Train-spotting is all very well. If you like cheap thrills involving dangerous, fast-moving objects, it's the perfect hobby. But for people with more mature tastes, it can seem just a bit too frantic. This is where drain-spotting comes into its own, writes Frank McNally.
I must admit that drain-spotting as a hobby had passed me by until recently. I'm embarrassed to say I had never even heard of the International Manhole Museum in Ferrara, Italy, which is inexplicably ignored in most travel books. Yet there was the museum's curator outside Dublin's Mansion House yesterday, being presented by the Lord Mayor with an "authentic Dublin manhole cover" to add to his already impressive collection.
For drain-spotters among you, I should point out that the mayor's donation was a 1960s "round Adams pattern", until recently employed at Fairview Avenue on the city's northside (manhole covers don't get any more authentic than that). Cast iron, of course. But you probably knew all this already.
There was a time when connoisseurs of the manhole cover would have had no one to share their passions with. Now, thanks to the internet, they can commune with fellow enthusiasts, posting photographs of the more exciting examples they find or exchanging information. And believe it or not, they do.
Like most people, I used to notice manhole covers only when they were missing. This could be a frequent occurrence, depending on where you travelled. Driving me around Nazareth once, for example, a guide had to swerve to avoid an open manhole: an occupational hazard, he said, especially when scrap metal prices are high.
The same trade is rife in China, where a thief can earn a good day's wages from selling a single piece. Only 4,000 were stolen last year, a dramatic reduction on 2004, when six times that number were taken. But the missing manhole cover is still a big threat to pedestrians in China and fatalities are not unknown.
In Ireland, the theft of covers peaked in the 1980s. For Dublin Corporation, it was a nuisance in itself. It also had a knock-on effect, however, creating employment in the small but highly specialised sector of compensation claiming. According to one council official I spoke to yesterday, a well-situated open hole in the mid-1980s would have people "queuing up to fall into it".
This makes the survival of Dublin's most artistic "manhole covers" - the small, footpath-mounted Joycean plaques, laid in the 1980s and presenting scenes from Ulysses - all the more remarkable. Not that they were ever likely to produce litigation.
You could hardly sue the Corpo because one of them caused you to plunge headlong into Joyce's masterpiece, to which you had previously been indifferent. But just the fact that the plaques are still there, lacking as they do anything like the weight of a real manhole cover, is a miracle.
There are drawbacks to becoming a drain-spotter. Thanks to my discussions with the council yesterday, I can never again watch a classic Cold War thriller in which people slip down manholes, pulling the lids after them, without scoffing at the implausibility of the scene. The next time I see The Third Man, for example, I will be compelled to share my knowledge on this subject.
"You know, in real life, he couldn't do that," I will mutter, just loud enough for the entire cinema to hear. "In real life, those covers weighed up to a quarter of a ton, including the frame. A single person couldn't have lifted one. Nowadays they use ductile iron, which is much lighter. But not in post-war Vienna. The ones in films are just plastic. Sure, if manhole covers were that light, there'd be one in every student's flat. People would use them as frisbees." Worse still, I may be persuaded to explain how a manhole cover became the first earth-made object shot into space, months before Sputnik 1. This sounds like an urban myth, and it is, partly. But there is a sound basis to the story, which makes it just possible that something approximating a manhole cover did escape the atmosphere.
The date was August 27th, 1957, when US scientists were conducting underground nuclear tests in the Nevada desert. Trying to prove that a particular type of device would not produce an unplanned nuclear yield, they set off an explosion in a 500-foot-deep shaft. The shaft was four feet wide and, as well as being sealed by concrete, was topped by a four-inch-thick steel plate (now popularly acclaimed as a manhole cover).
The cap was much heavier than Sputnik and lacked its aerodynamic qualities. But the scientists involved estimated that, when blown off the hole, it would be travelling at about 42 miles per second. Unfortunately, a film of the test using a high-speed camera recorded the cap in only one frame, when it was observed to be "going like a bat".
The belief that it made it into orbit rests mainly on the fact that it has never been seen since. On the other hand, the Nevada desert is a big place. It's possible that it came down again and just hasn't been found. But romantics and drain-spotters still prefer to believe that it travelled fast enough to escape not just the earth's gravitational field, but the sun's as well, and that it may now have passed Pluto, on an unplanned mission to outer space.