Every day, on the way to work we go down the street, and every day we see the sewers, but we never think - why manhole cover round?But this is no accident, and this is the explanation.Let us know and we will.
In fact, not all manholes round, a shape have only hatches located on the roadway.The round shape - convenient because to this hatch can be approached from either side, and on the road, with active heavy traffic - it is very important.
In addition, the circle - a geometrical figure having the largest area for a given perimeter, in other words - the round shape helps to save material, and given the mass of hatches, the savings will be quite substantial.Hence another conclusion - round hatch has the lowest weight at the same area, in comparison with other forms (square, oval, triangle, etc.).It should also be remembered that the hatch closes the pipe, which has a rounded shape, and in this case with a circular hatch pressure tube is minimal, moreover on a circular hatch pressure also evenly di
Probably everyone watched as workers come from the open hatch cover.They throw it on the asphalt (do not blame them for it, because it weighs about 53 kg), a circle has no corners that when such a collision could cobble together, durable - this is one answer to the question - why manhole covers round.
Recently, when the metal technique was very popular in our country, iron hatches changed to concrete.Concrete less durable, more cumbersome and, by design, Government, it did not have to steal.Cottagers clearly did not agree with this statement, and the government quickly began to elevate dachas sidewalks of concrete manholes.In the end, everyone returned to the cast iron.
But back to the subject and think - why round hatches?Perhaps the most important reason - is security.It would not have tried, but to throw a round hatch in the sewers you will not work, but other forms can cheat.This reason seems strange - someone will come to mind to throw off the manhole into the sewer?But, believe me, wanting very much.
These are the main reasons that make the round hatch.