Ball Trainmaster wristwatch

Probably mid to late 1960s. Wrist watches were accepted for use on railroads, likely in the early 1960s. Early railroad standard wrist watches were likely mostly of Swiss origin. Ball bought semi-finished pocket watch movements from a number of American watch makers, finishing them in their shops in Cleveland . By 1960, Hamilton was the only American watch company still producing watches made in the USA. I don’t think Hamilton ever produced USA made movements for use in railroad standard wrist watches. By the mid 1960s, the swing was away from mechanical movements for use in railroad watches, and toward electronic (I. e. Hamilton Electric, Bulova Accutron.) By the time yours was made, a large percentage of railroad standard wrist watches were electronic, and some were quartz.

A Ball Official Railroad Standard, 16-size railroad watch, made by Hamilton, for Ball.The case is known as the 20th Century model, with the patented stirrup bow. This one is from circa 1930, and the movement is based on the Hamilton grade 992. This case would have originally had a Ball ORRS, 23-jewel movement in it (based on the Hamilton grade 950).