Sunday, 11 January 2015

Why Are Manhole Covers Round?

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If you're in the habit of looking down at your feet as you walk, you may have noticed that most manholes, and their covers, are round. Of all of the potential shapes for manholes, why was a circle chosen?

2 comment(s):

Szwiszsz said...

They are round so they can't fall down the hole. Square or rectangular ones could fall in if oriented diagonally.

Rude African said...

A cover based on an equilateral triangle would also not fall through when diagonal.

Manhole covers are circular because manholes themselves are circular. They are circular because it is the traditional shape for wells, and its easier for a person to get in and out of.