Assessing LNG-By-Rail Safety

Written by Jim Blaze, Contributing Editor
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Chart Industries teamed up with VTG to develop cryogenic tank cars for the European rail network. Chart Industries photo.

Safety is important. Yet, we can do safety research and development a lot faster. It’s timely to ask why the regulatory process takes so long. Today in transport logistics, our society seems to lack a sense of urgency. As one example, it now takes regulatory agencies (and non-regulatory bodies like the National Transportation Safety Board) as long as 18 to 24 months to complete an accident investigation report. Why so long? It’s a mystery.

Regulatory lag has a direct impact upon the commercialized use of abundant natural gas as a much-more environmentally clean fuel. There is no question that natural gas is an abundantly available fuel source. Some estimate that there is a 200-year supply of natural gas in the U.S. alone. Getting the natural gas to market overland at an attractive price is the issue, so long as there are few pipelines available. Rail freight could be a viable business solution. But in the U.S., railroads are not yet a player in the natural gas supply chain.

What is LNG?

Natural gas from a well head consists of several elements, primarily methane (CH4), which in its natural state is a colorless, odorless, tasteless and non-toxic gas.

Liquefied natural gas (LNG) is processed natural gas that is mostly methane cooled down to a liquid form for storage or transport. Once liquefied by this cooling process, LNG takes up about 1/600th the volume it had in its gaseous state. LNG does have some potential hazards, including limited flammability after vaporization into a gaseous state, freezing and asphyxia. More about risks is cited below.

How is it liquefied? The liquefaction process involves removal of certain components, such as dust, helium, water and heavy hydrocarbons. The processed gas is then converted to a liquid by cooling it to approximately –162 °C (–260 °F). The nominal pressure in a special thermos tank configuration is around 25 kPa (4 psi).

LNG Basic Rail Transport Economics

The process of compressing LNG to such a degree makes it economical to move huge volumes of the LNG from production wells and/or cryogenic large ground storage tanks to remote areas of the world by rail. It lowers the consumers’ price paid for energy. It can be stored at destination and used to generate electricity or heat by local utilities.

Ocean transportation of LNG has been going on for a considerable time with very few reported safety issues. By using rail, LNG can be transported to otherwise energy-deficient regions relatively quickly using existing railroad infrastructure. Safety is still an unresolved public issue. And, yes, it should be addressed.

While awaiting additional safety studies, here are two market examples of how railroad movement of LNG is proceeding on a commercial basis.

In Europe, Germany-based VTG Aktiengesellschaft (whose U.S. subsidiary is VTG Rail) signed a contract in 2015 with Norway-based Skangass AS to haul LNG by rail. The operation involves leasing up to 20 LNG tank cars that can move as much as ~1,500 cubic meters of LNG per trip. That would replace use of over-the-highway tank trucks.

An LNG European disruptive force is Czech Republic-based Chart Ferox, a division of U.S.-based Chart Industries.

Translation: European railway regulatory agencies now have three or more years of actual operational performance with which to determine the safety aspects of transporting LNG by rail.

A second disruptive commercial example comes from the Florida East Coast Railway (FEC). Operating freight trains over more than 300 miles of track between Jacksonville and Miami, FEC introduced LNG-fueled locomotives in 2017. FEC is part of Grupo Mexico Transportes.

Chart Industries designed and built FEC’s LNG locomotive fuel tender car, a tanker that feeds a locomotive at each end. An investigation of the car design should be useful in examining the operational use risks from the point of view of several different types of side impact and derailment scenarios. In this design, the ISO container holds up to 10,000 gallons of LNG and dispenses LNG to the locomotives’ prime-mover fuel injectors via a gasification system. The locomotives are specially equipped Wabtec (GE) units modified to compression-ignite a blend of diesel and LNG (hence, no spark required).

William C. Vantuono photo.

Translation: There are now about two years of daily-use operational data and safety incident records involving more than 20 tank-car-supplied-LNG-fuel locomotives from FEC.

FEC Chart Industries fuel tender LNG gasification equipment. William C. Vantuono.

(Editor’s Note: Development of a rail-industry-standard fuel tender was under the auspices of the Association of American Railroads (AAR) Natural Gas Fuel Tender Technical Advisory Group (NGFT TAG), a joint effort of the AAR Locomotive, Tank Car, and Equipment Engineering Committees, Amtrak, BNSF, CN, Canadian Pacific, CSX, Kansas City Southern/KCS de México, Norfolk Southern and Union Pacific, with key support personnel from the AAR and Transportation Technology Center, Inc. (TTCI).—William C. Vantuono)

More than one year ago, FEC was exploring opportunities for moving LNG as a commodity. That included moving smaller lots of LNG in ISO LNG containers on flat cars along a short rail corridor between Hialeah to the Port of Miami and Port Everglades. An ISO tanker is much smaller in cubic capacity than is a full-size railroad tank car. (ISO tankers have been used for a long time on ships and intermodal trains elsewhere around the world.)

BNSF estimated capacity range of current 2019 rail LNG vessels.

Going forward, an examination of the fundamental LNG safety issue should review the risks associated with moving cryogenically cooled LNG against the risks of moving alternate hazardous materials and fuel including:

  • Liquid petroleum gas (LPG).
  • Diesel fuel.
  • Compressed natural gas (CNG).
  • Gasoline.
  • Crude oil.
  • A variety of rail- and truck-hauled chemicals.

On a positive note, The U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration (PHMSA), in coordination with Federal Railroad Administration (FRA), announced Oct. 21 that it is publishing a Notice of Proposed Rulemaking (NPRM) regarding LNG transportation by rail. The proposed rule will seek comment on changes to the Hazardous Materials Regulations (HMR) to authorize the transportation of LNG by rail in DOT-113-specification tank cars.

DOT-113 tank car. Chart Industries photo.


Public safety, commercial economic benefits and conversion substitution evidence is out there already. Taking multiple years to examine the issue would be embarrassing. What appears to be lacking is a passion for a rigorous yet expedient examination of facts already in evidence.

The FRA has already been collecting some safety data from the Alaska Railroad and the FEC projects. Beyond current monitoring, FRA can use the results of the Burlington Northern Railroad’s (now BNSF) extensive 1982-1987 natural gas research. Done by scientists at Los Alamos National Laboratory, those documents were donated by BN in September 1990 to the federal government. They can be obtained from the National Technical Information Service of the U.S. Department of Commerce. The Los Alamos tests included CNG, refrigerated liquid methane (RLM), diesel fuel (DSL), liquid petroleum gas (LPG) and methane (MTH) as part of five fuel sources against about 10 different types of possible railroad accidents. Let’s put that research to use as a baseline assessment.

In the table below are the initial Los Alamos safety results identifying the relative safety of five alternative locomotive fuels in each of 10 1982-1988 tested accident scenarios “equated to the percentage likelihood that no hazard occurs.”

I offer two suggestions to get things moving a bit more quickly.

One is to purchase a cryogenic tank car from one or more of the existing vendors (a one-time capital expenditure cost not likely to exceed $2 million), then subject it to stress and strain forces testing—and then a planned destructive-event test at TTCI in Pueblo, Colo.

The second is to commission a competitive quote from insurance analysts. After all, insurance companies are in the risk assessment business.

Fear of risks is a logical human reaction to new technology. Yet mankind has the wherewithal to overcome fear with knowledge. Let’s pick up the pace. (Editor’s Note: NASA would never had landed Apollo 11 on the moon 50 years ago without a willingness to assume and deal with risk—William C. Vantuono)


These are valuable resources for readers to consult with. My views do not necessarily reflect the specific scientific, safety or business views of these sources.

  • LNG and related railway use technical papers by Steve Ditmeyer, railway technical and logistics professor.
  • LNG by rail tank car work papers by Rich Thoma, Concept Strategy Developer at Red Rhino Disruptive Energy Solutions.
  • Railway Age Editor-in-Chief William C. Vantuono’s reports on LNG use on FEC, CNG locomotive fuel testing on Norfolk Southern, and other sources, 2013 to 2019.
  • National Technical Information Service, U.S. Department of Commerce, 1990: “Safety Assessment of Alternative Fuels” by Burlington Northern Railroad.
  • Joshua Soles, BNSF Market Manager-LNG at the October 2019 NEARS Conference.
  • LNG on the Rails –Precursor to LH2 on the Rails? Presentation by Reid Larson and Scott Nason, Chart Industries, at the H2@Rail Workshop, March 26-27, 2019, in Lansing, Mich., as part of the U.S. Department of Energy H2@Scale Initiative:


I disagree with your recommendation that an LNG tank car be procured (presumably by FRA, but you didn’t say) for destructive testing at TTCI in Pueblo, because I do not believe that it is necessary since FRA had done extensive destructive and non-destructive testing of tank cars at TTCI in the early 2000s while I was still Director of FRA’s Office of R&D. The destructive tests were conducted with instrumented tanks attached to the “crash wall” being struck by a ram on a railcar dolly moving at controlled speeds. Detailed data were collected on the forces experienced and the amount of deformation or puncture of the tanks. I do not have the videos or data from the tests, but FRA would have them, as well as TTCI . The tests were funded by FRA and the results were in the public domain. Even though all the various tanks on tank cars in service were not tested, engineering computations based on the data that were collected permits the determination of the ability of specific tanks to withstand specific forces.

Furthermore, around 1990, during my time as Director of R&D at Burlington Northern, BN contracted with TTCI to use its Train Operations and Energy Simulation (TOES) model (the development of which had originally been funded by FRA) to calculate the longitudinal buff and draft forces on the DOT-113 cryogenic tank car that we would be using as an LNG tender car between our two LNG locomotives. The analysis showed that the buff and draft forces would be less if the tender car were placed between the locomotives rather than behind the entire locomotive consist. Again, I do not possess any of the information from this analysis, which was proprietary to the BN, but which was presented to FRA to obtain permission for BN to place the tender car between the two LNG locomotives when hauling trains.

LNG is essentially pure methane, and is sometimes referred to as Refrigerated Liquid Methane (RLM). In the refrigeration process, the heavier alkanes—ethane, propane, butane, etc.—that are found in pipeline gas are separated out and can either be sold separately as fuels or inputs to chemical manufacturing processes, or they can be used to supply the energy to run the liquefaction process.

I made a presentation at the University of Delaware two years ago on natural gas locomotives. It contains some general information on natural gas and natural gas safety that may be useful in the discussion of LNG-by-rail safety:

Independent railway economist, Railway Age Contributing Editor and FreightWaves author Jim Blaze has been in the railroad industry for more than 40 years. Trained in logistics, he served seven years with the Illinois DOT as a Chicago long-range freight planner and almost two years with the USRA technical staff in Washington, D.C. Jim then spent 21 years with Conrail in cross-functional strategic roles from branch line economics to mergers, IT, logistics, and corporate change. He followed this with 20 years of international consulting at rail engineering firm Zeta-Tech Associated. Jim is a Magna cum Laude Graduate of St Anselm’s College with a master’s degree from the University of Chicago. Married with six children, he lives outside of Philadelphia. “This column reflects my continued passion for the future of railroading as a competitive industry,” says Jim. “Only by occasionally challenging our institutions can we probe for better quality and performance. My opinions are my own, independent of Railway Age and Freightwaves. As always, contrary business opinions are welcome.”

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