Above: On July 6, 2013, tank cars carrying crude oil derailed in Lac-Mégantic, Quebec. New tank car designs are intended to strengthen tank cars in the event of derailments.
Tank car companies are beefing up DOT-111 fleets to safely transport oil as the U.S. and Canada try to nail down standards
December 2014 - Around 1 a.m. on July 6, 2013, 72 crude oil tanker cars derailed in Lac-Mégantic, Quebec, igniting its downtown into an inferno that claimed the lives of 47 people. According to a National Post article, crude oil flooded the downtown area and billowing flames charred buildings, ultimately forcing 2,000 residents, about one-third of the town’s population, to relocate. The Lac-Mégantic derailment is by no means the only accident to occur involving rail, but is a stark reminder that thousands of tank cars loaded with hazardous liquids traverse the country at all hours, sometimes adjacent to our own backyards.
Derailments have various causes, but it’s disingenuous to think they can be entirely eliminated with improvements to rail cars, tracks and railroad operator training. To reduce the risk of hazardous materials, particularly crude oil, the rail industries in the U.S. and Canada are aggressively revamping tank car standards to make them stronger and safer in the dire event of a derailment.
These new standards affect production of new tank cars, known in the rail industry at DOT-111 cars, as well as the modification of the approximately 100,000 existing tank cars specified to carry hazardous materials like crude oil and ethanol, according to the Association of American Railroads (AAR). The AAR estimates there are 335,000 total tank cars in the active fleet (pressurized and nonpressurized), but it’s the approximately one-third toting flammables discussed here.
The debate over tank car designs began in 2011 when AAR established the CPC-1232 tank car standard, a newer design. In the wake of accidents like the one in Lac-Mégantic, calls have become louder to phase out the DOT-111 cars, or modify them for safety. (There are proposals to add thermal protection and sturdier valves to CPC-1232 cars, but this article focuses on their older cousins, the DOT-111s.)
DOT-111 vessels are built to last roughly 50 years, making them a legacy investment for companies expecting them to perform that long. However, petroleum corrodes the carbon steel tanks over time, making them susceptible to breaches if they derail. Because there are so many in service of various ages, it would be faster and make more sense to retrofit them—in effect, giving them thicker skin. In the U.S., federal tank car regulations are set by the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA). Canada’s equivalent is Transport Canada.
Modifying the tank cars entails adding a sheath of steel around the tanks, thick steel head shields to the front and rear caps and replacing the top and bottom valves with tougher designs to prevent their breaking off during derailment. These modifications take place in repair facilities certified to work on DOT-111 cars, and require crews to roll form steel sheet, weld it, and finish it for corrosion protection.
Metal jacket
The DOT-111 tank cars are the same ones we’ve all seen at a crossing but give little thought to. They’re cylindrical tanks with top and bottom valves, often painted black and bearing the number 1267 on a red placard—the DOT identifier for flammable crude oil.
The U.S. DOT laid out three proposed standards for how to build new tank cars, which tank car companies were invited to comment on earlier this year, according to Tom Simpson, president of the Railway Supply Institute (RSI) in Washington, D.C. Two of the proposals call for a 9⁄16-in.-thick tank shell. The third option involves making cars with a 7⁄16-in.-thick shell. All three designs would include jackets, which is the tank’s exterior, and heat protection. Thermal protection systems would likely consist of a steel or ceramic blanket installed between the tank and the jacket.
“We’re in the middle of the rule-making process,” Simpson says. “But our ultimate goal is to remove the risk of moving flammable liquids by railroad tank car by modifying the current tank car fleet.”
The proposed standard referred to as Option 2 is garnering support among tank car manufacturers. The Greenbrier Companies, Lake Oswego, Oregon, has been its most vocal supporter, calling it the “Tank Car of the Future.” Greenbrier manufactures, repairs, maintains and leases rail cars. Immediately following the Lac-Mégantic derailment, Greenbrier dispatched its chief engineer, Greg Sexton, to the wreckage because some of its cars were involved. After the tragedy, Greenbrier was the first company to announce new, safer tank car designs based on Option 2. Several other tank car builders declined to comment for this article, but based on conversations with RSI, most tank car companies support some form of Option 2.
In July, Greenbrier established GBW Railcar Services, a joint venture between its own repair business and Watco Companies, a Kansas-based transportation mechanical services company. GBW’s tank car repair network comprises 14 shops certified by the AAR, a designation required by federal regulations. Right now, GBW is modifying tank cars at four plants: Fitzgerald, Georgia; Marshall, Texas; Hockley, Texas; and Cleburne, Texas.
“We can do retrofits at a fifth and sixth facility, and my guess is we probably will as we see these standards firm up,” says Jim Cowan, senior vice president of operations at Greenbrier and head of the GBW joint venture.
Retrofit and repair
To retrofit legacy DOT-111 tank cars, rail industry participants are mostly on the same page despite the final rule, and some are moving forward with modifications: The cars need outer steel jackets, thermal protection, full-height head shields and high-flow pressure relief valves. At GBW, each car is first cleaned, inside and out. Often they’re adorned with graffiti ranging from crude to downright impressive. Next, the lining and safety appliances are removed. Depending on the condition of the attachments or the tank car owner’s preferences, new or modified valves are added, followed by ceramic insulation and steel jacketing.
The jacketing uses 11 gauge steel in roll-formed sections, according to Cowan. Each section is installed individually, then welded together. Once the jackets are fitted, 11 gauge end caps are welded on. Next, full-height head shields—made from 1⁄2-in.-thick steel based on Option 2—protect each end of the tank car from punctures.
Ruptures usually occur along the bottom half of a tank car, which endures higher stress because of its proximity to the wheels and because it bears the weight of the rest of the tank and its contents, up to 30,000 gallons.
Industrywide, says Cowan, “the head shields were just slightly more than half the height of the tank. That’s been modified to be a full head shield on both ends. If you do have a derailment, you generally end up with the ends punctured first due to inertia,” he explains.
Safety appliances and pressure relief valves are reinstalled followed by stress-relieving heat-treatment. Some of the cars get new coatings to protect the commodity (oil, ethanol). Lastly, they are painted and connected to the wheels and couplers. For GBW, retrofitting one tank car takes about eight days with one shift of workers, but GBW will likely ramp up to two shifts as retrofit orders increase. Painting takes another four days. About 30 workers will modify each car.
By spring 2015, says Cowan, “we’re going to be ready to run at over 2,000 units per year at these four locations. That’s assuming the Option 2 calls for full-jacketed insulated, full-height head shields, rollover protection and modified bottom outlets. That’s the full plan. The good problem for us is that we’re busy today and it’s requiring us to do quite a bit of hiring.”
GBW expects to hire, train, and certify 400 new employees over the next year in response to demand for both retrofitting and new car production. In Coffeyville, Kansas, GBW crews have just begun to requalify cars—a process tankers need to undergo every 10 years to remain on the rails. Supervisor Jeremy Veley says the facility can manage work on six cars at once. The corrosion on the cars, he says, is the biggest problem.
“We get them ready for lineablity and make general repairs outside the tank, including side and inside seals,” he says. Depending on what part of the car they’re repairing, crews will flux-cored arc weld or MIG weld inserts (or patches) of steel sheet if parts of the tank are severely corroded. Using nondestructive testing, the crew can determine if high-stress points need attention. It’s hot, tough work. “We go through a lot of boots,” Veley says.
The RSI estimates that there are 109,500 tank cars in flammable liquid service and that 56,500 tank cars will need to be retrofitted or phased out in the next three years, or about 18,800 per year. If all of those cars are retrofitted, the four GBW shops slated for tank car retrofit work will be able to handle about 11 percent of that fleet starting in August 2015.
Material matters
BP announced in mid-October that it will no longer allow DOT-111 tank cars into its refinery at Cherry Point in Washington, the largest oil refinery in the state. A Bellingham Herald (Washington) article indicated BP is permitting only CPC-1232 cars, which transport crude oil from the Bakken shale formation in North Dakota.
The retrofitting under way for thousands of DOT-111 tank cars, not to mention building the “Tank of the Future,” could be expected to create demand for welders and other skilled tradespeople, as well for fabricating equipment. But some observers question whether using carbon steel for new cars is the best solution to protect the cargo and people and property in the path of that cargo.
Ken Grantham, executive vice president of Crompion International, a Baton Rouge, Louisiana-based manufacturer and distributor of high-performance stainless steel products, suggests the tank car industry should be incorporating stainless for new tanks because it resists corrosion, requires little maintenance and is structurally stronger than carbon steel. The freight car industry has long used stainless steel for new cars for the aforementioned reasons. Deep-seated bureaucracy within the rail industry’s regulatory institutions and resistance to change among established tank car manufacturers have proved to be hurdles for competing materials.
“The tank car industry is its own beast,” Grantham says. “We’re promoting another way of thinking: To look at stainless to combat corrosion with a resistant material and not a coated carbon steel. It would keep cars lighter by using an advanced metal, and hence they could carry more payload with less tare weight.”
None of the tank car builders mentioned alternate materials for this story, so it may be unlikely they would switch in the short run based on the amount of discussions and proposals set forth. At any rate, railroads and railcar leasing companies want to prevent thousands of legacy cars from being phased out even though removing them from service altogether might be prudent. The hundreds of people seeking jobs welding new jackets and coating older cars will be glad for the retrofitting option that meets the new U.S. and Canadian standards for moving hazardous fuels by tank car. FFJ
