The Subject of British Railway whistles is a fascinating one, I shall bring few whistles from Private Collections, and hopefully would expand with time and article.
The following four examples of the four different types are all from late Victorian period.
Two Notes Tube Whistle (TNTW) shape, Grimsby Dock Police whistle, Manchester Sheffield and Lincolnshire Railway (M.S&L.R) which changed its name to the Great Central Railway in 1897.
There are 4 Main Basic mouth blown whistle types – Shapes used with British Railway companies, These are:
Escargots – referee type / (Most Common type)
Two notes Tube whistles (TNTW) as in first photo. (also known as General Service whistles)
Round Pea Whistle type, at time without pea.
Conical two notes (TNCW) ( also kknown as Beaufort)