I-5 bridge over Skagit River, WA collapses
 

[URL]http://www.king5.com/news/local/Report-I-5-bridge-collapses-over-Skagit-River-cars-in-water-208758631.html[/URL]

[QUOTE]MOUNT VERNON, Wash. -- The Interstate 5 bridge over the Skagit River at Mount Vernon collapsed Thursday evening, dumping vehicles and people into the water, the Washington State Patrol said.[/QUOTE]But we can't afford silly infrastructure spending.
[QUOTE]Bart Treece with the Washington State Department of Transportation tells KIRO Radio the bridge has been inspected on a regular basis. "We're checking the maintenance schedule. We wouldn't let anyone drive over something dangerous," he says.[/QUOTE]


Maybe this belongs in the "Things that make you go hmmm..." thread.

Bridge hit by truck with oversized load
 

Update:
[QUOTE]While the cause of the collapse was being investigated, witnesses reported seeing [URL="http://images.bimedia.net/images/052313skagitbridgetruck.jpg"][B]a semi-truck with an oversized load[/B][/URL] crossing the bridge and striking the beams on the north end before the bridge collapsed.
"I saw it. I was less than 50 feet away from the truck when it hit it," witness Dale Ogden told KING 5. "I had just passed it in the fast lane southbound and it had an oversized load. It was approximately 12 feet wide and over 14 feet tall. It was in the slow lane when I came by...I was behind the flag car and in front of the truck in the other lane and I saw the whip - normally tells you how high they can clear - start hitting the bridge. I looked in my rearview mirror knowing this was not going to turn out well."
"I saw the truck strike the right corner of the bridge. It almost tipped the truck over but it came back down. It tipped it up to about a 30 degree angle to the left and it came back down on its wheels and almost instantaneously behind that I saw girders falling in my rearview mirror."
[/QUOTE]

Video of bridge
 

There is a telephone voice-over from the driver quoted above, describing what he saw. He says that the pilot car preceding the truck was not far enough ahead for the truck to stop when the whip indicator on the car hit the bridge.

[url]http://www.king5.com/home/Witness-recounts-oversized-truck-striking-bridge-208767601.html[/url]

[QUOTE=kladner;341414]But we can't afford silly infrastructure spending.[/QUOTE]

Do you stand by that, or are your posts 2 and 3 intended as a retraction?

[QUOTE=ewmayer;341468]Do you stand by that, or [B]are your posts 2 and 3 intended as a retraction?[/B][/QUOTE]

Absolutely not. The age and design of this bridge could have contributed to the chain of events. That a collision precipitated this collapse does not diminish the crying need for infrastructure rehabilitation in this country. Such rehab would be money well spent as it would create a great deal of employment and economic benefit, as well as providing "for the general welfare" in terms of public safety.

I realize that you have a very strong anti-spending ideology. I do not share that view. The nation's credit is good. Interest rates are almost negative (if you are not taking out student loans). If the tailor-made loopholes for corporations and the wealthy were plugged there would be a great deal more revenue as well. When we see major oil companies, defense contractors, and fabulously profitable tech companies like Apple and Google paying small or even negative taxes by means off-shored profits (and jobs!) and other shell games, it is clear that they are not doing their part to support the society which makes their profits possible.

[QUOTE]The bridge is not considered structurally deficient but is listed as being "functionally obsolete" - a category meaning that their design is outdated, such as having narrow shoulders or low clearance underneath, according to a database compiled by the Federal Highway Administration.

The bridge was built in 1955 and has a sufficiency rating of 57.4 out of 100, according to federal records. That is well below the statewide average rating of 80, according to an Associated Press analysis of federal data, but 759 bridges in the state have a lower sufficiency score.[/QUOTE]

[QUOTE=kladner;341481]Absolutely not. The age and design of this bridge could have contributed to the chain of events. That a collision precipitated this collapse does not diminish the crying need for infrastructure rehabilitation in this country. Such rehab would be money well spent as it would create a great deal of employment and economic benefit, as well as providing "for the general welfare" in terms of public safety.

I realize that you have a very strong anti-spending ideology.[/QUOTE]
Not so. What I do have is a very strong "we must live within our means" ideology. Given current levels of taxation and the known "continuous maintenance" aspect of public infrastructure, there should be more than enough money in current revenue stream to maintain 'our crumbling infrastructure', but warped influence-peddling-dominated spending priorities instead cause it to go to "other uses" which have little to do with "the public interest", and many of which are directly contrary to the public interest. ("Rewarding corruption" being the broad rubric here).

[QUOTE]I do not share that view. The nation's credit is good. Interest rates are almost negative (if you are not taking out student loans).[/QUOTE]
By "good" you mean "the nation's central bank is willing to print money to buy as much newly-issued debt as needed"? Because it sure isn't getting funded via actual "markets" of willing buyers and sellers getting together and agreeing on terms. Give me a printing press and immunity from counterfeiting statutes and my credit becomes pretty good, too. U.S. has been averaging over $1 trillion in annual deficit spending for 5 years and counting, federal budget is over 20% of GDP (highest ever except for WW2) - and we're supposed to believe there's not enough money in there to maintain the nation's highways and major public infrastructure?

[QUOTE]If the tailor-made loopholes for corporations and the wealthy were plugged there would be a great deal more revenue as well. When we see major oil companies, defense contractors, and fabulously profitable tech companies like Apple and Google paying small or even negative taxes by means off-shored profits (and jobs!) and other shell games, it is clear that they are not doing their part to support the society which makes their profits possible.[/QUOTE]
So get the revenue, then fix the infrastructure. Because history has shown innumerable times that funding such stuff via borrowing ends in tears, by avoiding the need for fiscal discipline.

I agree that multinational corporations need to pay their fair share (meaning some % closer to average private-citizen income tax rates - and note that corporations would be paying taxes only on *net* income, whereas you and I pay based on gross), but use that to end the flood of red ink. Again, there is plenty of money in the current massive budgets to fund infrastructure, the problem is spending priorities. Unless the exponential growth in annual entitlement spending is stopped in its tracks, in a frighteningly short time not even 100% corporate taxation will be enough to balance the budget.

I simply found it interesting that you instantly leapt to the assumption that the bridge was ill-maintained, even after hearing of the big rig's damaging the structure. Sure, it may be that the bridge was poorly maintained as well, but all we know for sure is that a very large truck damaged the structure right before the collapse. You are making assumptions not in evidence.

Anyhoo, here is a [url=http://www.nytimes.com/2013/05/25/us/washington-state-bridge-collapse-highlights-infrastructure-needs.html?ref=us&_r=0]NYT piece[/url] on the infrastructure-funding aspects which predictably touts the "highlights funding needs" meme.

On the other side of the debate, here is a piece from [url=https://en.wikipedia.org/wiki/Governing_%28magazine%29]Governing.com[/url] - I include the Wikipedia link so you can see that this is not a right-wing screed - on the matter, which flatly contradicts the "crumbling bridge" claims:

[url=www.governing.com/blogs/view/gov-washington-bridge-collapse-not-example-crumbling-infrastructure.html]Washington Bridge Collapse: Not an Example of 'Crumbling Infrastructure'[/url]
[quote][i]Governing[/i] spoke with Paula Hammond, the former head of the Washington State Department of Transportation Friday morning. She led the agency from 2007 until February, when newly-elected Gov. Jay Inslee replaced her.

[u]She says even if the agency had vastly more resources, that bridge [i]still[/i] wouldn't have been a priority because it wasn't in poor condition[/u]. "I resist the notion that everyone says 'this is why we need more revenue,'" Hammond says. "There's a lot of reasons we need to invest... this isn't the example."

The bridge was rated 47 out of 100, according to the state transportation department, the [i]Associated Press[/i] reports. But Hammond says that's not a particularly bad rating, and the bridge wasn't considered unsafe.

The real problem, she explained, may have been its size: it wasn't designed to carry 70,000 vehicles a day, and it had narrow shoulder lanes. If it was built today, it probably would have had a taller truss span as well.

"Eventually, we probably would have gotten around to replacing it, but what we really were worried about and always were is the structural safety of these bridges," Hammond says. And according to her, that wasn't an issue with this crossing.

State officials are blaming the collapse on a truck with a high load that crashed into an upper part of the span, striking a girder and causing a chain reaction. There are also reports that the load was too wide for the bridge as well.

Joshua Schank, head of the Eno Center for Transportation, a Washington-based think tank, says it's clear that whatever reason the bridge collapsed, that truck shouldn't have been on it. Now the question is how, exactly, was the truck allowed to get there?[/quote]

Hi Ernst,

I can't take on everything you say right now. I will stipulate that I may have misconstrued your position on economics. Do not, however, take this point as a change in my position.

I will also mention that I was on this story and posted before the truck aspect had hit the news stream. The original local story may have been posted at 19:18 PDT. I posted at 22:28 CDT, or an hour and ten minutes after the original story. At the time it was uncertain how many people and vehicles were in the water, and what condition the people were in. Most likely the story I linked to had been augmented by the time you saw my post. My immediate thought was of the Twin Cities bridge disaster, which prompted my sarcastic reference to infrastructure investment.

I continued to update the next day when much more information was available. I will return to this when I can, but discussion with you does require rather careful work. Don't take it wrong if I comment on lighter topics which require much less effort in the meantime.

Kieren: Fair enough - I would rather wait for a well-considered reply than have things devolve into a shouting match.

[QUOTE=ewmayer;341491]Kieren: Fair enough - I would rather wait for a well-considered reply than have things devolve into a shouting match.[/QUOTE]

I will do my best to avoid such a devolution.

EDIT: Update: A very interesting explanation of the mechanics of a truss, and its collapse. This does raise the possibility that the amount of force required to cause catastrophic failure was substantially less than I had imagined. It still leaves other questions like clearances up for discussion.
[url]http://www.king5.com/video?id=208876421&sec=548932[/url]

[QUOTE]This does raise the possibility that the amount of force required to cause catastrophic failure was substantially less than I had imagined.[/QUOTE][url]http://www.mersenneforum.org/showthread.php?t=17572[/url]

:razz:

I have yet to try the bridge game, Mike. Perhaps I fear getting hooked.

Ernst- This is going to be a piecemeal effort as there are two components: structural and economic. The economics, along with the ramifications already alluded to are much more difficult to address, but I am not forgetting them.

On the structural front, the description of the impact is that the semi was tilted to an estimated 30 degrees before coming back down. Considering the total mass of truck, trailer, steel container, and contents (said to be drilling equipment-very massive stuff), we can suppose that there was indeed an incredibly energetic blow delivered to whatever part of the truss was involved.

The normal weight limit for large trucks of which I am aware is 80,000 pounds. I think we can safely guess that this rig weighed in at a lot more, and that the trailer would have had more than the usual number of axles to keep the per-axle loading within tolerances. This suggests that the rig itself would be far heavier than the average 18 wheeler.

These ruminations are in the vein of projecting hypothetical evidence related to the causes and mechanism of the accident. I lack real engineering background to make actual force estimates, so I am reduced essentially to saying that the forces involved would be really, Really Big.
[YOUTUBE]eBqe5xvYnNc[/YOUTUBE]

Granting then, that once the bridge component was hit, collapse is totally understandable, we are left with asking how it came to be hit. This will involve the dimensions of the truck and load, the various clearances within the bridge truss, and most of all, [I]the[/I] [I]distance between the pilot vehicle and the loaded truck, and the speed at which they were traveling.[/I]

If I remember my drivers' ed correctly, the rule of thumb for following distance is one vehicle length per ten mph of speed. However, this is for passenger vehicles. Large things like trucks, trains, and ships require much more distance to stop. Off the top of my head I would hazard a guess that the pilot should have been [I]at least[/I] half a mile ahead at Interstate speeds.

I will wrap up this episode by saying that it seems very likely that the load and pilot vehicles were traveling too fast and/or too close together.