Locomotive Duplex was original experimental 4-cylinder locomotive, builded 1862, worked to 1900 on the line Praha - Podmokly (part of Děčín today). Prague (Praha in Czech) is the capital and largest city of the Czech Republic. ... Podmokly coat of arms. ... Podmokly coat of arms. ...

This 4-2 locomotive was last from 12 engines of the same type. Only this one was equipped by 2 cylinders on each side. Angle between crankpins on one side was 180° - pistons are going oposit directions. They had one common valve gear with crossed steam chanels. Angle between pairs of engines on both sides was normal - 90°. The Walschaert valve gear on a steam locomotive (a PRR E6s). ...

Main idea was to elliminate dynamic forces. It was successfully exhibited by this locomotive hanged on chains. It silently simulated run by maximum speed (60km/h) without swinging.