Taking the bus to the station I’ve noticed that the London borough of Richmond, where my mother lives, has some odd signage. Take “Weak Bridge”:
In an ideal world, Richmond Bridge could bear the weight of an Atlas V rocket:
or two columns of Russian tanks blasting their way across the Thames,
but right now we’re all making do with the 18 metric tonne sign. The weight limit is there for any lorry drivers to see, so to freak everyone out with the unnecessary commentary is just a public display of passive-aggressiveness (“Don’t blame us. We TOLD you it was weak.”) from some whiney person down at the council offices.
The warning of ducks crossing the road near Ham Common is more sensible. Though I’ve never seen a duck there myself it doesn’t mean they don’t exist.
But what about this crossing sign I snapped from a bus on the same stretch of road. I’ve never heard of the Humped Pelican and Google knows it only as a sign. Surely it’s a whimsical British Tourist Board prop to make the punters feel they’re getting their money’s worth of wacky Englishness.
A Bad Guide 
Military troops are supposed not to march all together over a bridge. “Rompez le pas !” Otherwise lethal oscillations could be induced in the structure.
But 1.5 ton maximum load over a bridge, does that sound plausible?
Or is it 15 tons?
By the way, “ton” or “tonne” — short or long?
I think a “ton” is still 2,000 lbs (pounds) in US [and? UK measure?
While a “tonne” is a metric ton of 1,000 kilos.
Anybody got more up-to-date or politically correct ideas?
On the third hand, I’m not sure there aren’t “short” and “long” tons of some sort, not necessarily limited to orthography….?
sorry for typical and constant faillure to close assorted brackets
“t” will mean “tonne” though it scarcely matters: the calculations won’t be accurate enough for the difference between 18 tonne and 18 (long) tons to matter.
What I’d really like to see is a sign warning you to drive slowly because there are moles burrowing under the road.
Oooooo! The interwebs say that it is not the pelikans that are “humped”, but the crossing.
It’s just an ordinary pelikan crossing (common as they are…both the vulgar pelikans and their non-u crossings) but with sleeping policemen, or dos d’anes, or speed bumps. That’s what “they” say, anyway.
Damn. There aren’t even any pelikans (one sees them in parks, y’know…actual pelikans).
The name is derived from PELICON, a portmanteau of pedestrian light controlled.
How sad.
In England, “tonne” is only metric never Imperial. Often “ton” is metric too. The difference is very small (2,204 lbs vs 2,240 lbs). The “long” ton is the Imperial ton, the short ton is some weirdo US measure, 2,000lbs. You’d think, if they like round numbers, they’d go metric.
Have you ever heard of a bridge that fell apart because of that natural vibration thingy? I haven’t.
Oh well, here’s one: the Broughton Suspension Bridge, 1831. I suppose the Tacoma Bridge collapsed because of natural vibration, but the movement was caused by the wind, not by marching.
Why can’t they get the moles to burrow where the hedgehogs want to cross? Kill two birds with one stone.
“Tacoma Bridge” – tsk tsk.
Tacoma Narrows Bridge, aka, Galloping Gertie… said the Tacoman-by-adoption.
What I wanna know is do you Brits pronounce “tonne” the same as “ton”? And if so does this ever lead to confusion?
It’s (according to Wiki) pronounced the same except if you want to emphasise that you’re talking about tunnies and not tuns. But Imp. & met. are very close: 2240 vs 2204 lbs, so any confusion is no big deal, only 36 lbs per ton(ne).
That’s funny, because the Verrazano Narrows Bridge in New York Harbor is known just as the Verrazano Bridge.
1) The shooglie brig in London had to be closed when pedestrians set it ajumping and aleaping. God knows what the designers were thinking of.
http://en.wikipedia.org/wiki/Millennium_Bridge,_London
2) When the transition from tons to tonnes was being executed, we pronounced the new chaps as Tunnies: or at least we did where I worked. I imagine that stopped once everything had settled down. For many mechanical calculations the difference is slight. For buying and selling stuff, though, it can matter – that 36lb difference might be a non-negligible part of your profit margin if you are dealing with, for example, commodity chemicals.
Sometimes, Crown, the headline is enough.
“Parents of Cambridge bouncer Ian Grant tell of 18 years of pain after gangland slaying of ‘gentle giant’ who rescued hedgehogs”
P.S. Suddenly we have leaf fall. And still my believed comes in from the garden and says “shut your eyes and open your mouth”. Autumn raspberries!
God knows what the designers were thinking of.
Damn engineers! But the dampers they’ve put there made a nice feature in the end.
“All troops must break step when marching over this bridge”:
If he was sheltering hedgehogs, the gentle giant must have been done in by weasels. Hasn’t anyone in the Cambridge police read Wind in the Willows?
“But the dampers they’ve put there made a nice feature in the end.”
Yes, I like that bridge. Especially now it’s safe. And I blame Norman bloody Foster, not the engineer.
I doubt that troops marching in step have EVER caused a bridge to collapse. I think it’s all a myth. The breaking of step is just a tradition, nowadays. It makes the march a teeny bit less boring than it otherwise would be.
I believe the engineer was a firm called Arup, incidentally. Well known. In fact Alma went on a class trip to see round their London office. I wished I could have gone too.
I doubt that troops marching in step have EVER caused a bridge to collapse. I think it’s all a myth.
In the first half of the 19C many people were killed when suspension bridges collapsed – in each case from multiple causes, it appears. Various internet articles on these events often start off with a suggestion that the cause was resonance, then back down later on the the article. Perusing these articles, I conclude that monocausal arguments often collapse for a single reason – the assumption of monocausality – but not necessarily suspension bridges.
In 1831, the Broughton Suspension Bridge “collapsed, reportedly due to mechanical resonance induced by troops marching in step.” Farther down the WiPe article under Cause we read: “The conclusion was that, although the vibration caused by the marching had precipitated the bolt’s failure, it would have happened anyway.”
Similarly with the Angers Bridge (Pont de la Basse-Chaîne) in 1850. The “related bridge failures” section there links to other bridge failures in the early 1800s.
I tend to be suspicious of “vibrant” presentations precisely when they resonate with many people. So much agreement is statistically implausible: a million flies are more likely be wrong-headed, even when they are within their rights.
Well, it’s like this Scottish helicopter crash last night. It fell on the flat roof of a pub and then a few seconds later it went through the ceiling on to the dance floor:
The roof was reasonably constructed, probably, but it wasn’t designed to take the impact of a helicopter and so it failed. But it would be a pretty weird waste of resources to design all Scottish roofs from now on to take helicopter impact loads. Not that I’d put anything past Scotland’s idiot first minister, the smug-faced Mr Alex “we must all prepare ourselves for the likelihood of fatalities” Salmond.
Nowadays if you suggest two-or-more possible causes for anything, someone is bound to mention William of Ockham and his alleged razor.
It was when I read about the Broughton bridge that I realised this marching thing was probably nonsense. But armies aren’t run democratically and they sanction all sorts of unaccountable things (shooting people etc.).
Nowadays if you suggest two-or-more possible causes for anything, someone is bound to mention William of Ockham and his alleged razor.
If the two-or-more suggested causes would each by itself account satisfactorily for “the” effect, then it does not seem irrational to shave off all but one. I think it’s combinations of causes, each making a contribution but none sufficient by itself, that people are not used to considering.
However, I feel sure that Ockham had various razors for various purposes. The one that leaves a single hair standing may be the most well-known, but it’s also the most exotic and infrequently needed one. Completely useless for five-o-clock-shadow philosophy, the kind that suits me best.
To see people working in front of computer screens? Come on, Jeremy, there are better things to see in this world. There are the real things outside.
Yes, I like that bridge. — Me too, especially under the rain.
The metal grating that they’ve put on top of it is very much anti-slippery, which would help if the footbridge started swinging when wet.
She had a choice of Arup or Norman Foster or a bunch of other architects (Zaha Hadid, Richard Rogers etc.) & engineers (smaller ones). I’m sure they’ve got some interesting models and stuff, don’t you think?
Those fish are carp, that’s why they look Chinese.
Combinations of causes are much harder to write as equations.
That depends on the mode of combination Mere additivity is a snitch: flour + milk + butter + egg + sugar-and-spice + stirring + heat = cake. No one component causes cake. If you have a cake and want to determine its (possibly multiple) causes, assuming causal additivity makes it easier to solve for unknowns in succession, as follows.
Assume flour + x = cake. Subtracting the flour from both sides, we find that x = hot sweet gook. Now take hot + y = hot sweet gook. Subtracting the hot, we find that y = room-temperature sweet gook. Eventually we may reach egg, which can be decomposed into potential chicken, but this would take us into grill science, beyond the realm of baking.
Ockham said that entities should not be multiplied unnecessarily. He had no objection to addition, subtraction and division.
They do have that science of cooking course at Harvard now, it’s supposed to be massively oversubscribed and taught by the famous Spanish chef who closed his restaurant (I’ve forgotten why, perhaps he was bored) and whose name I’ll never remember in a million years…Oh, now I see he only gave the final lecture.
Speaking of blood-curdling: via a link on the Harvard page I found this under “10 Chinese Dishes That Real Chinese People Don’t Eat:
‘Kindly pass the curdled duck blood’ must be one of the things you find in a Chinese phrasebook.