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What Happened To the Bay Bridge?
farnsworth writes "Tony Alfrey has put together a fascinating page with some history, analysis, and possible explanations for what ultimately went wrong with the recent emergency repair of the San Francisco-Oakland Bay Bridge. The bridge has been closed for days and is not scheduled to open for days to come, hugely inconveniencing more than 250,000 people a day. His analysis touches on possibly poor welding, a possibly flawed temporary fix, and the absence of a long-term fix or adequate follow-up by Caltrans, the agency responsible for the bridge. Slashdot is a great engineering community; what other insights do you have on the bridge situation?"
For several work mornings the headline on "the new" CNN.com has been "Bay Bridge still closed."
In my head I hear it in the voice of Chevy Chase.
"General Francisco Franco is still dead!"
Four years ago I bought that bridge along with a package of subprime mortgages to highly qualified homeowners.
If you're interested, I can get you a great deal on a used bridge here in NY to replace it. Shipping and handling from Long Island not included.
McSweeny's has a great article on this, broad reaching in its investigation of the many problems at hand. One thing that troubles me: I have seen many times in the California University and Transportation groups, failure to use earthquake retro-fit funds - they simply use them elsewhere. Its only when a problem like this arises that we learn they have not been used.
They should have used duct-tape!
Things like this can't be rushed, plain and simple. Carefully executed planning is what's needed to take on these types of projects.
Sure the commuters will have to wait a little bit longer while repairs are done, but it sure beats the mess they're in now.
"The difference between genius and stupidity is that genius has it's limits" - Albert Einstein
The USA is small. Think bigger than just the 250k people. The whole infrastructure in the USA is lagging in maintenance, care, repairs and/or replacements. The USA needs trillions to fix this problem but other shenanigans of course have higher priorities. P
That's what a bridge IS. Alexander did it the expensive way when he went to Tyre, and every single bridge since then is an attempt to connect two places further apart, or more cheaply, or, often, both.
I knew people had been talking about the state falling apart due to budget problems, but i didnt think they meant it literally
Good people go to bed earlier.
Lets see, when you have a pretty much bankrupt state (California), a bridge that is too necessary to fully replace without inconveniencing many people, the fact that it isn't exactly in a stable environment, with wind, rain and corrosion everywhere is it any surprise that a bridge that has been up for over 70 years needs some emergency repairs?
Taxation is legalized theft, no more, no less.
No, Slashdot is mostly made up of computer janitors; the greatest insight you'll get out of most of the posters here is, "hurrr durr, the bridge must've been running Windoze! LOL!", with maybe a little "omg the twin towers were collapsed by EXPLOSIVES!!!!"-style conspiracy theory and "THE GOVERNMENT IS BAD!!!" braindead libertarianism thrown in for color.
Software piracy is victimless theft.
San France should have two bridges (or a secondary tunnel), so if one fails or needs repair, the second can still be used. In Baltimore we have two tunnels and one bridge over the harbor, so if one fails the traffic can be diverted on the other two routes. Redundancy.
In between D.C. and Baltimore we even have three parallel highways - I-95 and 295 and US-1. One might be closed but the other two will still be usable.
"I disapprove of what you say, but I will defend to the death your right to say it." - historian Evelyn Beatrice Hall
A private one would have been more Ron Paul
People use other bridges and the bart.
To say there isn't redundancy, is simply silly.
The engineering authority in charge of the bridge and repairs already gave their answer to this on the morning news (yesterday, I think):
They found the crack. They designed the "band-aid": the saddle, T-bar, rods, etc. They had it fabricated and installed.
In subsequent days, they went back up to look at how it was doing. They found that it was vibrating more than they thought it should: it wasn't as rigid as it was designed to be. They recognized that this would lead to fatigue and failure.
They began designing the improved "band-aid" and planned to install it sometime in coming weeks.
To their surprise, *perhaps* related to unusually high winds, the system failed sooner than they thought it could.
The completed their improved design and are now installing it. (And they are counting their blessings that nobody was killed: they got lucky, that way.)
-t
If their goal was to improve the safety of the bridge, then they totally succeeded.
It is old, 73 years, and may take a few days to identify and repair especially after first attempt failed.
Who says anything is wrong?
This all seems perfectly normal.
(I like the fact that many people here would rather their be multi-billion dollar solutions, rather than this is simply how it is).
According to the pics it seems evident to me that the cause of the crack is due to compression forces, if it was do to tension the crack would be on the top. The beam is able to rotate and shares both compression and tension forces depending on the load at the time. By using their solution and tension rods is an adequate solution for tension but the reinforcement is needed in compression so tension rods will not work, you would need something to handle the same compression forces that the beam is supposed to handle and you would need to weld it in a manner that the weld is not under stress while experiencing compression. The fix came of because the rods may be adequate to handle the tension forces, but when under compression the complete rig can come flying off even if welded. Tell them to email me I need work, not a PE but I do have a bit of experience and am able to work as a civil engineer. Tell them to send me an email at ctraveler_22@yahoo.com not 22 just personal email that I hardly use due to spam.
The Oakland Bay Bridge isn't much of a landmark, really. In any case, it is *extremely* important to note that the western span of the Bay Bridge, which is a suspension bridge, is perfectly sound, as is the landmark (but less used) Golden Gate Bridge. All of these problems are with the eastern span, which is a cantilever bridge.
The cake is a pie
As a hobbyist welder, and someone who has worked with welders in an industrial setting, I strongly doubt that the welding is the culprit. "Faulty welding" doesn't happen on something of the scale of a bridge. If it's one welder working, maybe. But this bridge repair would have had dozens of welders working. No one person's welding could have broken a bridge. Sure, they were under a time crunch, but that doesn't result in shoddy welds. It means more welders are put on task. Those guys are trained and certified and their work is defined by specs that they follow and then is inspected by city or state engineers. If the welding is the problem, it means the original spec was faulty.
Seth
$5 / month hosted VPS on linux = awesome!
Raids of Public Transportation Funds
nearly $2.5 billion was diverted away from transportation programs
A word fitly spoken is like apples of gold in pictures of silver --Proverbs 25:11
The real problem is that we should recognize that bridges, and especially landmark bridges, stay standing indefinitely and should therefore quit designing the damn things with puny 50-year design lives!
"[Regarding the 'cloud,'] ownership was what made America different than Russia." -- Woz
Meanwhile, in Segovia (Spain), the Roman aqueduct is still up & running :
http://en.wikipedia.org/wiki/Aqueduct_of_Segovia
Without mortar, with just granite blocks on top of each other, it is more than 2000 years old.
I can't help but wonder when mankind began to suck at building anything that should last more than a few years....
It took me a while to figure out but then I realized: CALTRANS only actually employes three guys.
Driving the 15 in San Diego, I wondered why there were all these construction sites with absolutely no one working. Eventually I pieced it together... CALTRANS only employs three guys and one of those has to hold the sign.
Sure, they could just do one tiny little roadwork at a time. But that'd completely give away the hundreds of millions CALTRANS budget is being spent on three construction workers with the rest going to hookers and blow. Instead, they dump cones everywhere, dig holes everywhere, then quickly move on to the next site. Sure, you'll never actually see a CALTRANS guy working but it sure as hell looks like they must have a lot of people doing the work if they can dig up that much crap and have roadworks every couple of hundred yards.
So, when judging the bridge collapse, try not to blame the three overworked guys. They're doing the best they can. Their job was to put up some cones, slap on some duct tape in the two minutes they had assigned, then get on to making somewhere else look busy. If you want to blame someone, figure out who spends the other 99.9% on those hookers and that blow. Imagine how much could be achieved if his habit went to pay for actual workers instead.
Consider yourself lucky Californians. Us dwellers of Northern New York have a much bigger problem than you have if we want to get to Vermont. The NY DoT let the Crown Point Bridge, one of only two bridges across Lake Champlain fall into utter disrepair and it is now closed indefinitely. The shortest 'detour' to go across the lake and into Vermont adds around 100 miles to the trip, just to get to the crossing.
The failed part was fabricated in Arizona.
The revolution will be mocked
It's how the state balanced their budget.
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
No, Slashdot is mostly made up of computer janitors.
I do get that feeling now and then.
Many years ago, I went to a serious engineering school. There, the final exam in a course in structural engineering was this:
At the final exam, each student had to design a link to attach two pins some distance apart. There were obstacles between the pins and the link had to go around then. The design was to be for a specified grade of aluminum and had to support a specified load. Students knew in advance what the exam would be, except for where the obstacles would be. For the exam, you sat at a drafting table, and turned in a drawing.
The link you designed was then machined out of aluminum by a machinist. It was put in a testing machine and placed under the specified load. If the link broke, you failed the course.
If the link didn't break, it was weighed. Lower weights yielded higher grades for the course.
This is how good structural engineers are trained. (I'm not one. I was in EE/CS, and we had a different make-or-break exam.)
I heard the problem was the weld between old and new steel. Temperature change caused the materials to contract or expand and, being slightly different, they changed at different rates, breaking the weld.
It may not be a pretty "landmark" like Golden Gate Bridge, but it is the most important one in Bay Area, certainly way more than the GG.
Fuck systemd. Fuck Redhat. Fuck Soylent, too. Wait, scratch the last one.
The city is so nice and uncongested today. I don't own a car, so admittedly I am very biased, but I would be quite content just to leave the bridge closed. Plus it puts the focus on public transit, where a compact city like SF should be focused. For example, BART (the subway) is running 24 hour service this weekend. As strange as it may sound, despite being an urban environment we don't have 24 hour subway service normally!!!
It's surprising that they had trouble there. That's a big, stiff truss span, with lots of cross-bracing. Those usually don't have serious wind problems. (The Tay Bridge disaster was, of course, one involving a truss bridge. But it was badly designed and very badly fabricated.) The worst case for wind is a long, narrow, thin span. The Tacoma Narrows Bridge collapsed through that kind of failure, and the Golden Gate Bridge was vulnerable to it. In 1951, during high winds, the Golden Gate Bridge deflected enough that one side of the roadbed was 11 feet higher than the other. Stiffening trusses were added under the span. (These are big trusses, each over 20' high, but the bridge is so huge that few people noticed the retrofit.)
In the 1989 quake, the Bay Bridge had an upper deck section break at the joint between the high truss span and the lower spans. That was an impedance mismatch - the two sections oscillated in different ways, and the stress at the transition point was enough to break bolts. When the Bay Bridge was designed in the 1930s, those problems weren't well understood, and could not yet be simulated.
The problem seems to be that the quick fix for the crack was underdesigned. That was recognized within days, and a second fix was under construction.
The damaged eyebar could be replaced, but that requires fabricating a new eyebar and some specialized tooling to take off the load from that whole eyebar chain during repair. This span will be torn down in a few years, when the new span is finished, so that may not be worth it.
Forgot to RTFA, eh?
deleting the extra space after periods so i can stay relevant, yeah.
I agree it is important. It keeps drivers from clogging up my train ride every morning. But it isn't a "landmark" in the sense that tourists don't go to look at it. (Except for the dumb ones suckered by locals saying "it's being repainted...the gray is the primer.")
The cake is a pie
This is exactly what happened with the Minneapolis bridge!
There is a huge difference between a bridge mostly used for long distance travel and a bridge 250,000 people use to get to their jobs every morning.
The cake is a pie
&.c &c. &c.
Sir, I can make no claims as to the veracity nor contrewise of your premises.
However, should they prove to be true then surely a far greater mystery is how it has stayed up so far.
Verily thine,
B. Franklin.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Help stamp out iliturcy.
I was hoping it wouldn't show here, after seeing it elsewhere.
This article is all supposition, and poor supposition than that. It presumes the fix was under-strength ('band-aid they installed was not strong enough to handle the total load') when the problem was most definitely not that the fix wasn't strong enough, but that it didn't stand up to wear-and-tear due to the motion of the bridge.
This is backed up by the failure info and the fact that CalTrans reports they saw the deleterious effects of wear in an inspection a week before the failure, but thought they had more time to fix it and so didn't repair it more quickly.
On another note, does anything really think there will ever be a new eyebar on this bridge? Traffic is slated to begin to be moved off the bridge next year, do you put a permanent fix on a bridge you're already in the process of replacing?
http://lkml.org/lkml/2005/8/20/95
Oh, no mystery there. The Bay Bridge predates basket weaving degrees. ;^)
Even in the '50's and '60's engineering took precedence over politics. Today, being "politically correct" takes precedence over everything, except maybe generating revenue.
If at all interested in traffic engineering, consider speed limits. Real traffic engineers believed in the "85th percentile". In effect, when you open a new road, you post no speed limits - but you monitor how fast people go. After a period of time, you tally up those speeds, and settle on the 85th percentile. Faster drivers will almost all slow down to that speed limit, slower drivers tend to speed up closer to that speed limit, and everything flows smoothly. Today - speed limits are set well below that 85th percentile, intentionally. This way, when the cops are detailed to generate some revenue for the courts, they don't have to spend all day waiting for "x" number of speeders to come along.
If you want something totally screwed up, give it to a committee. If you want it FUBAR'd, make it a committee of politicians.
Anyway - the proper fix for that crack on the bridge would have been to shut traffic down, and REPLACE the damaged part. Slapping a band-aid on the problem was a political BS thing.
"Windows is like the faint smell of piss in a subway: it's there, and there's nothing you can do about it." - Charlie Br
Bad, but it is a two lane bridge carrying 3800 cars per day. Actually, that should make it easier to fix.
The Bay Bridge is the Big Dig of the west. It is the largest public works project in California history, a ridiculous feat. Gov. Terminator tried to change it to a simple trestle, but the ensuing delay and furor only succeeded in adding to the cost.
Well played, sir. Well played.
512 MB RAM, 20 GB disk, 200 GB transfer, five datacenters. $19.95/month.
The real problem is the bay. Get rid of the bay, you have no more bridge problem.
That's the kind of mavericky thinking we need today and America.
If Nalgene water bottles are outlawed, only outlaws will have Nalgene water bottles.
You'd think it would be easier to fix. We just heard today that it won't be fixed until the spring at the earliest. I now consider the announcement that this was 'priority number one' for the NYS DoT to be funniest thing I've heard all week.
This bridge has been a problem from its start, its been a consistent problem since Loma Prieta, and the repairs cost as much as building a new bridge. How about, I dunno, do the logical thing here since it might actually be a safe bridge if it isn't this one.
"They confiscated everything, even the stuff we didn't steal!"
Slashdot is a great engineering community?
I thought this was the only Information Technology Comedy sight on the internet.
Epic failure, nice try. Even people who'd like to yell about that won't believe it.
... hugely inconveniencing more than 250,000 people a day...
That estimate is very low. First, the Bay Bridge typically hosts 270,000 vehicles per day. If we assume an average of 1.5 passengers per vehicle, we're still talking about 400,000 Bay Bridge passengers per day. Second, those diverting from the Bay Bridge are now overfilling BART trains and crowding on to other Bay Area bridges, indirectly inconveniencing many more people.
It makes me wonder if things would have gone better if it had been built according to the Emperor's instructions.
sub f{($f)=@_;print"$f(q{$f});";}f(q{sub f{($f)=@_;print"$f(q{$f});";}f});
In 1990, the Mohawk people (native Americans) blocked the Mercier Bridge in Montreal to protest against the expansion of a golf course on an alleged sacred land. The blockade lasted for *the whole summer*.
The Mercier Bridge is a major access point to the southwest of Montreal island, over 75000 cars are using this bridge daily. Of course all the people usually driving on this bridge got stuck in huge traffic jams, but this situation also created gridlocks on the other bridges and highways in the Montreal area. For months.
At first the cops tried to remove the Mohawk, but they had weapons and killed one cop (caporal Marcel Lemay). So the cops pulled back and the army was brought in. This was a highly political situation; the army was not allowed to use force and merely stood guard.
A crazy summer.
lucm, indeed.
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I suspect that California educated engineers had a lot to do with the problem. A panel had to decide how to fix the problem. The panel was composed, by law, of one gay, one lesbian, one transvestite, one Mormon, one Moslem, one Black, one Hispanic - the list goes on and on.
You REALLY don't know how things work in California.
We got rid of the Mormon after the Prop 8 debacle.
"God, if I were Scotty, I'd have fragged Kirk."
Yeah, some accidents are meant to be, lol.
30 seconds? I'll show you 30 seconds...
Truth isn't Truth - Guliani
And the problem is the fact that 250k people commute over a bridge that spans that sort of distance, and then proceed to complain about pollution from traffic.
Persistent Volume manager for Kubernetes - https://github.com/dwimsey/openshift-pvmanager
And, among the engineers, the various engineering disciplines had representation, including the Doctors of Basketweaving from Berkeley.
That's Underwater Basket Weaving - one of the majors presented in the Cal SOP (along with gems like Prevarication). And yes, I did get my engineering degrees from Bezerkeley.
A Shadeless room is a brighter room.
Why drive into SF?
Because living there costs twice as much as a similarly-appointed apartment anywhere else in the galaxy.
Combine that with the utter ghettoness of the whole city--even the new fancy million-dollar condo towers are surrounded by panhandlers and smash-and-grab thieves.
Combine that with the fact that anyone who lives in the whole western half of the city takes 45+minutes of hilly, car-destroying, non-freeway driving to get to the eastern half (where all the jobs are)...whereas on a good traffic day, Oakland is only 20 minutes from work, and most of the peninsula is only 15 minutes away. All of which is freeway. Thank the hippies (the 50s freeway revolt) for that one.
And finally, despite these things, companies still insist on putting jobs there. Lots of jobs.
San Francisco: Thousands of jobs for the taking, but not one nice place to live for less than $5,000 a month.
Welcome, Reverend Falwell
For justice, we must go to Don Corleone
Because of the geography, San Francisco has no smog, so you don't find drivers complaining about pollution.
The cake is a pie
But not as bad as these pictures:
There I fixed It
101 simple and efficent solutions for all types of repair from leaky water bowls to damaged utility poles and computers.
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http://cryptome.quintessenz.org/mirror/eyeball/gwb-shields/gwb-shields.htm ....
They could just be adding bridge blast shields to encase sections of the suspension bridge's cables
Or they needed a few days access to set something up
Domestic spying is now "Benign Information Gathering"
Perhaps if the state...
Perhaps if you know what the fuck you were talking about. This is why it is pointless to listen to anobody on Slashhdot, 99% of the comments are bullshit.
All the bay bridges, except the Golden Gate, are managed be the Bay Area Toll Authority and funded by tolls. Educate yourself.
http://bata.mtc.ca.gov/
Slashdot - The great and glorious cluster fuck of Internet wisdom.
FOR SALE:
One (1) Bridge.
Used, in fair condition. Needs work, but a good "Fixer-Upper". Breathtaking views of the San Francisco/Bay Area. Located in close proximity to major cities, recreational areas, marinas, beaches, city hot-spots, and only a short drive from Giant's Stadium. Historical and famous.
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Contact:
Arnie Schwartzenegger
State Capitol Building
Sacramento, CA 95814
Phone: 916-445-2841
Fax: 916-558-3160
das_governator@gov.ca.gov
Knowing Google's lust for data collection, the Soviet Union is still alive and well inside the psyche of Sergey Brin....
The threaded rod looked to be a very coarse thread , no washers - no lubrication, they used a 2-3foot wrench to tighten it - kicked it - from the caltrans pictures.
Is that enough force to even take the slop out this setup?
You are correct the Bay Area Toll Authority (BATA) handles maintenance of the Bay bridges:
However, funding for this maintenance comes in part from tolls collected, part from the state of California, and part from the federal government. These funds are overseen by the Metropolitan Transportation Commission (MTC):
On page 24 of the MTC Annual Report 2008 , I see that BATA took in about $492 million dollars in toll operations revenue. BATA also received $126 million in grants from Caltran and other agencies.
However, on the same financial statement I see $807 million was given to Caltrans and another $27 million given to the MTC. This proves my point that money flows in and out of both agencies. Caltrans, MTC, and BATA are intertwined.
What I cannot prove from the financial statement is whether maintenance was neglected so money could be diverted elsewhere. It is possible that even with 100% funding for maintenance & inspections, no amount of inspection would have prevented the bridge failure. My point in posting what I did was to show that California is diverting funds from transportation which may be the cause of bridge failure.
I live on the East Coast so my West Coast knowledge does not come from personal experience. I think from my research I've learned quite all I want to know concerning Bay Area bridges.
A word fitly spoken is like apples of gold in pictures of silver --Proverbs 25:11
You answered the wrong question. Your answer would be fine if the parent poster had asked, "Why not live in SF?", but his actual question was "Why not take public transit into the city rather than drive?"
And I agree. I spent a few years living in Berkeley/Oakland and working in SF and I never drove into the city unless I was going to be out past midnight. And if BART ran 24 hours (the way it is now with the bridge closed), I wouldn't have driven then either. With BART across the bay and MUNI in the city, you really almost never need to have your own car in SF.
Web consulting +
I live 15 minutes away from work by car and 45 minutes away by CalTrain. I calculated that if I took CalTrain I would save $3 a month, in exchange for sacrificing 20 hours of my time a month.
And CalTrain is the only public trans that wouldn't require a transfer onto the accursed MUNI for me. BART, as you probably know, has a grand total of 6 stations in SF, four of which are on Market Street.
I think the poster I replied to must work in the financial district. If your destination is right there in those 4 blocks or so where BART goes, and you're lucky enough to have BART nearby where you live... then I agree, it is great. Except it costs so damn much, but parking downtown is obviously even worse (more costly). If you happen to live right next to a Muni train line, well, as long as you don't mind getting robbed, or at minimum crammed literally like sardines with a bunch of rude, smelly people, then that's also more convenient than driving across SF.
I bet plenty of people who work downtown take BART into the city.
But I'd bet that the majority of Bay Bridge commuters work pretty far away from SF's pitiful subway network, and would have to take a train and one or more buses, requiring 1-2 hours to get to work, compared to the half hour or 45 minutes (or less!) to drive in.
Furthermore, I think at least some of the "drivers" are former public-transit riders who originally wanted to "do the green thing" but just got fed up with how bad the public transportation is in the Bay Area.
That kind of thinking is one of the things that messed up the economy just recently. The assumption that future returns will be like recent returns--which when you get down to it, is equivalent to assuming that investments have no risk.
Finance 101: you must assume higher risks to achieve higher returns. If your friend's investments were returning higher than the loan interest rate, that means that his investments are riskier than the loan would be at that rate. Or put in a different way: if the source for the repayment of the loan would be the income from investments that return more than the loan, then the bank would do better to invest the money in the same stuff your friend is doing.
Are you adequate?
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Greenspan was appointed chairman of the Federal Reserve about 5 years after Rand was dead. I've known about their association since reading his essays published in her books.
Him running the Federal Reserve always struck me as a very Dr. Robert Stadler kind of activity although to be fair his advice to congress was regularly ignored.
Looks like it's finally back up.
511.org (Traffic)
http://www.511.org/baybridge/default.asp
Bay Bridge site:
http://baybridgeinfo.org/
To get this man/woman the Funny mod it deserves.
[UID-HeinzIntel]
Cost cutting is not the issue. Time is.
Political pressure to not impact the commute is severe. The cost to productivity for each work day the bridge is closed is in the millions.
They would have gladly spent more money if it meant getting the bridge open sooner. They rushed it the first time, hopefully they took the proper amount of time this try.
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I'm not so sure.. while nobody likes a fucked up commute, I'm sure "we want to be sure its done right so tonnes of metal do not come crashing down in the middle of rush hour" would cause most reasonable people to calm down.
Calculating car-cost at .50/mile, (slightly lower than actual, but easier to figure), i suspect your savings on train are greater.
and how you gain so much time on the train is interesting, must not be peak times, but the quality of the time spent in either scenario, riding along doing what-have-you vs. piloting an automobile, should compare well also.
ymmv
look sig is kool
The commonly held view of the group of friends I used to ride with many years ago was that the American engineering philosophy was, whenever a crack appeared, modify the design with more angle iron and more weld. It was how we explained the development of the Harley Davidson motorcycle.