Monday, January 28, 2013

Boeing’s 787 Battery Eggs: All in One Lithium Basket


The 787, the latest-model wide-body jetliner from Boeing that seats up to 290 passengers, has been in commercial service since October 2011, less than a year and a half.  It boasts the latest high-tech advances such as a mainly carbon-fiber airframe for reduced weight and fuel consumption, and mostly electrical control systems, rather than the older pneumatic or hydraulic actuators.  Consequently, its electrical power requirements are about triple that of earlier comparable airliners, and so the electrical power system of the 787 was boosted accordingly.  Like a car, the engines (or turbogenerators driven by engines) provide most of the electrical power in flight, but for emergencies and times when the generators aren’t running, the 787 needs batteries, also like a car.  But lead-acid or even nickel-cadmium batteries were seen to be too heavy for the advanced jet, so designers chose to use two 60-some-pound auxiliary power units (battery banks) that employed lithium-cobalt batteries.

Now, lithium batteries have both virtues and vices.  Their main virtue is that they have the best energy-weight ratio of just about any commercial type of battery, meaning you get more stored energy in a 60-pound lithium battery than you would in the same weight of nickel-cadmium or lead-acid batteries.  So far, so good.  But lithium is one of the more reactive metals, and the chemistry of lithium batteries is very touchy with regard to storage temperatures, charging rates, and defects such as little metal needles that sometimes grow through insulating layers and short the things out.  When any of these problems happen to a severe enough degree, the battery can catch fire.  And once a lithium battery is on fire, there’s very little you can do except to wait till it burns itself out, because all the ingredients for the fire are already inside the battery.  Even the FAA recognizes this because it doesn’t require any fire-fighting equipment to put out lithium-battery fires—just adequate ventilation to make sure the hazardous fumes from the fire don’t harm passengers or crew, and don’t spread the fire to other parts of the plane. 

But there is evidence that in the two lithium-battery fires that occurred on 787s in the last couple of months, even these safety systems didn’t work properly.  After these fires in Boston and Japan, the FAA and most other national air-safety agencies grounded the entire fifty-plane fleet of 787s until the battery problem is resolved. 

This problem clearly could have been worse.  The planes could have crashed, but in the incidents so far, the pilots discovered the problem in enough time to land the planes safely.  In the past, lithium-battery fires in a plane’s cargo compartment have caused the loss of the plane, and that is why you are not allowed to carry loose non-rechargeable lithium-ion batteries in checked luggage on air flights.  (Didn’t know that, did you?)  But anybody who owns or leases a multi-million-dollar investment like a 787 knows that every day you can’t fly it is a big hole in your pocket, and also seriously disrupts flight schedules that were made assuming the new 787s would be available. 

It looks like the planes were designed almost in the expectation that the batteries would catch fire some time or other, even though the ventilation systems apparently didn’t work as well as planned.  The fix is likely to be a challenge, because the plane’s entire electrical system is designed around lithium batteries.  Substituting an older type of battery is feasible, but will involve a major redesign, adding weight and probably space and a lot of certification tests to ensure that the fixes aren’t worse than the original problem. 

We may be getting ahead of the game if we assume the lithium batteries are going to come out of the 787s altogether.  The fact that the fires happened so close in time, after over a year of service, says to me that there may have been some kind of well-controlled slipup either in the manufacture of those particular batteries, or the design of those particular planes.  If engineers and investigators can isolate—and ideally, reproduce—the cause of these fires, and it turns out to be fixable, then it may be a simple matter of making sure those particular conditions don’t happen again, and the planes can fly safely again with the lithium batteries they were originally designed for. 

The trouble with these investigations is that once you get a lithium fire going, there isn’t a lot left to pick through to see what started it.  In the “Sources” section at the end of this blog, I’ve put a URL for a little video that I must say about at the outset, “Kids, don’t try this at home.”  It shows a guy taking apart an ordinary consumer lithium battery and setting fire to it.  After you watch that video, you may have second thoughts about buying a lithium anything, though most people don’t go around taking propane torches to their batteries.

We can be thankful that the battery incidents did not result in any fatalities, and I for one hope that the problem turns out to be discoverable, reproducible under controlled conditions, and fixable.  But in any case, Boeing has some lithium-colored egg on its face for the time being, and has about fifty reasons—equal to the number of 787s sold—to get to the bottom of the problem and solve it to everyone’s satisfaction.

Sources:  I referred in the preparation of this piece to an article in the Tacoma, Washington News-Tribune by John Gillie published online on Jan. 27, 2013 at  I also referred to the Wikipedia articles on Boeing and the Boeing 787 Dreamliner.  The lithium-fire-from-battery video can be viewed at

Monday, January 21, 2013

Ethical Lessons from Lance

Trying to learn a lesson in ethics from bicyle-racing star Lance Armstrong’s public confession last week is a little like trying to learn a lesson in cooperation from the U. S. Congress.  Neither Mr. Armstrong nor Congress has recently demonstrated a good understanding of the concepts involved.  But as many engineers know, you sometimes learn more from things that go wrong than from unqualified successes.  Mr. Armstrong has given us a personal perspective of what it is like to violate rules for personal gain, and to maintain for years that you’re not violating them until the evidence to the contrary became overwhelming.  Before you say to yourself, “Well, I would never do such a thing,” recall Solzhenitsyn’s words that “the line dividing good and evil cuts through the heart of every human being.”  And hear what it is like to do things that even Mr. Armstrong himself now can hardly believe he did.

In his two-part interview with Oprah Winfrey aired last week, Mr. Armstrong contrasted his extraordinary public image with “the truth.”  The “mythic perfect story” of his overcoming advanced testicular cancer to win the Tour de France seven times, while in reality violating the sport’s rules against artificial means of enhancing performance (collectively called “doping”) leads to lesson No. 1:  what look like small or routine compromises with the truth early on in a process may lead to unforeseen consequences that are huge.  Most of the time, most of the things that we average people do have little or no effect outside a small circle of influence.  But sometimes, what looks at first like a small act of wrongdoing can cascade into a major disaster.  For example, the I-35W bridge collapse on Aug. 1, 2007 in Minnesota was traced largely to a small error in the size of gusset plates that held joints together, although overloading by construction machinery also contributed. 

Ms. Winfrey probed into Mr. Armstrong’s feelings at the time he was winning Tour de France prizes over and over again while knowingly violating the sport’s rules against doping.  She asked, “Was it a big deal to you, did it feel wrong?”  His reply:  “No. Scary.”  “It did not even feel wrong?”  “No.  Even scarier.”  “Did you feel bad about it?”  “No.  The scariest.”  When I teach engineering ethics modules, I usually ask students how they can tell the difference between right and wrong actions.  One of the most common responses is that they have a “feeling” or intuition that a thing is wrong, and that feeling is what they depend on.  While this feeling, called conscience, is quite often a good guide to what in retrospect turns out to be the right choice, consciences can be overpowered by other feelings or motivations.  In Mr. Armstrong’s case, he admits to being a competitiveness junkie and a control freak, putting it bluntly.  The desire to win at all costs was richly rewarded by the increasingly prominent sports competitions he entered, and whatever qualms he may have had about doping were swept away in the practical realization that doping was just a part of what it took to win races.  Lesson No. 2 is:  don’t always trust your feelings about an ethical matter. 

As many readers know, while allegations of doping have been made against Mr. Armstrong and others for many years, it took the United States Anti-Doping Agency’s multi-year investigation to produce results that convinced the Union Cycliste Internationale (the world body governing professional cycling) to revoke his Tour de France wins retroactively.  Despite Mr. Armstrong’s legal challenges to the process, the USADA’s nearly exhaustive thousand-page report contained enough testimony from enough people to convince the UCI, and gradually even most of Mr. Armstrong’s supporters, that the doping charges were basically true.  Only after losing all commercial sponsorships and being forced out of the leadership of his charitable Livestrong Foundation did Mr. Armstrong decide to make an extensive public statement about the matter, in the form of his interview with Oprah Winfrey. 

When someone else discovers that you have run aground ethically, what should you do about it?  For a time that even Mr. Armstrong now admits is too long, he continued an almost knee-jerk reaction to charges of doping by either threatening or filing lawsuits, including one against the USADA itself.  But losing the lawsuits, losing the money from sponsorship contracts, and losing his credibility even with former supporters finally convinced Mr. Armstrong to change tactics and to admit that what he was doing for so many years was a big lie, and involved lying and calling truth-tellers liars on a regular basis.  When a person is held up to millions as an ideal to strive for, an example of noble achievement against tremendous obstacles, that person has more than the usual obligation to keep his nose clean. 

Mr. Armstrong’s nose was not clean.  And now everybody knows it.  He himself points to a moment when he learned that the USADA was going to pursue its case against him.  He now wishes that he had simply asked them for three days in which to confess the truth to his family, his sponsors, and his foundation, and then he would have admitted to the rest of the world that the charges were true.  But even Mr. Armstrong can’t get in a time machine and go back and play that scene differently:  “I wish I could do that but I can’t.”

So we end with Lesson No. 3:  Fighting the truth once it is revealed usually hurts more than admitting you were wrong.  I’m reminded of a case in which some researchers analyzed the Citigroup Center tower in Manhattan in 1978, shortly after its completion.  They found that under some types of wind load, the unusual architecture of the building could cause oscillations that might lead to its collapse.  When its architect William LeMessurier recalculated the wind loads himself, he found that the researchers were right, and voluntarily contacted Citicorp to warn them of the problem.  Without any publicity, the owners worked with LeMessurier to correct the difficulties, but the story was not revealed in public for another twenty years.  LeMessurier came in for both criticism and praise, but the story is basically one of an honest engineer correcting his mistakes at the risk of his reputation.

Sources:  I used two sources for the transcriptions of Lance Armstrong’s interviews with Oprah Winfrey: for Part 1 and for Part 2.  I also referred to Wikipedia articles on Lance Armstrong, the Citigroup Center, the Missisippi I-35W bridge collapse, William LeMessurier, and for the Aleksander Solzhenitsyn quote, the site 

Monday, January 14, 2013

Mines of Tears: Uranium Mining and the Navajos

Suppose you are a member of the Navajo Nation living on a reservation near Shiprock, New Mexico in 1960.  You hear of a great opportunity to earn money and help the United States besides.  Uranium has been discovered in many locations in and around the reservation, and a private company has opened a uranium mine in Shiprock.  The work is hard and dirty, but the pay is better than anything else you can find without leaving your land and your people.  You apply for the job and you’re hired.

Something like this was the story for one hundred and fifty Navajos who worked at the Shiprock uranium mine at various times from the 1950s through 1970, when it closed.  A decade later, a public-health researcher managed to track down records of these 150 miners.  By that time, as little as ten years after some of them finally left their jobs when the mine shut down, 133 of these men had died of lung cancer or various forms of lung fibrosis.  That’s 88 percent mortality—a pretty big chance to take for earning a decent wage for a few years.  And it’s even worse when you realize that most of these men had no idea of the chance they were taking by working in a uranium mine.  The 150 Navajos studied are just a sample of the thousands of native Americans affected by uranium mining and its aftereffects.

Mining is dangerous, uranium can be dangerous, and uranium mining can be one of the most risky occupations of all in terms of long-term health hazards unless extraordinary precautions are taken to protect the miners from radon and its products.  Radon, a heavy, odorless, highly radioactive gas, is produced by the decay of U-238, the major constituent of uranium.  Breathing radon and its decay products is one of the best ways to get lung cancer, which is why basements with even very slight detectible levels of radon are a health hazard.  Extensive ventilation of uranium mines and continuous monitoring of radon levels can reduce the risks of uranium mining to reasonable levels, but in many of the mines in and near Navajo land in the American West during the “uranium-boom” period of 1948 to 1970, these safety precautions were neglected in a rush to exploit domestic sources of uranium for both peaceful nuclear reactors and nuclear armaments.  And worse, the miners—many of them Navajos who spoke little or no English—were not informed that they were working in conditions that would very likely shorten their lifetimes.  The Navajo language did not even have a word for “radiation.” 

Even after most of the mines closed following a global decline in uranium prices, the hazards continued.  In 1978, the same year that the Three Mile Island nuclear plant suffered a contained meltdown, a containment dam broke that was holding back 93 million gallons of radioactive and poisonous tailing solution.  This hot muck ran into the Puerco River and contaminated miles of the river and acres of aquifer recharge zones.  Judging by the total amount of radioactivity released, this was arguably the worst accident involving radioactive materials in U. S. history, far exceeding the radiation that Three Mile Island put into the biosphere.  But no official disaster declaration was made, few news outlets mentioned the Puerco River disaster, and only in the last few years has some effort been expended on investigating the full extent of the damage and cleaning up the contaminated areas. 

This story is not one of unmitigated gloom.  Because many of the mines and Navajo miners were in Utah, in 1989 congressmen of that state sponsored a Federal bill to provide monetary compensation for uranium-mine workers whose health was affected by their employment in mines and related processing industries.  This measure was signed into law by President George H. W. Bush in 1990, and by 2009 over 20,000 workers had received a total of over $1.4 billion in reparations.

But no amount of money will bring back the lives of those who died early deaths because they only wanted to earn a decent living doing something they thought was helping the nation that had treated them so shamefully in the past.  This situation echoes the dismal conditions imposed by early Spanish explorers on the native Americans who were forced to work in gold mines under circumstances that amounted to slavery.  A person of a different color who speaks a different language than you do is easy to regard as a different species, unworthy of the consideration and justice that you give to your own kind.  Some of the earliest protests against Spanish exploitation of the natives were lodged by Catholic missionaries who saw the maltreatment of mine workers as a blasphemy against the God whom they served. 

Perhaps not coincidentally, I first learned of the Navajo experience with uranium mining from a brochure I happened across which was published by the Maryknoll Missioners, a group of lay persons, religious sisters, and priests who devote their lives to serving the underprivileged of the world.  One of the sisters was featured in an article about her activities in trying to establish the extent of radioactive pollution from uranium mining in areas where Navajos live today. 

No doubt, there were engineers involved in the design and operation of the U. S. uranium mines, and it would be easy to blame them in retrospect for the harms done.  In their defense, it must be said that the hazards of uranium mining were poorly understood as late as the 1950s, because until the advent of nuclear weapons and reactors, uranium was only one of a number of specialty metals, and experience with mining it was limited to a few European mines and scattered studies of uranium miners.  The first substantial U. S. Public Health Study of the subject was done with a sample of Navajo uranium miners, and by the time the results confirmed that such mining without proper ventilation was very dangerous, most of the damage had been done, because the lung cancer and other problems that radon causes take twenty years or more to develop.  Nevertheless, enough information was available as early as the 1950s to indicate that the mining of uranium was especially hazardous, and little or nothing was done technically to account for this fact.  At a minimum, the financial reparations paid to the Navajos and their families are a partial acknowledgment that they were deeply wronged, and teach us that long-term health effects are worth considering in any kind of employment.

Sources:  Besides the Maryknoll brochure from which I first learned of this issue, I referred to a Science Education Resource Center website maintained by Carleton College at and the Wikipedia article “Uranium mining and the Navajo people.”

Monday, January 07, 2013









