In rail transport, a derailment is a type of train wreck that occurs when a rail vehicle such as a train comes off its rails. Although many derailments are minor, all result in temporary disruption of the proper operation of the railway system and they are a potentially serious hazard.
Train wreck in Leavick, Colorado in 1897
A c. 1890s picture by "C. Petersen" Fayette County, Texas [?] of a train derailment
A derailed freight train in Farragut, Tennessee (2002)
Detail of derailed express train in Prague, Czech Republic (2007)
A train is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives or railcars, though some are self-propelled, such as multiple units. Passengers and cargo are carried in railroad cars, also known as wagons. Trains are designed to a certain gauge, or distance between rails. Most trains operate on steel tracks with steel wheels, the low friction of which makes them more efficient than other forms of transport.
An electric locomotive pulling a passenger train in Russia
A rack railway in Switzerland
Diesel locomotives pulling a freight train in New Zealand
A suspended monorail in Germany