Editing Maintenance of way (section)

== Track ==
{{Further|Railroad track|track ballast|track bed}}
[[File:Belly on the Railroad Tracks (15124489932).jpg|thumb|300px|A section of jointed rail, on wooden ties, with spikes to secure the rails.]]
Railroad tracks consist of multiple key components: a track bed, and ballast forming the foundation of the tracks. Then the tracks themselves are place on the ballast, the tracks consist of a [[railroad tie]], fasteners to secure the rails to the ties, such as [[Rail_fastening_system#Rail_spikes|spikes]] or [[Rail_fastening_system#Clips|clips]], [[Rail profile|rails]], which are assembled on a bed of [[track ballast|ballast]], which is in turn on a track bed that supports it all.{{Sfn|Solomon|2001|pp=9-18}}

Ballast is a material used to support the ties and rails, and keep them in place. It is also a key part of drainage along railway lines to ensure the integrity of the tracks during rain and other wet weather. Ballast is often a [[crushed stone]]. Stones need to be irregularly shaped, in order to increase friction that holds the tracks in place.{{Sfn|Solomon|2001|pp=18}}

Railroad ties can be made of a number of materials: wood, concrete, steel. Wood is one of the older materials used, and is common for its simplicity and usability in most situations, as well as ease of connecting to rails. Concrete ties are desirable on high speed routes, as well as those dealing with unusually heavy trains, such as the [[Powder River Basin]]'s coal trains. In some situations, such as the [[Gotthard Base Tunnel]] rails are affixed directly to concrete, eliminating the need for individual ties and the ballast that supports them.{{Sfn|Solomon|2001|pp=14-16}}

Rails in use today are made of steel, formed into their final shape while still hot. Rails are frequently measured in weight per yard, such as {{convert|135|lbs|kg}} per [[yard]] (0.91 m). Through the mid to late 20th century, rails were typically bolted together, this has given way to continuously welded rails that have fewer joints. {{Sfn|Solomon|2001|pp=11-14}}

Rails are secured to the ties using a fastener. With wood ties, spikes are commonly used. Concrete ties are unable to use spikes, and use other styles of fasteners, like clips. {{Sfn|Solomon|2001|pp=16-17}}