The locomotives were built for the Valtellina Railway, a 106 km long line with many tunnels and curves.

Hungarian engineer Kálmán Kandó electrified the line in the early 1900s using high voltage three-phase alternating current.

[1] The three locomotives were leased to the Swiss Federal Railways (SBB) between 1906 and 1907 for the purpose of operating in the Simplon tunnel.

The testing of the Simplon line was carried out on 25 January 1906 by a train pulled by a steam locomotive.

The locomotives gave excellent service on the Simplon line, hauling over 10 trains a day.