Here’s an idea for keeping subway tunnels from overflowing with water: block their entrances. How? With a “one-ton bag of high-stretch fabric” that was designed to be used to in terrorist strikes, but which — hey, why not? — could have an application to flooding, too. The New York Times:

In theory, it would be like blowing up a balloon inside a tube. But in practice, developing a plug that is strong, durable, quick to install and foolproof to deploy is a difficult engineering task, one made even more challenging because of the pliable, relatively lightweight materials required.

If you happen to have seen a picture of this thing, you may have noticed that this barrier method for fluid is nothing new. In short, it resembles nothing so much as a giant tampon. Technically, this balloon has a different operational mechanism than a tampon, but it’s sort of the same idea, and a super-absorbent subway plug might also work for some storms.

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Is it this simple? Wouldn’t it be great if it were this simple? Either it is this simple and we’ll be hearing jokes about subway tampons forever, or it’s not and the first really heavy storm will pop the plug right out or burst the balloons and we’ll only hear jokes about subway tampons for a little while longer. Either way, we got to say “subway tampon” like four times just now, so we win.