NationStates Jolt Archive

WASHINGTON (AP) ― Safety investigators on Thursday singled out undersized steel plates as the chief cause of last year's deadly collapse of a highway bridge in Minneapolis.

But contractors working on the bridge had stockpiled construction material on the center span over the Mississippi River, and that additional weight contributed to the collapse that killed 13 people and injured 145, they said.
http://kstp.com/article/stories/S659887.shtml?cat=1

Seems the NTSB came to the same conclusion everyone with any background in stuctural engineering did, seems poor design and excessive weight are a bad combination. Failure to calculate the correct thickness of the gusset plates was the primary factor in the I-35W bridge collapse.

Conspiracy theorist Jim Oberstar is no doubt miffed about the findings.

I thought it was STB.... never mind.

when economic 'gain' (or any other idiological doctrine for that matter) is prioritised ahead of other considerations, such as durability, usefulness, longevity/sustainability, this is hardly anything to be wondered at.

when economic 'gain' (or any other idiological doctrine for that matter) is prioritised ahead of other considerations, such as durability, usefulness, longevity/sustainability, this is hardly anything to be wondered at.
What are you talking about? The bridge was decades old and miscalculation was ruled the cause of the collapse, not a misprioritisation or lack of money.

What are you talking about? The bridge was decades old and miscalculation was ruled the cause of the collapse, not a misprioritisation or lack of money.

yeah, but if only we would have spared the extra steel... :rolleyes:

Efficiency is at the heart of making everyone's lives better, economic considerations are absolutely valid if it saves a million dollars that sort of thing is what improves people's lives.

What happened? Nothing about that has been on the Finnish news.

What happened? Nothing about that has been on the Finnish news.
Nobody cares about Finnland.

A bridge collapsed in my homestate.

And the problem was not one of supply but of design.

when economic 'gain' (or any other idiological doctrine for that matter) is prioritised ahead of other considerations, such as durability, usefulness, longevity/sustainability, this is hardly anything to be wondered at.

It was built by the government in the 1960's. They probably spent $500 on each rivet.

I guess this just goes to show that you can't shortchange infrastructure spending for 40 years and expect things to go well. Just imagine if we took that $100 billion per year we're wasting in Iraq and invested it here instead...I can guarantee you there would be far fewer problems with our infrastructure than we have now.

Personally, I'd privatize a lot of this stuff and let them manage it. Have the government build it where it's needed, and then wherever possible turn in over to private companies to recoup the cost through corporate income taxes.

Nobody cares about Finnland.

A bridge collapsed in my homestate.

And the problem was not one of supply but of design.

It's Finland!

It was built by the government in the 1960's. They probably spent $500 on each rivet.

I guess this just goes to show that you can't shortchange infrastructure spending for 40 years and expect things to go well. Just imagine if we took that $100 billion per year we're wasting in Iraq and invested it here instead...I can guarantee you there would be far fewer problems with our infrastructure than we have now.

Personally, I'd privatize a lot of this stuff and let them manage it. Have the government build it where it's needed, and then wherever possible turn in over to private companies to recoup the cost through corporate income taxes.

How 'bout if we took the $700 Billion Congress just spent to keep AIG's board of directors in Caviar and Champagne, and applied it to infrastructure-I'd bet we'd get even MORE.

Or not...after all, Government will spend fifty grand on a toilet seat and ten grand apiece on claw-hammers. (not to mention the five thousand dollar ASE standard steel hex-nuts...or the fifteen thousand dollar bent-wire "tool" for adjusting the antenna on an F-15, a tool that most mechanics substitute with a section of wire coathanger.)

The bridge was badly designed...by GOVERNMENT engineers at excruciatingly high pricing (well above the rates normally paid for that sort of work elsewhere).

Personally, I'd privatize a lot of this stuff and let them manage it. Have the government build it where it's needed, and then wherever possible turn in over to private companies to recoup the cost through corporate income taxes.
To quote the owner of the M6 toll road: "it's like printing money!"

It was built by the government in the 1960's. They probably spent $500 on each rivet.

I guess this just goes to show that you can't shortchange infrastructure spending for 40 years and expect things to go well. Just imagine if we took that $100 billion per year we're wasting in Iraq and invested it here instead...I can guarantee you there would be far fewer problems with our infrastructure than we have now.

Personally, I'd privatize a lot of this stuff and let them manage it. Have the government build it where it's needed, and then wherever possible turn in over to private companies to recoup the cost through corporate income taxes.
No, the government let a contract to a construction company, who charged them $500 per rivet because of the excessive documentation that was required of them.

The true statement is that no mechanical structure can withstand 40 years of service with no preventive or restorative maintenance.

To the OP -- the bridge failed after 40 years, were the load calculations and gusset plates really deficient, or was the current contractor negligent for storing 300 tons of material at the center of the span? I know what the NTSB says, but what do you think?

No, the government let a contract to a construction company, who charged them $500 per rivet because of the excessive documentation that was required of them.

The true statement is that no mechanical structure can withstand 40 years of service with no preventive or restorative maintenance.

To the OP -- the bridge failed after 40 years, were the load calculations and gusset plates really deficient, or was the current contractor negligent for storing 300 tons of material at the center of the span? I know what the NTSB says, but what do you think?

well I know ASCE (american society of civil engineers) came to the same conclusion, there are codes and such for designing a bridge, and gusset plates. Including just about everything imaginable that could go across a bridge or be put on it, including construction loads. However, I think while the 300 tons is more than would normally be designed for (and its just stupid to do, for obvious reasons, especially at mid-span) I'm guessing the usual factors of safety should have accounted for the unexpected loading, and that the gusset plate was not designed properly, it'd be interesting to know the cause of failure exactly, as a few things could have gone wrong.

I found this interesting:
Rosenker's comments angered Rep. Jim Oberstar, a Minnesota Democrat who heads the House Transportation and Infrastructure Committee. Oberstar said the early pronouncement committed the safety board to a finding that might not bear out with further investigation.

eh? a gusset plate isn't that hard to design, I can do and I'm not yet out of College, I'm pretty sure the people they put on the board know what they're about, considering that failures like this are rare, its usually viewed as a good way to learn form mistakes in codes or requirements. Of course in this case it was just someone who couldn't properly design the part, or a drafting error.

From NTSB:

In an effort to determine why those gusset plates are undersized, we wanted to examine the bridge’s design methodology used in the 1960s to verify that it was sound. Unfortunately, the calculations used for the main truss gusset plates could not be found, so we cannot determine whether the error was a calculation error, a drafting error, or some other error in the design process.

Source: http://www.ntsb.gov/Speeches/rosenker/mvr080115.html

So apparently, the design for part of the bridge is missing so we'll never know if they actually designed it improperly or if somewhere along the lines, things were mistakenly written in the plans, where as the design was correct. Unfortunately NTSB doesn't have the full report on their website yet.

Personally, I'd privatize a lot of this stuff and let them manage it. Have the government build it where it's needed, and then wherever possible turn in over to private companies to recoup the cost through corporate income taxes.
Then the bridge would collapse from the number of tollbooths on it and poor design.
Private companies have no interest in furthering the public good; they only want to fleece the public for money.

...
eh? a gusset plate isn't that hard to design, I can do and I'm not yet out of College, I'm pretty sure the people they put on the board know what they're about, considering that failures like this are rare, its usually viewed as a good way to learn form mistakes in codes or requirements. Of cours ein this case it was just someone who couldn't properly design the part.
Or was given incorrect/misleading/confusing requirements for the loads.

As you said in your edit, we'll never know for sure.

Then the bridge would collapse from the number of tollbooths on it and poor design.
Private companies have no interest in furthering the public good; they only want to fleece the public for money.
Are you claiming that the government bureaucrats that administer these programs ARE interested in furthering the public good? That's rich.

Or was given incorrect/misleading/confusing requirements for the loads.

As you said in your edit, we'll never know for sure.

yup, I was under the assumption when I typed it that they had the design for it. But a little digging has shown, at least as of January they couldn't find it. However, the loading is generally fairly well defined in codes, and even if they're misleading or confusing, that doesn't mean you can go and design a shitty bridge (I'll vouch for the confusing part at least). Ethically, engineers should only design things they are competent in.

No, the government let a contract to a construction company, who charged them $500 per rivet because of the excessive documentation that was required of them.

Gods that might be the funniest thing you've ever said. I may have to re-do my sig.

Gods that might be the funniest thing you've ever said. I may have to re-do my sig.
Knock yourself out, pal.

Ironic is more like it, though -- Government contracts to private company to save costs, but requires additional auditing and documentation to make sure they get what they pay for. Prices rise to accommodate all that extra hand-holding.

You have clearly never been the recipient of a government contract.

yup, I was under the assumption when I typed it that they had the design for it. But a little digging has shown, at least as of January they couldn't find it. However, the loading is generally fairly well defined in codes, and even if they're misleading or confusing, that doesn't mean you can go and design a shitty bridge (I'll vouch for the confusing part at least). Ethically, engineers should only design things they are competent in.
I don't build bridges, but I do have a PE in Electrical Engineering. I would never use that to certify residential or commercial wiring because I find the codes too confusing to risk my license on a bad interpretation. If something as "simple" as a residential wiring code can be confusing, then I'm sure there's room for interpretation in structural codes, as well. Examples in school tend to be quite canned and I see many tables for exceptions to the general standard when reading through codes. If those exceptions aren't well known, then mistakes can occur.

Besides, the bridge did hold up for 40 years under all the conditions that it was exposed to. It wasn't until someone decided to add a tremendous concentrated load that it finally failed.

Incidentally, the families of the victims are now suing the contractors (and not the state) over the collapse.

http://www.kare11.com/news/news_article.aspx?storyid=529557&catid=14

Incidentally, the families of the victims are now suing the contractors (and not the state) over the collapse.

http://www.kare11.com/news/news_article.aspx?storyid=529557&catid=14
Someone does need to compensate them... I wonder if the missing calculations will magically appear in time for court? And which side will 'find' them?

Knock yourself out, pal.

Ironic is more like it, though -- Government contracts to private company to save costs, but requires additional auditing and documentation to make sure they get what they pay for. Prices rise to accommodate all that extra hand-holding.

You have clearly never been the recipient of a government contract.

Oh yes, the price on rivets rises 500x because the government is deeply concerned that they're going to get screwed. Contractors fuck the government because they can. They got the contract by buying a couple congressmen and they have a blank check.

Someone does need to compensate them... I wonder if the missing calculations will magically appear in time for court? And which side will 'find' them?

Well, it's interesting that they are choosing not to sue the state of Minnesota's transportation department. The state has a compensation fund for these victims that can pay up to $400,000, but in order to get those funds, they waive their right to sue the state. So, it appears that they are refraining from suing the state until they see how successful they are at suing the contractors. If they win, maybe they will decide to go ahead and name the state in a lawsuit as well? Who knows.

Oh yes, the price on rivets rises 500x because the government is deeply concerned that they're going to get screwed. Contractors fuck the government because they can. They got the contract by buying a couple congressmen and they have a blank check.

You're being too literal and too ignorant. Also wrong.

Then the bridge would collapse from the number of tollbooths on it and poor design.
Private companies have no interest in furthering the public good; they only want to fleece the public for money.
Actually, it worked with ships. Private companies do have a direct commercial interest, if the system is set up properly.

The shipowners always wanted insurance, and merchants appeared that offered it. So, if you have your ship insured, you can build it crappy? But the insurers understood it too. So the insurers created sets of rules. The most influential group, that formed Lloyd's, worked up to create a combined set, and since then, ships can only be insured if they're built up to Lloyd's Register rules. Eventually it caught up with ports too, so any civilian vessel in the world is basically forced to comply.

This system was created centuries ago, long before any government would even think of such a notion as bothering with safety regulations. It still works, and it works better than any other regulations, because it's created and developed by the industry, not gov't bureaucrats. These rules keep vessels built to a very high quality, yet cost-efficiently. It's the best upheld set of rules, because everyone has a vested interest, not just the need to satisfy a government inspector.
And note the "in the world" part above. Private enterprise easily created building codes that transcend national borders - see a government pull it off.

You're being too literal and too ignorant. Also wrong.

It's funny, you type words, and I read them. I can only interpret based upon what you type. Now when what you type is absolutely HILARIOUS I take no responsibility. Also is there any evidence that this particular contractor overpriced the government in any way? I'll admit to having not bothered to read up much on the case.

Someone does need to compensate them... I wonder if the missing calculations will magically appear in time for court? And which side will 'find' them?

That is a fine question.

To the OP -- the bridge failed after 40 years, were the load calculations and gusset plates really deficient, or was the current contractor negligent for storing 300 tons of material at the center of the span? I know what the NTSB says, but what do you think?
It didn't take the NTSB very long to figure out where the bridge failed and the gusset plates seemed a plausible cause from the start. It's easy to see how the contractor performing the resurfacing may have been negligent in placing so much weight in the middle but it probably wouldn't have been done if it wasn't believed safe. One of the lessons here is that you shouldn't trust the tolerances listed on a sheet of paper unless they have been double checked.

I've gotten really sick of people claiming that this was caused by a lack of cash, that it could have been prevented if only there were more inspections and work done on the bridge. It was being worked on when it fell, throwing money at it nor privatising every aspect of it's construction and maintanance would not have made any difference. I'm even more sick of politicians like Oberstar exploiting the tragedy to muscle through their pet projects. In the wake of the disaster he led the charge for an increase in state gas taxes saying that if it had been done before the collapse would never have happened. What's worse is that a week before I-35W he he snagged about $10 million for a LRT line, several hundred thousand for things like bike trails, and a scant $2 million for pothole repair. Nothing went to bridges but that didn't stop him from getting in front of the cameras to bitch and moan about how the world was going to hell and our govenor was to blame.

Sometimes I wonder what the world would be like if engineers, doctors, and scientists ran governments.

Sometimes I wonder what the world would be like if engineers, doctors, and scientists ran governments.
I like the Nextel commercials, particularly "What if Firefighters ran the World?"
http://it.youtube.com/watch?v=VO6DORwBzuA
Clearly, everything would run much better.

I don't build bridges, but I do have a PE in Electrical Engineering. I would never use that to certify residential or commercial wiring because I find the codes too confusing to risk my license on a bad interpretation. If something as "simple" as a residential wiring code can be confusing, then I'm sure there's room for interpretation in structural codes, as well. Examples in school tend to be quite canned and I see many tables for exceptions to the general standard when reading through codes. If those exceptions aren't well known, then mistakes can occur.

Besides, the bridge did hold up for 40 years under all the conditions that it was exposed to. It wasn't until someone decided to add a tremendous concentrated load that it finally failed.

Yup, I agree completely. As I said they are confusing, for example the AISC (American Institute of Steel Construction) manual on steel design is about as thick as a dictionary, and it doesn't even go into loading cases. I agree that textbook examples are extremely simplified, generally because they focus on one part of a problem, or even have assumptions that reduce the calculations by half or more. In my first post I recognized that the contractors who were doing the resurfacing were idiotic for putting all the materials at one part of the bridge, however cases similar to what the contractor did are designed for.



I've gotten really sick of people claiming that this was caused by a lack of cash, that it could have been prevented if only there were more inspections and work done on the bridge. It was being worked on when it fell, throwing money at it nor privatising every aspect of it's construction and maintanance would not have made any difference. I'm even more sick of politicians like Oberstar exploiting the tragedy to muscle through their pet projects. In the wake of the disaster he led the charge for an increase in state gas taxes saying that if it had been done before the collapse would never have happened. What's worse is that a week before I-35W he he snagged about $10 million for a LRT line, several hundred thousand for things like bike trails, and a scant $2 million for pothole repair. Nothing went to bridges but that didn't stop him from getting in front of the cameras to bitch and moan about how the world was going to hell and our govenor was to blame.

Sometimes I wonder what the world would be like if engineers, doctors, and scientists ran governments.

Yea, the NTSB found that no amount of inspections would have found a problem with the gusset plates, theres no way to find out if they are safe without doing alot of analysis or at least looking through the design papers.