The Hohenzollerische Landesbahn AG operates a private railway in South East Baden-Württemberg connecting rail routes and bus lines. New construction work was initiated for rail vehicles in Gammertingen on the Swabian Alb. A washing station was already erected on the company grounds to clean the traction vehicles at regular intervals that operated using rainwater harvesting.
Since 2000, most of the required water is provided by rainwater. It flows from the roofs of the new siding and maintenance building through a filter shaft to the storage tank. The required amount of water is automatically pumped into the wash water treatment system. Drinking water is saved and excess rainwater is avoided.
The central part of the system is a WFF 300 vortex fine filter by WISY AG which is integrated into an underground shaft and is easily accessed for regular inspections and cleaning.