Why are manhole covers round
The best correct answer as to why any given manhole cover is round is because the pipe which it caps is round also a round manhole cover won’t fall into a hole because it was rotated the wrong way so it’s safer. A round manhole cover can’t fall through its circular opening because no matter how you position it, the cover is wider than the hole. Therefore many manhole covers are round so they don’t need to be rotated.
Covers are round because the hole is round since a manhole covers is quite heavy (200 to 300 pounds) that’s pretty helpful. Thus it is easier to dig and maintain round holes and because it’s round it can be more easily transported. Another secondary reason manhole covers are round might be for the ease of putting the manhole cover in.
A number of possible explanations for why manhole covers are round include but perhaps the biggest reason that manhole covers are round is that round covers can’t fall through a circular opening. Round manhole covers & frames however not all manhole covers lead directly down to round holes, they often lead to a larger cavern easier to move round manhole covers around by rolling them. A cylinder is the optimal shape for stacking, loading and transporting manhole covers, as well as being easier to install and maintain.
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