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Space Shuttle Disaster (Boeing)

Joel linked to this:

>The report examined the potential damage
>caused by foam debris and used a NASA
>computer tool known as Crater to evaluate
>the damage. Crater predicted that serious
>damage probably occurred to the
>heat-resistant tiles that protect the orbiter,
>but Boeing engineers dismissed the Crater
>predictions. For reasons that are still unclear,
>Boeing engineers predicted a safe return for
>the shuttle.

Reminds me of the coal train and the tunnel through the mountains in "Atlas Shrugged"

Matt H.
Monday, August 04, 2003

In that there were certain people(the brass) who went ahead with something that the engineers knew was wrong/could result in disaster? -- Or just the incident in itself?

Mickey Petersen
Monday, August 04, 2003


In that the brass knew that a software program said that the wing was bad, but that some group said "no, really, it's ok"

And the brass now had someone to blame, and so every decision was "based" on what the group in texas said. 

Despite the fact that it didn't make sense, the brass now had a "fall guy", so giving in to pressure to "just let the dang thing land" was easier to do ...

Matt H.
Monday, August 04, 2003

Ah, right.

Mickey Petersen
Monday, August 04, 2003

I imagine the environmentalists deserve blame too.

http://www.foxnews.com/story/0,2933,77832,00.html

some guy
Monday, August 04, 2003

I think it is seriously unfair to blame environmentalists for the shuttle disaster. As the article makes quite clear, the desire to change the foam formulation to eliminate CFCs was in response to the US Government signing the Montreal Protocols. Given the reluctance of the US - in the face of world wide scientific opinion and increasingly strong evidence - to adopt a precautionary approach and sign up to the Tokyo protocols on carbon dioxide and climate change, then I think its fair to say that evidence of CFC/Ozone interaction must have been pretty convincing and not, as implied, some environmental flim-flam.

If NASA management didn't take advantage of an exemption to which they were entitled, then, personally, I'd blame the management, not the environmentalists.

David Roper
Monday, August 04, 2003

So, NASA didn't have the backbone to stand up to the environmentalists?  But politicians do?  Perhaps we have the treaty for the same reasons that NASA opted to not use the exemption.

some guy
Monday, August 04, 2003

"I imagine the environmentalists deserve blame too"

Errr, no, "they" (as if not causing global annihilation is the goal of only a select few. The fact that someone chooses to separate themselves from such people boggles, and really shows how far "big industry" has gone to brainwash people into believing concern for environmental, and hence human, wellbeing is the realm of just a few oddballs) deserve no blame whatsoever - It sounds like an organization didn't engineer with change: Maybe they could have designed a _better_ foam minus Freon if they did it right, and then you'd be writing in to call the "environmentalist"s heroes, right?

Choosing some easy scapegoat is pretty weak. Of course, this is exactly what happened when California had its energy crisis as well -- We all know now that it was a totally manufactured event by companies like Enron, but that didn't stop the kooks from running on every board to proclaim that it's all because the "environmentalist"s again were to blame because that crazy bunch wasn't up for power plants being built willy-nilly without any environmental considerations. Damn them!

Dennis Forbes
Monday, August 04, 2003

Crater did predict damage to the tiles, but wasn't viewed as a safety-of flight issue, rather that the resultant heat damage to the wing structure would require more turnaround time to repair the damage. (Crater wasn't designed to predict damage to the leading edge RCC panels and T-seals.)

This was discussed at one of the MMT meetings during the Columbia mission, though not for very long.

Mark Newman
Monday, August 04, 2003

It does sound remarkably like the train tunnel incident, for the same reasons. New management lacked technical knowledge and institutional experience with the vehicle, just as the railroad officials did in Atlas Shrugged.

But what are we to do?  Might as well ask who is John Gault?

Clay Dowling
Monday, August 04, 2003

Could someone explain the meaning of this allusion? I have not yet read "Atlas Shrugged"

Devil's Advocate
Monday, August 04, 2003

I think the other part of this is that some folks count on people leaving when you move operations from one spot to another.  It's like having layoffs without having layoffs or as much negative PR.

It's something that you think of if you are a subscriber to the dangerously incorrect "Plug-interchangable engineer" line of thought.  Generally the most senior people, who have put down roots, are the ones most likely to not move.

Flamebait Sr.
Monday, August 04, 2003

Devil's advocate,

In Atlas shrugged a series of people sitting in a stalled train engine(with an eletric motor) decide that they, despite the engineers screaming "no", to proceed ahead into a very long tunnel with a diesel motor because the other one died (forgot the exact reason why)-- the end result being that they all die of asphyxiation because the diesel smog saturates the air.

Mickey Petersen
Monday, August 04, 2003

Huh. The problem is that diesel exhaust, although carcinogenic, is totally nontoxic. You can put rats in 100% diesel exhaust and they survive. (You can try this yourself; it was my highschool science project.) This is because diesel exhaust does not contain any carbon monoxide, unlike gas engines, whose exhaust _is_ toxic.

Are you sure that it wasn't a standard engine in that locomotive?

Dennis Atkins
Monday, August 04, 2003

This was in the 1940-50s. I'm not at all familiar with the fumes generated from a train engine, and i can only assume Ayn Rand wasn't either?

Mickey Petersen
Monday, August 04, 2003

It was an old coal engine used in the tunnel catastrophe in "Atlas Shrugged" and was never to be used on that line BECAUSE of the tunnel. However, some politician who had to get to California and burnish him image by giving away more taxpayers dollars (sounds familiar) orders all the safety precautions to be put aside and the coal engine used for the tunnel passage. He got his just deserts.

Mike Sivertsen
Monday, August 04, 2003

Yeah, my reaction was also ... "Huh.  Does this really happen?"  A train running through a tunnel at a good clip is constantly encountering new air; any toxic exhaust would always be behind the train.  Maybe if you were the tenth train in a row to go through the tunnel like that ... there might be a buildup of toxic fumes.

At any rate, no sense picking at the analogy ... we all get the point she was trying to make.  I'm sure if she was a better writer she could have come up with a lot better of an example ...

Alyosha`
Monday, August 04, 2003

Well, Ayn Rand is a little bit of a nutball on a good day.  Given the amount of stuff she wrote to support her philosiphies that probably wouldn't work in real life, is it really necessary for there to be any sense of reality to her stories?

I think your major danger would be CO2 concentration, because it doesn't take that much CO2 to asphyxiate somebody.  It will sink to the bottom of the tunnel, which might cause some problems.

But the consumption of coal in a steam engine is astonishingly not high, especially given that it's spewing excess carbon soot out the top in bulk.  So I'd rate that anything other than the Chunnel would not likely be a problem.

Flamebait Sr.
Monday, August 04, 2003

I have the memory of a goldfish(a demented one at that), so it's an amazement in itself that I could even remember the basic outline of what happened.

Sorry about the confusion.

Mickey Petersen
Monday, August 04, 2003

I'll bow out of the debate with a reference to http://www.junkscience.org.  The environmentalists have lots of opinions, but not lots of facts.

someguy
Tuesday, August 05, 2003

Interesting how a thread that began with a dispute over knowledge domains; NASA has overall project control; Boeing knows about wings; became a rant about environmentalists.

In environmental sciences (as I understand it) the problem is not a paucity of facts but rather that there are so many facts and they are part of myriad intermeshing systems such that butterfly wings can perturber the hind leg of a dog in Kansas.

Simon Lucy
Tuesday, August 05, 2003

That dog isn't in Kansas any more, it was swept away on a tornado.

Isn't there a certain poetic justice in the USA being battered by seemingly ever more, ever more violent storms year on year, when they produce 25% of the world's pollution? You might almost think that someone up there was trying to tell them something.


Tuesday, August 05, 2003

continued at http://www.gaia-is-smarter-than-you.com/~apocalypse-now

Simon Lucy
Tuesday, August 05, 2003

I'm no Randriod, but the US Dept. of Labor (first google hit I could find) lists CO as one of the major components of diesel exhaust. I'm fascinated by the account of rats surviving in this atmosphere. Do they have a higher tolerance for CO and CO2 concentrations than people?

If memory serves, a CO2 concentration of 5 percent is considered the safe limit for humans. I think CO is about a tenth of that number.

Rob VH
Tuesday, August 05, 2003

Diesel exhaust does not contain CO, unless the injectors are so badly clogged that the engine can barely run, or unless compression has been lost in some chamber, in which case the engine will run very poorly or not at all . CO is a byproduct of an incomplete combustion. A complete combustion, such as one has in a diesel engine that ignites vaporized fuel under 20:1 air compression, has no CO byproduct.

If this was not so, you'd have to explain why no one ever asphyxiated due to diesel exhaust in any of the tens of thousands of diesel submarines built, many of which are still being used today.

Dennis Atkins
Tuesday, August 05, 2003

Because they only run the diesels when surfaced or use a snorkel when submerged. In either case, intake air for the diesel comes from the outside and the exhaust is vented outside as well.

Mark Newman
Wednesday, August 06, 2003

Diesel engines do produce much lower CO levels then gas engines. But the primary exhaust of any combustion engine is CO2 and that will kill you eventually if the CO doesn't first.

DJ
Wednesday, August 06, 2003

This confirms that many of the JoS posters are members of a reptilian species from outer space to whom CO2 is toxic. I am referring to humans and rats, not alien species.

FYI, an idling diesel puts out 2% CO2. Put it under a humungous load at you can get that up to 12% but no larger. Now, find yourself a human (this won't work with your reptilian brethren) and check your respiration product -- 5-6% CO2 coming out of your own lungs! So you can't use a diesel to raise the CO2 level above 12%. And to do that - you'd have to be breathing pure diesel exhaust! (Which contains enough oxygen to breath by itself). Now, the 12% might cause some trouble for a really old person with serious heart problems, but not in any normal person. CO2 is NONTOXIC. You guys saying CO2 is toxic are extremely misinformed. Show me the material data safety sheet that lists CO2 as toxic.

Also FYI, a diesel puts out NO CO unless you arerunning to under -full- load or the engine is air-starved, or the injectors are in sore need of a rebuild. Even in these extreme cases, it only puts out nontoxic amounts of CO, although if you creall ypush it you can get to the point where it will give you a headache. But you'd have to be running it full tilt with a load and bleathing 100% diesel exhaust for at least 3 hours straight. Under all normal circumstances, a diesel engine will pull in some CO from the atmosphere (which has been expelled by gas engines) and emit NO CO. That's right folks -- a diesel engine running will REDUCE the amount of CO in its environment because it will convert that CO into CO2.

So... you just are either uninformed or deliberately spreading anti-diesel propaganda from uninformed environmentalists. Diesel engines are  -the- safest petroleum products engine in terms of combustability (diesel fuel is not combustable  - drop a match in a can of diesel if you doubt this), toxicity (you can drink diesel fuel before additives are added to it -- in some countries, diesel fuel is given to children as treatment for croup), and emissions (it stinks but it won't kill you).

Dennis Atkins
Wednesday, August 06, 2003

Dennis,

First off, it would be nice to see some of your sources. Second, yes diesel fuel is much safer than gasoline. Third, is diesel exhaust really that safe? Gasoline exhaust will certainly kill you quicker but diesel exhaust can still be dangerous.

It  is not as dangerous as a lot of things but it _will_ kill you if you get enough of it.

It is hard to find a lot of documents on the component gases. But all the sites I have found say it comprises CO2, NOx, SO2 and CO, plus a lot of carcinogen particulate matter. Definitely not something you want to breathing in everyday.

Please see: http://www.nett.ca/faq_diesel.html

You state CO2 is not toxic and that 12% concentration would be fine for most people.  I have sources saying that over 10% would be fatal for most people.

“Emergency Overview:  Carbon Dioxide gas is colorless. At low concentrations, the gas is odorless. At higher concentrations it has a sharp, acidic odor. It will act as an asphyxiant and an irritant. Carbon Dioxide is a powerful cerebral dilator. At concentrations between 2 and 10%, Carbon Dioxide can cause nausea, dizziness, headache, mental confusion, increased blood pressure and respiratory rate. Above 8% nausea and vomiting appear.  Above  10%, suffocation and death can occur within minutes.”

From: http://www.uigi.com/MSDS_gaseous_CO2.html  (Note that is also an MSDS!!!)

Also see:
http://www.genome.iastate.edu/edu/PIH/104.html
http://www.epa.gov/spdpublc/snap/fire/co2/appendixb.pdf
http://www.hoopersupply.com/msds/co2.htm

for more descriptions of C02 toxic effects.

As far as CO levels you state the Diesel engines do not produce _any_ CO at all, but then allow that they may produce some under heavy load.  It doesn’t take much CO to kill you because it accumulates in the blood.  The OSHA limit of 25-50 ppm
http://www.osha-slc.gov/dts/chemicalsampling/data/CH_225600.html

Diesel engines can produce 5-1500 ppm of CO with newer engines being much better.  Above 800 ppm CO will kill you so it is not unreasonable to conclude a old or badly running engine may kill you with CO alone.

The exhaust from any combustion engine will kill you. Either by high CO concentrations, high CO2 concentrations, or simply by displacing enough O2 to lower than 19.5%.

Also, I would like to mention the long term effects of exposure to diesel fumes:
http://www.arb.ca.gov/toxics/dieseltac/de-fnds.htm

So it may by the safest fuel, but I sure wouldn’t want to be breathing it and drinking it!!

DJ
Wednesday, August 06, 2003

I don't get it.  It was a coal-fired engine in the book, not diesel ...

Alyosha`
Wednesday, August 06, 2003

It's the thread that will not die...

OK, you have found some really novel info there and I can see why you are confused.

First, the particular MSDS sheet you found at that company is bizarre and not consistent with the MSDS for CO2 at most other companies. The section you quote states serious health problems from C02 starting at 2% concentration. Since human respiration product has around 5% CO2, we can immediately see that that MSDS is obviously unreliable and inconsistent with reality. It also states that death can occur within minutes from CO2 levels of 10%. Well, the LCLo (minimum observed lethal dose) of CO2 for mammals is 90%. At THAT point the issue is the lack of oxygen and not the concentration of CO2. It's possible there is some case in which a severely ill person died from 10% CO2, but it's not something that is going to be observed in any normal situation. There is no LC50 for CO2 (lethal dose at which 50% of subjects die). Also, note that CO2 gets a level of 1 for it's health risk category, which is not very risky for something that can kill within minutes at low doses, as your sheet alleges. Also note that the OSHA IDLH level for CO2 is 50% -- OSHA states people can survive at least 30 minutes in a room with 50% CO2 levels.

The CO in an enclosed space with a diesel engine under normal load will decrease not increase since the diesel will convert CO to CO2. Theoretically,  such an enclosed space would lead to asphyxiation if all the oxygen was burnt, but I suspect the diesel would stall before that happened since diesels need much more oxygen to run than regular engines. Still, it should be possible to come up with a recirculating system where a diesel could lower oxygen levels to below safe ones and cause asphyxiation. You imply that people will suffocate if O2 levels fall below 19.5%; this is not true for people in fair health. At sea level the O2 level in the atmosphere is 21%! 19.5% is certainly not as bad as what you'd get by moving to Denver.

The statement of 1500ppm (1.5%) of CO does represent a toxic concentration. What sort of diesel they are thinking of is beyond me; I have never seen a diesel that could produce above 900ppm and only under extreme conditions. But maybe there is some weird engine that can do it; it's certainly not normal performance and must be some extreme case, perhaps involving some archaic diesel, or maybe they are thinking of those diesels that have been retrofitted to run on wood furnace fumes -- those things produce something like 35% CO but aren't used anywhere I know of anymore.

Regarding accumulation in the blood -- the level to kill you in a few hours is 600ppm and above. Gas engines produce in this range. I would be interested to know what diesels under what conditions will get to this level. I am sure this is not a normal situation. I also suspect that if you ran a diesel at the full load condition necessary to produce this level, it would probably overheat or blow a gasket long before the hours to kill someone had passed.

It's quite likely that long term exposure to diesel exhaust increases the risk of cancer. That is also true for exhaust from gas engines and anyone driving regularly on a highway or living in a city assumes this risk.

Dennis Atkins
Thursday, August 07, 2003

Chris,

I would still like to know your sources.

Here is another I found:

"Gaseous carbon dioxide is an asphyxiant. Concentrations of 10% (100,000 ppm) or more can produce unconsciousness or death. Lower concentrations may cause headache, sweating, rapid breathing, increased heartbeat, shortness of breath, dizziness, mental depression, visual disturbances or shaking. The seriousness of the latter symptoms is dependent on the concentration of carbon dioxide and the length of time the individual is exposed. The response to carbon dioxide inhalation varies greatly even in healthy normal individuals. "

http://www.osha-slc.gov/dts/hib/hib_data/hib19960605.html

Also OSHA regulations say you must wear breathing apparatus when O2 levels are below 19.5%

DJ
Thursday, August 07, 2003

Sorry I meant Dennis

DJ
Thursday, August 07, 2003

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