Bureaucracy can be intractable in Japan; many tasks can be surprisingly complicated as layer upon layer of government officialdom has to be negotiated. Back in the 1980s, the Japanese central government decided to standardise their sewerage systems - seem reasonable, huh? Well, every municipality had different ideas about what the standard should be and this seemingly simple agreement got drawn out into long and complicated negotiations with every party wanting their design to prevail. The manhole covers proved to be a horrendous sticking point. Eventually one bright chap put forward the idea of standardising the shape of them, but allowing each municipality to have their own design on top.
So what was looking like years of bickering and grandstanding turned into an outpouring of local creativity. Each municipality has its own design and many of them are delightful and quite beautiful. Quite amazing for something that's basically covering a pipe of effluent.
All the covers are made in Nagashima Foundry. The original designs are carved into wooden masters which are stored at the foundry. I wonder if they're open to the public. That'd make for an excellent museum trip.
It appears that originally the designs were all just patterns in the steel, but as time went on, the foundry figured out how to add coloured inlays and the regional designers took advantage of this, leading to some remarkably detailed and beautifully-coloured examples. Some of the old plain covers still exist in various parts of Japan, but they are becoming rarer these days.
Many moons ago, I used to run a pub quiz. It was easily the best pub quiz ever until it began to turn into a chat show. I think it was supposed to last an hour but, at its longest, it ran to four. In an effort to avoid smartphone interference, I tried to ask questions that required thought rather than knowledge. One night I asked "Why are manhole covers round?" expecting answers along the lines of "It's to make it impossible for them to be dropped through the hole." But when it came to reading out the answers, one chap decided to dispute my reasoning. When I challenged him with "And I suppose you're a manhole cover designer" it turned out that he was. So I got him up on the microphone to explain the design process and show us schematics. From that point on, I had guests every week and themed question sections around their area of work or expertise. And that's how manhole covers turned a pub quiz into a chat show.
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| Photographed in Hiroshima by M Louis |
These are just a few examples of the huge variety of covers out there. There are books about them, whole websites and there's a
Flickr group dedicated to photographs of them (which is where I got all these photos). Click the link to the group above to see thousands of pictures, including many fascinating ones that I'd have love to included here, but couldn't for copyright reasons.
So... come on... what is the explanation for round manhole covers? And, just because it never made much sense to me, why is it a 'manhole' cover?
ReplyDeleteRound ones can't fall down the hole they're covering. No matter which way you turn them, they won't fit through. Square and rectangular ones can fall down the hole if turned diagonally. And once down there, they're a bitch to get back up.
DeleteIt's a "manhole" simply because it's 'a hole through which a man may pass'. Probably only a few of them are actually manholes, but it seems to have come to apply to all such openings.
Ah. So they are round for pretty much the reason you expected. I thought this fellow who gave the talk had lots of other details.
DeleteAnd I thought the manhole cover answer was too simple to be true. Dammit. Now I will have to re-think my belief in the Bermuda Triangle mystery.
I am now deflated and will have to look at the Battle Fart pictures again to cheer myself up.
Actually, I do remember him making the point that water and sewerage accesses tend to be round, whereas those of utilities tend to be rectangular. Not forgetting that some are triangular, which apparently indicates the direction of the flow.
DeleteBut there are other reasons why covers might be round (if I recall correctly):
Round pipes and tubes are the most most material-efficient shape against the compression of the earth around them.
The edges manhole covers and their frames are machined for flatness and round ones can be done on a lathe to ensure their flatness.
Oh and you can move them by rolling.
I did mention to manhole expert that there are shapes other than circles that cannot fall through their own diameter, but he wasn't having any of it. They're called Reuleaux polygons and the 20p and 50p coins are examples of them (basically they're got rounded sides).
http://en.wikipedia.org/wiki/Reuleaux_polygon
Good collection of manhole frames, I would like to suggest some more words on manhole cover
ReplyDeleteregards,
Joshua.