No practical technology exists to detect someone carrying
explosives onto a subway or a bus the way four men did in
London 12 days ago, federal authorities said yesterday.
The most effective method for finding explosives in a
backpack or on a person boarding a subway or bus remains the
use of dogs trained to sniff explosives, said officials from
the Bureau of Alcohol, Tobacco, Firearms and Explosives.
Bomb-sniffing dogs are used by a number of agencies, but
there are only about 100 ATF-trained "explosives-detection
canines" nationwide. Experts also said the bomb-sniffing
dogs are limited in their abilities by a range of factors,
including the strength of the explosive's odor and how far
away the dogs are from a person carrying a bomb.
Private companies, government agencies and scientists at
U.S. laboratories and defense research centers are working
to develop technologies that could possibly be used on
mass-transit systems that carry 14 million people to work
every day.
"If there was anything else out there now, we would be
screaming that everyone on Metro should walk through a
detector," ATF spokesman Richard Marianos said. "It just is
not there."
Washington has received, along with New York City, the most
federal money for its transit system -- more than $49
million since Sept. 11, 2001 -- for cameras, canine units
and other equipment designed to "harden" the system and
discourage a terrorist attack.
After the London bombings, transit officials in Washington
stepped up security using dogs, cameras and police toting
automatic weapons. But even its most sophisticated equipment
-- the PROTECT system of chemical sensors installed at half
of Metro's underground stations -- is not designed to
prevent an attack but rather to minimize casualties and
reduce the impact of a chemical release.
"How can you possibly sniff out everyone carrying
explosives?" asked Fred Goodine, Metro's assistant general
manager for system safety and risk protection. "The
technology isn't there, at least today. Not if you want it
to be an open system, which is what mass transit is."
After the terrorist bombings of commuter trains in Madrid
that killed nearly 200 people in 2004, officials at the
Department of Homeland Security began an experiment at a
Maryland train station to explore whether it was feasible to
screen rail passengers with bomb-detecting equipment.
During the 30-day, $1 million pilot project in May at the
New Carrollton Amtrak/MARC station, riders had to walk
through a high-tech "sniffer," developed by General Electric
Infrastructure Security, that checked them for bomb residue.
Passengers had to pause in a security portal for 12 seconds
while a sensor in the ceiling "sniffed" for traces of
explosives. The equipment shot eight puffs of air at the
passengers' upper thighs to help free any particles that may
have been clinging to clothing.
Transit officials said the system was too time-consuming and
trains were delayed. It has not been installed in any
mass-transit systems, where the high volume of riders and
trains spaced just minutes apart make the screenings too
difficult.
The bomb-sniffing device "doesn't practically fit into the
open infrastructure of mass transit," said Greg Hull,
director of safety and security programs at the American
Public Transportation Association, who worked on the New
Carrollton project.
The "puffer machines" are being used, however, at about 16
airports nationwide -- along with X-ray machines that scan
luggage and a trace-detection machine that uses a cotton
swab to test for residue, a spokesman for the Transportation
Security Administration said.
Police used portable trace-detection machines at two subway
stations in Boston during last summer's Democratic National
Convention. But officials said they worked only because
passengers were understanding about the security delay and
they would not be feasible during normal operations.
Although a CNN-Gallup poll showed that 69 percent of
Americans favor "requiring every American to go through a
metal detector when using public transportation, including
trains, buses or subways," Homeland Security Secretary
Michael Chertoff said authorities will never install metal
detectors in the nation's subways because the volume of
passengers is too great.
"Can you envision magnetometers on the New York subway?" he
asked during an interview at The Washington Post last week.
"If the subway doesn't work because of the security
measures, then we have lost the war, because then they have
driven us out of the subway."
Chertoff said some train stations now have devices that can
detect certain biological agents in the air, "but there is
no single system that exists that allows us to guarantee
people are not going to get on a train with explosives."
Joseph M. Riehl, the chief of the ATF arsons and explosives
programs division, said that about 100 dogs have been
trained at Front Royal, Va., to detect about 19,000 types of
explosives. An additional 400 dogs are being used across the
world, including one dog who is working to detect explosives
in Iraq.
Bomb-detecting dogs can "alert" on firearms, explosives and
ammunition hidden in containers and vehicles, on people and
buried underground, Riehl said.
"There is nothing we have identified at this point that
would work any better than the dogs," he said.
All Rights Reserved