Shipping oil by rail is booming. Technology can make it safer
However, movement toward such legislation has presented considerable challenges due to the fact that the vast majority of tank cars are owned by private companies other than the railroads that transport them.
As a result, questions arise regarding who should bear the economic burden of replacing and/or retrofitting the crude oil tank car fleet. Due to safety and economic incentives mentioned above, some railroads have already begun to purchase their own improved tank cars, but this has not become a universal trend across the industry.
Role of research
Researchers, too, are exploring how technology can improve safety in a variety of ways, including:
Improved Tank Car Design: The Association of American Railroads (AAR) is working to promote tougher federal standards for tank cars carrying crude oil and other hazardous liquids. Extensive research is ongoing both within the Federal Railroad Administration and at various universities to assess tank car safety and develop an optimized tank car design: Cooperative Research in Tank Car Safety Design.
Track and Infrastructure Inspection: Railroad track failures have been found to be a leading derailment cause in the United States. As a result, railroads have begun to perform more track inspections, including the use of advanced track geometry vehicles — which use laser systems to measure the profile of the rail — on routes carrying crude oil trains. Ultrasonic rail inspection methods as well as ground-penetrating radar systems are also being developed to improve the ability of railroads to detect track defects.
Risk Assessment: Railroad transportation risk research associated with hazardous materials is ongoing. Risk assessment has included rail defect inspection, evaluating routing and train speed, track quality, and an integrated framework to reduce risk. This framework addresses operating practices, train routing, infrastructure, and car design to identify the financial and safety risk associated with hazardous materials transport by rail.
Automated Condition Monitoring Technologies: Various wayside detector systems have been developed and installed across the country at locations adjacent to track to assess the condition of locomotive and freight car components en route. These systems incorporate various technologies to identify critical defects resulting in both safety and economic benefits. Some key technologies include:
- infrared temperature sensors used to measure overheated wheels/bearings
- acoustic bearing detectors to identify worn roller bearings in railcars
- laser systems to measure wheel profiles and identify worn wheels
- machine vision systems to detect low air-hoses, structural defects and broken or missing railcar safety appliances
- load impact sensors to identify damaged wheels that are out-of-round or exhibit flat spots
Advanced Braking Systems: Both technology and operating practices can play a role in improving braking for oil trains. Some have suggested the use of Electronically Controlled Pneumatic (ECP) brakes. ECP brakes allow for faster application of the brakes on all cars in a train using an electric signal, instead of an air signal, to initiate a brake application.
ECP brakes have been used on a limited basis for coal trains, but the costs have not been proven to justify the safety and economic benefits. A better option may be the use of either:
- distributed power, where locomotives are dispersed throughout the train (i.e. front, rear and even in the center) and/or
- two-way end-of-train devices (EOTD) that allow brake signals to be initiated from the rear of the train.
Both of these operating practices result in faster braking and reduce “run-in”, where the cars in the front of the train begin braking before those on the rear, causing the rear cars to “run-into” the cars in front of them, creating higher in-train forces. After these measures were proposed by the US Department of Transportation in July of 2014, U.S. Class I railroads agreed to implement enhanced braking in the form of distributed power or two-way EOTDs on all oil trains.
Positive Train Control (PTC): This technology will automatically slow or stop a train to prevent a collision or derailment due to human error, such as speeding or missing a signal. After a federal mandate in 2008, railroads have begun to develop and install this GPS-based safety overlay system, which will eventually cover more than 60,000 miles of track in the United States.
Emergency Response: Railroads are working together with various organizations to improve community safety through emergency response training.
Reducing risk
In addition, new technologies are being developed to improve the speed and effectiveness of environmental cleanup efforts. For example, researchers at Penn State University have developed a patented technology called Petro-SAP to absorb oil from the environment after a spill. Technologies like this can be used in the future to mitigate environmental impact of train related oil spills.
While the risk associated with oil train derailments has not been eliminated, the transportation of crude oil by rail has certainly become safer through extensive research, development, and implementation of new technologies.
Continued efforts by railroads, government agencies, research institutions, and universities will continue to improve the safety of crude oil transportation by rail, reducing risk and potentially alleviating public fears associated with railroad transportation.
Bryan W. Schlake is Instructor in Rail Transportation Engineering at Pennsylvania State University.This story is published courtesy of The Conversation (under Creative Commons-Attribution/No derivatives. See also Bryan W. Schlake, “Despite disasters, oil-by-rail transport is getting safer,” HSNW, 16 April 2015.
