Train wheel

A train wheel or rail wheel is a type of wheel specially designed for use on railway tracks. The wheel acts as a rolling component, typically press fitted onto an axle and mounted directly on a railway carriage or locomotive, or indirectly on a bogie (in the UK), also called a truck (in North America). The powered wheels under the locomotive are called driving wheels. Wheels are initially cast or forged and then heat-treated to have a specific hardness.^[1] New wheels are machined using a lathe to a standardized shape, called a profile, before being installed onto an axle. All wheel profiles are regularly checked to ensure proper interaction between the wheel and the rail. Incorrectly profiled wheels and worn wheels can increase rolling resistance, reduce energy efficiency and may even cause a derailment.^[2] The International Union of Railways has defined a standard wheel diameter of 920 mm (36 in), although smaller sizes are used in some rapid transit railway systems and on ro-ro carriages.^[3]

^ Lewis, R.; Olofsson, U. (25 September 2009). Wheel–Rail Interface Handbook. Elsevier Science. ISBN 9781845694128. Retrieved 2020-10-29.
^ Lewis, Roger; Olofsson, Ulf (2009). Wheel-rail interface handbook. Boca Raton, Florida: CRC Press. ISBN 978-1-61583-153-1. OCLC 500906475.
^ Licitra, Gaetano (2012-09-06). Noise Mapping in the EU: Models and Procedures. CRC Press. ISBN 978-0-203-84812-8.

[1] Lewis, R.; Olofsson, U. (25 September 2009). Wheel–Rail Interface Handbook. Elsevier Science. ISBN 9781845694128. Retrieved 2020-10-29.

[2] Lewis, Roger; Olofsson, Ulf (2009). Wheel-rail interface handbook. Boca Raton, Florida: CRC Press. ISBN 978-1-61583-153-1. OCLC 500906475.

[3] Licitra, Gaetano (2012-09-06). Noise Mapping in the EU: Models and Procedures. CRC Press. ISBN 978-0-203-84812-8.

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