To increase train speeds, Sweden chose to use tilting trains on existing lines rather than to build dedicated high speed lines for even faster trains. So ABB developed the X2 that was built by Kalmar Verkstad. Each set consisted of a 4,000 kW power car, four trailers and a driving trailer. The power car had four three-phase traction motors and a GTO thyristor. Only the trailers and the driving trailer could tilt, but all axles in the whole train had radially adjustable axles. They were designed for a speed of 210 km/h, but only operate at 200 km/h in daily service.
The services operated by the X2 trains became known as X2000. The first sets became operational in 1990 and by 1998, 43 had been built for the SJ. In 1993, one set a new Swedish speed record with 276 km/h. Around the same time, some received a fifth trailer. They are also operating over the Öresund bridge into Denmark. Individual sets were brought to the USA and Norway for trials and one was even newly built for China. After the turn of the millennium, SJ evaluated an increase of the top speed to 250 km/h, but this was too costly. Plans for restoration in other respects became known in 2014 and the first modernized set was put back into service in 2021.
