Each day, more than 800,000 shipments of hazardous materials crisscross the United States via highways, railways and pipelines. Railcars transport only a fraction of these shipments, yet create a disproportionate amount of risk to both the chemical and rail industries — and to average citizens in general. By virtue of the amount of chemicals each car carries, railroad tankers are a slow-moving bull's-eye for potential saboteurs. STRATFOR has addressed the vulnerability of large stores of commercial chemicals — found throughout the United States — to a potential terrorist attack. Of particular concern is chlorine, because of its lethality and its widespread availability. U.S. Department of Transportation and Department of Homeland Security authorities have worked together with chemical and railroad industry officials to ensure that railyards are secure. Many, however, still harbor doubts about the security of the railcars that transport these chemicals. In his April 8 address at the National Fire and Emergency Services dinner, Secretary of Homeland Security Michael Chertoff announced the department's intention to continue marking dangerous chemical-bearing railcars with the current placard system. Since the Sept. 11 attacks, many have wondered whether these signs act more as an advertisement than a warning. But a recently concluded survey commissioned by Homeland Security's Transportation Security Administration found that the placard system — the diamond-shaped signs found on many railcars and trucks that identify various types of hazardous materials — is the best solution for addressing the situation. This is one of the many issues surrounding the security implications of transporting hazardous materials by rail. Although almost 95 percent of hazardous material (HazMat) shipments each year are sent via tanker trucks, railroads transport more than 40 percent of the total tonnage, meaning that at any given time more than 40 percent of chemical HazMat moved around the country is on a railcar. The final terminals receiving HazMat supposedly are secured and monitored by facility security, but the cargo's intermediate resting places — known as interchange stations — remain conspicuously vulnerable. A successful breach of just one 90-ton tanker car could result in a chemical gas cloud 41.5 miles long by 4 miles wide. A survey conducted by the U.S. Naval Research Laboratory estimates that in a major urban city, a successful attack against a railcar transporting chlorine would cause 100 deaths per second as the cloud grows throughout the city. Despite this kind of information, rail systems remain conspicuously vulnerable to attack. Note, for instance, the amount of graffiti on railcars — including adjacent to HazMat placards themselves. Each instance of this graffiti represents a security breach. Someone had to get to the car while it was stopped, spray it and then exit without being seen. Some of these tanker cars could be empty when they are painted — and thus not as closely watched — but each instance of vandalism represents a security breach. Such vandalism usually occurs in rail depots and at interchange stations, which act as transshipment, brief storage and refueling points for trains. The general Department of Transportation allowance for one train to remain in the same depot is 48 hours, unless it sits idle over a weekend or holiday. But the 48-hour standard was enacted in the early 1900s for economic — not security — reasons. In the past, oil companies used transshipment points as cheap storage places to keep their costs down. But these transshipment points become textbook choke points for a potential saboteur, since there is only a finite number of intermediate stations. If a potential saboteur knows the starting and terminal locations of a particular train, the intermediate station can easily be determined. A would-be saboteur would not even have to get close to the train itself to attack it. A source at the Bureau of Explosives said that though the steel construction and heat capacity of these cars has been improved — largely to prevent chemical spills in case of derailment — but that the cars remain vulnerable to attacks from rocket-propelled grenades and shoulder-fired anti-tank missiles. Although the consequences of such an attack would vary depending on the cargo, highly dangerous material frequently is moved by rail, often through major cities. Just one successful breach could be environmentally and economically devastating — and could threaten the lives of an untold number of people. Terrorists have recognized the vulnerabilities of rail systems and their potential for exploitation. Starting in 2003, the extortion group AZF planted several bombs on French railroad tracks, but did not detonate them. In the United States, two incidents in Arizona and South Carolina illustrate the vulnerability of rail lines to attack. In October 1996, Amtrak's Sunset Limited passenger train derailed after hitting a break in the track between Phoenix and Los Angeles. The train plunged down a 30-foot embankment, killing one crewmember and injuring 78 passengers. Suspecting foul play, authorities investigated the Viper militia group, but no tangible lead ever developed. In January, a train carrying chlorine collided with a parked train in a railyard in Graniteville, S.C. The tank cars ruptured, causing a relatively small cloud of chlorine gas to be released — which killed nine people and prompted mass evacuations. Unless drastic improvements occur in the security of HazMat transportation along the nation's railways, vulnerabilities will remain.