Diesel and Electric Locomotives

Rail locomotives whose prime mover is a diesel engine, an electric motor drawing power from a third rail or overhead line, or a diesel-electric hybrid drivetrain, the traction technologies that displaced steam on most of the world's mainlines over the twentieth century. Belongs here: any freight or passenger locomotive built around one of these traction types, including shunting and switching locomotives. Does not belong here: steam locomotives, or self-propelled passenger trainsets, which are grouped under passenger rolling stock even when diesel- or electric-powered, because the whole vehicle rather than a separate locomotive is the unit of interest there.