The Ae 6/6 is a heavy electric locomotive used by the Swiss Federal Railways (SBB-CFF-FFS). It is sometimes also referred to as canton locomotive ("Kantonslokomotive"), because the first 25 locomotives were named after the cantons, and carried the canton's coat of arms on the side and chrome embellishments (a single raised stripe on each side and three raised stripes on each end), and the Swiss coat of arms on the front, between the chrome stripes. These adornments made them internationally famous. The other 95 locomotives received the names of capital cities of Swiss cantons, and other towns and cities, but without the chrome embellishments. The namings were held as ceremonies in the respective cities. A less flattering moniker is Schienenwolf ("railroad plough") as the three axle bogie construction stresses the tracks heavily.
Originally designed for heavy services on the Gotthard route, as many Swiss locomotives were, the Ae 6/6 was one of the classic Gotthard locomotives.
All locomotives were originally painted in the SBB CFF FFS green livery, with the number, and either SBB CFF, or SBB FFS on each side, all raised numerals in chrome. Nowadays about half are painted red, and a proportion of the fleet have been repainted in SBB Cargo livery, with all raised chrome embellishments removed apart from the Swiss coat of arms on each end. These locomotives have been renumbered (as class 610) in line with the current Swiss numbering scheme
