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How does the Dwight D. Eisenhower Lock lift ships into Lake St. Lawrence?

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Map showing the St. Lawrence hydrographic system and the five main sectors of the St. Lawrence Seaway project, stretching from Lake Ontario near Kingston through various locks, canals, and dams along the Canada-United States border to Montreal. The map highlights key locations such as the Thousand Islands, International Rapids, Lake St. Francis, Soulanges, and Lachine sections, with detailed labeling of major locks, canals, and power dams. Cross sections of the lock and canal system are depicted — St. Lawrence Seaway The St. Lawrence hydrographic system, with the five main sectors of the St. Lawrence Seaway project.

The Dwight D. Eisenhower Lock is a navigation lock that lifts ships 11.6 metres (38 feet) into Lake St. Lawrence as part of the St. Lawrence Seaway.12

Like other locks on the seaway, it functions as a rectangular chamber with movable gates at each end. To lift a vessel, the process follows these steps:34

Entry: The ship enters the lock chamber from the lower water level (the lower pound).34
Sealing: The downstream gates are closed to isolate the chamber.34
Filling: Water is introduced into the chamber through sluices—typically located in culverts within the lock structure—until the water level inside the chamber rises to match the higher level of Lake St. Lawrence.34
Exit: Once the water levels are equalized, the upstream gates are opened, allowing the ship to proceed into the lake.34

This operation is managed via a control panel, often by a single operator, and is designed to minimize turbulence while maximizing the speed of the lift.534