Who invented a train horn?
Air Chime Limited was the pioneer in introducing the train horns by the work of Robert Swanson in 1949. Prior to the early 1950s, locomotives were equipped with air horns that sounded but a single note. Swanson, using ancient Chinese music theory, sought to develop an air horn which would mimic the sound of a classic steam whistle and managed to produce a six-note model which was known as the famous H6. Later Swanson refined his H6 model in H5, which gave the sound of a five-note chord.
