Some lines use softwoods, including Douglas fir while they have the advantage of accepting treatment more readily, they are more susceptible to wear but are cheaper, lighter (and therefore easier to handle) and more readily available.
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Historically wooden rail ties were made by hewing with an axe, called axe ties, or sawn to achieve at least two flat sides.Ī variety of softwood and hardwoods timbers are used as ties, oak, jarrah and karri being popular hardwoods, although increasingly difficult to obtain, especially from sustainable sources. Rails in the US may be fastened to the tie by a railroad spike iron/steel baseplates screwed to the tie and secured to the rail by a proprietary fastening system such as a Vossloh or Pandrol which are commonly used in Europe.Ī variant fastening of rails to wooden ties The number of ties is 3,250 wooden crossties per mile (2019 ties/km, or 40 ties per 65 feet) for wood ties or 2640 ties per mile for concrete ties. The crosstie spacing of mainline railroad is approximately 19 to 19.5 inches (48 to 50 cm) for wood ties or 24 inches (61 cm) for concrete ties. As of January 2008, the approximate market share in North America for traditional and wood ties was 91.5%, the remainder being concrete, steel, azobé (red ironwood) and plastic composite. Steel ties are common on secondary lines in the UK plastic composite ties are also employed, although far less than wood or concrete. Railroad ties are traditionally made of wood, but prestressed concrete is now also widely used, especially in Europe and Asia. Generally laid perpendicular to the rails, ties transfer loads to the track ballast and subgrade, hold the rails upright and keep them spaced to the correct gauge. In the background is a track with concrete ties.Ī railroad tie, crosstie ( American English), railway tie ( Canadian English) or railway sleeper ( Australian and British English) is a rectangular support for the rails in railroad tracks. People who live close to railways can find the noises and vibrations from the track and the trains annoying.īallast does a good job of dampening the sounds between the wheels and the tracks.Wooden ties are used on many traditional railways. Quieter trains running on smoother tracks aren’t just a good thing for people inside the train itself… It not only makes them stronger and easier to look after – there are fewer gaps. Those sounds might be a thing of the past though with most rail today being welded together. The clickety clack is just the wheels going over these small gaps! That’s where the click-clack noise comes from… Normally each bit is about 20 metres long and they used to be bolted together using pieces of metal called fishplates. They have to take a lot of wear and tear – on busy lines, hundreds of trains go over the points every day.
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It’s quite common in tunnels and around stations, and where you want to reduce noise.Īs well as the parallel rails, there are also switches or points – moveable sections of track that guide trains from one track to another.
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Sometimes track doesn’t have ballast at all! This is called slab track – and the track is fixed to a concrete base. But sometimes, you need something different… Special machines are used to lay it so that it’s steady and level. This is made up of irregular shaped stones that go under and around the track to form a foundation that helps water to drain away and keeps the track in place. Special fasteners connect the rail to the sleepers. They can be made of wood, concrete or metal.
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Sleepers are the horizontal supports which lie underneath the rails, helping hold them in place. Because they’re metal, they can be affected by changes in temperature, which can cause them to expand and contract. First you’ve got the rails – these are the long metal strips on which the train wheels run.