Rail squeal is a screeching train-track friction sound, commonly occurring on sharp curves. Squeal is presumably caused by the lateral sticking and slipping of the wheels across top of the

railroad track A railway track (British English and UIC terminology) or railroad track (American English), also known as permanent way or simply track, is the structure on a railway or railroad consisting of the rails, fasteners, railroad ties (sleepers, ...

. This results in vibrations in the wheel that increase until a stable amplitude is reached. Wind powered railway equipment sept 21

Lubricating the rails has limited success. Speed reduction also appears to reduce noise levels. 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 The Green Line is a light rail system run by the Massachusetts Bay Transportation Authority (MBTA) in the Boston, Massachusetts, metropolitan area. It is the oldest MBTA subway line, and with tunnel sections dating from 1897, the oldest subway ...

, 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. The mechanism that causes the squealing also is the cause of

wear and tear Wear and tear is damage that naturally and inevitably occurs as a result of normal wear or aging. It is used in a legal context for such areas as warranty contracts from manufacturers, which usually stipulate that damage from ''wear and tear'' w ...

that is happening in the

wheel–rail interface The wheel–rail interface is the area of contact between wheels and rails of railways Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are i ...

Factors

Factors include: * Accelerating, coasting or braking *

Diameter In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circle. It can also be defined as the longest chord of the circle. Both definitions are also valid for ...

wheel A wheel is a circular component that is intended to rotate on an axle Bearing (mechanical), bearing. The wheel is one of the key components of the wheel and axle which is one of the Simple machine, six simple machines. Wheels, in conjunction wi ...

* Powered or unpowered wheels * Radius of curve * Rail lubrication * Slant of rail (typically 1 in 20) * Superelevation or

cant Cant, CANT, canting, or canted may refer to: Language * Cant (language), a secret language * Beurla Reagaird, a language of the Scottish Highland Travellers * Scottish Cant, a language of the Scottish Lowland Travellers * Shelta or the Cant, a la ...

* Type of train * Weather (rails wet or dry) (

slippery rail 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 ...

) *

Wheelbase In both road and rail vehicles, the wheelbase is the horizontal distance between the centers of the front and rear wheels. For road vehicles with more than two axles (e.g. some trucks), the wheelbase is the distance between the steering (front ...

* Worn profile of wheel * Worn profile of rail

References

{{Rail-transport-stub Permanent way

Factors

See also

References