Several times every year, the operational historic locomotives of SBB Historic in Olten are showed during "fitness runs" for preventing standstill damages. Here we can see the express train locomotive Be 4/7 # 12504. which was built in a small series of 6 by SLM and SAAS in 1921/1922 for the Gotthard line, with 1770 kW and 80 km/h maximum velocity. Together with SLM, SAAS had offered a locomotive that did not have a rod drive, but a single-axle drive. The proposed drive came from the Westinghouse company in the USA. The Sécheron company had acquired the license for exclusive use in Switzerland. There were no experiences, particularly with an output of over 500 kW per wheelset. Nevertheless, an offer was submitted. The 6 locomotives proved themselves well, and the staff particularly appreciated their excellent running smoothness. After the newly delivered Ae 4/7 locomotives were increasingly used on the Gotthard line from around 1930, the 6 Be 4/7s were transferred to western Switzerland and used on the Simplon line, among others. For a long time, the Bern depot and later Biel were the places of operation, so the locomotives were never actually seen in central or eastern Switzerland again. The decommissioning of the 6 locomotives took place between 1966 and 1976, # 12504 was classified as a historic locomotive and was stationed in Biel until 2014, since then in Olten. The locomotive is not part of the core fleet of SBB Historic, but is maintained and operated by the "Team 10439" group.
