Ships Horns

[fly258]

After hearing the QE2 leave from Southampton I was really impressed with the sound of it's horn. I was wondering how they work to produce such a powerful sound.

[Clanad]

Compressed air... A basic air horn includes a chamber of compressed air which is attached to a valve which allows air to pass through it into a resonant horn. You could think of an air horn as a souped up brass instrument, since these horns work on the same principle. Just like a trombone or a trumpet, an air horn can be calibrated to generate specific notes or tones. In some parts of the world, specific notes are reserved for particular classes of vehicle, and trains actually produce chords, not single notes.
The air horns used on trains and ships are quite large, and capable of generating a formidable sound due to the large size and volume of compressed air... (Thanks to Wise Geek)

[shylock73]

I thought someone put the mike near their bottom and blew a good`un!!!!!!!