It has been suggested that this article be merged into Train noise. (Discuss) Proposed since October 2024. |
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.[1]
Lubricating the rails has limited success. Speed reduction also appears to reduce noise levels.[2]
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.[3]
The mechanism that causes the squealing also is the cause of wear and tear that happens in the wheel–rail interface.