SNCB Class 25.5 locomotives were part of the 1950s generation of SNCB electric locomotives that included Series 122 (later 22), 123 (later 23), 125, (later 25) and 140 (later 25 and 25.5) built between 1953 and 1961. There were 50 Series 122, 83 Series 123, 16 Series 125 and 6 Series 140 for a total of 155 locomotives. They were seen across Belgium on passenger and freight trains until they were retired in 2012. There was no difference in power between the classes as they all used the same traction motors and control equipment. 2551 has been preserved by the PFT-TSP railway preservation group.