Lock Operator

• No pumps. "No pumps are used at the Panama Canal, the water does its work by force of gravity alone." (ACP). Here too: water only moves downhill through the culvert valves.
• Real dimensions. Chambers are 110 × 1,000 ft, and the Gatun flight lifts ships 85 ft in three steps (ACP). Each step here is 85 ÷ 3 ≈ 28.3 ft, so filling one step takes about 110 × 1,000 × 28.3 ft³ ≈ 23.3 million US gallons.
• Gates. The miter gates can only open when the water is level on both sides, which is why operators equalise through the culverts first.
• Simplified. Flow follows Torricelli's law (faster with a bigger height difference) with one tuned valve size, time runs 90× faster than real time, the three steps are equal, and the ship moves between chambers without locomotives. The water bill counts only water in the lock system, not the ship's own displacement.
• For scale: the Panama Canal Authority said in 2002 that a full transit of the original locks uses about 52 million gallons of fresh water.

Sources: ACP, Design of the Locks · ACP statement, March 2002