Railfanning during the early days of Conrail saw a number of old locomotive models still slaving away in service. Though at one time the Penn Central and Erie Lackawanna rosted a large number of F7As, by the time Conrail was formed only a hodge-podge of units survived. Being old and worn out, most F7As found themselves retired and cut up quickly. The EMD F7 was a 1,500 horsepower (1,100 kW) Diesel-electric locomotive produced between February 1949 and December 1953 by the Electro-Motive Division of General Motors (EMD) and General Motors Diesel (GMD). A total of 2,366 cab-equipped lead A-units and 1,483 cabless booster or B-units were built.