Roco H0 Ro Express steam locomotive 18 201 with caboose

In the 1960s, the testing facility in Halle needed another high-speed steam locomotive to test new passenger coaches. The new machine, 18 201, was developed from the high-speed tender locomotive 61 002 and parts of the high-pressure experimental locomotive H 25 024. A modified new boiler from the series 22, featuring an extended smoke chamber and a Giesl ejector, served as the steam generator. To ensure precise speed maintenance during fast travel, the locomotive was equipped with a counter-pressure brake. Fast travel meant speeds of up to 175 km/h, as the 18 201 was initially approved for this maximum speed ‒ later increased to 180 km/h ‒ but only in the forward direction.