They were built in 1925 using motors and electrical equipment from Class E.10 [it] railcars which had been withdrawn in 1923.

After World War II they were converted to 3,000 volt DC operation and became FS Class E.621.

They were equipped with six nose-suspended direct current traction motors with a total output of 950 kW (1,270 hp).

This power was transferred to the axles via a geared final drive and through this they had a maximum speed of 85 km/h (53 mph).

They received power from a 650 V DC third rail system, with the traction current being picked up by contact shoes.