"We have met the enemy and he is us." Pogo Possum "We have met the anemone... and he is Russ." Bucky Katt "Prediction is very difficult, especially if it's about the future." Niels Bohr, Nobel laureate in physics
Wow, somebody just got fired.
That wasn't a minor buckle, that was a major failure.
Hope everyone is okay.
terrible.........God Bless em all
live pics at 8;08 ET it collsped on some rail cars as well....
Terrible!
Looks like a Minnesota Commerical train. Watching on MSNBC.
My prayers are with the people involved.
Something heavy on top of something that wasn't ready to support that heavy of a load. I pray for those affected by this.
Dan
It's not completely off-topic, because the bridge collapsed on top of some covered hopper cars on tracks running parallel to the river. A tank car is sitting beside them undamaged. If it contains anything toxic, that's too close for comfort.
My thoughts and prayers go out to those in the Twin Cities area. They've apparently rescued people from the river, so let's pray the death toll will be low.
This gives me the heebie-jeebies. I used to travel the Pulaski Skyway everyday.
Nelson
Ex-Southern 385 Being Hoisted
Prayers to all the families that will be affected by the bridge collaspe.
I wonder whos rail line it crossed. How will it effect rail traffic in the area. What about the river traffic since it did fall in the Mississippi River.
Paul
http://www.youtube.com/user/pavabo
http://www.flickr.com/photos/paulvbox
I looked on Google maps, and it appears that the bridge goes over a train yard, which dead-ends west of it, so it must have been freight cars in the yard that the bridge collapsed on, not a mainline train. Still, this is terrible. My prayers are with all of the people involved. Hope most get away safely.
Brian (IA) http://blhanel.rrpicturearchives.net.
blhanel wrote:A couple of covered hoppers are partially crushed. It looks like the tank car mentioned earlier has quite a dent in it as well. The Fox reporter speculated while we were looking at a close-up of the hoppers that they could be part of a passenger train...
DennisHeld wrote: blhanel wrote:A couple of covered hoppers are partially crushed. It looks like the tank car mentioned earlier has quite a dent in it as well. The Fox reporter speculated while we were looking at a close-up of the hoppers that they could be part of a passenger train...My prayers to those involved, as well. I tend not to listen to Fox News for 'catastrophy' coverage. I know that the anchors have to fill the air with talk, but that talk has ranged from unfounded speculation to just plain stupid comments. About a year ago a coal train hit an SUV northeast of St Louis. The Fox News anchor noticed that the coal train was headed into the sunrise and speculated that the engineer couldn't see the SUV in the sun's glare. He said it wasn't known if the train was braking. The last straw was when the Blue Angel jet crashed a couple months back. The Fox News anchor said that there was no way of knowing, this early, what the cause was. But, the Blue Angel's make tight turns and the pilot may have blacked out. Or, the jet probably hit a bird. Or, there was a mechanical problem. Or.......more drivel.
Rest assured, the other stations are guilty of mindless speculation as well. Fox just has a stranglehold on some of the worst (ever see Geraldo?)
Anyway, just caught a snippet of the news and the mayor has stated that 6 people have passed away as a result of this. The news gets worse and worse, it would seem.
If you look closely at the ACF Center Flow type 4-Bay Covered Hoppers they appear to have prevented the section of the bridge above them from sloping down further. The Petroleum Type Tank Car might have been damaged. Everything is perched very precariously. It looks like they will need every large crane to lift those sections safety.
Andrew
Watch my videos on-line at https://www.youtube.com/user/AndrewNeilFalconer
Bucyrus wrote:I have heard of cases where a piece of freeway deck suddenly drops. Earthquakes taken down bridges. A barge can hit a bridge. But I have never known of something this big happening in the normal life a bridge. They must have large safety factors, and I am sure they keep track of deterioration issues. Homeland Security said they cannot link it with terrorism. One thing is for sure: This cannot possibly go down as something that just happened to happen with no clear reason.
I was wondering. Is this the first case of a steel arch bridge collapse for no immediately apparent reason? I've read about past bridge disasters and can't find anything like this.
>I looked on Google maps, and it appears that the bridge goes over a train yard, which dead-ends west of it, so it must have been freight cars in the yard that the bridge collapsed on, not a mainline train.
Looks to me like that is the only rail line out of a large grain elevator complex, and it also serves to deliver coal(?) to the large electric generating plant nearby. If so,there are going to be a lot of trucks running on the streets thereabouts for some time.
Anyone know for sure?
Im not certain of the precise location yet but there is an old Truck Stop in the immediate area on one of the banks of the river. I may be thinking of another bridge elsewhere. I remember what a pain it was to cross that river there in that part of town with all the ramps.
The last time I was on the bridge it was doing ok, but that was years ago.
Apparently we are losing people with passing time, my prayers out to the lost and those who are affected.
Tomorrow's Commute is going to be a anvil breaker in that town.
I am totally curious as to why that big strong bridge failed. Me thinks someone didnt catch something in time or fix something right. These big bridges need people walking on them daily checking rivets, bolts, welds etc. All the time, checking.
I understand that the people worked hard by themselves to help each other. I say OORAH go Minnesota! That's the way to do it.
futuremodal wrote: Bucyrus wrote:I have heard of cases where a piece of freeway deck suddenly drops. Earthquakes taken down bridges. A barge can hit a bridge. But I have never known of something this big happening in the normal life a bridge. They must have large safety factors, and I am sure they keep track of deterioration issues. Homeland Security said they cannot link it with terrorism. One thing is for sure: This cannot possibly go down as something that just happened to happen with no clear reason.I was wondering. Is this the first case of a steel arch bridge collapse for no immediately apparent reason? I've read about past bridge disasters and can't find anything like this.
The cause is definitely baffling. Nobody has a feasible explanation. MNDOT inspects the bridge on a cycle not to exceed two years, usually every single year. I saw one guy interviewed who said he has been in the bridge business for over 30 years, and has never seen or heard of anything like this.
solzrules wrote: DennisHeld wrote: blhanel wrote:A couple of covered hoppers are partially crushed. It looks like the tank car mentioned earlier has quite a dent in it as well. The Fox reporter speculated while we were looking at a close-up of the hoppers that they could be part of a passenger train...My prayers to those involved, as well. I tend not to listen to Fox News for 'catastrophy' coverage. I know that the anchors have to fill the air with talk, but that talk has ranged from unfounded speculation to just plain stupid comments. About a year ago a coal train hit an SUV northeast of St Louis. The Fox News anchor noticed that the coal train was headed into the sunrise and speculated that the engineer couldn't see the SUV in the sun's glare. He said it wasn't known if the train was braking. The last straw was when the Blue Angel jet crashed a couple months back. The Fox News anchor said that there was no way of knowing, this early, what the cause was. But, the Blue Angel's make tight turns and the pilot may have blacked out. Or, the jet probably hit a bird. Or, there was a mechanical problem. Or.......more drivel.Rest assured, the other stations are guilty of mindless speculation as well. Fox just has a stranglehold on some of the worst (ever see Geraldo?)Anyway, just caught a snippet of the news and the mayor has stated that 6 people have passed away as a result of this. The news gets worse and worse, it would seem.
As the news was breaking on CNN, the question was asked of several about the number of lanes. Interesting that the aerials clearly show 4 lanes each way. Appearantly one or more were closed for the resurfacing. Watching the TV, I couldn't quite figure the orientation of the cameras. Since the lock and dam is slightly upstream from the bridge and to the right from the TV views, the cameras are to the north on the St Paul side.
It will probably take some time to get the answers, but the forensic structural engineer types are really very good at figuring out just how failures occur. I am thinking about the collapse of the walkway over the lobby in the Kansas City hotel, and of course, the World Trade Center Towers.
It looked like this morning that the bridge fell on the train and not the train derailing, hitting the bridge. There was only two lanes of the bridge open to traffic as well. I don't think something too heavy was on the bridge at the time.
One telling point I heard on ABC this morning was about how dated and dilapidated the highway system was. The anchor actually said on air that people "should look to using mass transit, such as rail systems to help alleviate the crunch on the nations stressed and overloaded highways." I found that interesting.
1. Which railroad is that? MapQuest only lists BNSF several blocks away.
2. CNN called the hopper cars tank cars.
3. Almost immediately, Homeland Security said it wasn't a terrorist attack. With the cause still unknown, how can they say that????? I just don't believe the government anymore (not that I think it was an attack, just how can they speculate like that when no one knows the cause). I'm stupified.
FJ and G wrote: 1. Which railroad is that? MapQuest only lists BNSF several blocks away.
BNSF. Ex-Great Northern trackage.
Used to be the track that connected Great Northerns Union Freight Yard at Saint Anthony with the Depot in Minneapolis - crossing the river a little upstream on the famous Stone Arch Bridge. With a couple of sidings on the east bank (north side) of the river.
The Stone Arch Bridge hasn't carried RR traffic since 1978 and is now a foot/bike path across the river.
As far as I can tell from google earth, the tracks now form a small storage yard with a few tracks, where the BNSF apparently was storing some covered hoppers and a few tank cars.
Google earth image:
FJ and G wrote: 2. CNN called the hopper cars tank cars.
Both covered hoppers and tank cars under the bridge. Pictures show at least one, maybe two covered hoppers with damage from falling bridge, and a tank car (closer to the bridge supports) that seems reasonably undamaged.
FJ and G wrote: 3. Almost immediately, Homeland Security said it wasn't a terrorist attack. With the cause still unknown, how can they say that????? I just don't believe the government anymore (not that I think it was an attack, just how can they speculate like that when no one knows the cause). I'm stupified.
Can't help you with any stupification you may feel. There is no sign of a terrorist attack. No sign of car bombs, no particular reason why terrorists should attack one of thousands of interstate highway bridges, no one has claimed responsibility for a terrorist attack.
It is a reasonable null hypothesis that it was not a terrorist attack. Further investigation will probably show what the cause of the bridge collapse.
Stein
FJ and G wrote: 1. Which railroad is that? MapQuest only lists BNSF several blocks away.2. CNN called the hopper cars tank cars. 3. Almost immediately, Homeland Security said it wasn't a terrorist attack. With the cause still unknown, how can they say that????? I just don't believe the government anymore (not that I think it was an attack, just how can they speculate like that when no one knows the cause). I'm stupified.
HC did not say that it was not a terrorist attack. They basically said they have no indication that it was a terrorist attack. They cannot rule out sabotage until they get into the structural elements under the decking in the river.
jeaton wrote: It will probably take some time to get the answers, but the forensic structural engineer types are really very good at figuring out just how failures occur. I am thinking about the collapse of the walkway over the lobby in the Kansas City hotel, and of course, the World Trade Center Towers.
Based on a report from 2001 MNDOT declared "poor fatigue details" on the main truss. I would put money down on fatigue being the cause of the collapse. Fatigue faliure is most often catastrophic in nature, which would explain the sudden and rapid nature of the collapse.
While it is true that there are factors of saftey built into structures, accurately predicting loading patterns 40 years in the future can be hit or miss. The construction could have contributed by altering the resonance of the structure, but that isn't too likely. The damage would have been there for years in the form of microcracking, which is detectable, but usually after 90% of the fatigue life is over.
In my opinion, MNDOT really dropped the ball in 2001, but the PE on the original construction will probably take the heat. Hopefully, he will be long retired. I am praying that there is no more loss of life.
Who owns the bridge?
Why was it not replaced last year?
I saw one of the latest abc news footage earlier and they had a flew around the whole site and mentioned about the trains as they flew pass and I thought I saw a NS single unit at the front just missed out been crushed because it was almost right underneath the partially collapsed section and the crushed hoppers was just a few cars behind it. IT was amazing that the chassis is still standing holding up tons of concrete and steel despite the hopper body been crushed beyond recognistion.
The Washington Post reported this morning that a train had been passing beneath the roadway at the time it fell, hitting a cars carrying a chemical (unidentified) and polystyrene beads and that the fire chief said was not particularly hazardous.
They did mention this morning on CNN that the last two summers had been hotter than average (they have to try and tie it to global warming) and that it may have contributed to the collapse. They also mentioned in other reports that the bridge had gotten a 50 out of 120 on the last structural inspection, but that it did not indicate the bridge was dangerous. They were also acting all amazed that people who were not too seriously hurt were actually evacuating themselves rather than waiting for someone to come save them.
There have been annual reports in the news about the crumbling infrastructure of the US, including bridges, water and sewer pipe, etc. They also constantly talk about how what is in place is handling way more traffic and use then it was ever designed for.
It might actually be more amazing that this type of event does not happen more often.
Hey Dewey,
Thanks for the post..nice to see someone has a good head on their shoulders,and that some people "hopefully" would add heat to the cause of this tragic accident!!!!As for the rail cars....plastic pellets in the covered hoppers,and the tank car..its owned by MCP-Minnesota Corn Processers.Looking at the length of it,it could have been loaded with ethanol at one time,or corn syrup,your guess is good as mine.
>"HEAT" may be the culprit for this collapse?!!!!!!!!! After all, Minneapolis has had a week, if not more, of excesssive 90 degree temperatures in the city.
Maybe next you will blame "Global Warming" for the collapse?
Theres video now, from AOL
http://news.aol.com/story/_a/divers-search-for-bodies-after-collapse/20070801194509990001
Sad, they've been telling us for years that we need major investment in our intrastructure, but our leaders prefer burning billions on anything but...unless that bridge was in alaska
Have fun with your trains
Bucyrus wrote:There will be calls for spending over one trillion dollars to fix it.
In some cases, a repeat of calls.....
IIRC, the bridge was described as a box truss structure. The word truss says it all. One member fails, especially those under tension, the whole shebang fails. Given the reports of fatigue and cracking, I'd say that's where the culprit will be found.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
What a random tragety. Such a shame. When I heard of this event, I gave every member of my family an extra hug before bed. You just never know what can happen when you leave the house. My hopes and prayers go out to those who were involved.
dalien wrote: >"HEAT" may be the culprit for this collapse?!!!!!!!!! After all, Minneapolis has had a week, if not more, of excesssive 90 degree temperatures in the city.Maybe next you will blame "Global Warming" for the collapse?
Gee,if you think I'm wrong,then maybe YOU should watch ICE ROAD TRUCKERS,on the History Channel,and drive a 80,000 pound rig,hauling a 96,000 pound load to a diamond mine,traveling only 15 miles per hour, on 38 inches of ice!!!!! Hmmmm...think the weather conditions wont have an effect on that?
FJ and G wrote:I heard on CNN about an hour ago that an average of one bridge collapses each week in the US. I wasn't aware of this. I thought these structures are made to last forever. How come the Romans could make stuff last and we can't?
Money. Government Indifference and Fumbling. It took 30 years to get 6 seperate entitys to come up with a plan to replace the I-495 Woodwrow Wilson Bridge before it too falls into the River south of DC.
Well, I buried family in Arlington some years ago and happily report that a brand new replacement is just about done or nearly so. The old one is going to be scrapped and sent to the sea for reef work or something. And good riddiance to that worn out old bridge.
I gotta tell ya, there are many bridges in the USA that I dont feel good driving onto with a 40 ton vehicle. Some of these were built "Just good enough" and future problems left to the grand children who will be the Government officials someday.
cnwfan2 wrote: dalien wrote: >"HEAT" may be the culprit for this collapse?!!!!!!!!! After all, Minneapolis has had a week, if not more, of excesssive 90 degree temperatures in the city.Maybe next you will blame "Global Warming" for the collapse? Gee,if you think I'm wrong,then maybe YOU should watch ICE ROAD TRUCKERS,on the History Channel,and drive a 80,000 pound rig,hauling a 96,000 pound load to a diamond mine,traveling only 15 miles per hour, on 38 inches of ice!!!!! Hmmmm...think the weather conditions wont have an effect on that?
Actually the ice is not a constant thickness. There is a risk of a fall through. I have been all over that show since it started and love it. Especially that Hugh, he is a Trucker I understand very well. I wont go onto that Ice, oh no, not me, done enough of that climbing out of Ft Bridger. Actually a little too much.
It aint the loud creaking, groaning Lake Ice that youre driving on... it's the super sheer, thin slipperyiest sheet barely perceptaible to the eye that brings down the mightest truck, usually on a steep hill. I laugh at the big ice, but cower when the thin stuff is around.
Not everyone gets the history channel.
This is my last post about the bridge problem.
My fear is simple. The media will carry this story and Jam it down our throats daily for 6 months to a year. First the incident, then the investigation, then the blame game and followed by every individual anywhere near that bridge on that day. UGH.
Let's move on shall we?
One other thing, certain hospitals in my area should grease and maintain those elevators from time to time. Those things creak along good to the last drop. I dont want to be on it when it does.
Especially when the owners are pouring billions to build new facilities next door.
tree68 wrote: IIRC, the bridge was described as a box truss structure. The word truss says it all. One member fails, especially those under tension, the whole shebang fails. Given the reports of fatigue and cracking, I'd say that's where the culprit will be found.
I think that is an excellent observation. I have not seen an absolutely definitive diagram of the collapse, but what I have seen suggests that the first break was right in the center of the big truss that allows the river to be spanned without any piers. It broke in the center, and both halves tilted downward into a "V" shape. Then adjoining decks on each side went down. If the center span truss broke in the middle, the bottom chords would have parted in tension as the break began. The box truss design does seem a bit like have all your eggs in one basket.
I heard an interview with someone who said he knew one of the construction workers. That person told him that there was appprehension and speculation all day amoung many of the construction workers about whether the bridge was going to collapse. He said they all felt that the bridge was vibrating in a very unusual and excessive manner all day, and it concerned them enough to discuss it with each other.
That would have been a good time to go below and eyeball the bottom chords to make sure there was not a one-foot gap where one of them had already parted.
FJ and G wrote:I'm not sure what you mean about wire story. Is there a link or something to get there?
That's the Newswire at Trains.com. (Trains magazine subscription required)
>...maybe YOU should watch ICE ROAD TRUCKERS...
I do watch it. But even better, I know a real Ice Road Trucker and listen to his stories with amazement. Now long retired, as one of the original Ice Road Truckers he helped haul the Dew Line equipment north over uncharted lakes. But I never heard him blame "Global Warming" for anything. That fantasy had not yet been invented.
Any other irrelevant comments?
Link please.
Yes, I'm a subscriber but am unfamiliar with this newswire and do not find it referenced on the front page. Tnx.
vsmith wrote: Theres video now, from AOLhttp://news.aol.com/story/_a/divers-search-for-bodies-after-collapse/20070801194509990001Sad, they've been telling us for years that we need major investment in our intrastructure, but our leaders prefer burning billions on anything but...unless that bridge was in alaska
Seems like that security video might give the investigators some clues on where to start looking.
The Federal Highway Administration had the 35W bridge on its deficient list. It should be noted that a bridge can make that list and still be structurally sound. No doubt the details of the deficiencies will be forthcoming.
Bucyrus wrote: I think that is an excellent observation. I have not seen an absolutely definitive diagram of the collapse, but what I have seen suggests that the first break was right in the center of the big truss that allows the river to be spanned without any piers. It broke in the center, and both halves tilted downward into a "V" shape. Then adjoining decks on each side went down. If the center span truss broke in the middle, the bottom chords would have parted in tension as the break began. The box truss design does seem a bit like have all your eggs in one basket.
I suggest watching CNN's security video of the bridge going down. It appears as if the big truss dropped straight down, as if the piers holding it up had been pulled out from under it. That's why I think the first failure occurred off to the right of the camera's view on that approach.
blhanel wrote: Bucyrus wrote: I think that is an excellent observation. I have not seen an absolutely definitive diagram of the collapse, but what I have seen suggests that the first break was right in the center of the big truss that allows the river to be spanned without any piers. It broke in the center, and both halves tilted downward into a "V" shape. Then adjoining decks on each side went down. If the center span truss broke in the middle, the bottom chords would have parted in tension as the break began. The box truss design does seem a bit like have all your eggs in one basket.I suggest watching CNN's security video of the bridge going down. It appears as if the big truss dropped straight down, as if the piers holding it up had been pulled out from under it. That's why I think the first failure occurred off to the right of the camera's view on that approach.
I think you are correct that the failure began out of the video frame to the right. I think that would be where the center of the span was. But I really cannot say that I am certain how it all came down from seeing the video or the computer model. There have been press conferences all afternoon with a ton of engineering and inspection information being discussed in tremendous detail by engineers and state officials. I would not have expected such forthright addressing of the public's question about the cause at this early point in the investigation.
http://www.nytimes.com/slideshow/2007/08/02/us/20070802BRIDGE_index.html
http://www.nytimes.com/slideshow/2007/08/02/us/20070802_BRIDGEB_index.html
http://www.visi.com/~jweeks/bridges/pages/ms16.html
http://media.startribune.com/smedia/2007/08/01/21/bridges200110.source.prod_affiliate.2.pdf
Dave
dalien wrote: Link please. Yes, I'm a subscriber but am unfamiliar with this newswire and do not find it referenced on the front page. Tnx.
Ain't it the pits what we have to go through just to read what they earned money for us to read????
On the TRAINS.COM website, in the center column is a link about "Where to find the Trains News Wire".
It is an explanation of WHY you can't find it, but really does NOT tell you HOW to find it. There are some images that are too small to be intellegable that do show the link you can use to find the newswire, but unless you KNOW already where to find it, you won't recognize it.
Fortunately, on that page, at the top is a slightly different banner/header that contains a link to the "news wire".
Unfortunately, that link took me to a fairly non-functional page that has a search function where all you can do is select one or more checkboxes and click a SEARCH button. I had no idea which category to select, so I picked "General" and the result of the search WAS that there are no articles that matched my search.
At the top of the Search page there is a link to the bridge collapse and clicking on it shows you an early article about the collapse, but there WAS no photo on that page.
Now that I have gone back to verify my sad tale, the SEARCH seems to be functional and there is a photo on the article page.... but I cannot find the original article I read.
Sorry if I don't include a direct link to the article here... my humblest apologies... but since it is a subscriber only area, I am not sure what would happen for a non-subscriber that happened to click on a link I supply.
It only took me about 10 minutes of clicking on links to get to the article, since I didn't read EVERYTHING on EVERY page, I missed the simple links to the area I wanted.
Hopefully my words here will spare you the inane random clicking.
Oh yeah, the photo in the article is small (as is the article), but if you click on it, a new window will open giving you a much enlarged view. (Clicking the article will not give you an "expanded view", if you get my drift.)
Semper Vaporo
Pkgs.
I live in the Twin Cities, and went down there today to see for my own eyes. The camera's really dont do justice. Ive had two or three people who would have taken that bridge yesterday, but decided not too. A friend of mines dad left work early because he didnt have a good feeling about something, and my mom decided not to take the bridge (at around 10 minutes before it happened) because of the construction and rush hour.
Yes, the line is Minnesota Commercial, and the train was not moving. At the other end, most cars had bad order tags on them.
Alec
Semper Vaporo wrote: dalien wrote: Link please. Yes, I'm a subscriber but am unfamiliar with this newswire and do not find it referenced on the front page. Tnx.Ain't it the pits what we have to go through just to read what they earned money for us to read????On the TRAINS.COM website, in the center column is a link about "Where to find the Trains News Wire".
Or you can do it the simple way instead of taking the scenic route.
At the bottom of every page on this website there are some blue ribbons with links. Look at the row that says "Magazines". Click on "Trains".
The Trains Magazine News Wire is on the middle of the page that comes up.
Thank You, SV. I totally missed it amongst the subtle blast of RED on the front page which I guess is meant to get attention. Maybe I should have tried it with the polaroids before commenting.
And I do agree with your comments.
This incident, occuring so close to the Stone Arch (Jim Hill) bridge, brought back thought of a column in the Chicago Tribune many years back. They had a columnist who must've been a fan (the name escapes me...Graham something?)-he often wrote of trains & railroads; a little too often and too accurately to have been a "civilian". One of the columns I clipped and saved for many years was about the Stone Arch bridge and how all the things we build today are built to be good for 20 years and we think that's good enough, but that someone built something to last for the ages and it still was doing just that. Kind of a generic lament that "we don't build 'em like that anymore" but a good one. I wonder if the I-35 bridge was one of the "good enough" structures he had in mind when he was there?
A few winters ago we had a part of the Hoan bridge "sag" orrealisticly a beam cracked and almost gave way durring morning rushhour. People called the police when they noticed a "dip" in the road.That section of the bridge was imploded (cool to see first hand) andre-built. I never even questioned that bridge before hand I worry moreanout the little "lift" bridges that cross the Milwaukee riverdowntown. My 16,000lb truck empty Im ok........when theres 9 skidsloaded and then I have to cross a bridge I have watched them woking onfor the last few years.....scare the crap out of me EACH DAY!
This is a sad day in transportation and enginering history. I only pray that we learn from our mistakes.
My thoughts and prayers go to those who have to burden this event.
Kevin C. Smith wrote: This incident, occuring so close to the Stone Arch (Jim Hill) bridge, brought back thought of a column in the Chicago Tribune many years back. They had a columnist who must've been a fan (the name escapes me...Graham something?)-he often wrote of trains & railroads; a little too often and too accurately to have been a "civilian". One of the columns I clipped and saved for many years was about the Stone Arch bridge and how all the things we build today are built to be good for 20 years and we think that's good enough, but that someone built something to last for the ages and it still was doing just that. Kind of a generic lament that "we don't build 'em like that anymore" but a good one. I wonder if the I-35 bridge was one of the "good enough" structures he had in mind when he was there?
True enough. I just did a 'pilgrimage' to Starrucca Viaduct. Built in 1853 and still in use...
Unless this collapse turns out to be an act of God, the cause will be negligence. The I35W bridge was rated structurally deficient; and it did fall down. However it is not true that all bridges rated structurally deficient have achieved that status through negligence and are in danger of collapse. Yet that was the blatantly dishonest theme of the "Aging Infrastructure" pieces last night on ABC, CBS, and NBC. That was complete and utter political propaganda put forth by those who want to expand the role of government and their willing accomplices in the media. They even broke down the price tag so we would know how much it would cost us individually.
In order to drive home their lie that structurally deficient bridges are dangerous, they presented an old concrete bridge with holes through the deck and rebar hanging out of crumbling concrete. The bridge was closed, blocked, and obviously out of service. But all that mattered was that it was in the group of bridges rated structurally deficient, and it could therefore serve as an example to reinforce the bald face lie that all bridges rated structurally deficient are dangerous.
Because if we built things the way the Romans did, with today's costs, the bridges would be so expensive that there would be very few built. Have you priced stone or stonemasons lately?
Bridges get the "structurally difficient" tag for all sorts of reasons, not safety reasons. If a bridge looks like it is going to fall, they close it. A 2 lane bridge with 3 lanes on either end is "structurally difficient" because it does not match up to the roads (the Bay Bridge in Maryland is a good example). A bridge designed to carry 150,000 cars a day is difficient when it carries 160,000. The news channels like to make it sound like they are all going to fall down tomorrow.
I just hope while people are cringing driving over the bridges and overpasses tonight that they hang up their phone and pay attention so they don't hit me or someone else.
Here are some photos. Miraculous that so many people came out of this alive. Thoughts and prayers to the families, friends, and others affected.
The media?
We got the bubble-headed-bleach-blonde who Comes on at five She can tell you bout the plane crash with a gleam In her eye Its interesting when people die- Give us dirty laundry
-Eagles-
http://www.conphoto.net/collapse.html
Bucyrus wrote: Unless this collapse turns out to be an act of God, the cause will be negligence. The I35W bridge was rated structurally deficient; and it did fall down. However it is not true that all bridges rated structurally deficient have achieved that status through negligence and are in danger of collapse. Yet that was the blatantly dishonest theme of the "Aging Infrastructure" pieces last night on ABC, CBS, and NBC. That was complete and utter political propaganda put forth by those who want to expand the role of government and their willing accomplices in the media. They even broke down the price tag so we would know how much it would cost us individually. In order to drive home their lie that structurally deficient bridges are dangerous, they presented an old concrete bridge with holes through the deck and rebar hanging out of crumbling concrete. The bridge was closed, blocked, and obviously out of service. But all that mattered was that it was in the group of bridges rated structurally deficient, and it could therefore serve as an example to reinforce the bald face lie that all bridges rated structurally deficient are dangerous.
I'm confused here. I know that a very few public highways, toll roads actually, and their bridges have been sold to private parties. The Chicago Sky Way and the Indiana Toll Road come to mind. However, hasn't it always been role of government to build and maintain highway bridges along with the rest of the public highway system? Where on earth did you get the idea that there is some sort of conspiracy on the part of the media and the government to "expand" their roll? How would that even be possible, given the fact that that is their roll.
"Negligence" means not paying attention. In fact, the Minnesota Highway Department and the Federal Highway Administration have been paying attention to the I-35W Bridge and every other bridge in Minnesota. The same is true in every other state. The reason that bridges are deficient is a shortage of funds. Unless you have another idea for getting the money to do the repairs or replacements, I am afraid it is going to come from taxes.
I agree with you that not every bridge that is considered deficient is dangerous, but the simple truth is that we are not keeping up with repairs, rebuilds or replacement of either our bridges or highways-let alone building more to meet growing demand. One doesn't need to read government studies to get that. Just go for a drive. If we don't start to catch up, eventually deficient bridges will become dangerous. I guess if we don't want to spend the money we could just close them down. Yeaah! That's the ticket!
WIAR wrote: I was surprised to hear the speculation about the Minnesota Commercial train moving slowly underneath possibly having something to do with the collapse. I hardly think so - I'm no structural engineer but I have been down in that area before and I'd never believe the vibrations from a train moving at 8 MPH in that area could affect the highway bridge.
There was no train moving under the bridge. The tracks under the bridge is a dead end - a very small single ended storage yard, where the Minnesota Commercial keeps a few old cars.
Hadn't been an engine there for days before the accident, according to the Trains Magazine News Wire.
Whatever it was that made the bridge fall, it was not a moving train passing under the bridge at the time of the collapse.
On the note of construction occurring along I-35W, an initial thought when this happened was whether the construction along the highway actually saved lives. I was in the Twin Cities about a month back when they were doing construction on segments north of the bridge. As a result, we generally followed the Cedar Ave detour. I wonder if people were actually saved because they were on Cedar Ave instead of I-35W. This assumes the decking work on the bridge was not involved in the collapse. Hopefully so.
And, again, still keeping the victims in my thoughts this evening.
jeaton wrote: Bucyrus wrote: Unless this collapse turns out to be an act of God, the cause will be negligence. The I35W bridge was rated structurally deficient; and it did fall down. However it is not true that all bridges rated structurally deficient have achieved that status through negligence and are in danger of collapse. Yet that was the blatantly dishonest theme of the "Aging Infrastructure" pieces last night on ABC, CBS, and NBC. That was complete and utter political propaganda put forth by those who want to expand the role of government and their willing accomplices in the media. They even broke down the price tag so we would know how much it would cost us individually. In order to drive home their lie that structurally deficient bridges are dangerous, they presented an old concrete bridge with holes through the deck and rebar hanging out of crumbling concrete. The bridge was closed, blocked, and obviously out of service. But all that mattered was that it was in the group of bridges rated structurally deficient, and it could therefore serve as an example to reinforce the bald face lie that all bridges rated structurally deficient are dangerous. I'm confused here. I know that a very few public highways, toll roads actually, and their bridges have been sold to private parties. The Chicago Sky Way and the Indiana Toll Road come to mind. However, hasn't it always been role of government to build and maintain highway bridges along with the rest of the public highway system? Where on earth did you get the idea that there is some sort of conspiracy on the part of the media and the government to "expand" their roll? How would that even be possible, given the fact that that is their roll."Negligence" means not paying attention. In fact, the Minnesota Highway Department and the Federal Highway Administration have been paying attention to the I-35W Bridge and every other bridge in Minnesota. The same is true in every other state. The reason that bridges are deficient is a shortage of funds. Unless you have another idea for getting the money to do the repairs or replacements, I am afraid it is going to come from taxes.I agree with you that not every bridge that is considered deficient is dangerous, but the simple truth is that we are not keeping up with repairs, rebuilds or replacement of either our bridges or highways-let alone building more to meet growing demand. One doesn't need to read government studies to get that. Just go for a drive. If we don't start to catch up, eventually deficient bridges will become dangerous. I guess if we don't want to spend the money we could just close them down. Yeaah! That's the ticket!
You are correct in that the government owns the bridges and must collect taxes to pay for them. I am not opposed to that. The government does have a roll as you say. However, I disagree that the government has no ability or motive to expand its roll beyond what it legitimately needs to be. In fact I believe it is highly motivated to expand, and if there were no resistance by the electorate, the public sector would simply expand until there was no more private sector. It is not a conspiracy. It is not a secret plan that was hatched out in the dead of the night in a secret room. It just naturally flows through the veins of the public sector.
I agree that there is a shortage of funds for bridges and roads, but what government function is not short of funds? In my opinion, government is always short of funds because of its inherent motivation to expand its power, which it does by collecting taxes and spending money. The primary objective is to spend money and come up with reasons to spend more. So they over-spend. And unlike the private sector, government spends without any financial risk, and without much accountability. And when they collect taxes that are justified by a targeted application such as roads and bridges, they spend the money on a lot of unrelated things. Then they come back to the taxpayers and tell them they are not paying enough to cover the target application. I think it is a serious mistake to believe that government simply spends money as legitimately needed, like a responsible head of household seeking a return of value for the money spent.
But back to the bridges. It is true that bridges will fall down if not maintained, and that maintenance costs money. It is also true that many bridges are rated structurally deficient due to a shortage of funds. However it is not true that bridges fall down because of a lack of funds. That would be impossible because we have a federal bridge inspection program that monitors the condition of all bridges in great enough detail to know how close they are to the point where they would fall down, and prescribes the most cost effective maintenance necessary to get the most life out of them. If there are not enough funds to perform the maintenance, then the bridge needs to be closed. If there are not enough funds to inspect the bridge, then the bridge needs to be closed. These are not just my suggestions. They are the rules of the game.
The job of the inspectors is to go over the bridge with a fine-tooth comb to the extent that they know exactly how strong the structure is. There is no guesswork. A component of this inspection is to monitor the traffic load and keep it within the safe limit. So if a bridge falls down because of corrosion, broken members, stress cracks, missing bolts, etc., it has to be due to negligence of this inspection routine. There is no option to compromise that inspection routine because of a lack of funds. So a lack of funds cannot possibly be the cause of the I35W bridge collapse even though many Minnesota politicians and all Minnesota media are saying it is so.
Made it up to the Twin Cities this weekend- while the ladies held a bridal shower for my daughter, I, my father, and my future son-in-law made a trek downtown to check out progress on the clean-up. Here's one of the shots I got- looks like those poor covered hoppers are finally about to be freed.
Pushing over a concrete support...
A couple of large sections left to remove yet...
I didn't really see or hear any speculation while I was up there, other than from my Dad (former MnDOT bridge inspector until he retired 20 years ago). He doesn't talk much about it, but when asked by one of my siblings, he said he felt it was heat stress.
Perhaps some of the members here who live in the area have heard or read more about it?
....Brian: Those are good photos. Appears lots of demolition and clean up work all ready accomplished. I wonder if it has been decided what type of bridge will replace the destroyed one. And if the authorities are ready to start right in to construct the "new" one. That is pretty harsh climate up there that we're going into now a few months hence.
In looking over the scene, I see the falling bridge was close to some of the river lock structures. If it had broken some of that, that certainly would have added to the woes....Don't have any idea what kind of river traffic moves thru those locks that far north.
Quentin
Thanks, Quentin- yeah, things are progressing quickly on the clean-up, but the construction of a new bridge promises to be a different matter altogether. There was alot of concern in the news that other state highway projects might have to be postponed in order to get this one done, because the federal money hasn't been officially approved yet (it's part of the latest bill that President Bush is threatening to veto). Not only that, but bids have already been accepted and a contractor chosen, but the one chosen was one of the higher bids, and I guess the lower-bid contractors are considering suing over the deal...
That lock I believe is the last lock going north on the river, and as such doesn't get alot of use- it only handles one or two barges at a time by the looks of it.
....From all of that, it seems we'll be hearing more about that bridge situation. Might even become a campaign issue if it delays the start of rebuild....And....also saps money from other projects.
I thought emergency money was going to be made available for that rebuild....
Yes the collapse was just the opening act of this fiasco. Multiple investigations of the cause are underway. I would be surprised if they all reached the same conclusion, considering the complexity of the collapse event. My prediction is that the cause will be unsettled in the minds of a majority of observers indefinitely. The cause of the collapse poses a potential threat to some of the organizations that are investigating it. A sure refuge for them is to keep the investigation going a long, long time under the excuse of diligence.
And if there were not already enough controversy surrounding the probable government negligence that caused the collapse, a new heap has been added by the act of MNDOT awarding the rebuild contract to the highest bidder with the longest delivery time. There are many elements to this latest chapter of the bid that are just beginning to emerge. The news coverage of the winning bid has been very uneven and difficult to absorb. More will be learned as soon as all the contestants assume their positions for this battle.
From what I've read, there are likely three factors that lead to the collapse. My speculation is based on the UofM report done a few years ago and reading Henry Petroski's commentaries on previous structural collapses.
First was lack of redundancy (a Design failing). There were many structural elements whose failure could lead to failure of the whole structure - sound engineering practice is to never design a structure where failure of a single element could lead to total structural failure (possible exception - a large margin of safety in the design of that element). Note that the bridge was completed about the same time as the Silver bridge collapsed in Ohio - which became a textbook example of why you design structures with redundancy - and note that the I-35 bridge design was never repeated.
Second was inadequate inspection. My understanding was that inspection did not go beyond a visual look-over, no ultrasound or other NDE was performed.
Third was a lack of appreciation of how much the concrete deck aided the structural rigidity of the bridge. The UofM report discussed developing a model of the bridge that agreed with measurements of controlled truck traffic - the model was only close when the stiffening action of the concrete deck was taken into account.
As for comments about the relative impact (pun somewhat intended) of car versus truck traffic - consider that 80,000 pounds of cars will be generating a lot less impact than one 80,000 pound truck - a couple of reasons: the impact of the cars will be relatively incoherent while the impact of the truck will be coherent; the springs on cars are typically a lot softer than springs on a truck.
erikem,
I think your assessment is fairly accurate. As you point out, the bridge design was relatively unique, pushing the envelop on the efficient use of materials, but thus lacking prudent reserve or redundancy. I speculate that, for this design to be viable, it must be perfectly inspected and maintained, which did not happen. So it appears that the design may have been structurally viable, but impractical, given the high probability of inadequate maintenance.
I too have wondered about the structural effect of removing the concrete deck, which was underway at the time of the collapse. I would assume that the structural performance of the bridge would be rated and stipulated completely independently from the deck, but I wonder about that. If the concrete deck were cast in a way that it became one with the top chord of the truss structure, it would have added compression strength to the top chord, which would stiffen it against downward buckling of the truss. If this were the case, removing the deck would reduce strength. It would also remove loading, so it is hard to say how a reduction of strength and a reduction of load would tally up.
I can see this possible scenario: The deck removal would reduce the load, partially offsetting a weakening effect, but leaving a net weakening of some amount. That amount would be considered acceptable because it was not necessary to the bridge design capacity and its proper safety factor. However, the bridge had already been weakened by a lack of maintenance, and had lost its safety factor or worse. So the amount of weakening caused by removal of the deck made the difference between holding and failing. In other words the strength added by the deck was not an essential part of the design, but became essential as the design failed over time due to structural decay.
Bucyrus wrote:I too have wondered about the structural effect of removing the concrete deck, which was underway at the time of the collapse. I would assume that the structural performance of the bridge would be rated and stipulated completely independently from the deck, but I wonder about that. If the concrete deck were cast in a way that it became one with the top chord of the truss structure, it would have added compression strength to the top chord, which would stiffen it against downward buckling of the truss. If this were the case, removing the deck would reduce strength. It would also remove loading, so it is hard to say how a reduction of strength and a reduction of load would tally up.
The U of Minn study on the bridge specifically mentioned the strengthening effect of the concrete deck - probably should try looking it up and posting the URL. You're right in that the concrete would be under compression and adding to the strength - heaven help us if it was under tension...
I'm looking forward to reading what Henry Petroski has to say about the collapse - though it might be a couple of years before enough data comes out of the failure analysis to paint a coherent picture.
- Erik
Most trucks do not gross out at 80000. I have not seen any mention of the deicer they use on the roads and bridges. This stuff will rot steel in no time. I'm talking about the liquid deicer not the rock salt. Some bridges in the Twin Cities have this sprayed any time the weather looks bad. Could dip down and rot the bridge.
I live in a suburb of Minneapolis and I was watching it on the news about 30 minutes after it happened. I believe the bridge overpassed a BN line. My old man and I biked down a month after (to the day) and saw the devastation. There is still a portopotty standing on the slanted deck leaning on the barrier. The construction was minor resurfacing and supposedly had no influence on the collapse. Thank god there was only 4 lanes of traffic instead of the 8 that are usually open due to the construction. But man the piers on the north side had been partially lifted out of the water and it was a mess. The one hopper had been crushed like a pop can. Hope I cleared some of the confusion,
Robbie.
The people of Minnesota want a practical new bridge at the lowest cost. The political class empowers themselves by spending our money, so naturally they want the most expensive bridge. To make an expensive bridge, you design it with a lot of bells and whistles. A good way to make bells and whistles expensive is to make them intangible and hard to measure. And then when the three bids come in, you award the highest bidder because their price includes the best meeting of your intangible bells and whistles.
But, apparently nobody told two of the lower bidders how this works, and they were actually trying to bid low so they could win. However, the winning formula was to bid high and then sell your bid for intangible bells and whistles to the state with an intangible sales pitch.
Quote from the above linked article:
"Executives of the joint venture promised to erect a bridge with structural redundancies that would allow it to last 100 years, 60 more than its predecessor."
That sounds like it is comparing a bridge built to last 100 years to one built to last 40 years. It is true that the old one lasted 40 years, but how long was it supposed to last according to its designers? Certainly it was not built as a bridge with an intended lifespan of only 40 years.
Bucyrus wrote: Quote from the above linked article:"Executives of the joint venture promised to erect a bridge with structural redundancies that would allow it to last 100 years, 60 more than its predecessor."That sounds like it is comparing a bridge built to last 100 years to one built to last 40 years. It is true that the old one lasted 40 years, but how long was it supposed to last according to its designers? Certainly it was not built as a bridge with an intended lifespan of only 40 years.
It is interesting that the contractors apparently submitted their bids base on their own bridge designs. How can you compare bids when the item being bid is different with each bidder?
In addition to the comparison of the actual price of each bid for the new bridge, the state used a technical score based upon criteria other than price. Here are the criteria used by the state to score the bids:
Evaluation Criteria Utilized (Corresponded to Criteria Contained in the RFP)
Note the item called, Public Outreach weighted at 15%. I can understand how experience, quality control, and safety would be needed to build a bridge, but I do not understand why the state needs to pay the bridge builder for public outreach.
Or in other words, how much public outreach does it take to screw in a light bulb?
I don't think that by saying the new bridge will be designed to last 100 years, they are trying to say the original was designed to last only 40. They are just pointing out that it did last ONLY 40.
Surely the catastrophic failure of the original was never planned as transpired
Bucyrus wrote: It is interesting that the contractors apparently submitted their bids base on their own bridge designs. How can you compare bids when the item being bid is different with each bidder? In addition to the comparison of the actual price of each bid for the new bridge, the state used a technical score based upon criteria other than price. Here are the criteria used by the state to score the bids: Evaluation Criteria Utilized (Corresponded to Criteria Contained in the RFP)Quality (50 percent)Experience and authority of key individualsExtent of quality control/quality assuranceSafetyMeasures to evaluate performance in constructionAesthetics/Visual Quality (20 percent)Visual enhancements to the structureInvolvement of the public after lettingEnhancements (15 percent)Geometric and structural enhancementsPublic Outreach/Involvement (15 percent)Impacts to the publicApproach to communicationsNote the item called, Public Outreach weighted at 15%. I can understand how experience, quality control, and safety would be needed to build a bridge, but I do not understand why the state needs to pay the bridge builder for public outreach. Or in other words, how much public outreach does it take to screw in a light bulb?
Just my opinion, but the 'outreach' comment looks like a cover for something along the lines of using minority owned contractors/sub-contractors... You know, making sure ALL the community feels involved? etc.
Convicted One wrote: I don't think that by saying the new bridge will be designed to last 100 years, they are trying to say the original was designed to last only 40. They are just pointing out that it did last ONLY 40.Surely the catastrophic failure of the original was never planned as transpired
Convicted One,
I understand and agree that that is what they were saying, but there are implications in the overtone. The old bridge failed to meet its projected 50-year lifespan, which surely must have been proudly heralded when it was opened in 1967 just as the 100-year life is proclaimed about the new bridge today. I would hate to think the citizens of Minnesota could be led to believe that the reason the bridge collapsed was that they bought a cheap, low quality bridge the last time.
You may be right about the public outreach. Public outreach may be a bridge to the community. The more I read about this project, the more apparent it becomes that this is about so much more than just building a bridge. There are statements to be made about the tragedy and loss, and also about the fabric of the riverfront. But as a taxpayer, it would be nice to know the workings of MNDOT's so-called technical score that justified their awarding the contract to the contractor that bid $57 million higher than the next highest bidder.
Bucyrus wrote:. But as a taxpayer, it would be nice to know the workings of MNDOT's so-called technical score that justified their awarding the contract to the contractor that bid $57 million higher than the next highest bidder.
I share COMPLETELY your sentiment there. So the following should not be taken as an argument against your position, just stating facts.
At one time I was heavily involved in contract work with the General Services Administration. Where EVERYTHING is supposed to be bid competitively. Anyone who is qualified to bid the various projects (supposedly) being welcome to do so. Often the contracting officers know before the original solicitation for offers is even made public, exactly who it is they intend to have do the work. The bidding process is (often) a mere formality to maintain a charade of protecting the public interest.
In such instances there are unlimited opportunities to make the prefered contractor somehow appear to be 'uniquely qualified' in order to steer the work towrds the intended awardee'.
It feels great when you know you are the contractor that they prefer to use anyway, and EXTREMELY frustrating in the instances where you figure out that they have a prefered source OTHER than you. Making you feel like you are beating your head against a wall even writing the bid.
Sometimes the rationale in determining a 'prefered' awardee is semi legitimate, maybe a contractor has an extensive track record of completeing the type project at hand in an expedient and trouble free (to the contracting officer/government) manner.
And sometimes the motives are LESS than honorable. Hard telling which is which in the example at hand.
Funny that the government does not feel the need to be more forthright in explaning the conditions you mention. Usually when the government is at a loss for words, that runs up a red flag, fwiw
Convicted One wrote: Bucyrus wrote:. But as a taxpayer, it would be nice to know the workings of MNDOT's so-called technical score that justified their awarding the contract to the contractor that bid $57 million higher than the next highest bidder. I share COMPLETELY your sentiment there. So the following should not be taken as an argument against your position, just stating facts.At one time I was heavily involved in contract work with the General Services Administration. Where EVERYTHING is supposed to be bid competitively. Anyone who is qualified to bid the various projects (supposedly) being welcome to do so. Often the contracting officers know before the original solicitation for offers is even made public, exactly who it is they intend to have do the work. The bidding process is (often) a mere formality to maintain a charade of protecting the public interest.In such instances there are unlimited opportunities to make the prefered contractor somehow appear to be 'uniquely qualified' in order to steer the work towrds the intended awardee'. It feels great when you know you are the contractor that they prefer to use anyway, and EXTREMELY frustrating in the instances where you figure out that they have a prefered source OTHER than you. Making you feel like you are beating your head against a wall even writing the bid.Sometimes the rationale in determining a 'prefered' awardee is semi legitimate, maybe a contractor has an extensive track record of completeing the type project at hand in an expedient and trouble free (to the contracting officer/government) manner.And sometimes the motives are LESS than honorable. Hard telling which is which in the example at hand.Funny that the government does not feel the need to be more forthright in explaning the conditions you mention. Usually when the government is at a loss for words, that runs up a red flag, fwiw
That sure sounds like what this I35W bid looks like. There was a little hubub in the news right as the story revealed that the highest bidder won, but it quickly faded. I can understand the state not stepping forth to expose the process behind the technical scoring. It was challenged by the other two bidders, but apparently that has gone nowhere. They claimed that they did not know that the bridge project included public outreach. What is most disconcerting is the complete lack of curiousity on the part of the local press and TV news.
If you will remember, some comedian said:
"Remember: Interstate bridges are built by the lowest bidder."
This alluding to the fact that they MIGHT not be safe.
Now, one has collapsed, adding credence to the quip.
Could the Authorities have awarded the bid to the lowest bidder this time, without public recrimination for doing so?
Would it be prudent for the news media to begin some journalistic investigation as to why it was not awarded to the lowest bidder? What kind of headline would this be:
"The old bridge fell down, why aren't we building a cheaper one!"
Semper Vaporo wrote: If you will remember, some comedian said:"Remember: Interstate bridges are built by the lowest bidder."This alluding to the fact that they MIGHT not be safe.Now, one has collapsed, adding credence to the quip.Could the Authorities have awarded the bid to the lowest bidder this time, without public recrimination for doing so?Would it be prudent for the news media to begin some journalistic investigation as to why it was not awarded to the lowest bidder? What kind of headline would this be:"The old bridge fell down, why aren't we building a cheaper one!"
I know the joke about getting something you want to be safe built by the lowest bidder. However, it seems to me that there should not be any connection between the bid price and the safety or quality of the bridge. There would definitely be a correlation between the quality, strength, and durability of the bridge as those characteristics are embodied in the design. If you design an inferior bridge, its performance will reflect that, but the performance should not be affected by the construction. If the contract is properly enforced, you get the same bridge, no matter whether the bid is high or low.
While the bidders on the I35W bridge apparently were given latitude on the design and style of the structure, it is ultimately up to the state to design a bridge that won't fall down. Ideally, they would then get multiple bids on that specific bridge, then consider price, delivery, and competence, and then select the best-suited bidder on that basis.
Selecting a high or low bid would have no effect on the strength, durability, or longevity of the bridge, because those characteristics would be established by the design and specifications. It would be up to the state to guarantee that the specifications have been met.
Many politicians blamed the collapse on a lack of funds for proper maintenance, but of course this is nonsense. A lack of funds cannot possibly be the reason for the collapse. This is axiomatic because the state has a responsibility to know the bridge's condition, and maintain it in safe condition. If they cannot perform either one of these tasks for any reason, they must close the bridge. Letting the bridge collapse for lack of funding would be criminal. Even MNDOT officials ran for the hills when they heard the reckless politicians blaming the collapse on Minnesotans not paying enough taxes.
Today the NTSB is scheduled to give a news conference to announce its results concerning the Interstate 35W bridge collapse in Minneapolis.
Story
Early in the investigation of the Minneapolis case, the safety board identified the plate, called a gusset plate, as a possible cause.
eastside wrote: Today the NTSB is scheduled to give a news conference to announce its results concerning the Interstate 35W bridge collapse in Minneapolis. StoryEarly in the investigation of the Minneapolis case, the safety board identified the plate, called a gusset plate, as a possible cause.
....And I believe they are indicating many other bridges scattered over the country have the same type gussets....If they are the culprit, I wonder if it is a straight forward matter of doubling the thickness of them by adding another layer on the original...If so they better get busy. But how can they be sure that was the only problem. Has maintenance been eliminated as an issue....?
Modelcar wrote: ...Has maintenance been eliminated as an issue....?
...Has maintenance been eliminated as an issue....?
I think that is the official burning desire.
I think the real blame should fall on Gravity, ofcorse gravity cant be fired or sued so who ever designed the bridge should get introuble because if they didnt build it then it wouldnt have fallen so its gotta be there fault
Mr_Ash wrote: I think the real blame should fall on Gravity, ofcorse gravity cant be fired or sued so who ever designed the bridge should get introuble because if they didnt build it then it wouldnt have fallen so its gotta be there fault
Gravity is probably an explanation that most Minnesotans would accept.
spokyone wrote:Here is article about press conference.http://www.startribune.com/local/13796646.html
On the 2nd page of this link, they talk about center barrier, higher outside walls and 2" thicker paving. Can anyone guess how much extra weight that would be? They also mentiontioned 300 tons of equipment. But that would only be 8 loaded semi trucks.
There's some leaping to conclusions and conspiracy theory here.
The NTSB has not determined a cause for the collapse. All that it said today is that 8 of 112 gusset plates of the main trusses were significantly undersized for the load the design called for them to carry. The gussets have not been determined to be a cause of the collapse or even a contributor to the collapse; all is known is that one of the gussets (identified as U10) appears to have failed early in the collapse event.
The NTSB released this preliminary finding in order to alert owners of similar bridges to a risk factor. This is normal and conservative.
Quote: "The Safety Board has issued this recommendation, at this time, to ensure that the original design calculations for other bridges of this type have been made correctly, before any planned modification or operational changes are accomplished affecting such bridges and before any additional stresses are placed on them," said NTSB Chairman Mark V. Rosenker.
The NTSB report is found here: http://www.ntsb.gov/Pressrel/2008/080115.html as is a link to an FHWA interim report. If you want to skip the math just read the introduction and look at figures 5-6-7-8, then read the Interpretation of Results. That's depressing enough, I think.
Weights of materials:
Plain reinforced concrete, 150 lb./cf
Asphalt paving, 120-140 lb./cf
The deck supported by the bridge main truss was 1,064 feet long x 104' wide curb face to curb face. I have no idea of the dimensions of the curbs, center divider, etc., which are important.
A question is posed about liability. That would depend upon applicable law, which might only be the State of Minnesota. Generally ordinary negligence in professional services is a civil matter and can result in payment of damages, civil fines, and loss of professional license for the Engineer of Record, assuming no intervening Statute of Limitations. Gross negligence -- a willful and reckless disregard of safety -- can result in criminal penalty or punitive damages, depending upon applicable law. Given that the bridge was designed more than 40 years ago, the parties to the design are likely deceased.
RWM
Stepping way out on a limb... (or was that thin ice?) My background is in EE not CE, so take what I write with a large grain of salt.
From what I have read so far, this looks like a case of ordinary negligence for the bridge designers and builders, after all the bridge did stay up for 40 years. What looks to me as the critical design flaw was a lack of redundancy in the structure - that is failure of a single component could lead to failure of the whole structure. This point was driven home by the failure of the Silver Bridge in Ohio/WV in December 1967, also about 40 years after construction. If I recall correctly, design work was already underway on the I-35W bridge before the collapse of the Silver Bridge. Incidentally, FAA regs on large aircraft design require the airframe to have enough structural redundancy to survive failure of a major member, e.g. a wing spar.
As for the crowd responsible for maintaining the bridge, it remains to be seen if the point of failure was something that could be detected by inspection.
Just to clarify, I did hear the NTSB say they had not concluded that the design flaw caused the collapse. However, most if not all of the news during the last 24 hours unequivocally declared that the design flaw was the cause of the collapse. Even listening to the NTSB press conference, one would have to work hard parsing words in order to conclude that the NTSB was not announcing that the design flaw was the cause of the collapse.
And they certainly did rule out the possibility of the collapse being caused by a lack of inspection and/or maintenance. I don't understand how a potential cause can be ruled out while the actual cause is still unknown.
http://www.designnews.com/article/CA6466909.html
Here is an interesting article from last fall that discusses the rust-frozen roller expansion bearings, which impeded expansion / contraction movement of the truss. It says that prohibition of this movement caused the truss to deflect out of plane, and speculates as to the amount of extra stress this loading caused, and whether it pushed the bridge past its design limit. At one point, last fall, I heard that this condition of locked expansion bearings had caused the force of expansion / contraction to tip one of the piers out of plumb. However, that is not confirmed by this article. The following is from the article:
Seventeen years ago, the federal government first said the bridge was structurally deficient, citing significant corrosion in its bearings. Seven years later, significant out-of-plane distortion was noted in the main trusses connected to cross girders due to resistance to motion at the connection cross bearings, according to a report released by the University of Minnesota civil engineering department. The cracks in the girders were drilled to prevent further propagation. Support struts were also added to the cross girder.
Bridge bearings, such as the multiple roller bearings used in the I-35W bridge, are used to transfer loads from the deck to the superstructure as weight burdens vary or weather conditions change. Their primary purpose is to redistribute major longitudinal shifts in load.
squeeze wrote:The sad part is that there are 547 bridges that are similar to this bridge across America. I'll bet each state is scrambling to find out how there's are constructed. Here in Pa. we have 54 that are of the same build. Kinda makes you wonder.
Wonder things like what? If the bridge your driving across could suddonly fall out from under you leaving you suspended in midair with sign reading "Help!"
Bucyrus wrote:Do bridge designers just get to make mistakes without any consequences?
The answer is no. There is almost guaranteed a Professional Engineer's seal affixed to the plans for that bridge who is accountable for design errors. But, there really needs to be a thorough investigation. It is entirely possible that the wrong pieces were installed in places that no one caught. People tend to assume that the proper thickness widget or length whatcha-ma-callit was supplied and installed. It could be a design error, supplier error, contractor error, or even inspector error.
Kind of makes you wonder, though, when engineers (all kinds) make mistakes, lots of people may die, but athletes and other entertainers get paid the big money.
Krazykat112079 wrote: Bucyrus wrote:Do bridge designers just get to make mistakes without any consequences?The answer is no. There is almost guaranteed a Professional Engineer's seal affixed to the plans for that bridge who is accountable for design errors. But, there really needs to be a thorough investigation. It is entirely possible that the wrong pieces were installed in places that no one caught. People tend to assume that the proper thickness widget or length whatcha-ma-callit was supplied and installed. It could be a design error, supplier error, contractor error, or even inspector error.
Well that would be my take on it too. But as I listen to all the local news, I detect virtually zero curiosity about the accountability for the design flaw. The general thrust seems to be that the bridge fell down, and it is nobody's fault because the design occurred so long ago. It makes you wonder how many other Minnesota bridges have lost all accountability for their designs because their designers went out of business, sold out, retired, or died.
I wonder why the NTSB, after lecturing us all fall about not jumping to conclusions, would come out now, nine months before their final report, and tell us they stongly suspect that a design flaw was at fault, but they are not sure.
The problem with that I-35W bridge was that if you've seen the pre-collapse pictures, the bridge sported a very spindly structure with lots of exposed structural steel and only four relatively small concrete pillars to hold up the bridge--it was a disaster just waiting to happen. The new bridge now under construction is built from reinforced concrete designed with withstand the considerable temperature changes of weather in Minnesota.
It is interesting that the NTSB said in effect that they did not intend to point fingers of blame for the collapse, and then proceeded to point the finger of blame at the designers. But apparently, if the designer no longer exists, there is no finger of blame.
Here is an interesting article that seems to be going against the popular orthodoxy that the question of what caused the collapse is settled.
http://www.twincities.com/ci_7992046?source=rss&nclick_check=1
It mentions that there was considerable corrosion on the very plates that were made too thin by the flawed design. The corrosion made them even thinner. Here is a quote from the article:
Jim Schwebel, a lawyer who represents the surviving relatives of three victims, said those issues are worthy of follow-up.
Bucyrus wrote:It is interesting that the NTSB said in effect that they did not intend to point fingers of blame for the collapse, and then proceeded to point the finger of blame at the designers. But apparently, if the designer no longer exists, there is no finger of blame.Here is an interesting article that seems to be going against the popular orthodoxy that the question of what caused the collapse is settled.http://www.twincities.com/ci_7992046?source=rss&nclick_check=1It mentions that there was considerable corrosion on the very plates that were made too thin by the flawed design. The corrosion made them even thinner. Here is a quote from the article: Jim Schwebel, a lawyer who represents the surviving relatives of three victims, said those issues are worthy of follow-up. "If investigators have any of (the gusset plates) that were compromised by corrosion, you've got to put that into the computer model," Schwebel said. "Do they have a right to make that assumption (that corrosion wasn't a factor) if they see that the plates are undersized? And if they don't see that, are they blind?"
"If investigators have any of (the gusset plates) that were compromised by corrosion, you've got to put that into the computer model," Schwebel said. "Do they have a right to make that assumption (that corrosion wasn't a factor) if they see that the plates are undersized? And if they don't see that, are they blind?"
Corrosion over the design lifespan of the bridge is usually a factor used in the design of engineering components. The thicker the piece is, the longer it will last against corrosion. That is probably the reason they claim it is a design flaw.
I guess I just don't see where the lawyer is going with this one. Since he is representing victims, I assume that he esentially is looking for ultimate blame to be placed.
The quote I find interesting is this:
"But Rosenker said the NTSB investigation has found no evidence that cracking, corrosion or other wear “played any role in the collapse of the bridge.” "
I just cannot fathom this statement from an engineering standpoint. Surely the load on this bridge was not high enough to meet the yield stress of the original design, since that is pretty much the only way for the bridge to fail if no wear played a role.
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