Milwaukee Road class F6
 The Milwaukee Road classes F6 and F6-a comprised twenty-two steam locomotives of the 4-6-4 configuration commonly nicknamed “Hudson” but known as “Baltic” on the Milwaukee Road. They would have been the first 4-6-4 tender locomotives in the world were it not for the Milwaukee's financial difficulties which culminated in bankruptcy in 1925.The fourteen class F6 locomotives were not delivered from their builder the Baldwin Locomotive Works of Philadelphia Pennsylvania until 1929–1930.