This video demonstrates the engine sounds from 4 different classes of British Rail diesel locomotive. They may look visually (slightly) similar but they each have a characteristically different engine sound. The class 37 and class 40 have different types of engines, but both were built by the English Electric Company. The class 44 has a Sulzer engine, and the class 55 has a Napier Deltic engine. So there you go! | Adrian Watson