The smallest means of rail traffic was the 600mm narrow gauge (apart from the fun railways). They sometimes operated extensive tracks while pulling unbelievable weights.
They were responsible for many villages being connected to the "world" and transported farming and forestry products at low costs to the readily growing towns.
Their weight and speed also caught the interest of the Army which made use of the narrow gauge system in both world wars.
But they also helped to repair the damage caused by these two destructive events by acting as rubble trains afterwards.
Forgotten for a long time, museums and clubs have rediscovered the narrow gauge in the last 15 years operating them on rebuild or new tracks.
The Steam Spectacle hosts two steam field railtracks:
the heavier variety on the Ehrenbreitstein bank of the river Rhine
the lighter version along the river Moselle.