To replace their older electric shunting locomotives, SBB put a new model out to tender in 2007. Since electric shunters are not the norm outside of Switzerland, there was no standard model to order. Stadler won the tender and developed the Ee 922. The original order included 21 locomotives and another order for four followed in 2013. According to the requirements, it is equipped for both 15,000 and 25,000 volts and can be towed with 100 km/h, despite its top speed of 40 km/h when running alone.
To save costs, the power electrics are mostly identical to the power module of the GTW. In contrast to the older shunters, it only has two axles. Special dampers had to be installed in the chassis to ensure smooth running at 100 km/h. To enable the operation on sidings which are not approved for an axle load of 22.5 tonnes, the locomotive's service weight can be reduced from 44 to 40 tonnes by the removal of two ballast weights.
