Down where the city of Boston meets the Atlantic Ocean, where a salty wind swirls amid 30-foot-tall stacks of giant cargo containers, two customs inspectors are doing something few of their colleagues nationwide are able to do: They're scanning roughly 70 percent of the containers that pass through the mid-sized port.
In the cramped control room of a massive mobile X-ray machine, Larry Campbell and Joe Crowley electronically peer into steel boxes, hunting for terrorist weapons among the frozen fish, shoes, shirts, and other cargo.
Every year, 16 million containers move through America's 361 ports. Only 4 percent get scanned - leaving what may be the biggest hole in the nation's terror shield. In a sense, Boston's 70-percent scan rate makes it one of the most secure US ports. It also highlights a fundamental question now circling among port officials, political leaders, and the shipping industry: Would scanning more containers - even up to 100 percent - boost security?
The answer has big implications for the US homeland security effort, global trade, and even retail prices, as scans can add time and money to the shipping process. Yet, even as the debate grows, security experts warn that scanning is only one component of effective seaport security.
"As part of a layered approach, scanners make sense, but the idea that we will scan every container and therefore be confident that everything is hunky-dory - that's pretty much removed from reality," says Stephen Flynn, a former Coast Guard officer who's now a senior fellow at the Council on Foreign Relations in New York. He and others say security requires improvements in intelligence, cooperation with foreign ports, and tracking of containers.
Inside Boston's $2.25 million machine, Messrs. Campbell and Crowley inspect black-and-white images generated as their truck with its X-ray boom slowly rolls past containers. Campbell's three decades of experience are evident when, after just glancing at an image, he declares, "That's frozen fish."
Campbell and Crowley have spent the past 30 years doing mostly low-tech searches - crawling inside containers, randomly poking at contents. So scanning an entire container in just seconds astounds them. "I could retire any day I want," says Campbell, "but I'm staying put because this technology is so amazing."
This X-ray machine is at once revolutionary and insufficient. Increasingly being used at US ports, it was designed to find stolen cars and big drug caches, not briefcase-sized dirty bombs.
Soon, however, the Boston truck will get a radiation sensor.
Yet such sensors are notoriously fickle. The port in Norfolk, Va., tried mounting them on portport cranes - with the intent to scan every incoming container. But harsh operating conditions and ever-changing levels of background radiation rendered the devices virtually useless.
One increasingly popular tool is the $120,000 "portal system" - two radiation-detecting panels that containers pass between.
With various technologies proliferating - and with ports seen as one of the weakest security links - the idea of boosting the number of scans is gaining political momentum. A plan by Rep. Jerrold Nadler (D) of New York would require 100 percent scanning. "It's very ambitious, but it's necessary," says Eric Schmeltzer, a Nadler spokesman. "Even if you upped it to 50 percent, there's still a 50 percent chance a boat has a bomb on it."
But others see a more complicated picture. A major upgrade in scanning would detain legions of containers at ports, making them more vulnerable to sabotage or tampering. It would also require thousands of new government inspectors and billions of dollars in salary and equipment costs.
Ultimately, says Dr. Flynn, a more layered approach may be more effective - and cheaper.
For example, the customs bureau's new Container Security Initiative, under which lists of container contents are forwarded to US authorities 24 hours before a shipment leaves a foreign port, gives officials time to assess the risk. They can analyze the contents, the history of the container, and the boat it's traveling on. High-risk cargo is then marked for special scrutiny.
Another key element is securing containers. Most "seals" are now quarter-inch-thick pieces of plastic and metal, and safer seals are being developed.
There's also a growing effort to track shipments with global positioning devices. If a container is diverted - perhaps by terrorists - it would be flagged for inspection.
The global shipping industry can indeed benefit from boosting "supply-chain visibility," Flynn argues. By spending $100 to $150 per container, shippers can get real-time information about the location and security of cargo.
Yet, until big systemic changes actually occur, even skeptics of ramping up scanning admit it may be a necessary option.