Train noise

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Pass-by noise of a passenger train is measured in Switzerland. 2021-02-05 IC2000 Kiesen.jpg
Pass-by noise of a passenger train is measured in Switzerland.

Train noise is vehicle noise made by trains. Noises may be heard inside the train and outside.

Contents

Subway systems, light rail transit and freight trains can send loud train noise into neighborhoods. Organizations such as the World Health Organization [1] and the U.S. Environmental Protection Agency have set guidelines for noise level decibel limits for rapid transit. Noise levels can be reduced by installing noise barriers next to the track. [2] Traditional clickety-clack sounds occur as a result of gaps in the rail to allow for thermal expansion. On most railways, the gaps are opposite each other and if the carriages are about the same length as the rails, an even clickety clack sound is generated. In the USA the rail joints are staggered, so not being opposite each other, a different and irregular sound is heard.

Sources

Several distinct sounds are created by various parts of the train, such as engines, traction motors, brakes, and the wheels rolling on the rails.

Rail squeal

Rail lubrication cabinet in the UK Wind powered railway equipment sept 21.jpg
Rail lubrication cabinet in the UK

Rail squeal is a screeching train-track friction sound, commonly occurring on sharp curves. Squeal is caused by the flanges of the wheels scraping across the railhead. The "Howling sound" is caused by lateral sticking and slipping of the wheels across top of the railroad track. This results in vibrations in the wheel that increase until a stable amplitude is reached. [7] Lubricating the rails has limited success. Speed reduction also appears to reduce noise levels. [8]

The sticking of the rim of the wheel causes the wheel to ring like a bell, so rubber dampers or tuned absorbers are a possible solution to lower the volume. The MBTA Green Line, for example, suffers from severe rail squeal on the sharp curves within the central subway. Flange stick graphite lubricators have been installed on trains to attempt to mitigate the rail squeal issue. [9] The mechanism that causes the squealing also is the cause of wear and tear that happens in the wheel–rail interface.

Factors affecting rail squeal include: [10]

See also

Related Research Articles

<span class="mw-page-title-main">Bogie</span> Chassis for wheels and suspension under vehicles

A bogie comprises two or more wheelsets, in a frame, attached under a vehicle by a pivot. Bogies take various forms in various modes of transport. A bogie may remain normally attached or be quickly detachable. It may include suspension components within it, or be solid and in turn be suspended. It may be mounted on a swivel, as traditionally on a railway carriage or locomotive, additionally jointed and sprung, or held in place by other means.

<span class="mw-page-title-main">Locomotive</span> Self-propelled railway vehicle

A locomotive is a rail transport vehicle that provides the motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, motor coach, railcar or power car; the use of these self-propelled vehicles is increasingly common for passenger trains, but rare for freight trains.

<span class="mw-page-title-main">Rail transport</span> Mode of transport

Rail transport is a means of transport using wheeled vehicles running in tracks, which usually consist of two parallel steel rails. Rail transport is one of the two primary means of land transport, next to road transport. It is used for about 8% of passenger and freight transport globally, thanks to its energy efficiency and potentially high speed.

<span class="mw-page-title-main">Rack railway</span> Steep-grade railway with a toothed rack rail

A rack railway is a steep grade railway with a toothed rack rail, usually between the running rails. The trains are fitted with one or more cog wheels or pinions that mesh with this rack rail. This allows the trains to operate on steep gradients of 100% or more, well above the 10% maximum for friction-based rail. The rack and pinion mechanism also provides more controlled braking and reduces the effects of snow or ice on the rails. Most rack railways are mountain railways, although a few are transit railways or tramways built to overcome a steep gradient in an urban environment. The first cog railway was the Middleton Railway between Middleton and Leeds in West Yorkshire, England, United Kingdom, where the first commercially successful steam locomotive, Salamanca, ran in 1812. This used a rack and pinion system designed and patented in 1811 by John Blenkinsop.

<span class="mw-page-title-main">Railroad switch</span> Mechanism to transfer trains from one track to another

A railroad switch (AE), turnout, or [set of] points (CE) is a mechanical installation enabling railway trains to be guided from one track to another, such as at a railway junction or where a spur or siding branches off.

In railway engineering, the term tractive effort describes the pulling or pushing capability of a locomotive. The published tractive force value for any vehicle may be theoretical—that is, calculated from known or implied mechanical properties—or obtained via testing under controlled conditions. The discussion herein covers the term's usage in mechanical applications in which the final stage of the power transmission system is one or more wheels in frictional contact with a railroad track.

<span class="mw-page-title-main">Railway electrification</span> Conversion of railways to use electricity for propulsion

Railway electrification is the use of electric power for the propulsion of rail transport. Electric railways use either electric locomotives, electric multiple units or both. Electricity is typically generated in large and relatively efficient generating stations, transmitted to the railway network and distributed to the trains. Some electric railways have their own dedicated generating stations and transmission lines, but most purchase power from an electric utility. The railway usually provides its own distribution lines, switches, and transformers.

Rail transport terms are a form of technical terminology applied to railways. Although many terms are uniform across different nations and companies, they are by no means universal, with differences often originating from parallel development of rail transport systems in different parts of the world, and in the national origins of the engineers and managers who built the inaugural rail infrastructure. An example is the term railroad, used in North America, and railway, generally used in English-speaking countries outside North America and by the International Union of Railways. In English-speaking countries outside the United Kingdom, a mixture of US and UK terms may exist.

<span class="mw-page-title-main">Railgrinder</span> Railway maintenance vehicle

A railgrinder is a maintenance of way vehicle or train used to restore the profile and remove irregularities from worn tracks to extend its life and to improve the ride of trains using the track. Rail grinders were developed to increase the lifespan of the tracks being serviced for rail corrugation. Rail grinding is a process that is done to stop the deformation due to use and friction on railroad tracks by removing deformations and corrosion. Railway tracks that experience continual use are more likely to experience corrugation and overall wear. Rail grinders are used to grind the tracks when rail corrugation is present, or before corrugation begins to form on the tracks. Major freight train tracks use rail grinders for track maintenance based on the interval of tonnage, rather than time. Transit systems and subways in major cities continue to use scheduled rail grinding processes to combat the corrugation common to heavily used tracks. Rail-grinding equipment may be mounted on a single self-propelled vehicle or on a dedicated rail-grinding train which, when used on an extensive network, may include crew quarters. The grinding wheels, of which there may be more than 100, are set at controlled angles to restore the track to its correct profile.

<span class="mw-page-title-main">Derailment</span> Form of train incident

In rail transport, a derailment is a type of train wreck that occurs when a rail vehicle such as a train comes off its rails. Although many derailments are minor, all result in temporary disruption of the proper operation of the railway system and they are a potentially serious hazard.

<span class="mw-page-title-main">Rolling resistance</span> Force resisting the motion when a body rolls on a surface

Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation of the wheel, roadbed, etc., is recovered when the pressure is removed. Two forms of this are hysteresis losses, and permanent (plastic) deformation of the object or the surface. Note that the slippage between the wheel and the surface also results in energy dissipation. Although some researchers have included this term in rolling resistance, some suggest that this dissipation term should be treated separately from rolling resistance because it is due to the applied torque to the wheel and the resultant slip between the wheel and ground, which is called slip loss or slip resistance. In addition, only the so-called slip resistance involves friction, therefore the name "rolling friction" is to an extent a misnomer.

<span class="mw-page-title-main">Adhesion railway</span> Railway relying on adhesion to move trains

An adhesion railway relies on adhesion traction to move the train, and is the most widespread and common type of railway in the world. Adhesion traction is the friction between the drive wheels and the steel rail. Since the vast majority of railways are adhesion railways, the term adhesion railway is used only when it is necessary to distinguish adhesion railways from railways moved by other means, such as by a stationary engine pulling on a cable attached to the cars or by a pinion meshing with a rack.

<span class="mw-page-title-main">British Rail Class 97/6</span> British diesel locomotive

The British Rail Class 97/6 0-6-0 diesel shunting locomotives were purpose-built for departmental duties by Ruston & Hornsby at Lincoln in 1953 (97650) or 1959 (97651-654). There are minor technical differences between 97650 and the 1959 batch.

This article contains a list of jargon used to varying degrees by railway enthusiasts, trainspotters, and railway employees in the United Kingdom, including nicknames for various locomotives and multiple units. Although not exhaustive, many of the entries in this list appear from time to time in specialist, rail-related publications. There may be significant regional variation in usage.

<span class="mw-page-title-main">Sandbox (locomotive)</span> Container used in locomotives to drop sand on the rail to improve traction

A sandbox is a container on most locomotives, multiple units and trams that holds sand, which is dropped on the rail in front of the driving wheels in wet and slippery conditions and on steep grades to improve traction.

<span class="mw-page-title-main">Slippery rail</span> Loss of traction in locomotives

Slippery rail, or low railhead adhesion, is a condition of railways (railroads) where contamination of the railhead reduces the traction between the wheel and the rail. This can lead to wheelslip when the train is taking power, and wheelslide when the train is braking. One common cause of contamination is fallen leaves that adhere to the railhead of railway tracks. The condition results in significant reduction in friction between train wheels and rails, and in extreme cases can render the track temporarily unusable. In Britain, the situation is colloquially referred to as "leaves on the line".

<span class="mw-page-title-main">Wheelset (rail transport)</span> Pair of railroad wheels fixed onto an axle

wheelset is a pair of railroad vehicle wheels mounted rigidly on an axle allowing both wheels to rotate together. Wheelsets are often mounted in a bogie – a pivoted frame assembly holding at least two wheelsets – at each end of the vehicle. Most modern freight cars and passenger cars have bogies each with two wheelsets, but three wheelsets are used in bogies of freight cars that carry heavy loads, and three-wheelset bogies are under some passenger cars. Four-wheeled goods wagons that were once near-universal in Europe and Great Britain and their colonies have only two wheelsets; in recent decades such vehicles have become less common as trainloads have become heavier.

Wheel slide protection and wheel slip protection are railway terms used to describe automatic systems used to detect and prevent wheel-slide during braking or wheel-slip during acceleration. This is analogous to ABS and traction control systems used on motor vehicles. It is particularly important in slippery rail conditions.

<span class="mw-page-title-main">Train wheel</span> Wheel designed for railway tracks

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, also called a truck. 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. 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. 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.

<span class="mw-page-title-main">South African Dutton road-rail tractors</span> 1923 narrow-gauge steam tractors

The South African Railways Dutton road-rail tractors of 1923 were road-rail steam tractors.

References

  1. World Health Organization. Regional Office for Europe. (2018). Environmental noise guidelines for the European Region. https://apps.who.int/iris/handle/10665/279952
  2. International Union of Railways (UIC), Sustainability, Railway Noise in Europe, State-of-the-art report, 2021, ISBN 978-2-7461-2990-0
  3. Grassie, Stuart L (Nov 2009). "Rail corrugation: characteristics, causes, and treatments". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit. 223 (6): 581–596. doi:10.1243/09544097JRRT264. S2CID   110689793.
  4. Thompson, D.J.; Squicciarini, G.; Ding, B.; Baeza, L. (2018). "A State-of-the-Art Review of Curve Squeal Noise: Phenomena, Mechanisms, Modelling and Mitigation". Notes on Numerical Fluid Mechanics and Multidisciplinary Design. 139: 3–41. doi:10.1007/978-3-319-73411-8_1. hdl: 10251/137594 . ISBN   978-3-319-73410-1. S2CID   125601090.
  5. "J. Le Besnerais et al., Characterization of the audible magnetic noise emitted by traction motors in railway rolling stock", Noise Control Engineering Journal, ISSN 0736-2501, Vol. 57, Nº. 5, 2009, págs. 391-399
  6. J. Le Besnerais, V. Lanfranchi, M. Hecquet and P. Brochet, "Characterization and Reduction of Audible Magnetic Noise Due to PWM Supply in Induction Machines," in IEEE Transactions on Industrial Electronics, vol. 57, no. 4, pp. 1288-1295, April 2010. doi: 10.1109/TIE.2009.2029529
  7. Rudd, M.J. (1976). "Wheel/rail noise—Part II: Wheel squeal". Journal of Sound and Vibration. 46 (3): 381–394. Bibcode:1976JSV....46..381R. doi:10.1016/0022-460X(76)90862-2.
  8. Barnt Green Rail Noise - summary by Les Bailey [ permanent dead link ]
  9. Why the MBTA's Wheels Squeal -- And How It's Trying to Dampen the Noise
  10. Thompson, D.J.; Squicciarini, G.; Ding, B.; Baeza, L. (2018). "A State-of-the-Art Review of Curve Squeal Noise: Phenomena, Mechanisms, Modelling and Mitigation". Noise and Vibration Mitigation for Rail Transportation Systems. Notes on Numerical Fluid Mechanics and Multidisciplinary Design. Vol. 139. pp. 3–41. doi:10.1007/978-3-319-73411-8_1. hdl: 10251/137594 . ISBN   978-3-319-73410-1. S2CID   125601090.

Bibliography