rail transport Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in Track (rail transport), tracks. In contrast to road transport, where the ...

, guard rails or check rails are rails 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, freight and passenger cars (or coaches), and non-revenue cars. Passenger vehicles can b ...

in alignment to prevent

derailment In rail transport, a derailment 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 ...

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

tunnel A tunnel is an underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube const ...

, or

level crossing A level crossing is an intersection where a railway line crosses a road, path, or (in rare situations) airport runway, at the same level, as opposed to the railway line crossing over or under using an overpass or tunnel. The term also ...

. 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 Lake ...

, 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 ...

, 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

* Permanent way Railway safety {{Rail-transport-stub