train whistle

A train whistle or air whistle (originally referred to as a steam trumpet) is an audible signaling device on a steam locomotive, used to warn that the train is approaching, and to communicate with rail workers.

Train whistles are safety devices that alert motorists and pedestrians to the presence of an approaching train. They also warn trespassers away from the rail right-of-way.

A train horn is an air horn used as an audible warning device on diesel and electric-powered trains. Its primary purpose is to alert persons and animals to an oncoming train, especially when approaching a level crossing. They are often extremely loud, allowing them to be heard from great distances.

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.

Sound and motion You may have noticed that a train whistle gets lower as it passes you. The whistle is not changing pitch, but you are hearing a change. This principle is known as the Doppler effect. The Doppler effect is named after the Austrian physicist, Christian Johann Doppler, who discovered it.

A calliope (see below for pronunciation) is an American and Canadian musical instrument that produces sound by sending a gas, originally steam or, more recently, compressed air, through large whistles - originally locomotive whistles. A calliope is typically very loud.

The maximum volume level for the train horn is 110 decibels, and the minimum sound level is 96 decibels.

Since their inception, railroads have sounded locomotive horns or whistles in advance of grade crossings and under other circumstances as a universal safety precaution. During the 20th century, nearly every state in the nation enacted laws requiring railroads to do so.

(i) 'Choo', 'chug' and 'chuff' are onomatopoeic words for the sound a train makes. (ii) Washing machines make noises from 'swoosh' to 'click'. (iii) 'Wee woo' is the sound a siren makes.

As a train gets closer, it makes a rumbling sound. As it leaves the station, it makes a steadily increasing chugging sound. The whistle sounds like a forlorn call in the night. The brakes hiss and screech when the train slows down to a stop.

A train whistle goes 'whooo” or “toot”; even the harsh two-tone ones that go “hee-hah” are still called whistles in the “trade”.

The sound that you hear, the 'Tchjk Tchjk' is because of the wheels hitting the joints between two pieces of rails. The track is not one single continuous piece, but is made up of many pieces held together.