Rail
Main article: Rail profileModern track typically uses Hot rolled steel with a profile of an asymmetrical rounded I-beam. Unlike some other uses of iron and steel, railway rails are subject to very high stresses and have to be made of very high-quality steel alloy. It took many decades to improve the quality of the materials, including the change from iron to steel. The heavier the rails and the rest of the trackwork, the heavier and faster the trains the track can carry.
Other profiles of rail include: Bullhead rail; Grooved rail; Vignoles rail ('flat-bottomed rail'); Flanged T rail; Bridge rail (inverted U shaped used in Baulk road; Barlow rail (inverted V); and Grooved rail.
North American railroads until the mid- to late-20th century used rails 39 ft (11.89 m) long so they could be carried to and from a worksite in gondola cars (open wagons), often 40 ft (12.2 m) long; as gondola sizes increased, so did rail lengths.
According to the Railway Gazette the 150 kilometre rail line being built for the Baffinland Iron Mine, on Baffin Island, will use older carbon steel alloys for its rails, instead of more modern, higher performance alloys, because modern alloy rails can become brittle at very low temperatures.
Read more about this topic: Track (rail Transport)
Famous quotes containing the word rail:
“We rail at trade, but the historian of the world will see that it was the principle of liberty; that it settled America, and destroyed feudalism, and made peace and keeps peace; that it will abolish slavery.”
—Ralph Waldo Emerson (1803–1882)
“For this is the mark of a wise and upright man, not to rail against the gods in misfortune.”
—Aeschylus (525–456 B.C.)
“Old man, it’s four flights up and for what?
Your room is hardly any bigger than your bed.
Puffing as you climb, you are a brown woodcut
stooped over the thin rail and the wornout tread.”
—Anne Sexton (1928–1974)