The National Transportation Safety Board (NTSB) has warned that public safety is at risk if a proposed rule to allow shipping liquefied natural gas (LNG) on U.S. railroads goes ahead without further study.
The comments were submitted last month ahead of a Monday (Jan. 13) deadline to weigh in on the Pipeline and Hazardous Materials Safety Administration’s (PHMSA) proposed rulemaking. Under the proposal, LNG could be transported in DOT-113 tank cars, or those capable of moving cryogenic liquids.
PHMSA has said the regulations are warranted given growing domestic natural gas supplies and increasing pipeline constraints. It has also justified the rulemaking by noting that public risk would be reduced on roads across the country, where LNG is moved by truck. In addition, PHMSA said moving LNG by rail would be no different than other flammable cryogenic liquids already authorized for bulk rail transport.
NTSB, however, found very few DOT-113 cars (405), commonly used for cryogenic ethylene service, are available. Even fewer (67) exist that meet the specifications PHMSA is considering for LNG transportation.
Because LNG has not been moved by rail in high volumes, PHMSA used the transport of liquefied petroleum gas and LNG by truck as proxies to examine safety risks. It also used engineering assumptions to find comparable data.
“We believe that relying on data for the accident history of similar hazardous materials transported in the small fleet of DOT-113 tank cars or making engineering assumptions based on the performance of pressure tank cars with completely different features and operating parameters, does not provide statistically significant or valid safety assessment and calls into question how PHMSA determined the specification DOT-113C120W tank car is an acceptable package to transport LNG,” NTSB wrote.
PHMSA expects LNG to move in small quantities initially on manifest trains, but that could eventually shift to the use of unit trains, or those composed entirely of LNG tank cars. NTSB also cautioned against finalizing the rulemaking without implementing any additional operational controls. The agency suggested that at a minimum, rail operators should be required to meet additional route planning, speed restrictions and braking rules.
“A gradual initial ramp-up of LNG rail transportation would likely occur because of the limited availability and high cost of DOT-113 tank cars,” NTSB said. “Nonetheless, we believe the risks of catastrophic LNG releases in accidents is too great not to have operational controls in place before large blocks of tank cars and unit trains proliferate.”
The agency noted that federal regulators were unprepared to “address the spate of flammable liquids accidents” involving ethanol and crude oil that occured between 2009 and 2015 until more stringent operational controls were imposed for high-hazard flammable liquid trains (HHFT).
Hazardous materials regulations don’t currently authorize transporting LNG by rail across the United States. Instead, a special permit must be obtained from PHMSA or approval must be granted by the Federal Railroad Administration (FRA) to move it in a portable tank.
The FRA has in the past granted special permits to Florida East Coast Railway to move the fuel by ISO, i.e. International Organization for Standardization, containers, which can be trucked to trains for transport. Federal regulators have also approved a pilot program to move LNG by rail in Alaska. Some International railroads already move LNG by rail.
The LNG by rail rulemaking has been underway since 2018 to develop a framework to transport gas across the country. Last year, President Trump issued an executive order to speed up the process. Fifteen states and the District of Columbia also objected to the proposed rulemaking, citing the potential safety risks.
Federal regulators recently approved a special permit allowing a New Fortress Energy LLC affiliate to carry LNG by rail from the shale fields of Northeast Pennsylvania to the shores of the Delaware River in New Jersey, where a logistics terminal is under development. Both states were among those that objected to moving the fuel by rail.
The permit indicated that Energy Transport Solutions LLC would start with single car shipments, progress to multi-car shipments and ultimately unit trains, with 20 or more cars. The unit trains can carry about 3 million gallons of LNG, or about the equivalent of what 300 trucks could carry.
The permit for New Fortress, which is focused on introducing LNG to stranded markets, was a milestone for what could be rapid growth in the small-scale LNG space as the industry searches for ways around pipeline constraints. Rail transport would also allow sellers to move more fuel as much larger LNG export terminal development is facing pressure amid a global gas glut and a more competitive market.
Trade groups including Natural Gas Vehicles for America and the Pennsylvania Independent Oil and Gas Association support the rulemaking, claiming in comments that LNG by rail would increase access to and use of domestic natural gas and help strengthen economic development.
The Association of American Railroads and the American Short Line and Regional Railroad Association also support the rulemaking. According to the trade groups, railroads have about 3% of the hazardous materials incidents that trucks are involved in, despite what they said is “roughly equal hazmat ton-mileage.”
While the rail groups are opposed to implementing any more operational controls, they also urged PHMSA to consider the DOT-113C140 tank car as another suitable package in which to move LNG. The specification, according to the groups, requires a thicker product tank shell, “which would allow a higher pressure relief valve setting and provide additional protection.”
In all, PHMSA received more than 300 comments from a wide variety of stakeholders, including citizens and municipalities, many of which expressed their opposition for the rulemaking, citing health, safety and climate risks, along with previous disasters involving other HHFT. The other states that objected included California, Delaware, Illinois, Maryland, Massachusetts, Michigan, Minnesota, New York, North Carolina, Oregon, Rhode Island, Vermont and Washington.
It’s unclear when the regulations might be finalized. After the public comment period, a final rule is to be prepared and sent to the Office of Management and Budget for review.