where they're concealed.
EM tags cannot really be permanently deactivated without physical destruction,
and they require relatively strong fields to detect. These two downsides lead
to the development of a variation on magnetic EAS, called AM EAS. The label is
a little confusing here as most would read "AM" and assume "amplitude
modulation," but in this context it's actually an abbreviation for
"acousto-magnetic." These tags rely not just on the interaction of a material
with a magnetic field, but also on acoustic resonance of the material. That's
AM tags contain a thin strip of a material that demonstrates
"magnetostriction," or a change in physical shape when exposed to a magnetic
field. They are sized such that they are resonant when vibrated at a particular
frequency, usually 58KHz. The AM portal system emits short bursts of a 58KHz
field and then, after transmitting, uses a receiving antenna to observe for any
continued 58KHz magnetic oscillation. An AM tag will continue to vibrate for a
short time after the original field disappears, causing a detectable "trail"
from the transmitted burst. Once again, modern portals repeat this process rapidly
and use DSP methods to check for multiple indications of a real tag.
AM tags can be deactivated much like EM tags, but there are important
differences. AM tags also contain a strip of a ferromagnetic material, but its
function is different. The ferromagnetic strip is magnetized normally and
serves as a "bias magnet." As a bias magnet, it is carefully tuned so that it
offsets the magnetic anisotropy of the magnetostrictive strip---its tendency to
only react to magnetic fields coming from one direction. Without this bias
magnet, the AM tag cannot be reliably detected. To deactivate AM tags, the
magnetic strip is demagnetized by exposing it to a strong and alternating
field. AM tags are the opposite of EM tags when it comes to activation and
deactivation, and so they have a bias towards deactivation. This bias is weak
though: the proximity of the bias magnet to the magnetostrictive strip and the
inconsistent placement of these tags makes it impractical to remagnetize or
reactivate them, so they're designed for one time use only. This means that the
ferromagnetic material used for the bias magnet can be of relatively high
coercivity and is less affected by normal environmental fields.
I'll go into a little bit more depth on typical AM equipment, because AM is the
most common EAS technology used in US retail. Virtually every retailer has at
least AM portals, and you have certainly seen AM tags. AM tags are relatively
thick but small compared to EM tags. They're usually in a plastic housing of
perhaps 4cm long (as common as they are I couldn't find one around to measure)
and a few mm thick. The largest manufacturer of AM tags is Sensormatic, and so
they often have the old "hand in crosshairs" Sensormatic logo printed on them.
AM tags are ubiquitous in part because they are the accepted technology for
source tagging. Source tagging is a common industry convention in which
anti-theft tags are placed in products by the original manufacturer rather than
the retailer. There are a few advantages to source tagging: not only does it
save labor on the part of the retailer, the manufacturer can usually place the
AM tag in a more discrete and difficult to tamper with location. For example,
it's very common for power tools to come from the manufacturer with an AM tag
inside of the tool, often adhered to the inside of the plastic molding for the
handle. I recently encountered an item of clothing with an AM tag sewn into a
label, although fortunately this practice isn't common... AM tags are quite
rigid and not especially comfortable to wear.
Source tagging also allows for the use of EAS throughout the supply chain.
Fulfillment and shipping warehouses, for example, can use AM portals to deter
theft by employees, even before delivery to a retailer.
AM deactivators consist of a large coil antenna, which may be constantly active
but on modern equipment usually runs in a low-power "detection mode" where it
behaves similarly to a portal. The coil only runs at full power to demagnetize
when it detects the presence of an AM tag. This saves a bit of money on
electricity but more importantly makes the deactivator less likely to
deactivate someone's credit card, which had been an occasional problem with AM
deactivators despite the high coercivity of payment card magnetic strips. Some
AM deactivators, probably those that have received some physical abuse,
demonstrate magnetostriction of the coil itself in the form of an audible
"ping" or "twang" each time the coil is powered .
AM portals are the most common type you see. Older AM portals (and EM portals
as well) sometimes stayed unpowered until they were activated by a
pressure-sensitive mat or deck between the antennas, and you might still see
this in libraries in particular where continued use of EM gives little
motivation to upgrade equipment, but most portals today are able to use
electronic and DSP methods to detect the possible presence of tags with a very
low power consumption. This sometimes takes the form of "search" and
"interrogate" modes (these terms are often used in remote sensing due to its
military origin and so I tend to use them), where the portal normally operates
in a low power mode and the detection of any kind of magnetic interaction
causes the portal to switch to a higher power mode to distinguish tags from
Sensormatic is the largest manufacturer of AM portals as well as tags, so you
will likely recognize the Sensormatic product lineup that varies from "big
beige towers" to clear lexan sheets with coils embedded in them. Newer portal
systems are relatively small, and Sensormatic even offers a "concealed" option
that mounts against the door frame (not really very discretely at all) instead
of requiring freestanding towers for the antennas. Of course it is limited to
a fairly short range due to the small size of the antenna coils and so it
doesn't seem to be that common. A more recent innovation is the installation of
surveillance cameras either on the antennas or at the door frame. Sensormatic
controllers can trigger video surveillance systems  or retrieve images from a
video surveillance system, either way offering correlation of detection events
with video of the person walking through.
While AM portals are mostly effective and extremely common, they do have
distinct downsides. They share with the EM the property that AM tags cannot be
differentiated. A common downside emerges with source-tagged items: if you
purchase a source-tagged item at a retailer that does not have an AM portal,
they will likely not deactivate the tag on sale. It will then set off the
portals at other retailers. This is an extremely common cause of false-positive
alarms. The portal also cannot indicate how many items or what types of item
were detected, which makes it difficult to investigate an alarm.
As a partial mitigation, vendors including Sensormatic now offer handheld
"wand" AM tag detectors with a short range. These can be used much like a wand
metal detector to identify the item, or at least location on the body, that
triggered the alarm. WalMarts are usually equipped with one of these in a
wall-mount charging cradle near the door, but I have never actually seen one
used, which foreshadows a later point I'll discuss.
Another downside is the size of AM tags. They're not exactly large, but they
are thick... too thick to be easily integrated into some types of packaging.
Their larger size also makes them easier to locate and remove, if they're not
hidden somewhere by source tagging. Retailers that apply AM tags to items will
sometimes apply a larger sticker with anti-removal features (scoring so that it
will not peel away in one place) to frustrate shoplifters that simply peel off
the tag, but of course this isn't entirely effective.
As I mentioned, genuine RFID has been applied to retail EAS. It remains
relatively uncommon because, despite advances in low-cost manufacturing of
small electronics, active RFID tags remain considerably more expensive than AM
Perhaps the greatest champion of RFID EAS is WalMart, which has invested
considerably in both the installation of RFID equipment (manufactured by
Sensormatic) and the standardization and promulgation of RFID Electronic
Product Code or EPC tags. Much like UPC (Universal Product Code) or the closely
related EAN (European Article Number), EPC is an effort to assign a unique
numeric ID to every product in a retail environment... but EPCs tend to be more
specific than UPC, to the SKU (stockkeeping unit) level rather than price
level. This means that products that are offered in multiple variations (e.g.
flavors) at the same price may share the same UPC, but will have distinct EPCs.
One of the driving motivators behind this technology is its advantages for
inventory management. In order to effectively track shrink (theft, spoilage,
loss, damage, etc) and other "dispositions" of purchased inventory other than
sale, retailers need to actually count the inventory on the floor. This is also
a required step in financial auditing, insurance underwriting, and various
other business processes. Basically, large stores need to actually send people
out to count everything.
In practice retailers rarely handle this in house, particularly because the
auditing use of this information makes it valuable to have it collected by an
independent third party. For example, the use of an inventory contractor makes
it more difficult for an insider (employee) who is stealing products to cover
for the loss by inflating inventory counts. The largest such contractor in the
US is a company called RGIS, which regularly sends an army of temp workers
equipped with handheld barcode scanners into each of America's stores in order
to scan every individual item on the shelves.
Sidebar which is Critical of Capitalism, You Have Been Warned
Actually the history of retail inventory is itself rather interesting as RGIS
has historically been a pioneer in the design of highly usable wearable
computers, and in the era before the universal use of UPC/EAN labels the
incredible speed at which experienced RGIS employees could operate a belt-worn
ten-key was something of a legend. Of course in one way, the invention of the
barcode was a labor-saving device that ought to accelerate the inventory
However, as potently observed by Brian Justie in The
Magazine), many "automation technologies" are better viewed as "labor
technologies" in that their primary purpose is not actually to speed up a
process but to reduce the level of operator skill required, thus making the
labor more readily replaceable. This phenomenon is rather clear in the case of
RGIS, where more than speeding anything up the transition to barcodes
facilitated RGIS's transition to nearly complete use of short-term temp agency
Since RGIS workers no longer needed to learn the skill of rapid and accurate
manual entry, they no longer needed to be paid at a level that motivated them
to stick around. Anecdotally, it seems that the modern barcode-based RGIS
system is quite possibly slower than the earlier belt-pack ten-key, but the
operator only needs the barest of training and therefore only the barest of pay
or benefits. This is one of numerous cases in which advancing technology has
reduced costs as promised, but by facilitating lower wages, rather than by
actual improvements in efficiency.
End of leftist discourse
The EPC scheme promises to significantly accelerate the inventory process by
allowing "drive-by" inventory with a good sized antenna. It also offers a
significant enhancement in EAS: an EPC-based EAS system can determine exactly
which items are detected and report the list of items to the operator. Even
better, EPC can include a unique serial number for each item. This way,
"deactivation" of the tag can be performed in an "online" manner by marking
that individual item as sold. This promises significantly more accurate EAS,
easier investigations of alarms, and better overall inventory control and
market research insight via end-to-end lifecycle tracking of individual products.
It is also, according to a surprisingly large segment of the American
population, a sure sign of the coming apocalypse. I'm sort of kidding about
this but only sort of. A meaningful vein of opposition to RFID technology in
public discourse has been its potential resemblance to certain aspects of the
Book of Revelations. To discuss this fascinating and surprisingly important
artifact of American culture would be its whole own article, but I will note
the comedy of "Not Today Satan Cross Christian Religious Credit Card RFID
Blocker Holder Protector Wallet Purse Sleeves Set of 4" listed on WalMart.com
coming up in the same search results as "ALERT, RFID CHIP READER IS AT WALMART
THE MARK OF THE BEAST IS HERE IN VIRGINIA."
A much larger problem with RFID than its satanic origins remains the cost of
tags, which has lead to a lot of hesitation on the part of manufacturers and
distributors to participate in RFID source-tagging schemes. WalMart is of
course a large enough part of the US economy that it has a powerful ability to
push its suppliers around, and WalMart just recently announced that it will
mandate source-tagging with EPC for a large portion of their products. This
needs to be done at the expense of the supplier, of course, although WalMart
notably continues to exclude groceries from the requirement. The required
categories for EPC tagging are basically all higher-value and higher-theft
products, showing the practical impact of the tag cost. This same trend is seen
throughout the world of EAS: the cheaper and less attractive to thieves an item
is, the less likely it will have any sort of tag. The more expensive or
theft-prone an item, the more likely it is to feature AM and then RFID tagging.
Although the expansion of EPC tagging at WalMart is recent, the system itself
is not, and WalMart has used EPC tags on product cases and some apparel items
since 2003. So have other retailers, although usually not on as large of a
scale. The technology lead to enough debate around privacy (and rapture)
implications that WalMart attempted to placate public concern through
"transparency" by putting an "EPC In Use" decal on entry doors somewhere
between the other ten regulatory decals. Of course this has never achieved any
type of benefit, but I do like the design of the sticker.
Another stronghold for RFID EAS technology is the library industry. The same
requirements that kept libraries on EM make RFID attractive, and so most
libraries are transitioning from EM to RFID (or already have in the case of
most larger libraries). Besides allowing for very accurate online tracking of
checked-in/checked-out status of books, it speeds up the circulation desk (or
self-service kiosk) by allowing a whole stack of books to be scanned at once.
Since library books are fairly expensive and have fairly long service lives,
the cost of the tags is not so much of a deterrent to libraries, and RFID tags
are readily available in a thin sticker format the goes just fine inside the
cover of a book.
Most RFID EAS tags are thin stickers made of either paper or plastic. They're
often square or fairly close to square. Usually either peeling one up and
looking underneath or shining a light through an RFID tag will reveal a spiral
or otherwise packed antenna, similar to PCB traces but more often just a metal
foil on a paper or plastic backing. Some RFID tags have a serial number or
barcode printed on them, but many are just blank. In the case of EPCs on
apparel, it's common for the RFID tag to be adhered into the middle of a
two-layer paper hangtag. Libraries usually put them inside of the front or back
cover, and retail products often have them placed somewhere near the UPC/EAN
barcode since this gives the cashier a good idea of which side of a large box
to put against the reader.
RFID EAS portals are mostly not distinguishable from AM portals, since RFID
support is usually just an add-on feature to an AM system (by adding extra
antenna coils in the same tower enclosure). RFID EAS systems are a lot more
likely to have some sort of operator interface like a display and keypad on the
wall, rather than a simple alarm, since they're able to show a list of items
Unexpected part break...
This has already become quite long and I have quite a bit more to add... as
sometimes happens to me, everything I've said so far is really just background
to what I really wanted to discuss. Let's break this up a bit by calling this
part 1, and soon I will post part 2... which will cover both cutting-edge
retail loss prevention technology and the reason why both existing and brand-new
systems are increasingly ineffective. There will be more criticism of capitalism,
but also more weird technology!
 Iron is slightly magnetostrictive and this effect is the source of a lot of
cases where you can "hear electricity." The 60Hz hum of large power transformers,
for example, is primarily the result of the transformer windings vibrating due to
 Support for external triggers is a longstanding feature in video surveillance
systems, allowing video to be recorded on demand or just tagged with the time of
events. In older systems this takes the form of a relay on the EAS system that
energizes a digital input on either the video recorder or a camera (digital
surveillance cameras usually include one or two digital input/output pins and
a protocol to inform the recorder when their state changes). In newer systems it
is more likely to be all IP.