Walking home from the market one day I found my eyes drawn down to the pavement and I noticed how many different manhole covers there are in the street. As I prepared to write this I looked for some more information and discovered amongst other things that there is a famous question put to candidates in interviews, ‘why are most manhole covers round?’ It was meant to be a psychological assessment of reasoning but some of the answers are interesting. One is that it is not possible for a round cover to fall through the hole while a square one could go through diagonally.
Here are some examples of both shapes and also a rectangular one which I think could easily slip into the potable agua.
It’s incredible how many there are in just a short stretch of road.
The ones above are in Castellano. This one below in Catalan. The difference is in the agua/aigua.
If they were newly made now I wonder if they would be done with the same variety of designs?
Here is one I saw in Buenos Aires while we are on the subject – it always made me smile
Do the different patterns signify different services below? Or something else? Aren’t they just amazing? I have never thought about why manhole covers are round – don’t know if I will be able to go to sleep now!
Keep up the good work, I love your posts 🙂
Hi Joanna these ones are mostly water but there are gas and electricity ones too and I was just out with Duna and saw another small one that I will add later. It looks specially made for parks and gardens. It’s a bit covered in sand from the play area so I’ll have to wash it first. My reputation here for being slightly weird will be confirmd by this I think! Kx
I’m loving your blog, I’m following!
Would love you to enter my amazing GIVEAWAY- to win a pasta making course and meal with wine for two:
http://thoroughlymodernmilly5.blogspot.com/2011/02/best-gievaway-yet-ida-restaurant-pasta.html
xx
Hello, I think the only one you fographed for people goes inside, is the one of “Saneamiento” (“Sanejament” in català). It is round because the form of our body is also roud, isn’t it? I agree too with your less danger theory! The others are smaller, only for hand manipulation, and they are square because it’s easyer to store and install. This is my unexpert opinion… I prefer the round things!
Good question that really made me think! Hard to answer in an interview but good answers here:
I there a reason manhole covers are round?