Minneapolis, Minnesota disaster

Jim O'Dell

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Between Aledo and Fort Worth, TX
Everyone keep our members in the Minneapolis area in your prayers. Major castrophe with the bridge collapse. I have a friend there that purchased one of our pups from the 1995 litter, and I can't get through to make sure he is ok. Tyler, and all the others there, hope you are all ok. Jim.
 
Jim, this is certainly a catasrophe. don't worry too much about your friends. phone circuits in the Twin Cities are tied up pretty badly and likely will be most of the night.

Hennepin County Medical Center reports 26 injuries. North Memorial, the other hospital that got a large quantity of injured haven't reported numbers yet. The mayor of Minneapolis reported 6 dead.
 
Prayers and blessings from PA. to victims, family of the victims and
rescue workers in this disaster.

Strange seeing a bridge collapse in this way, have they ruled out
terrorists?
 
Dunno what happened, but it was "Under Repair" when it broke, so the cause may be complex. Tagic to be sure, prayers go out to those in need.

What a lousy way to die. :(
 
Dave, as of last night they didn't think it was anything other than a structural failure.

A reporter I heard on Minnesota Public Radio managed to dredge up an inspection report from, I think it was, 2001 which indicated that although there were no structural problems but there is a worrying lack of redundancy in the supporting structure.

I also read a suggestion that a worker with a jack hammer might have been working and that the jack hammer set up a sympathetic osscillation at the right frequency to get the bridge moving.

A design flaw perhaps. Maybe everything came just together at that moment.

I expect the new bridge will be a lot different.
 
They said on CNN that the repairs were being performed on the road surface, not structure. You make a good point Dave. We've all seen the video of the suspension bridge swaying violently form a wind that was not that strong. Once set in motion, it's hard to stop. And sympathetic vibration, and harmonics can do some weird things. It's for this reason that every 10 feet the Shuttle is made out of a different material/alloy so that this phenominon doesn't rip it apart on launch.
Tried to get ahold of my friend up until bed time last night, but phone still busy. Not sure what part of town he lives and works in. Jim.
 
All speculation of course but I heard someone else conjecture that a truck or a pair of them might have set the bridge in motion. Due to construction with lanes closed traffic speeds were much lower than normal. The number of vehicles on the bridge was also reduced due to the construction. I'm sure that plays a part in the relatively low death count.
 
Another possibility, though, is that it was down to 2 lanes one direction, 1 lane the other direction, instead of 4 each way. Bumper to bumper traffic not moving much. It's possible that there were more cars in the 2 lanes standing still than there would have been with 4 lanes moving at normal speed, with several car lengths between each of them. The fact that the cars that fell weren't also doing 60+ mph did probably save some lives. Jim.
 
Now they're saying there were structural problems....

From CNN
" A 2001 study conducted by the Minnesota Department of Transportation found "several fatigue problems" in the bridge's approach spans and "poor fatigue details" on the main truss.

The study suggested that the design of bridge's main truss could cause a collapse if one of two support planes were to become cracked, although it allowed that a collapse might not occur in that event. But, the study concluded, "fatigue cracking of the deck truss is not likely" and "replacement of the bridge ... may be deferred."

Two years ago, the U.S. Department of Transportation's National Bridge Inventory database said the bridge was "structurally deficient." "

I'd imagine a harmonic failure would have been much more prolonged and spectacular, sounds to me like someone should have paid attention to that study.
 
I agree with John that harmonic failure is unlikely. Given the size of the bridge, the period would be very long - which would be experienced as a significant swaying of the bridge. From the press reports, the failure was quite rapid.

It seems to me that either one of the support structures in the river was under scoured and collapased or some important structural element(s) failed (but I'm not a structural engineer).

Think of all the other bridges in the US that are rated "structurally deficient". It's going to be interesting to see what's done to fix all of them and where the money is going to come from.

Mike
 
The media (at least CNN) is harping on that "structurally deficient" statement. Someone from DOT or NTSB stated that this does not mean dangerous. That isn't stopping the "hey I've driven on a bridge so I know all about them" types in the media from speculating. No one is going to know for months or perhaps years what happened.
 
We may never know what happened.
as I started on another forum
It's a terrible accident, and I do feel for the victims. But you reap what you sow. You got to figure these jobs are handed out to the lowest bidder. While there are design specs that are "supposed" to be followed you have to ask yourself how one company can do it cheaper than another without cutting a corner somewhere.
This country is going to learn someday cheap will only get you so far

Dad always said
You can have it cheap
You can have it good
Pick one!
 
We may never know what happened.
as I started on another forum
It's a terrible accident, and I do feel for the victims. But you reap what you sow. You got to figure these jobs are handed out to the lowest bidder. While there are design specs that are "supposed" to be followed you have to ask yourself how one company can do it cheaper than another without cutting a corner somewhere.
This country is going to learn someday cheap will only get you so far

Dad always said
You can have it cheap
You can have it good
Pick one!
One company can do the work for less money than another company because they're better organized, smarter, and more productive. That's the whole basis of our economic system, which has produced very effectively for all of us.

When a contract for some public works is let, the bidders are rated on whether they can perform the work before their bid is accepted, then they're monitored and inspected each step of the way. Additionally, most construction companies are in the business for the long term - to screw up a contract is to lose all future business.

When you build a house, for example, you'll do the same things in evaluating and monitoring the contractors you choose to work for you. There's simply no other way to get the work done that doesn't waste public money - and certainly can't show that it produces better results. Any process other than bidding will eventually choose companies based on their connections to those in charge of awarding the bids (or to politicians who can influence the decision).

Mike
 
My thoughts are with all those affected.Tragedy which arises from the ordinary and everyday like commuting to and from work always seems doubly shocking.

I was reading an interesting book recently (The World Without Us). Part of the premise is to desrcibe what might happen when maintenance ceases because there is nobody left to maintain. It suggests that with items like bridges which were built some time ago may last longer than more recent designs. I believe it cites Brooklyn bridge as an example where the original design was overengineered against more modern standards because there was less finesse available in the calculations and therefore a much bigger margin for "error" was included. I guess that this would not be the case in a bridge built in the 60's?
 
My thoughts are with all those affected.Tragedy which arises from the ordinary and everyday like commuting to and from work always seems doubly shocking.

I was reading an interesting book recently (The World Without Us). Part of the premise is to desrcibe what might happen when maintenance ceases because there is nobody left to maintain. It suggests that with items like bridges which were built some time ago may last longer than more recent designs. I believe it cites Brooklyn bridge as an example where the original design was overengineered against more modern standards because there was less finesse available in the calculations and therefore a much bigger margin for "error" was included. I guess that this would not be the case in a bridge built in the 60's?

I have worked on several bridges as a machinist and its often said, it is very easy to over-engineer a bridge, but very tough to engineer a bridge that can withstand the loads and yet come in on budget.

It is a very true statement. Just like many years ago, the Pilgrims had plenty of beams and wood to pick from. If they thought a 8 x 8 beam would hold up, they might throw in a 12 x 12 beam just to be sure. It cost the same money and the same amount of labor to saw out either beam. Today of course, there is more research and testing done on the toothpicks that are called roof trusses then the whole village of pilgrim's homes. Of course the engineering does not take into account the effects of a fire, or the lack of maintenance. It is just assumed that no fire will occur, or that maintenance will be sufficient for the bridges/ beams life. Unfortunately that maintenance money comes from a very fickle society.

The railroad I used to work for was just on the other side of this bridge and I crossed it many times a day in the 7 years I worked out of MN. It is a very busy highway and I can only hope my fellow railroading buddies made it through unscathed. For the ones that perished, I feel for them. Hopefully this tragedy will free up more money for future bridge repairs so that more family's are spared.
 
Mike
So you think an inspector has never been bribed on a state or federal job?

I can show you a company not 5 miles from my house that does water line and sewer work, in fact the are running a water line from right up the road from me to one the next small towns right now.

Every time I went around the corner the inspector was sitting in his pickup, never mind that they where working a mile down the road at the time. Amazing what an envelope full of money can do.

That same company has had guys killed on the job a couple times. You would think that OSHA would have hung them out to dry by now but they are still in business.

We had one of our township trustees resign recently, Seems she was handing out contracts to her brother and he wasn't always the cheapest bid. She apparently didn't grease enough other palms since she got caught.

Our road was repaved 2 years ago, in a one mile stretch there are 3 places it is falling apart all ready.
Why? because the swept the road and laid the black top over it. The places it's breaking up needed dug up and fixed before it was paved. With a cheap job you don't get fixed you get patched.

We can build roads that last, but we don't since the government wants it cheap. The road my brother lives on is a prime example. Prior to the 3 gravel plants going in it was a ten ton road. Part of their bond agreement with the state was that they had to either maintain it or pay the state to maintain it. at first they paid the state to do it. after 4 years of funneling money into it and a road that kept falling apart due to the amount of truck traffic all 3 of them got together and paid to have the road rebuilt. That was 12 years ago and there isn't a pothole or a patch in it anywhere in that 5 mile stretch.

All our government can see is what it cost's today, not what it's going to cost over the life of the project.

Like I said, you can have it cheap, or have it good. you can't have both. It simply doesn't work.
 
Mike
So you think an inspector has never been bribed on a state or federal job?

I can show you a company not 5 miles from my house that does water line and sewer work, in fact the are running a water line from right up the road from me to one the next small towns right now.

Every time I went around the corner the inspector was sitting in his pickup, never mind that they where working a mile down the road at the time. Amazing what an envelope full of money can do.

That same company has had guys killed on the job a couple times. You would think that OSHA would have hung them out to dry by now but they are still in business.

We had one of our township trustees resign recently, Seems she was handing out contracts to her brother and he wasn't always the cheapest bid. She apparently didn't grease enough other palms since she got caught.

Our road was repaved 2 years ago, in a one mile stretch there are 3 places it is falling apart all ready.
Why? because the swept the road and laid the black top over it. The places it's breaking up needed dug up and fixed before it was paved. With a cheap job you don't get fixed you get patched.

We can build roads that last, but we don't since the government wants it cheap. The road my brother lives on is a prime example. Prior to the 3 gravel plants going in it was a ten ton road. Part of their bond agreement with the state was that they had to either maintain it or pay the state to maintain it. at first they paid the state to do it. after 4 years of funneling money into it and a road that kept falling apart due to the amount of truck traffic all 3 of them got together and paid to have the road rebuilt. That was 12 years ago and there isn't a pothole or a patch in it anywhere in that 5 mile stretch.

All our government can see is what it cost's today, not what it's going to cost over the life of the project.

Like I said, you can have it cheap, or have it good. you can't have both. It simply doesn't work.
I do not agree with your analysis.

First there can be criminal behavior on any project. But it is that: criminal and can be addressed unless we create a society the allows bribes and kickbacks. The US, in general, is not that kind of society.

When a project is built to specifications and does not last the way you expect it to, I would suspect that the specifications were not sufficient to allow that kind of lifetime. But that's a problem with the specifications.
I expect that some projects may be under specified because building the project to higher specifications might result in cost that would be unacceptable to the voters. If "the government" wants it cheap, that's our fault as voters for not demanding higher specifications from our elected officials and being willing to pay for it.

The only other alternative is that the project was not built to specifications - and if so, that's a problem with the management of the project (maybe bribery of the inspectors).

Our elected officials are not dumb, uncaring people - they are us. They live in the community, pay taxes, and want the best, just like everyone else, and most of them try to do a good job (at least that's true around here). You get the kind of government you demand. As Pogo said, "We have met the enemy and he is us."

Mike
 
Robert and Mike, if it's any consolation, I agree somewhat with both of you. Let me qualify this by saying I've been an inspector (civil and structural) on a number of public works projects (including bridges, river channels and dams), and I think failures like this can be the result of bad ethics, bad design, bad judgement, or any combination thereof.

Sure, there are inspectors (or other officials) on the take. In my experience, they were very rare. (I never saw or knew of any in the part of the country I was working in.) Then there are inspectors who don't really care, and are only there to collect the paycheck. (Getting paid to watch other people work...seems like easy money. I'm guessing that may be why the guy up the road from Robert is sitting a mile away from the site in his pickup, assuming he wasn't doing something legit like checking grade stakes.) Also keep in mind that sometimes inspectors are only required to do periodic spot checks, not necessarily watch every shovelfull of dirt turned. On a number of occasions I was working on three or four different sites daily. Or in other cases, the site itself might be miles long. Needless to say the inspectors don't necessarily see it all. To categorize all inspectors as dishonest or lazy is an insult to all the dishonest and lazy people out there. :p Seriously, it's like saying everybody with a cell phone is a drug dealer.

Then there are designs that are not sufficient. Engineers build in a "safety factor", but sometimes new construction methods are not fully proven, and the expected performance doesn't happen. Or technology advances and we learn what we thought was plenty good really isn't. For example, in the past decade or two, structural engineers here in California have learned that some of their design guidelines for earthquake loads was off, and as a result the building codes are more strict now than they were 30 or 40 years ago. And of course there's always the underlying issue of trying to do it with as little money as possible.

There are also daily judgement calls that get made regarding the interepretation or execution of the specs. Not only on the inspector's part, but on the part of the engineers and contractors, too. (Here again, sometimes the cost plays a role.) I have yet to see a project that matched the specifications exactly. There are times when, in the process of construction, it's discovered that the prescribed method or material is not feasible, or a less expensive alternative is proposed. Any substitutes are generally intended to meet or exceed the specs, but as I said, sometimes judgement calls are made. And sometimes they have to happen fast, and things can and do get missed.

All that said, I'm not claiming any of these are the reason for the bridge collapse, but those are my observations as a former inspector. :wave: And my thoughts and best wishes go out to the victims and those close to them.
 
Vaughn, I wasn't implying that all inspectors where on the take.
But it is a fact that money exchanges hands sometimes, whether it,s just to secure a bid or to have someone look the other way. It does happen.
All I'm saying is with the system of going with the low bid I feel you increase your chance of asking for trouble. sure some companies can do it better cheaper through good management and production, way to many do it by cutting corners.
 
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