Portuguese State Railway series 2500 and 2550

The series 2500 was a four-axle electric locomotive for service on the line between Lisbon and Porto that was electrified with 25 kV AC. Designed by the 50 c/s Group, the first 15 locomotives were built in France in 1956 and 1957 with traction motors from Alstom. As mixed-traffic locomotives, they had a top speed of 120 km/h and an output of 2,053 kW.

A second batch of 20 were built in Portugal in 1963 and 1964 which became known as series 2550. These had an exterior of unpainted, corrugated stainless steel that had been licensed from Budd, while the series 2500 had a painted exterior. From the nineties, both were only used in freight service. They were retired in 2009 after they had been replaced by the series 4700 that is a member of the Siemens Eurosprinter family.