Along the course of the Main-Danube Canal there are 16 locks with lifting heights of up to 25 metres (81 ft). The 16 locks are managed from four remote control centres which are manned day and night.
Thirteen locks are designed to conserve water, which they do by piping first the top third, and then the middle third of the lock water into side tanks during the down cycle. On the up cycle, these tanks replenish first the bottom third and then the middle third of the lock volume. The remaining top third is supplied by water from the upper level of the canal. For an animation of this operation see: https://en.wikipedia.org/wiki/Rhine–Main–Danube_Canal
The photo sequence above illustrates our negotiation of the Leerstetten 24.7m deep level lock. A similar sequence of photos can be found at: http://dkiel.com/danube/maindanubeoverview/maindanubeoverview.html
This link also has a 3D profile of the canal as it rises and falls over the European Divide.
