Want to know why hatches are round?

Every day, when we move to the city, the cover of the sewerage hatch will constantly fall in our field of vision. This object of the urban landscape has become so familiar from the very childhood and, I would even say prose, that, as a rule, we do not pay attention to it at all.

And in vain ... You never wondered why hatches are round? Not square, not rectangular, not oval, round?

I'm afraid that if earlier this question did not arouse interest, now you just want to get an answer.

Section 1. Hatches sewer: polymer, cast iron, rubber, plastic. What role do they play?

First of all, it should be noted that they are an important part of any manhole, and they are installed directly into the hull. Moreover, this item should be placed in such a way that it fits snugly enough, and does not create obstacles either when it hits it or when carrying out certain types of communication work.

If you look closely, you can see that each cover has a hole, which is designed to allow you to measure the level of gas contamination of the well.

The lid is heavy, weighing from 50 kg. And such massiveness is not accidental, it is created intentionally in order to exclude any probability of its displacement. It should remain stationary even with a very strong movement of land vehicles.

Today in the CIS countries there is not only a massive theft of lids, but also their active delivery to the points of reception of scrap metal. That is why it was decided to cover the hatches with special concrete slabs. However, this method carries a lot of shortcomings. First, this coating collapses quickly enough, and secondly, when you hit a car, it simply turns into a potential danger, causing massive accidents.

Section 2. We try to answer the question posed.

As it turned out, there are a lot of guesses about this, and in this article I will focus on three versions.

• Why are hatches round? The first explanation. Logical.

What would happen if such a cover had, say, a square shape? Well, as a matter of fact, nothing terrible would happen. Although to be frank, I'm sure it would cause some inconvenience. First of all, from purely geometric considerations. With a square cover, the diagonal dimension is greater than the length of the side, and therefore it can collapse inwards. With the round, even hypothetically this will not happen. It turns out that the latter is much safer, because It will not fall inward, and, therefore, when a freak situation arises inside the collector, workers will not be harmed, and the car will remain unscathed without driving into a hole suddenly formed on the asphalt.

• Why are hatches round? The second explanation. Funny.

Somehow I heard, as tired, apparently from a thousand "why?" A young mother, tried to answer a similar question of the baby. She said something like this: "Well, the holes are round, you see, how else can they be covered?" I smiled and thought. But in fact it is in principle right, only, but why, then, do not make square holes or is it a mere coincidence? I asked my architect friend. It turns out that a round sewer is much easier to excavate, besides it turns out to be more technological, it lasts longer and is not so much subject to transformation and temperature changes. Well, well, in this interpretation, too, there is some truth.

• Why hatches are round. The third explanation. Interesting.

Workers believe that the lid of this type is easier to transport. Well, imagine that you will need to transfer it from one place to another. If it were square, it would have to be carried, they would not have coped themselves, that's why no less than 2 people would be involved, and not weak men, because This object, as was said above, has a decent weight. But the round, if necessary, you can easily roll. In addition, the round lid is better placed on a specially designed place, because it does not need to be twisted, combining the necessary holes. And if you think about it, it's safe to transport the circle easier than a square or a triangle: hands and feet will be intact, and the edges of the hatch will not break.