GG1.

Pennsylvania Railroad 4800, nicknamed "Old Rivets", is a GG1-class electric locomotive located at the Railroad Museum of Pennsylvania, outside of Strasburg, Pennsylvania in the United States. It is the prototype GG1 and was originally numbered 4899. Built by General Electric in 1934, the locomotive competed against a prototype, the R1, built by rival company Westinghouse. 4800 was kept in service by the Pennsylvania Railroad and its successors, Penn Central and Conrail, until 1979. It was sold the next year to a local chapter of the National Railway Historical Society. 4800 was dedicated in 1982 at the Railroad Museum of Pennsylvania and was designated a Historic Mechanical Engineering Landmark in 1983.