An accident in which one or more wheels of a railcar or locomotive leave the running rails, potentially causing car damage, lading spills, and injuries. Derailments result from track defects, mechanical failures, excessive speed, improper loading, or obstructions on the track. They are investigated by the FRA and NTSB and are a leading focus of railroad safety programs.
A wayside infrared sensing device that measures the temperature of passing railcar journal bearings and alerts dispatchers when a bearing is overheating (a condition called a hot box), which can lead to a bearing failure and derailment. Hot box detectors are spaced at regular intervals along mainlines and are a primary defense against bearing-related derailments. A positive detection triggers a mandatory train stop and inspection.
A wayside device installed between the rails that is triggered when an object hanging below a passing car contacts it, alerting dispatchers to a potential dragging equipment condition such as a broken brake rod, loose air hose, or fallen lading. Dragging equipment can cause derailments, track damage, and grade crossing accidents. Detection triggers an immediate train stop for inspection.
A general term for any wayside device that monitors passing trains for mechanical defects including hot bearings, dragging equipment, shifted loads, broken wheels, and wheel impact loads. Modern defect detectors transmit data in real time to dispatching centers and maintenance databases. A network of detectors provides continuous surveillance of the entire train as it moves through the system.
The U.S. Department of Transportation agency responsible for railroad safety regulation and enforcement, including track standards, equipment inspection, operating rules, and hazardous materials transportation. The FRA conducts safety inspections, investigates accidents, and issues emergency orders when immediate safety threats exist. It also administers federal rail investment programs.
A railcar that has been removed from service because it has a mechanical defect, damage, or other condition that makes it unsafe or unsuitable to move loaded. Bad-ordered cars are set out at a repair facility until they are inspected and restored to serviceable condition. The term is used as both a noun and a verb in railroad operations.
A general-purpose non-pressurized tank car specification that was the most common type used for petroleum products and chemicals before safety upgrades were mandated. DOT-111 cars were found to be prone to puncture in derailments, leading to regulatory requirements to retrofit or replace them with DOT-117 standard cars. The phase-out of older DOT-111 cars for flammable liquids was a major regulatory initiative following the Lac-Megantic disaster.