KNOW WHY MANHOLES ARE ROUND IN SHAPE !!

You might have noticed that most manholes, and their covers, are round in shape.We will discuss the reason behind the round shape of manhole cover in this article.

1.Mishandling the Manhole cover-A round manhole cover cannot fall through its circular opening, whereas a square manhole cover could fall in if it were inserted diagonally in the hole.

2. Rolling the Manhole Cover -A round manhole cover is easily moved and rolled.

3. Strongest shape-When a square or rectangular manhole cover is subjected to sudden vertical compression (think of a very heavy truck driving over it), the weakest spot, the center, isn't equidistant to all supporting sides, especially the corners, which give support from two directions and are thus the strongest points (for similar reasons, experts recommend you stand in the corner of a room during an earthquake). With a circular cover, the center is equidistant from all supporting sides, and due to the gradual curve, any point along the edge gives almost as much support as a corner on a square cover. Circular shape results in uniform stress distribution.

4. Circular covers don’t need to be rotated or precisely aligned when placing them on the opening.

5. Round tubes are the strongest shape against the compression of the earth around them, so the cover of the tube would naturally be round as well.

6. It’s easier to dig a circular hole.