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I was trying to think of something to say about the Minneapolis bridge collapse but having looked at the pictures on the news the best I can come up with is ' I'm glad I wasn't there' - my deepest sympathies to all involved.
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"One onlooker said he thought he heard a pneumatic drill being used at the bridge shortly before the disaster."
If true, just imagine how the drill guy feels this morning if he's still with us.
Pretty nasty business and the worst timing (as disasters tend to be) right in the peak of rush hour.
I just hope lessons are learned (for once, though wouldn't be tempted to hold my breath) and it doesn't turn into a witch hunt.
Obviously there are people out there who have lost loved ones.
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Sometimes you see these thing - bridges, tall buildings etc, and wonder to yourself, 'are they really safe?', and then you dismiss that thought as being ridiculous. Just goes to show.
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Tacoma Narrows was another bridge failure in the US, though I think there were no fatalities. The bridge developed vibrations that were induced by the wind, and it shook itself to bits.
www.enm.bris.ac.uk/anm/tacoma/tacoma.html
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On CNN there is video footage of the bridge going down. It seems to just fall, very much unlike the Tacoma Narrows bridge which swayed violently for ages.
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I have been looking at the CNN live footage for several minutes now. Some very good close up shots from the helicopter. There is a crane lorry with its flashing lights still on and it is half underwater. Roadworks were obviously taking place. It will be interesting to find out what caused this one.
Sympathies to everyone involved. Can't think how the people on the other bridge must have felt.
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SNIP - although your comment was tongue in cheek, please try and show some respect - DD
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With lane restrictions, there will have been far fewer vehicles than a normal rush-hour so surprised it came down unless some serious structural problem. And they were only resurfacing the bridge so not doing much structurally.
My thoughts are with those lost or injured. A terrible tragedy for all.
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This bridge was apparently deemed structurally deficient 2 years ago but not being replaced until 2020. So if not 100% okay why still let so many vehicles use it? In fact it got a 50% sufficieny rating but still carried the same amount of traffic.
Furthermore, the bridge design is referred to as a "non-redundant structure" meaning one failed part could bring the whole lot down! So the centre span is on four pillars, any one of which could have brought the whole lot down. If this bridge was built only a few years later it would have been designed differently then.
www.visi.com/~jweeks/bridges/pages/ms16.html
Makes one realise how we rely on such structures and entrust our safety and lives on the judgement of others.
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Forgot we cannot reference that other newspaper: tinyurl.com/2kxaas
Looking at one of the pictures in the newspaper article, you see another (4-lane) concrete type bridge with "pillars" in the water. In 1967 the failed bridge was built without supports in the water to allow river traffic to navigate underneath. So how come the Cedar Avenue Bridge in the background is built this way...
And if there is a four lane bridge next to the eight lane bridge surely a diversion could be implemented whilst the I-35 interstate bridge was fixed or even replaced. Heck there's loads of other bridges near (looking at Google Earth) including:
- Hennepin Av
- Third Av
- Washington Avenue
- Northern Pacific
- Dartmouth
I know this was the Interstate bridge but it was 40 years old.
And now instead of planning for a closed bridge we have a tragedy.
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Not detracting from the severity of this situation but makes you wonder what they are playing at with the Forth Road Bridge.
Resent survey reported it has rusty main cables but they are OK until 2018, but HGV's might not be able to use after 2013...which means they have no idea beyond the end of next week how long it's going to last really.
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And how would the Forth Road bridge take a few 44-tonne HGVs? Aren't they still debating what to do... it's obvious something needs doing and the sooner they start...
A bridge over some railway lines just north of Stockport is being replaced/repaired because not strong enough anymore. Causing some chaos as it's one of the main roads into Manchester.
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they're currently trying to 'dry out' the cables on the FRB. If you'd seen all the reinforcements they've had to do to the towers over the years it beggars belief that they've dragged their heels over a replacement for so long. Maybe this will make them sit up a bit.
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Shocking news.
I was surprised to hear this morning that the search/rescue/recovery attempts had been suspended overnight?? I thought at the time that was a bit odd for such a disaster when not all had been accounted for. Then at lunchtime I hear on the radio that the decision to halt proceedings overnight has now been widely criticised.
Old Steve
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Very sad incident!
Just wondering how does it happen! Is USA now becoming 3rd world country? Depreciating dollar and these incidents are probably saying something!
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I bet few remember the Tasman Bridge collapse in 1975. 12 died, it was still discussed when I was there some 20 years later It is also now a case study of how a major transport artery failure can cripple the local economy. Some say it put back the Hobart economy back by 12 years,
Mind those who have been to Hobart consider it to be in a 30 year lagging time warp anyway.
------------------------------
TourVanMan TM < Ex RF >
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I Googled "Bridge collapse" this morning and there were 3.45 Million articles. Try it and just read page 1 and look at the severity and then reply telling me how many you remember. I was quite taken aback.
BR........MD
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I have always been uncomfortable about this bridge in our area
As an aside, look at the steel industry that was underneath it in 1970.....
www.rotherhamweb.co.uk/tinsley/viaduct.htm
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Ah, good old Tinsley Viaduct. It used to be interesting to be rolling along up to the traffic lights on the lower deck, and feel the whole thing oscillating due to the motorway traffic. Does it still do that, I've not been on it for a while?
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don't know about Tinsley viaduct but I've got fond memories (?) of being on the Forth Road Bridge and looking across at the other carrigeway and being able to see and feel the up and down motion. A most disconcerting feeling as you drove across.
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Tinsley viaduct.
What is happening with it ? I recall, from living in Sheffield, that the original idea of removing/replacing it was sounded as early as 1970.
Did they manage to remove the old power station cooling towers or are they also an ongoing issue there ? A quick Google earth (not sure how up-to-date these maps are) shows them as still being there.
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Yes the cooling towers are still there. There was talk of demolishing them some years ago but there were fears that the impact of the collapse could damage the viaduct. There have been various proposals of what to do with them, just found a website that says one was to turn them into a vase sculpture with giant flowers in them... What a terrible idea!
www.peakdistrictview.com/?page=place&placeid=1625
When they did the latest viaduct stengthening works, the M1 was reduced down to 4 lanes to reduce the loading in line with EC standards, and its going to remain as 4 lanes from now on. So there could be plenty of life in it yet.
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Tinsley viaduct always reminds me of the US bridge that pancaked onto the bottom deck some years ago. Or was it Japan?
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What about the Warburton Toll bridge near Warrington. That's pretty rusty. Okay does not take many cars... but who pays for upkeep when the toll is 12p each way!
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Better late than never I suppose:
news.bbc.co.uk/1/hi/uk/6929574.stm
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We are going to read a lot about 'redundancy' in bridge engineering in the near future.
The bridge that collapsed in Minneapolis was a spidery steel structure with virtually no redundancy. In my opinion it was an elegant structure in an up-yours sort of way, but that is because I like things that are functional but cheap and don't try to hide the fact.
However building cheap is one thing, neglecting maintenance is another. And if deep corrosion is going to be allowed to take hold of the thing, it would be better not to build it too cheap, capisce?
It is no coincidence that Ronan Point has already been mentioned in this context. They don't build flats like that any more, and my guess is that they won't be building many more bridges like that in the US. Pity, because as I said the thing had some elegance.
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Yes the cooling towers are still there. There was talk of demolishing them some years ago but there were fears that the impact of the collapse could damage the viaduct. There have been various proposals of what to do with them just found a website that says one was to turn them into a vase sculpture with giant flowers in them... What a terrible idea!
They could put several wind turbines in there disguised as sun flowers :)
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I know bridges in UK now under scrutiny just in case but this on the beeb website I find a bit worrying:
'The Forth Road Bridge is having an £8m dehumidification to dry out the cables, after engineers recorded the sound of wires snapping inside seven layers of waterproofing. And the Severn Bridge is getting a similar £20m "blow-dry". '
Wires snapping! So how many snapped. Whereas far older bridges like the Clifton Suspension (over-engineered?) they say:
"The Clifton Suspension Bridge, for example, has six parallel chains which could each be taken away without causing the bridge to collapse."
Although I assume you could not take them all away...
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It is fortunate that bridges were built with a great deal of redundancy as far back as the middle ages, built well in excess of the demands expected to be put upon them simply because engineers could not calculate loads and stresses so as to be able to build something only 10% stronger than it needed to be so they ended up with structures that are many, many times stronger than they needed to be.
This enables bridges that were designed for half a dozen horse & carts a day to cope with 100 arctics and a 1000 cars.
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I believe it was a truss girder bridge and from the reports the bearings on which the bridge rested were corroded and prevented proper movement (expansion/contraction due to temperature).
All it would have neededis to overstress the tops or bottoms of the trusses over a few years until metal fatige set in ... and one sudden shock...and it could collapse along the whole length of the bridge...
It may be a coincidence that remedial work was underway at the time...
madf
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