Rollbock

[3] The Langbein system uses pairs of claws which are folded up laterally by hand, to form a yoke around the axles of the standard gauge bogies.

This method enables the Rollbock wagons to traverse curves as sharp as 15 m (49.2 ft) radius and, when fully loaded, they could be moved over narrow gauge tracks at a safe speed of 13 mph or 21 km/h.

They are also in use on the Harz Narrow Gauge Railways to transport limestone from the Unterberg quarry to Nordhausen, where they are transferred to the DB system at a pit between the station and Hesseröderstraße.

Trains are diesel-hauled and typically consist of 12 22 m3 (780 cu ft) Fccpps ballast hopper wagons from Voestalpine Railpro; the Rollböcke are painted bright pink.

Until the 1990s the Rollbock sidings at Wernigerode were used every day to transport goods to and from the various metallurgical factories attached to the Harz Narrow Gauge Railways in the immediate area.