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FreightWaves Flashback: Customs X-rays containers

X-ray machine shows what is inside trucks and containers, but Customs decides the cost is too high and will shut down installation at Tacoma. Meanwhile, machines are being put to use at two border crossings into China, the Paris airport, Le Havre and Hamburg. Mideast authorities are interested.

Image: X-ray images of a chassis-mounted container (American Shipper)

FreightWaves Classics articles look at various aspects of the transportation industry’s history. If there are topics that you think would be of interest, please send them to fwclassics@freightwaves.com.

The many industries that make up the world of freight have undergone tremendous change over the past several decades. Each week, FreightWaves explores the archives of American Shipper’s nearly 70-year-old collection of shipping and maritime publications to showcase interesting freight stories of long ago.

The following is an excerpt from the December 1994 edition of American Shipper (pages 80-81).

Look inside


Containerization has added efficiency to shipping but also has made it easier for smugglers to hide drugs and other contraband from the Customs Service.

So Customs, together with a high-tech agency of the Defense Department, is trying to develop ways to use X-rays to look through the steel walls of a 40-foot box.

The agencies have tested a system at the Port of Tacoma that zaps containers with 20 million electron volts of X-ray power — about 100 times what your briefcase gets at airport security.

It works, but the cost is high in relation to results, and the Tacoma facility is being shut down this month.


Another system, using lower voltage and a backscatter technology that bounces X-ray signals off objects, is being tested on tanker trucks and trailers at Otay Mesa, California, near San Diego.

Meanwhile, the Defense Department’s Advanced Research Projects Agency (ARPA) has awarded several contracts for development of a variety of other systems to X-ray containers and smaller shipments.

It will be years before X-rays of containers become common, but officials at Customs and the Defense Department see promise in the use of X-rays for cargo inspection. 

Separately from the U.S. government-sponsored efforts to develop systems for X-raying containers, private companies have been developing systems for use elsewhere.

The technology used at Tacoma also has been used at two border crossings in Shenzhen, China; the Port of Le Havre and De Gaulle airport in France; and at both ends of the English Channel Tunnel for screening trucks.

Another system, with Heimann Systems of Wiesbaden, Germany, as systems integrator and Siemens Medical Systems of Concord, California, providing the X-ray accelerator, is scheduled to open next spring at the Port of Hamburg.

Siemens officials also report interest in the Mideast and in Southeast Asia, where there is interest not only by government authorities but by commercial interests wanting to ensure that containers are loaded with what they’re supposed to contain.

As always, the speed at which the technology spreads will be a function of how widely the systems can be used and how much they cost. “At the right price, there is a market for this,” especially if it can be designed for commercial use as well as law enforcement, said Raymond Mintz, director of Customs’ office of enforcement support.


Bigger job

Customs operates about 150 X-ray systems for various types of examination pallets and smaller shipments. But X-raying a 40-foot steel container requires a bigger, more powerful system.

The Defense Department got involved in research on a container X-ray system a few years ago when Congress decided the military had the money and expertise to help wage the war on drugs.

ARPA, the Defense Department’s central research and development agency, enlisted contractors to develop X-ray systems capable of examining an entire container.

That system has been tested at Tacoma since earlier this year.

The Tacoma system was developed jointly by several companies. Analytical Systems Engineering Corp. of Burlington, Massachusetts, is systems integrator and site operator. Siemens supplied the linear accelerator, an industrial product based on hospital medical systems; Heimann Systems supplied the detector arrays and image-processing analyst workstations; and Automated Handling Systems of San Francisco provided the data processing and archiving systems.

Tacoma test

The Tacoma system is housed in a shielded chamber through which cassis-mounted containers are rolled slowly. A 40-foot container can be scanned in less than a minute. The boxes are simultaneously X-rayed from the side and from the floor.

The X-ray images are converted to digital gray-scale values that are displayed on large, high-resolution monitors similar to those used in hospitals for diagnostic imaging. Analysts then can use image processing tools to determine what’s in the container.

The images are near photographic quality. “Very, very, very clear,” Mintz said. “With that kind of energy, it’s blowing through the steel walls as if they didn’t exist.”

In simulated shipments, the X-rays have spotted small items such as a 2-pound bag of sugar or a handgun concealed among the contents of a 40-foot container.

Indeed, one question Customs is asking is whether the X-rays provide so much detail that they inhibit rather than aid the identification of contraband. “There’s a trade-off of information and time and the likelihood of a right decision,” Mintz said.

On the simulated shipments, the system recorded a 92% accuracy rate in identifying the presence or absence of contraband in containers and vehicles, according to tests developed by Analytical Systems Engineering. Customs, which uses a different measurement formula, calculates a 72% accuracy rate — lower but still a good percentage, Mintz said.

Cargo, humans

Although X-ray technology requires precautions to protect humans from excess doses of radiation, it does not damage the cargo, Customs officials say.

The Tacoma system hasn’t been used for foodstuffs, medicines or the like because the Food and Drug Administration hasn’t gotten around to approving it. However, Mintz said, “We’ve had a lot of people tell us there is no residual radiation.”

Humans are kept out of the X-ray chamber while the container and chassis are rolled through. “We’d prefer not to have a person go through it, but it wouldn’t kill them as long as they kept moving,” Mintz said.

During preliminary tests last spring, before the system was used on commercial cargo, simulated shipments of more than 40 different commodities, ranging from frozen chicken and green coffee to bales of recycled cardboard, were X-rayed after being stowed in containers by Customs staffers.

The Defense Department has leased the Tacoma system from the suppliers and is paying the $2-million-a-month operating costs.

But although the tests have worked well, it probably will end when the current funding expires in December. The Tacoma site is scheduled for demolition in February.

Customs said that despite the system’s effectiveness, it doesn’t appear to provide enough bang for the buck to justify Customs picking up the operating costs.

One reason is that Tacoma isn’t a hot spot for smuggling of drugs and other contraband — none was found in the approximately 60 commercial loads that were examined in the first two months of tests on commercial cargo. Another is that the system, which includes a 220-foot-long X-ray building in an eight-acre complex that’s separate from the regular Customs inspection station at Tacoma, can’t be moved.

Customs hopes ARPA’s current contracts will yield new designs that are cheaper, smaller and more mobile.

Dive into American Shipper’s archives:

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