How do you identify and address a potential thermal runaway condition on a loaded tank car containing hazardous materials during a pre-departure inspection?

Thermal runaway is a condition where a chemical reaction inside a tank car accelerates uncontrollably, generating excessive heat and pressure. This can lead to a tank car rupture, explosion, or release of hazardous materials. Identifying and addressing this condition during a pre-departure inspection is crucial. During the inspection, first refer to the shipping papers. The shipping papers will identify the hazardous material being transported and any specific instructions or warnings related to that material. Pay close attention to any instructions regarding temperature monitoring or special handling requirements. Next, use your senses. Carefully approach the tank car and use your senses to detect any signs of a thermal runaway. Look for visual cues such as bulging of the tank car shell, discoloration, or condensation. Listen for unusual noises such as hissing, popping, or crackling. Smell for any unusual odors that may indicate a chemical reaction or leak. Next, temperature monitoring is important. If the shipping papers require temperature monitoring, use a remote temperature sensing device to measure the temperature of the tank car shell. Compare the measured temperature to the safe operating temperature range specified in the shipping papers or other relevant documents. Significant temperature increases may indicate a thermal runaway condition. Next, check the pressure relief devices. Inspect the pressure relief devices on the tank car to ensure they are in good working order and are not obstructed. These devices are designed to vent excess pressure in the event of a thermal runaway. If a pressure relief device has activated, it may indicate that a thermal runaway is in progress. If a potential thermal runaway condition is identified, take immediate action. First, immediately notify the train dispatcher and other relevant railroad personnel. Provide them with all of the information you have gathered, including the type of hazardous material, the temperature of the tank car, and any other signs of a thermal runaway. Next, isolate the tank car. If possible, isolate the tank car from other cars and equipment to minimize the risk of damage or injury in the event of a rupture or explosion. Third, evacuate the area. Evacuate all personnel from the immediate vicinity of the tank car to a safe distance. Refer to the Emergency Response Guidebook (ERG) for recommended evacuation distances. Fourth, follow emergency procedures. Follow the emergency procedures outlined in the railroad's operating rules and the Emergency Response Guidebook. This may involve contacting local emergency responders and providing them with assistance. Do not approach the tank car or attempt to extinguish any fire unless you are properly trained and equipped to do so. Addressing a potential thermal runaway condition requires a combination of vigilance, knowledge, and decisive action. By following these steps, railroad personnel can help prevent accidents and protect the public and the environment.