The Ae3/5s were a fleet of 26 1-Co-1 electric locos built in the 1920s and which lasted in main line service until the 1980s. They were among the first production electric fleets procured by the Swiss, their electrification programme given renewed vigour during and immediately after World War 1 due to a shortage of coal (a resource that Switzerland was not naturally endowed with).
These 26 machines – 10201 to 10226 – were a development of the experimental Be4/7 “Grosse Sécheron” locos; being smaller, these became known as “Kleine Sécheron”. They entered traffic in four batches between May 1922 and July 1925 with the mechanical components manufactured by SLM in Winterthur and the electrics from SAAS in Genève. An Achilles heel of the design was the locos’ short length, and therefore it is no surprise that they were superseded by longer machines – the Ae3/6 IIIs – which put paid to any further orders of Ae3/5s.
They worked generally on passenger trains in the area around Lac Léman, but from the 1960s began to be cascaded away from these duties as a consequence of the arrival of newer, faster locos. At the same time, the explosion of private car ownership meant that traffic for the car-carrying trains through the Simplon and Gotthard Tunnels had increased significantly, and therefore 10218 to 10226 were rebuilt specifically for these duties, most notably by being fitted for push-pull working.
Other than through accident damage, the first withdrawals occurred to non-car train Ae3/5s in 1973 and this continued until the last had been consigned to the bin in 1982. The car train machines lasted a little longer (except for 10218 which succumbed to collision damage with BLS Ae8/8 272 in Brig in February 1979 and 10220 which caught fire in the Simplon Tunnel in October 1980), but all were gone by the middle of 1983. A major factor in their withdrawal was not in fact their age, but the opening of the Gotthard road tunnel – at the time, the longest such tunnel in the world – in September 1980, which resulted in a decrease in the overall number of locos needed for car traffic in the country.
One Ae3/5 survives – 10217, which is in the care of Team 10439 Historische Loks at Olten. It makes occasional forays onto the main line.