2007-12-12 19:43:53 · 25 answers · asked by Dr. VanNostrand 4 in Entertainment & Music ➔ Polls & Surveys
I've heard that it's because it's the only shape that can't be turned on it's side in such a way as to fit through the opening and fall in.
2007-12-12 19:46:45 · answer #1 · answered by Some Guy 6 · 3⤊ 0⤋
Just about all of the newer ones are round but there are still some rectangular covers in use.
In general there has been an effort to standardize the sizes of the manholes and if a dimension is for a circular shape it requires only one number to specifiy its size whereas recangular shapes require 2, doubling the occassion for error. Thickness is of course importan dimension too but both require that.
Standard sizes are better since getting a replacement for those that dissappear (over night when some druggie has hauled a bunch off to the scrap iron dealer) is easier than rectangular shaped covers.
Many of the rectangular covers have attachments that make their passing through the opening less likely. Mostly now one sees the rectangular shapes at Drain Inlets along curb lines. The rectangular shapes are more difficult to handle.
2007-12-12 20:22:06 · answer #2 · answered by klby 6 · 1⤊ 0⤋
Because some guys that go down into the manhole have big bellies and it is a perfect shape for them.
2007-12-12 19:47:34 · answer #3 · answered by Anonymous · 2⤊ 1⤋
manhole covers are round so they dont fall in
2007-12-12 19:46:27 · answer #4 · answered by froggy_logic 6 · 2⤊ 0⤋
To fit over the round holes.
2007-12-12 19:45:56 · answer #5 · answered by MenifeeManiac 7 · 5⤊ 0⤋
any other shape is easier to displace and harder to readjust
provided the manhole cover and mahole itself changed shape
2007-12-12 19:46:08 · answer #6 · answered by fetal 4 · 1⤊ 0⤋
a circle shape would need less amount of cement or any metal, from which the manhole covers are made , and also giving a large volume of space........
2007-12-12 19:49:07 · answer #7 · answered by deepak jay 3 · 2⤊ 1⤋
I have never seen a round man hole cover only square ones
2007-12-12 19:51:14 · answer #8 · answered by M 5 · 1⤊ 1⤋
So that they will better fit over the round openings.
2007-12-12 19:46:30 · answer #9 · answered by nytebreid 7 · 1⤊ 0⤋
A very funny question and easy to answer because the circle is the smallest angle to a stairway walking down a ladder.
2007-12-12 19:46:57 · answer #10 · answered by bigapple 3 · 1⤊ 1⤋