Search results
Results From The WOW.Com Content Network
The appropriate thickness of a layer of track ballast depends on the size and spacing of the ties, the amount of traffic on the line, and various other factors. [1] Track ballast should never be laid down less than 150 mm (6 inches) thick, [5] and high-speed railway lines may require ballast up to 0.5 metres (20 inches) thick. [6]
A railway track (CwthE and UIC terminology) or railroad track (NAmE), also known as permanent way (CwthE) [1] or "P Way" (BrE [2] and Indian English), is the structure on a railway or railroad consisting of the rails, fasteners, sleepers (railroad ties in American English) and ballast (or slab track), plus the underlying subgrade.
[9] [10] The ballast factor of practical ballasts must be considered in lighting design; a low ballast factor may save energy, but will produce less light and short the lamp life. With fluorescent lamps, ballast factor can vary from the reference value of 1.0.
Steel ties are lighter in weight than concrete and able to stack in compact bundles unlike timber. Steel ties can be installed onto the existing ballast, unlike concrete ties which require a full depth of new ballast. Steel ties are 100% recyclable and require up to 60% less ballast than concrete ties and up to 45% less than wood ties.
Concrete sleepers are up to 300 pounds (136.1 kg) heavier than their wooden counterparts. As a result, larger sized ballast is required to both support and hold in place the sleepers on the roadbed. Additionally, they do not absorb as much vibration from passing trains as wooden sleepers do.
A modern version of the grooved block rail has a lower mass and is inserted into a prefabricated spanning concrete girder such as the LR55 [2] without web but fully supported by noise reducing polyurethane grout or a girder rail such as P-CAT City Metro [3] is embedded. The prefabricated units if used with ultra light trams can be embedded into ...
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. [3] Railroad ties can be made of a number of materials: wood, concrete, steel.
Slab track with flexible noise-reducing rail fixings, built by German company Max Bögl, on the Nürnberg–Ingolstadt high-speed line. A ballastless track or slab track is a type of railway track infrastructure in which the traditional elastic combination of sleepers and ballast is replaced by a rigid construction of concrete or asphalt.