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Big Dig - One of Engineering's Greatest Mistakes?
Enggirl1 writes "Design News discusses Boston's Big Dig and begs the question - is it one of engineering's greatest failures? The article reveals that forums and blogs are popping up all over the Internet as vehicles for engineers and contractors to discuss, under the guise of anonymity, their skepticism, thoughts and reactions to one of the biggest infrastructure failures in the news today." From the article: "One blogger, whose profile notes that he is an ICC Reinforced Concrete Special Inspector and an ICC Pre-stressed Concrete Special Inspector, among other specialties, says he has nearly 20 years of experience performing both placement and post-placement inspections of rebar, post-tensioning systems, concrete, masonry, etc. He says if structural engineers who specify epoxy for dowels and the like believe that the work is being done correctly then they live in a world unfamiliar to him."
I have a relative who is a civil engineer that has done high-profile (space program, public construction, etc.) work for both the public and private sector.
From the sound of things, I'd guess it's not an engineering failure so much as a management failure. The things I know about public construction are scary. Like when an engineer can't finish a design under the schedule that management wants, management steps in after hours, "throws in numbers" and tosses together a design, then sends it out with the engineer's seal on it. Or when an engineer refuses to sign off on an incomplete or incorrect design, the manager brings in a new graduate because they're more "cooperative" (read: will sign anything to get a paycheck) and they go ahead and build it that way.
The cost and political pressure in public engineering projects often leads to engineers being the least powerful people that have input in the design (i.e. ass backward).
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So it has a few bugs to work out. So it was delayed.
It beat Duke Nukem Forever and even Vista. It's probably better quality too, and will last much longer.
Patch it up and it'll be fine.
I think you'll find most of the problems with the big dig do not stem from any one dumb engineer, but the huge amount of contractors that are awarded contracts by the corrupt locat and state governments. No where in the world have I seen contruction contractors living so well as in Boston.
One of the main problems the team had on the Boston Dig project was that some genius decided to hire the same contractors for both the construction and the inspection of the tunnel. Consequently, the inspector gets put in an awkward position, for if he finds anything wrong, he can either...
A) blow the whistle, cost the company extra money, and then get fired for "undisclosed reasons"
B) look the other way like a good little puppet of the company, get paid, and never have to really deal with the consequences face to face
Seriously, whoever thought that it was a good idea to hire the same company for both construction and inspection is a little naive. Would you let McDonald's do the FDA testing on their own food?
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Rock bolts are a staple in the mining industry. There are darn few failures. Of course the rock bolts are specified by engineers who work for the mining company and installed by miners whose safety depends on them. You tend to do things better if your life depends on it.
In the case of the big dig, you have contractors who are trying to make the maximum possible amount of money. I also bet that there weren't enough government inspectors or that they weren't properly qualified. Cutting costs is just as dangerous in the government as greed is in the private sector. The Canadian province of Ontario laid off all their government water inspectors and a bunch of people died in the town of Walkerton. If you don't give folks the tools they need to do a job then you shouldn't be surprised if the job doesn't get done.
The concrete ceiling tiles were used to create a separate space for supplying air to the tunnel. This is typically how you would do it in a building. In the case of the Chunnel between England and France, they dug a separate tunnel for that purpose. People have wondered why the panels had to be made of concrete. Something lighter would have worked just as well and might have been cheaper and safer.
As a Boston resident I've been following this semi-closely, and it seems that the main problem is not so much the engineering itself, but the way in which the overall planning occurred. This project was started in the late 1980's, and was supposed to cost something like $3 billion and take a few years. Now it has taken more than 16 years and cost tens of billions of dollars.
It wasn't just a bad estimate - it was that they gradually expanded the scope of the project and added new goals once the project was underway. As a result it took longer and cost more money. Then came the double-whammy - because it took so much time, and occurred at a time when people were moving back into the city making overall traffic worse, they had to revise the project again to make it even more ambitious. Otherwise, when it was done the traffic would still be bad and people would wonder why they spent so much time on a project that didn't solve the problem. So the Big Dig has always been in a race with time, which paradoxically has caused them to take more time than they otherwise would.
Most of the problems that have happened with the Big Dig have been due not to poor engineering, but use of the wrong materials and deliberate corner-cutting by the contractors. The woman who was killed a couple of weeks ago when the ceiling fell on her car died not because of poor engineering, but because the ceiling part was held up with substandard materials. They actually realized that this was a problem and changed the materials, but not before that part was built, and they never went back and fixed it.
So the contractors cut corners to make more money than they otherwise would, sometimes illegally. But my theory is that the underlying reason why they were able to get away with it is that the ballooning costs (remember it expanded by a cost of something like 900% in money and 400% in time) made accounting that much more difficult.
Another thing I would add to my previous post is that the irony is that the traffic alleviated by the Big Dig will come back within 5-7 years. The bottleneck for the Central Artery is the part where it actually goes underneath a skyscraper (technically it does this twice, but the other part isn't as crowded). They can't make it any wider there because it would eliminate the foundation of the skyscraper enough that the whole thing could collapse. This limits the size of the entire Central Artery and will eventually force the city to develop ways for people to get in and out and around using completely different traffic patterns.
The one major improvement to traffic that the Big Dig accomplished was diverting traffic going to the Airport through a separate tunnel (the one that just had part of the roof collapse). That reduced traffic in the Central Artery by something like 50%. Ironically, that was also the least expensive part of the Big Dig.
As usual with engineering disasters of this sort, the failure seems to have been caused by a confluence of lesser mistakes that would not have been tragic in isolation. The root causes, however, seem to be:
Anyone who has lived in Boston can tell you that this is only the latest in a string of cost overruns and management failures. The actual mode of failure (i.e. the bolts) and the immediate causes of that failure should not overshadow the idea that the contractors who screwed this one up should be held responsible. The ongoing investigations should reveal whether the contractors were merely incompetent or whether they willfully ignored problems like these and crossed their fingers that nothing would happen.
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The exact story is still being discovered but it seems that the original builder was replaced by someone cheaper who cut corners.
In itself bad enough but stories are starting to emerge that this kind of stuff has been going on all over. Not a real suprise, we have had a couple of incidents of collapsing balconies because of shoddy building but because this scandale is so public the stories off other scandals also gets more attention.
Then again it is nothing new. Every time there is a disaster like an earth quake anywhere in the world you will learn that some building collapsed because the builder did not follow regulations or even the blueprint.
Cost cutting is almost everytime the reason and who is to blame for that? Well us. We want our buildings build as cheaply and as fast as possible so we hire the guy with the lowest contract and then expect to get quality.
Nobody on the world would expect a ten dollar watch to have the same quality as a ten thousand dollar watch so why do we expect the guy who can do the job for a million to be as good as the one who wants two million?
The fact that a live was lost in this Boston incident is tragic. That it involved such a god awfull amount of money makes it however fortuanlly headline worthy. If we a truly upset about this we will demand more and better inspection of every building project and demand very stiff penalties for those who ignore regulations. Oh and we won't mind paying extra for it.
Did you hear just hear that massive sound of everyone taking a step back? Yup, we want the best but at the least cost. That is how it is supposed to work in a free market. Sadly it doesn't.
Shoddy building by the lowest bidder is nothing new. Just because this one involves a costly project that has already been controversial does not make it new. Shoddy building will go on as long as contracts are awarded to the lowest bidder.
But why doesn't it work to go for the lowest bid? Because it is an ongoing race. There is always another party who wants the contract who is just going to have to find some way to lower costs. At a given point there is no more fat to trim and you have to start cutting in essentials. Think of it as anorexia. When all the fat is gone you can only loose weight by reducing vital organs and tissues until finally you die. In losing weight you need to know the limit, the point were you simply cannot loose weight anymore. In lowering cost you also need to know that limit. Were any further cost savings are coming from critical areas like following the blueprint to the letter, proper inspection and using the right materials. It can be as simple a something as continueing work on days to hot/cold/humid for some materials to properly set. A great cost saving but a gigantic risk.
This woman paid the price for our penny pinching and the great joke? Now the costs are going to be much higher to us all then if the job had been done right by the non-lowest bidder in the first place. Yet how much do you want to bet that in a few years time the next boston city goverment contract will again go to the lowest bidder?
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Posting anon here - I worked on the Big Dig (environmental) during peak construction (1997-2000) and I'm currently contracting with another MA state agency, and I don't want to ruffle any state feathers. I also want to write a book someday ;)
First a couple of general statements:
Now back to the facts - I have no knowledge of roof panel construction (I spent little time in that area), but I will note that working on the project during 1999 and 2000 was an interesting experience. Already at the point there was heavy pressure on project managers and contractors to reduce costs (this was before the national stories hit that led to the ouster of James Kerasiotes). It got to the point that office supplies were locked up - you had to get the office manager's permission to get a notebook or pens!
In any event, I wouldn't be surprised at all if cost pressures let to reduced safety factors, etc. The construction site was also the source of many stories about various screw-ups that I won't get into here (wait for my book!). There was of course several times that money was spent to shut people up (at least once against my direct recommendation), but the PTB felt it was needed for the project to move along smoothly. I suppose that it would have been better for B/PB to take the Vista approach, and wait for the tunnel to be "finished" but that wasn't going to happen because of the political pressures.
Now was the project a failure? I'll just say this - is used to take me 1.5 to 2 hours to drive from Braintree to Cambridge during midday traffic. I did the same trip a month or so ago during a Friday afternoon rush hour in abut 20-25 minutes.
One of the problems with the Big Dig ceilings is that some of the engineers that designed it have never actually built anything. These guys must not have ever gotten their hands dirty on an actual jobsite. Their the guys in ties, hard hats and a slight look of confusion on an actual site. The book says epoxy has the strength, it must, use it. When the accident occured and it first came out that the bolts were epoxied in place, my first thought was "what kind of idiot makes suspended ceilings out of concrete, then tries to epoxy them in place?" Epoxy is a wonder material, but this is just so obviously not a smart use for it. No, i'm not an engineer.
s /2006/07/28/bolt_system_graphic/
I've got a running bet with anyone that'll take it that the Big Dig is closed down in less time than it took to build the beast.
My wife is a news designer for the Boston Globe, she made this graphic to explain what happened, it's pretty cool. No complaints about it being in Flash, that's what she uses:
http://www.boston.com/news/traffic/bigdig/article
Enjoy,
Josh
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What are you talking about? Massachusetts has the best politicians money can buy!
You create a false dichotomy, because there are many American construction workers who can't read the instructions for assembly.
Quality isn't an illegal immigration issue. Doesn't matter if it's a Mexican illegal or American just off the farm, if they don't have the skills its the problem with the construction company. They didn't do a sufficient job of ensuring their laborers had the skills and ensure the quality of work. Illegal immigrants are just a pool of labor, the impact they have is on the value of labor in certain industries. Those who make hiring decisions are the ones responsible for sacrificing service and quality for price.
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As Yoda might have said, "Break me a fscking give!" --
The big dig constitutes several of the most ambitious and complex infrastructure projects imaginable. They had to freeze the ground in the back bay by piping supercooled fluid through it while digging in that part. They have completely re-routed one of the largest transportation networks in the world without closing the old one (other than a few hours at a time at night or weekends). As the last phases are completed -- the cleanup of the old site -- Boston becomes one of the most beautiful cities in the world. What used to be a hideous elevated six lane highway becomes a walking park with small shops, museums, and playgrounds that connects the entire downtown area from Haymarket and Fanuel Hall past the New England Aquarium, all the way to South Station.
It was typically corrupt on a scale only an eastern (or European) city could manage, it was over budget and time on an epic scale -- but did anyone really expect otherwise? Someone really screwed up on these bolts. They'll get fixed, the lawsuits will settle, and in the meant time this project will be the pride of Boston for many years to come.
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I'd trust a kid "off the farm" to be able to do construction work before about anyone else the same age. You grow up building and repairing big structures, welding, operating equipment that costs as much as most folks houses, etc you appreciate how to do things properly. Any random 20 year old kid off a farm might easily have ten years experience in what would be considered adult professional work in most of the trades. He's grown up wiring at high voltages, working on very large and complex plumbing installations, doing all sorts of carpentry, cement work, equipment maintenance, etc. It's a pretty thorough and complex process to keep a large farm operating. And today's farm kids are using automated and computerized devices, all the way to GPS enabled equipment that uses robotic steering. maybe it is past time to put that "country bumpkin" meme to rest, it no longer applies.
With that said,back on subject, that entire big dig project has a long history of controversy and accusations of weirdness around it. I am (somewhat) surprised it has taken this long to start to fall apart.
As to the illegals versus legals and so on, it's a crapshoot. I have worked on jobs with illegals that were a menace,totally incompetent and dangerous to be around, hired merely because it was a body to throw at a job for cheap pay obviously. A few have been quite good from recollection, most are pretty common, some skills, but a lot of enthusiasm. They come from a culture of lower resources, recycling old junk more, cob jobbing as normal, etc. I think it is just too large a variable to really be able to quantify it adequately. What can't be denied though, is that hiring illegals in a general sense is a cost cutting measure so the boss class can skim a few more bucks off the project, and when that becomes the primary focus on a job, the job suffers. Jobs should cost what they cost, not the lowest crap possible then cut corners from that point. You get your "problems" then. When you have something as important as a big dig styled project, you shouldn't screw up. If it is deemed to be unaffordable to do correctly, don't do it.
If your new garage roof sags and leaks after a few years because you hired the local cut rate guy with his "crew" of casual pickups from the home depot parking lot..well, it's no big deal to anyone but you and not a major threat. Something like the big dig is a totally different situation.
Several points I think you got wrong.
First, it's not a city project. It's a Federal highway project.
Secondly while there are a large number of illegals in the construction industry, this has nothing to do with the project. The project wasn't done with day laborers and cheap fly-by-night contractors. It was done 100% union labor with major engineering firms directing.
Finally, it's too early to call the project a failure. The fatality was the result of a single bad design element, after all. From a traffic standpoint, the artery works far better than I expected. The question is, what other design elements are faulty? The waterproofing issues I think were ones that the engineers doing the actual grunt work ere expecting, although politics forced management to take an excessively hopeful view. The bolt failure that killed the unfortunate worman is a bigger concern. It's not so major a concern in itself, because the design in question was used only on one section of the project, a connector tunnel to funnel turnpike to airport traffic off the main artery. Furthermore, it is likely that this will be resolved; it will be expensive, but no in the overall context of the project.
The concern is that this raises questions about the management process that directed the project's engineering. Are there other design elements which had similar faults?
There's no question the fatality was a result of bad engineering. You don't put a design element in that requires perfect craftsmanship to install, and that kills somebody if it fails. The bolts in question fail on both counts. First of all you have a situation where workers are supposed to drill in a uncomfortable and dirty environment. Then they're supposed to clean the hole very carefully so they're expoxying the bolt to rock, not milliions of dust particles. And the workers are supposed to do this overhead. And in an almighty rush. Even the best and most conscientious workers cannot be trusted to do this at better than 99% perfection, and 99.99% perfection wouldn't be enough.
The second problem is that you don't design things that fail in ways that kill people. Civil engineers do this all the time: when this beam fails, the floor should sag not collapse. The bolt that failed held up a concrete panel. The panel was a nonstructural component that was there to create an air return plenum. The plenum was needed because you'd poison any motorist who had a break down or was stuck down there in a traffic jam. The dividing element had to meet a number of safety requirements, the most important had to do with fire. That's why you couldn't use a lightweight panel. But the design should have resulted in a visible but non-fatal failure on failiure of any single element, not a cascade of bolts pulling out of the ceiling. And you have to plan that if one bolt is bad, all the bolts around them are bad too. Remember that worker who's drilling overhead holes and supposedly cleaning them perfectly before applying the nasty and finicky expoxy mixture. Imagine he's had a bad day. If he fails on one bolt, you have to assume he fails on a series of them, maybe all the bolts he did on that shift.
So, this was one piece of bad design. The fact that it was in a non-structural element probably explains, if not excuses the bad design. You don't make mistakes on things like girder design because everyone is thinking about the possibility that bridge will collapse or the tunnel implode. It's a small, easily overlooked design element that, it turns out, given the right circumstances can kill somebody.
We computer guys understand this phenomenon well. It's an error that comes from complexity. This incident may become the Therac 25 error of the civil engineering world. If the right engineer had been assigned to look at this at the right time, it wouldn't have happened. The fact that the right engineer was never tasked with checking the design was a management error. It was a rush job.
For this reason, I expect there are other flaws of this sort in the project: small details that weren't got right.
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Having moved around the country a bit I found that in LA the construction has a lot of Latinos, in Atlanta it is largely African-Americans, and in Boston (where I now live) it is largely White people. While I don't expect any illegal aliens from Mexico worked on the Big Dig, there is a very large (white) Brazilian population here and I wouldn't be able to tell if they are on construction sites or if it's Boston natives. In any case, this area is heavily unionized, and I expect the government insisted on "higher skilled" union workers.
Having said that, and being half-Mexican myself, you're a moron if you think that some low paid white trash who thinks he's underpaid is going to do a better job than a Latino worker happy for the chance to make some money. Your comments remind me of Governor Ronald Reagan's idiotic comment about Mexicans thriving in the fields (for which my dad never forgave him). In any event, it is more likely that Bechtel and the like had their heads up their a@@ (you'd think after the Big Dig the gov't would have known better than to hire them in Iraq), while Italian-American owned construction companies were probably cutting corners on jobs they got based on connections.