Locomotives on the Northeast Corridor, 1977.

From left to right, this photograph shows four electric locomotives: a GG-1, E-60CP, Swedish Rc4 and a French CC 21000. According to the caption from Amtrak NEWS , "A strange combination of locomotives moves down the Northeast Corridor tracks toward Washington on Thursday morning, March 31 [1977]...[All but the GG-1] were put on display in Washington Union Station that evening from 5 to 8 p.m. for viewing by members of the combined Institute of Electrical and Electronic Engineers, Inc. and American Society of Mechanical Engineers convention..."

The GG-1s, built for the Pennsylvania Railroad in the 1930s and 1940s, were used by Amtrak through the 1970s. Amtrak purchased the E-60s as replacements for the GG-1s, but continued to search for a faster, lightweight electric locomotive. From 1976-1977, the company tested the Swedish and French locomotives in this photo. The Swedish Rc4 designed by Allmanna Svenska Elektriska Aktiebolaget (ASEA), was designated the x995 during its testing phase, while the French CC 21000 built by the SNCF was designated the x996.

The Rc4's design won out and became the basis for the Amtrak dual cab AEM-7, produced from 1978 to 1988.