Why Are Water Tanks Cylindrical In Shape?

I don’t know about you but i’ve always wondered that: why are water tanks usually cylindrical in shape? I mean, why not rectangular? 

I know, i know. This might sound like a silly question but it’s the way we like our articles here at I’m A Useless Info Junkie and we are proud of it (remember when we answered the question Why Are Manhole Covers Round?)

Anyway, enough with the bragging, let’s see why. (the article continues after the ad)

Water tanks are cylindrical because this is actually the best shape as it has the most uniform stress distribution. You see, the internal stress generated by the water in the tank is distributed evenly in all directions, whereas a shape with corners (such as a rectangle) will cause high pressure in its corners. This will create “weak spots” in the whole structure and which will eventually fail faster. This is actually the same reason why airplane windows are round:

Photo: ScienceABC

A rectangular airplane window, in order to cope with the extreme pressure, it will need extra reinforcement on its corners; however, the pressure on a round window is equal in all directions.

Now you know!

If you like what you read, then you will definitely love this one: Why Some Feasts Are Moveable While Others Always Fall On The Same Day? 


Main Article Photo: 6sqft
Photoshop: I’m A Useless Info Junkie

Sources: Why Do Liquid-Carrying Trucks Have Cylindrical Tankers? | Why is a water tank square and not cylindrical? | Why Airplane Windows Are Round, Explained in 2 Minutes