| In the 1920s stronger locomotives were needed for the Swiss rail system (which has grades up to 12‰ outside mountain lines). The existing locomotives with three driven axles were a bit weak for their services. Because the Buchli drive already proved to be reliable on the Ae 3/6 I, two prototypes of the Ae 4/7 were ordered in 1925. Subsequently, in total 127 were built between 1927 and 1934. These two Ae 4/7 are stored and getting rusty, maybe they never run again. |