The Surprising Efficiency of Canal Locks

Practical Engineering · 2M views · 2020 · 10:37

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Civil engineering & constructionShips, submarines & maritimeexplainer

Why Hacker News recommends it

Linked in Panama Canal threads as a clear diagrammatic explanation of how locks save water.

What it is

Practical Engineering explains how canal locks work, including the water-saving basins of the new Panama Canal locks.

Recommended by 2 HN commenters across 2 different months, 2023 to 2024.

What Hacker News said

Recommends stickfigure · 2023-08 · on “Panama Canal Draught Restrictions Spark Liner Surcharges”

For anyone interested in how the new (bigger) locks use less water than the old locks (reclaiming 60% of the water - without pumps!), this old Practical Engineering video explains with diagrams: [this video] They store the water in a series of basins at different levels, and use those basins to fill the portion of the lock below. It's more obvious with diagrams.

Recommends FriedPickles · 2023-11 · on “Panama Canal is so congested that one ship owner just paid $4M to skip the line”

I enjoyed this well made video illustrating how it works: [LINK] And this one explaining how reservoirs can be used to trade-off water consumption for land requirements using side ponds: [this video]

Cites krisoft · 2024-01 · on “Panama Canal drought forces Maersk to start using land bridge for Oceania cargo”

> without saying anything about which one is used how and where I agree that it is strangely edited. But to help you out with the info: both are used on the Panama canal. There are two paralel sets of locks, the older ones and a more modern ones. The more modern ones can fit a bit bigger ships and they are more efficient with water. This is a wikipedia page about the expansion project (the one which also constructed these more modern locks): [LINK] And here is a video on how one can construct a “water saving lock” from Practical Engineering: [this video]

Cites nostrademons · 2024-01 · on “A drought has forced authorities to further slash traffic in Panama Canal”

They do pump water out and back into the locks from neighboring storage. There is a limit to the minimum amount of water that you can use, though, since the potential energy to raise the ship comes from the loss of water. [this video]