Do you know why Manhole is in Circular shape Instead of Square
1. It has to be ensured that the cover of the manhole does not fall into the hole while uncovering it. To understand this, let’s assume the manhole cover to be square with side length . The diagonal will be . The cover can easily fall into it along a side. This won’t happen in case of round shape. The diameter is same along all directions.
2. The manhole circular cover will require least amount of material as the area of circle is least. Thus, the weight of the cover will be slightly less and it would be easier to move the cover.
3. The sharp corners are natural weak spots where stress concentrates. In a round manhole cover, no corners are present and the stress applied on it will be distributed evenly.
4. The manhole round covers can be easily placed and it will fit the hole without needing much precision in aligning it. The square covers will need to be aligned properly.
5. The round-shaped covers can be manufactured easily.
6. The manhole round shaped hole can also be dug easily.
7. The maintenance staff can go down/up comfortably in any orientation.
This is the reason why manhole covers are in circular shape instead of square shape.