Ship lock operation
How a navigation lock raises and lowers vessels between water levels, the chamber and gate types, filling systems, and the water cost of a lockage.
A navigation lock raises and lowers a vessel between two water levels by enclosing it in a chamber and changing the water level inside, using gravity rather than pumps wherever the topography allows. Each lockage spends water from the upper level, which is why a lock canal crossing a summit reach is limited by its water supply as well as by its chamber dimensions.
The full article will cover chamber geometry and how it fixes the largest vessel that can pass, miter and rolling gate types, culvert filling and emptying systems, the role of locomotives and tugs in positioning a vessel, and the conservation techniques used where water is scarce, including lateral saving basins and cross filling between paired lanes. It will draw its worked examples from the Panama Canal, the Kiel Canal and the Saint Lawrence Seaway.