Making Hazmat Transport Safer

In a typical year, about 1.8 million carloads of hazardous materials, consisting of hundreds of different commodities, are transported by rail throughout the U.S. Nearly all of those shipments reach their destinations without incident. When railroad accidents have resulted in the release of dangerous chemicals, however, the consequences have been deadly. Department of Transportation (DOT) statistics show that since 1973, 47 people have died in the U.S. as the result of tank cars either failing or derailing.

"The importance of efforts to improve the safety of tank car transportation cannot be overstated," says Robert E. Fronczak, assistant vice president for environment and hazardous materials at the Association of American Railroads (AAR), the Washington, D.C.-based trade group that represents the major North American freight rail operators.

In the past four years, he notes, there have been three fatal train crashes involving chlorine and anhydrous ammonia, the two most common chemicals that are shipped by rail and can be lethal if inhaled.

The derailment of a Canadian Pacific Railway train near Minot, N.D., on Jan. 18, 2002, resulted in the failure of five tank cars, each holding almost 30,000 gal of anhydrous ammonia. One resident of Minot died, and more than 300 others were injured.

On June 28, 2004, a westbound Union Pacific Railroad train struck an eastbound Burlington Northern Santa Fe Railway train as the BNSF train entered a siding near Macdona, Texas. As a result of the collision, a tank car loaded with chlorine was punctured. The conductor from the Union Pacific train and two nearby residents died after inhaling chlorine gas.

Most recently, on Jan. 6, 2005, a Norfolk Southern Railway train traveling through Graniteville, S.C., encountered an improperly aligned switch that diverted the train from the main track onto a siding, where it struck a parked train head-on. A single chlorine tank car was breached, releasing a cloud of gas across the surrounding hills and valleys. Nine people died, and more than 500 others were taken to local hospitals.

Although such catastrophic accidents are extremely rare, the string of deadly crashes has prompted railroad officials to ask Congress to either provide the industry with liability limits or eliminate its government mandate to carry highly hazardous chemicals. At the same time, in an effort to reduce the probability of a release of toxic materials should an accident occur, railroads have launched a highly controversial initiative to impose a new design standard for tank cars carrying chlorine and anhydrous ammonia.

Chemical shippers and federal regulators agree that safer tank cars are needed, but they say a new design standard should be based on research being conducted by a DOT laboratory. They also believe that the enhancements should extend beyond cars carrying only chlorine and ammonia and that changes are needed in how freight railroads operate.

Above all, what is required, the shippers maintain, is a return to the stewardship process that has yielded so many significant improvements in the rail transportation of hazardous materials over the past century. "Chemical transportation safety requires cooperation between shippers, transportation service providers, and public and private partners who have the responsibility for public safety," says Henry Ward, director of transportation safety and security at Dow Chemical.

Railroads cannot refuse to haul hazardous chemicals because they are defined as "common carriers" by the Interstate Commerce Act. That designation requires them to provide service for any paying customer, whether or not they want the business. "Norfolk Southern does not make enough money transporting these highly hazardous materials to justify the risks the federal government requires us to take," Charles W. Moorman, the company's president and chief executive officer, told the House Transportation & Infrastructure Committee's Rail Subcommittee at a hearing this summer.

"Nevertheless, Norfolk Southern assumes an enormous risk every time we comply with this federal statutory requirement by transporting a carload of highly hazardous material," he testified. Railroads purchase insurance to mitigate the financial risk of carrying hazardous materials, but according to Moorman, this coverage is both expensive and limited in availability. Norfolk Southern recorded a pretax charge of $41 million last year to pay for expenses associated with the Graniteville wreck that were not covered by insurance.

According to the railroad association, highly hazardous commodities constitute only 0.3% of all rail carloads but account for half of the railroads' total insurance cost. "Every time a railroad moves one of these shipments, it faces potentially ruinous liability," AAR President Edward R. Hamberger declared at the House hearing. "Railroads should be permitted to decide for themselves whether to accept, and at what price they are willing to accept, such materials for transportation."

Chemical industry officials believe the existing system appropriately places legal liability on the party that is responsible for an incident. Manufacturers generally own or lease the tank cars in which the railroads transport their products.

Thomas E. Schick, the American Chemistry Council's (ACC) senior director for distribution, says railroads, as well as shippers and other entities, should continue to bear liability for their own actions. "We think the system that's currently in place, where liability is on the party that has responsibility for the operations when an incident occurs, is a pretty sound system," Schick remarks.

Similarly sound, he says, is the common carrier obligation under which railroads are required to ship commodities for their customers, which is the framework on which the entire national rail transportation system was founded. "The railroads are here to carry the traffic of the industries that depend on rail transportation, whether it's hazardous or not," Schick says. "Chemicals are essential for the life of the nation, including some materials that are hazardous. The goal of the hazardous material transportation system is to ensure these products are delivered safely and reliably, not to prevent their movement."

Hoping to ease their financial risk, railroad officials say the design and performance of tank cars that carry highly hazardous chemicals need to improve. After the accidents at Minot, Macdona, and Graniteville, the chief operating officers of AAR members directed a committee of experts organized by the association to create a tank car design that would reduce by 65% the potential for a chemical release in the event of an accident.

The committee, a group of technical experts from railroads, shippers, and tank car builders that works closely with DOT, has been evaluating new requirements for chlorine and anhydrous ammonia tank cars that would lessen the probability of a rupture. The effort relies heavily on a risk analysis prepared by University of Illinois researchers indicating that strengthening tank cars could substantially reduce the likelihood of a spill in a railroad accident.

Last month, the committee finalized new standards, effective Jan. 1 for new chlorine and anhydrous ammonia tank cars, that call for thicker steel shells, more durable fittings for connecting hoses used during loading and unloading, and extra padding for valves and car ends. Existing fleets would have to be retrofitted over the next 11 years.

An empty standard tank car now in use typically weighs about 83,000 lb, and the modified car would weigh an estimated 93,400 lb. The heavier cars would cost about $130,000 each, compared with $100,000 for the current model. The investment by industry would be substantial; about 12,000 of the roughly 270,000 tank cars now in service are used to haul anhydrous ammonia and chlorine.

Paul G. Kinnecom, AAR's executive director of tank car safety, says the new design requirements can be implemented quickly by the railroad association because it has the authority to set standards for equipment interchanged between railroads. The redesign effort does not require review or approval by DOT's Federal Railroad Administration (FRA), he asserts, because the tank car committee did not propose any changes to DOT tank car specifications. "The committee has only adopted changes to AAR's interchange standards for tank cars," Kinnecom says. "Therefore, the specifications at issue would be binding only through AAR's interchange rules. The parties to the interchange rules are bound as a matter of contract law."

Chemical shippers, however, believe the changes in tank car design advocated by the railroads are a rush to judgment. "Basically, we agree with AAR on the need for safe transportation of ammonia. Where we disagree with them is on how to achieve that," says Kathy Mathers, vice president of public affairs for the Fertilizer Institute. The organization's member companies transport more than 50,000 rail cars of anhydrous ammonia annually and own or lease approximately 6,000 tank cars.

Mathers says the "heavier is better" approach to tank car safety overlooks some potential problems, including the likely increase in truck shipments because of track restrictions that would prevent many facilities from receiving the heavier cars. "From just a pure logistics standpoint, the heavier tank car isn't going to work well on some of the short-line tracks, which a lot of the retail facilities we deliver ammonia to are on," she says. "That particular car is just too heavy for those tracks." Railroads and cargo trucks carry roughly equal hazmat tonnage, but DOT statistics show that trucks have 16 times more hazmat releases than freight trains.

Mathers also says "the jury is still out" on whether the thicker cars endorsed by AAR would be significantly safer than the cars currently in service. She notes that a congressionally mandated study under way at DOT's Volpe National Transportation System Center in Pueblo, Colo., is developing a model to quantify the relevant dynamic forces acting on rail tank cars under accident conditions.

Once that research is complete, FRA plans to implement new design standards for these cars. "We continue to believe that any action on tank cars ought to take the findings of the Volpe study into consideration," Mathers says.

The results of that research, which are expected to be released next year, "will give you the inputs you need to design a better rail tank car," adds Frank Reiner, vice president of transportation and emergency preparedness at the Chlorine Institute.

Reiner, who has been involved with AAR's tank car committee for more than 15 years, says the dispute over the redesign is unusual. "The committee has been very effective over a long period of time. Its roots trace back to the first part of the 20th century," he notes. Because of its expertise, the committee has been given the authority by FRA to review tank car designs and make recommendations on specifications. In the past, committee members have worked well together, and the consensus process has led to dramatic improvements in tank car safety.

But at a meeting in July, the consensus process broke down, and committee members had to vote on AAR's proposal to toughen design requirements for tank cars carrying chlorine and anhydrous ammonia within an accelerated time frame and without provision for DOT review. Over the objections of shippers and all but one tank car builder, the railroad-dominated panel voted 13-8 to pass the new requirements, which were finalized and formally adopted at an Oct. 12 conference in Kansas City, Mo.

"I can't think of an issue where there's been a schism before," Reiner says. "Typically, what happens is that task forces are set up, and there is a process to review things from a technical standpoint. That didn't happen this time." The railroads, he adds, "saw a way to quickly reduce their liability. It was an easily available solution in their minds." Although FRA has historically given the railroad industry wide latitude to set and implement changes to tank car standards, Reiner points out that carriers, shippers, tank car builders, and government officials have usually worked together in a cooperative manner. "Clearly, this is a deviation from the consensus process," he says.

An FRA official insists that final policy judgments lie with the agency. "Federal law requires that proposed changes to existing DOT tank car specifications, as well as new specifications or design standards for tank cars used to transport hazardous materials, need to be approved by DOT before such cars can be manufactured and put in service," FRA spokeswoman DeDe Cordell tells C&EN. She says FRA intends to complete a rulemaking by the end of 2007 that will establish "enhancements to DOT specifications for tank cars." In developing the rule, Cordell says, FRA will consider "the proposed standards developed by AAR's tank car committee, as well as proposals from other parties."

In any event, Reiner says, it isn't clear whether a rail tank car can be built that can survive the worst collisions. "In general, if you go to thicker material, you're going to reduce the likelihood of puncture. But you also have to look at the incidents that have occurred and the forces and energy in those instances. Can you design something that would have prevented a puncture at Graniteville? We're not certain. We have ongoing research. We're working with Dow on the technical end of it."

Reiner says a better approach to designing a safer, more secure tank car is a collaboration announced in August 2006 among Dow Chemical, Union Pacific???the nation's largest railroad???and Union Tank Car, a tank car manufacturer. The project began early last year, when Dow reviewed its transportation activities. Recognizing that action was needed to manage and reduce the risks of transporting highly hazardous chemicals, the company decided to take a number of steps, including the development of a new type of rail tank car.

"This is a multigenerational project, with generation one focused on toxic inhalation hazards (TIHs) like chlorine," Dow's Ward says. The initial objective, he explains, is to design a next-generation rail tank car for transporting highly hazardous chemicals that is five to 10 times better than existing cars in safety and security performance and to put those enhanced cars on the tracks by 2014. Subsequent generations of the project will address shipments of flammable gases, such as ethylene oxide, and then a group of environmentally sensitive chemicals that includes chlorinated hydrocarbons.

"We have a plan to work through those different classes and take these new designs and apply them to our fleets by 2029," Ward says. "Our project is broader than AAR's in that it addresses in generation one all TIHs, not just chlorine and anhydrous ammonia. And when you look at generations two and three, where we address flammable gases and environmentally sensitive chemicals, it's even broader yet."

In addition, Ward says Dow is "looking at innovative, nontraditional technologies that have not really been considered and used in the rail industry previously. We believe that by doing this, we can develop solutions that will achieve our objectives in terms of performance and do it at a competitive cost and at lower tank car weight." Ward says the path followed by AAR's tank car committee is the traditional approach. "Let's add more steel to the car, make it thicker, heavier, and better able to resist things. But there's only so much additional improvement that you can achieve with that approach, so people have been reluctant to go in that direction," he observes.

The Dow executive says there is "tremendous support for our project," because the new design standard approved by AAR's tank car committee "is only an incremental improvement over our current rail car. If we're going to replace the entire fleet, then one would like to think we're making a significant change that's going to result in significant improvement moving forward," Ward remarks. "So people look at our project as the opportunity to make a significant step-change improvement in performance and really make that a sound business investment in terms of replacing cars."

Ward says a dozen task teams have been set up to focus on specific technologies that would be components of the new rail car design. Project members are consulting with experts in the aerospace, automotive, and maritime industries, as well as the military. "Our approach is to look at layers of functionality in the design of our car. There is no silver bullet here, no single solution like a better type of steel," Ward says. "It's a combination of steels and other materials that, put together, will give us the overall performance that we're looking for."

Another difference with AAR's approach, he says, is that Dow plans to build security features into the design of its new tank car "that would give us added protection from things like a ballistics attack or an improvised explosive device on the side of the rail." An explosive-resistant coating that has been used to enhance the armor protection of military vehicles in Iraq is among the technologies being evaluated for potential use.

Another concern that Dow wants to address is the possibility of people tampering with a shipment while it is in transit. "Some of the work that we're doing will provide improved protection for valves and fittings and make it more difficult for people to gain access to or release the materials that are in the car," Ward says. The company is already adding location- and condition-monitoring devices to its tankers.

"We will put global-positioning systems and condition sensors on all of our TIH cars over the course of the next two years," the Dow executive says. "But with this new rail car design, instead of having these as add-on devices, we can actually build them into the design of the car, which will reduce the ability of someone to access those things and take them out of service," Ward explains. "It will enable us to know exactly where a car is at any point in time, the condition of the materials in the car, and whether someone has attempted to gain access to the car."

Chemical industry officials stress that none of the deadly railroad accidents that have occurred since 2002 were caused by tank failure or weakness. The National Transportation Safety Board has concluded that human errors were to blame in the South Carolina and Texas crashes, and the North Dakota derailment was linked to track defects. Reiner says there have been at least 1.5 million rail shipments of chlorine since record-keeping began in 1965, and only 11 tanks have been breached. "It's a pretty tremendous safety record but one that obviously has to be improved when you look at these recent incidents," he remarks. "That's why we support efforts, and are part of efforts, to come up with a better package. You can't look at the package as the total system, though. It's only one part." He says similar intense efforts are needed to prevent accidents. "But if they do occur, we want to come up with a tank car that will survive that more readily. We understand our responsibility and accept it," he says.

ACC's Schick adds that any review of hazmat transportation safety requires a holistic approach that examines the full range of factors involved, including car design, track maintenance, rail operations, and safety management practices. Citing FRA data, he notes that rail accidents and safety enhancements have reached a plateau after an earlier period of continual improvement. "We must all work together to do a better job," Schick says.