If a car horn, a truck horn and a motorcycle horn are important on the road to give fellow motorists and pedestrians a warning, then a train horn serves of equal importance on the railroad tracks. Not only does a train horn serve as a warning to pedestrians, passengers, other vehicles, and even animals, it also is used as a signal system for railroad personnel. Many decades back, when the trains used to be powered by steam engines, train horns or train whistles also operated on steam wherein a pull cord or a lever was used to blow the train's whistle. Train engineers got to "personalize" the sound they made when they were blowing the train horn, and train personnel could even distinguish who was currently operating the train. But with the improvement of the train engine system that is now running on diesel, it was observed that the steam train whistles were becoming inefficient. That is why a train horn can now be activated with a push button control to make it easier for the train engineer to give the signal. Do you want to know how the train horn mechanism actually works?
Some people might think that a train horn is a pre-recorded sound that just plays when activated, but that's not how it works. A train horn is operated mainly by compressed air. Air tanks are used to store and generate compressed air for the train horn to operate. When the train engineer presses the train horn button, a strong burst of compressed air from the air tanks will flow through the narrow opening of the horn. This pressure makes the diaphragm of the train horn vibrate or oscillate towards the external opening of the horn or the nozzle and it creates the loud sound that we hear when the train is approaching. The sloping structure of the train horn helps in making the oscillated sound even louder to hear. The sound produced by the train horn can actually reach up to 150 decibels.
Many enthusiasts wanted to imitate the train horn and use it for their trucks and SUVs, so there are scaled down versions of train horns in the market. Make sure to check first if it is legal in your area to install a train horn in your SUV so that you know how to avoid problems.
I have always been fascinated whenever I hear a train horn as it brings back a lot of good memories, and it's nice that along with the fascination of train sounds, I now have a concrete idea of how the train horn actually works.