Electric locomotive CP 2551

Although the Cascais line has operated on electric power since the 1920s, this form of traction would only reach the rest of the network in the 1950s. As a consequence, it was necessary to purchase or manufacture more electric locomotives. Locomotive CP 2551, produced by SOREFAME, was the first of a series produced under the II National Development Plan to reinforce the electric locomotive fleet. It was also the first in the world to have a stainless steel bodyshell. This material allowed the locomotives to be lighter and have lower maintenance costs.
For this reason, this model was a prototype, being the first locomotive in the series to be used for testing and it first operated in July 1963 on the Northern Line. It hauled the more important trains (such as fast ones), international traffic (such as Sud-Express or Lusitânia-Expresso) and other regular or special services (such as the Presidential Train). It hauled SOREFAME coaches built from the same material. It ended service in 2009, having latterly been used for freight workings.