Railroad Tracks as a Potential Source of Ignition in Hazardous (Classified) Locations

Transporting raw materials and finished products by rail is essential to many industries. Rail car loading and unloading facilities for liquids, gases, and solids may have fire and explosion risks and must be designed to eliminate ignition sources. The rail lines supporting cars at these stations may extend for miles outside of the process area and can conduct electrical energy into the process area due to remote lightning strikes, downed power lines in contact with the track, and power system ground fault currents. The temporary bonding devices commonly used in loading/unloading operations are intended to mitigate the effects of static electricity ignition and are not suitable for suppressing arcing from these possible high current sources. This paper will use a case history to illustrate how railroad tracks are a source of ignition, and will provide a comprehensive overview of industry standards, design requirements and operating procedures to ensure the proper isolation, bonding and grounding of railroad tracks and rail cars at loading/unloading facilities.