Why are manhole covers round?

Answer by  jackrichard (22)

Manhole covers are round for primarily two reasons. The first is that most manhole covers are heavy, so making them round allows people to move them more easily just by rolling them on the ground. The other reason is that manhole covers of other shapes would be able to fall through the manholes.

Answer by  Tk74 (37)

It is impossible for a round manhole cover to fall down a manhole, while all other shapes can fall if dropped at the right angle.

Answer by  SubhashChander (1773)

The manhole covers are round because if the manhole is round it would be easy for the sweeper to enter into the same for cleaning and go all around without any difficulty. Moreover, the manhole covers are heavier to carry, so if they are round, these can be taken to the desired place just like a wheel.

Answer by  esteban (1334)

Manhole covers are round because manholes are round. And manholes are round because most are actually just large pipes. Pipes are used instead of square shafts because they are more cost effective and quicker to install. Sometimes, manholes are made by using augers, which are just giant sized drills for cutting into the earth. They also make a round hole.