This is a GG-1 electric locomotive - it is powered by electricity received from overhead wires via pantographs (here, one is folded down & one is extended). It was built in April 1943 by General Electric and the Pennsylvania Railroad's Juniata Shops. The engine was used as Pennsylvania Railroad # 4935, Penn Central Railroad # 4935, and Amtrak # 4935. The unit is now in the collection of the Railroad Museum of Pennsylvania in the town of Strasburg.

Museum info.: "When the Pennsylvania Railroad embarked on its ambitious mainline electrification project in the 1930s, it also continued testing new designs of electric locomotives. The Railroad's first mass-produced class of engines, the P5, was too rough-riding and prone to breaking axles at high speeds to be placed in passenger service. In 1933, the Pennsylvania Railroad set out to produce a new electric locomotive capable of pulling heavy passenger trains at speeds of up to 100 miles per hour.

Of the two designs testing, the GG-1, with its tremendous power and articulated frame, was chosen as the foundation for a new roster of electrics. The Pennsylvania Railroad ordered 138 additional units in 1934, to be delivered over the next nine years. Although identical internally, the production units benefited from the design work of Raymond Lowey who designed a smooth, welded carbody and the now famous pinstriped paint scheme. Lowey intended for the locomotive to appear as if it were in motion even while sitting still.

One in service, the Pennsylvania Railroad quickly found additional uses for the GG-1. Regeared and assigned to freight service, GG-1s could be found at the point of everything from ore trains to the Broadway Limited from the 1940s to the 1970s. Despite the relatively small space afforded in the cab, crews liked the GG-1s for their power, performance, and smooth ride.

Despite their age, most of the fleet outlived the Pennsylvania Railroad, serving Penn Central, Amtrak, Conrail, and New Jersey Transit before the final unit was retired in 1983. Most of the locomotives had racked up four to five million miles in service, earning a reputation as the most successful as well as recognizable and beloved locomotives of all time.

Built in April of 1943, No. 4935 was among the last of the GG-1s delivered to the Pennsylvania Railroad. The Pennsylvania Railroad built the frame and body themselves in the Juniata Locomotive Shops, with General Electric supplying the electrical components. Because the sum of its road numbers was 21, crews nicknamed the locomotive "Blackjack".