In the wake of the success met by three-phase electric locomotives on the Valtellina line, in the early 20th century the newly formed state-owned Ferrovie dello Stato, led by Riccardo Bianchi, decided to electrify the important mountain line of the Giovi Pass as well, which connected the port of Genoa to the industrial cities of northern Italy.

The decision was taken because the line was close to full saturation despite the use of the powerful 470 class steam locomotives.

The whole project, initially developed by the FS central design studio, was later completed by the Società Italiana Westinghouse of Vado Ligure.

The wheels were small, and thus adapted to heavy freight or slow passenger services at low speed.

E.550.025 is at the National Museum of Transportation in St. Louis, Missouri, in poor cosmetic condition due to being stored outside since 1968.

[2] E.550.030 is at the Museo Nazionale Scienza e Tecnologia Leonardo da Vinci in Milan, Italy.