It is hard to say exactly when shipping began on the River Lahn. The Romans almost certainly used the lower reaches of this small river to transport people and materials in their manoeuvrable boats. There has been barge traffic on the Lahn at least since the High Middle Ages.
Navigating the Lahn is grueling work at first. The boatsmen use long round wooden barge poles to manoeuvre the boats through the shallow water. Downstream they are aided by the current and the wind. When travelling upstream, however, the boats have to be towed from the riverbank on long ropes by teams of people and horses.
This requires the creation of towpaths along the river banks and these have to be regularly maintained and cleared of vegetation. There are numerous mills and forges along the Lahn. Their weirs have narrow passages which are difficult to navigate.
The Lahn is continually improved to make navigation easier – as early as 1600 the navigation channel is slightly deepened along certain stretches of the river. With the advent of steam power the boats, which transport mainly marble, ores and coal, become larger and heavier. For this reason the Lahn waterway undergoes large-scale deepening and improvement in the mid 19th century. This even includes the construction of a 195 metre long navigable tunnel near Weilburg.
Only a short time later, from 1858 onwards, the Lahn shipping trade is faced with strong competition from the new Lahn Valley Railway. Rail transport is faster and remains unaffected by water levels. As a result, the number of cargo vessels steadily decreases – even new improvement measures to the navigable waterway at the beginning of the 20th century are unable to stop this trend. In 1981 the last cargo boat passes along the Lahn laden with wire rod. The barges are now replaced by passenger ships and pleasure boats that ply the idyllic river which is among the most beautiful in Germany.