Lock Uelzen

The Uelzen lock is a double lock about seven kilometres southeast of the district town of Uelzen on the Elbe Lateral Canal, which connects the Mittelland Canal near Wolfsburg with the Elbe near Lauenburg/Elbe. In addition to the Lüneburg ship lift, the Uelzen lock is the second descent structure in the course of the Elbe Lateral Canal. Near Wrestedt at canal km 60.62, the lock overcomes a height difference of 23 metres. After its completion in 1976, it was the lock with the highest drop height and the largest savings lock in the world in Germany.
In order to ensure the reliability and continuity of the Elbe Lateral Canal in the long term and to enable an increase in shipping traffic, the construction of a second lock was started in 1998, so that two locks that can be used independently of each other are available for shipping. Both locks are capable of smuggling convoys with two barges or two large motor cargo ships at the same time.

Wikipedia