This FINEL animation shows the locking process of a ship lock, including the culvert.
Salt sea water (red) is at the left side of the lock and fresh water (blue) at the right side, in the canal.
Successively the following processes are shown:
- filling the lock to canal level: fresh water enters the lock through the culvert;
- opening the doors at canal side;
- salt water flows from the lock into the canal;
- by opening the culvert between the upper and lower reach, the salt water flows through the culvert back to the sea;
- closing the doors at canal side;
- levelling down the dock to sea level: water flows from the lock through the culvert to the sea;
- opening the doors at sea side;
- salt-water wedge enters the lock at the bottom, reflects at the end of the lock and flows back at the surface.
The grid used for the calculation is shown below.