page_title: Rail profile
section_title: Strap rail
hierarchical_section_title: Rail profile / Types / Strap rail
caption_attribution_description: English: A section of strap rail used in the early Cog Railway at Mt. Washington between 1866 and 1874. Spikes are used to fasten the strap rails to the timbers.
context_page_description: The rail profile is the cross sectional shape of a railway rail, perpendicular to its length.
  Early rails were made of wood, cast iron or wrought iron. All modern rails are hot rolled steel with a cross section approximate to an I-beam, but asymmetric about a horizontal axis. The head is profiled to resist wear and to give a good ride, and the foot profiled to suit the fixing system.
  Unlike some other uses of iron and steel, railway rails are subject to very high stresses and are made of very high quality steel. It took many decades to improve the quality of the materials, including the change from iron to steel. Minor flaws in the steel that may pose no problems in other applications can lead to broken rails and dangerous derailments when used on railway tracks.
  By and large, the heavier the rails and the rest of the trackwork, the heavier and faster the trains these tracks can carry.
  Rails represent a substantial fraction of the cost of a railway line. Only a small number of rail sizes are made by steelworks at one time, so a railway must choose the nearest suitable size.
context_section_description: The earliest rails were simply lengths of timber.  To resist wear a thin iron strap was laid on top of the timber rail.  This saved money as wood was cheaper than metal. The system had the flaw that every so often the passage of the wheels on the train would cause the strap to break away from the timber. The problem was first reported by Richard Trevithick in 1802.  The use of strap rails in the United States (for instance on the Albany and Schenectady Railroad c. 1837) led to passengers being threatened by "snake-heads" when the straps curled up and penetrated the carriages.
caption: Strap rail and spike
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