Despite the expansion, boats on the Lahn could travel fully loaded only from Gießen to Löhnberg. There, they had to lighten their load in order to reduce their draft and continue the journey. Also, this was only during two to three months. In a further four to five months per year, the load had to be reduced even earlier due to the low water level. The rest of the year the Lahn was not passable. From Wetzlar to Lahnstein, where the freight was unloaded onto the large barges of the Rhine, the boats took three to four days. A trip from Wetzlar to the mouth and then towed back with horses lasted for about 14 days in good conditions. At that time, there were mainly two types of transport boats in use: those with a capacity of 350 hundredweights and a larger variant with a capacity of 1300 hundredweights.