All passenger trains passing through the City of Baltimore must stop at least three minutes at the principal station of the company operating said trains, and the stoppage of all trains must be announced in such manner as will give passengers ample opportunity to get off. P.L.L., 1915, §792C 1927, §792C 1930, §792C 1938, §976 1949, §604 1969, §18-3 1902, ch. 615