rail transport Rail transport (also known as train transport) is a means of transport using wheeled vehicles running in railway track, tracks, which usually consist of two parallel steel railway track, rails. Rail transport is one of the two primary means of ...

, guard rails or check rails are

rails Rail or rails may refer to: Rail transport *Rail transport and related matters * Railway track or railway lines, the running surface of a railway Arts and media Film * ''Rails'' (film), a 1929 Italian film by Mario Camerini * ''Rail'' (1967 fi ...

used in the construction of the track, placed parallel to regular running rail to keep the wheels of

rolling stock The term rolling stock in the rail transport industry refers to railway vehicles, including both powered and unpowered vehicles: for example, locomotives, Railroad car#Freight cars, freight and Passenger railroad car, passenger cars (or coaches) ...

in alignment to prevent (or at least reduce the severity of)

derailment 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 sys ...

. They are generally used along areas of restricted clearance, such as a

bridge A bridge is a structure built to Span (engineering), span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the path underneath. It is constructed for the purpose of providing passage over the obstacle, whi ...

, trestle,

tunnel A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, though there may be access and ve ...

, or

level crossing A level crossing is an intersection where a railway line crosses a road, Trail, path, or (in rare situations) airport runway, at the same level, as opposed to the railway line or the road etc. crossing over or under using an Overpass#Railway, o ...

. They also help to minimize damage to the structure and allow easier post-accident cleanup.

History

Although guard rails in some form have been used as long as there have been trains, the precursor of the guard rails in use today was detailed in , filed in 1893 by Gorham B. Ames, based in

Laconia, New Hampshire Laconia ( ) is a city in Belknap County, New Hampshire, United States. The population was 16,871 at the 2020 census, up from 15,951 at the 2010 census. It is the county seat of Belknap County. Laconia, situated between Lake Winnipesaukee and ...

, US.

Applications

Bridges

Guard rails are an essential component of railroad bridges. Their presence prevents a derailed train from striking and damaging bridge components, or deviating from the track enough to leave the tracks entirely and roll over or fall.

Sharp curves

On sharp curves, guard rails may be placed inside the inner rail, where they engage the back of the flange of the wheel on that side.

Switches

Guard rails may be incorporated in

switches In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type o ...

, where they serve to prevent derailments caused by a train's wheels passing through the wrong side of the frog (the point where the straight and diverging rails cross). Guard rails in this case are typically bolted to the traffic rails on each end, with a clamp placed towards the center to prevent movement.

References

External links

* {{Commons category inline Permanent way Railway safety