Sniff, Watch, Guide

You take a seat on the subway and prepare for a crowded trip into the city. You dig through the day’s headlines and fiddle with your iPod. A seemingly normal commute.

But what you don’t know is that, in the tunnel and terminal, a system of detection technologies may be quietly helping to protect you from dangerous chemicals … lethal chemicals that could be unleashed intentionally by terrorists. It’s a system developed by the DHS S&T Directorate, and it’s sniffing for danger in more and more transit systems across the Nation.

The chemical threat to subways became very real on March 20, 1995. On that day, members of a religious cult released poisonous gas in the Tokyo subway system, killing 12 people and injuring as many as 5,000. There were no detectors or security cameras. There was no formal emergency plan. More than an hour passed before authorities arrived, and two more hours went by before the gas was identified as the chemical warfare agent sarin.

Learning from that day, U.S. researchers set out to arm subways with detectors, cameras, communications, and training, designed together as a system. As a result, subway riders in a growing number of U.S. cities can now breathe a little easier because of the Program of Response Options and Technology Enhancements for Chemical Terrorism (PROTECT). Initiated in 1998 by the U.S. Department of Energy, PROTECT has been transitioned by the Directorate to DHS’s Transit Security Grants Program.

PROTECT helps rapidly identify a chemical release, alerts authorities, and guides their response.

Here’s how it works (photo): When a chemical is released , it is detected by a sensor . In the station’s operations control center, a warning sounds, calling attention to a live image from the sensor’s closed-circuit television camera. The control center operator pans, zooms, and tilts the camera while watching the video . If all appears normal—people are walking, standing, reading—the detector probably got a whiff of floor cleaner. But if people are vomiting, gasping, or rubbing their eyes, a chemical attack is under way .

If that’s the case, the operator summons responders, bad air is vented, and trains halt so the chemical won’t find new victims in the next train or the next station. Out on the street , the incident commander receives vital data while responders “plug in” to monitor events using the Chemical/Biological Emergency Management Information System (CB-EMIS). This system shows where the trains are, the chemical plume’s concentration, where the plume is drifting, and how fast. CB-EMIS can point the way into danger … and back out.

PROTECT was piloted in 2001 in select stations of the Washington, DC, Metro. In a simulation exploring the system’s benefits, responders were on the scene within five minutes. Impressed, Washington set up PROTECT for more stations. Soon, PROTECT was deployed in Boston and New York. Today, other cities are considering installation of the system.

“The program works. It guides my people in plain English,” says Ron Masciano, Deputy Director of Security at New York’s Metropolitan Transportation Authority (MTA), where in 2004 a detector and its pivoting camera spotted a man spraying a wide area of Grand Central Terminal with a wand jutting from a black box. Within seconds, security mobilized. “As he walked out to Lexington Avenue,” says Masciano, “boy, was he surprised.” The sprayer turned out to be an exterminator, but MTA’s response became a textbook training scenario.

For more information about this story, click here

Booming Research

Results from coated (top) and uncoated ammonium nitrate–packed drums. Most of the blast in the top photo is from the C4 plastic explosive used to initiate the blast.

Down in the green rolling hills and farmlands around Lexington, Kentucky, Darrell Taulbee can often be found mixing up a fresh batch of homegrown fertilizer. But he’s not looking to grow an heirloom tomato or distill a smoother bourbon. He has his sights set on something sinister.

With funding from the S&T Directorate, Taulbee putters with the stuff to make sure that an Oklahoma City bombing never happens again.

It was common fertilizer—ammonium nitrate (AN)—that Timothy McVeigh used to build the ferocious bomb that ripped through the Murrah Federal Building in 1996, killing 168 men, women, and children. AN is used to create bumper crops, but when combined with hate and fuel oil, it becomes a lethal mix.

Taulbee is looking for ways to reduce AN’s destructive power. Right now, he’s eyeing coal combustion by-products—fly ash from electric power plants (where 120 million tons are produced yearly)—to make AN less deadly. He coats the fertilizer pellets with fly ash, packs them into metal canisters, and takes them deep into the Kentucky hills. There, he blows them up.

Taulbee is methodical. With the help of Tom Thurman, a retired FBI bomb-scene investigator now at Eastern Kentucky University, he has learned that a mix of 20% coal ash to 80% AN prevents such an explosion from burning all its fuel. This renders a blast far less violent.

“There are no commercially available options totally effective in preventing ammonium nitrate from being used as an explosive,” says Taulbee. “Coal ash won’t stop the blast from initiating, but it will stop it from propagating.” What’s more, he adds, the ash is classified as nontoxic by the Environmental Protection Agency and may have some beneficial effects for crops. It’s inexpensive and coats easily onto AN particles, forming a hard outer layer that is difficult to remove.

Future research will include confirmation of Taulbee’s results by the Bureau of Alcohol, Tobacco, Firearms, and Explosives, and the New Mexico Institute of Technology and/or the FBI. There will also be more extensive evaluations of the potential impacts on agriculture.

Mike Matthews oversees Taulbee’s research for the Directorate. “If Taulbee can eliminate much of the ‘McVeigh’ factor in ammonium nitrate,” says Matthews, “he’ll go a long way in helping to contain the threat of these homegrown fertilizer bombs.”

For more information about this story, click here

Shield Activated

Researchers are testing the strength of strands used in cable-stayed bridges (an example is in the right-hand photo) by seeing what kinds of explosives can blow them apart.

These days, a drive across a bridge is not always a pleasure cruise. Mindful of the war on terrorism, it can often be a cautious experience.

In one scenario, someone sets off a series of bombs to weaken the cables and the key structural connections of a major city bridge, all during rush hour. Not easy to do, but now thinkable. Earlier this month, the possibility of sabotage was quickly examined—then dismissed—when a bridge tragically collapsed in Minneapolis.

As authorities monitor and stand guard over bridges, the S&T Directorate is looking to scientists and engineers for the security technologies of tomorrow. What if, for instance, we could one day not only guard bridges but fortify them? Like Superman’s blue suit, what if the cables and connections on bridges could be shielded with protective sleeves or covers, making them nearly impossible for the villains to penetrate?

This is the goal of DHS’s bridge-strengthening research. Through a partnership with the U.S. Army Corps of Engineers’ Engineer Research and Development Center, the Directorate’s Infrastructure and Geophysical Division is testing current bridge designs and investigating advances in steel and reinforced concrete to explore whether such shields could work.

The first step is to determine which bridges and materials are most vulnerable, says Stanley Woodson, who oversees the project at the Center’s Geotech and Structures Lab. A major focus, he says, are the cables and the support columns—or towers—that are used in the cable-stayed design of bridges. Unlike the cables of a suspension bridge, which are attached from tower to tower, the cables in a cable-stayed bridge are connected directly to accessible points along the horizontal bridge deck.

In controlled experiments, Woodson’s team has been re-creating the forces holding up these bridges and blowing up samples of their cables, using various kinds of explosives. They then use sophisticated software to analyze the impact and results. “We tension the cables just like a real bridge,” he says. “We want to see just how they’d react in an actual terrorist event.”

The next step will be more complicated, says Woodson: Determining what material would suffice for another layer of protection, and what form it should take. “We’re looking at the practical as well as the innovative,” he says, recognizing the potential for high costs.

By the end of 2008, Woodson and his team will be imitating concrete bridge towers and subjecting them to the same explosive testing.

For more information about this story, click here

S&T Snapshots is a monthly newsletter produced by the DHS Science and Technology Directorate in partnership with the Homeland Security Institute. HSI is a Studies and Analysis Federally Funded Research and Development Center.