The 4DD4Ek6 Class is a class of Electric Locomotives designed by Conan Diederich at the Eastern & Atlantic's Richmond Works.
The Eastern & Atlantic's has many electrified branches, and a continually electrified track on it's main line. Two of the most important electrified branches are the route from Atlantic City to New York, and the route from Washington, DC to Baltimore. After the war, these two branches were lacking a medium-powered dual purpose locomotive.
Thus, the 4DD4Ek6 Class was designed. This meant that it had two unpowered axles on each side, with two sets of 4 powered axles connected by a hinge in the middle.
34 locomotives were built at the Richmond Electric locomotive works, and 24 were sent to Miami to haul fast freight and express trains on the route from Atlantic City to New York, while the rest were sent to the route between Washington, DC and Baltimore. They were built between 1948 and 1950.