SBB Re 420

The Re 420, originally and still widely called Re 4/4II, are a series of versatile standard gauge electric locomotives of Swiss Federal Railways (SBB CFF FFS), but are also used by BLS AG (BLS Re 420.5) and private companies (previously also by the Swiss Südostbahn, SOB). They were produced over a period of 21 years, from 1964 to 1985, and are currently used mainly for freight operations but still also for some push-pull passenger train services. It is the largest series of locomotives of Swiss Federal Railways, and they are the most common type of locomotive in Switzerland. The Re 420 LION are refurbished Re 420 engines used for peak-hour commuter rail services of Zurich S-Bahn. The Re 421 is an upgraded version built for cross-border operations. The Re 430 (Re 436 of private companies), originally known as the Re 4/4III, are a derivative of the Re 420, modified for higher traction but lower speed.