Monday, November 25, 2019

West's Unsatisfying Legacy

When some half-million pounds of ammonium nitrate fertilizer exploded in the small Texas town of West on Apr. 17, 2013, it not only killed fifteen first responders and other people, injured 160, and damaged or destroyed dozens of buildings.  It showed what can happen when critical information about explosive-material storage is not shared with local authorities.  The West fire department did not know what they were dealing with, and if they had, many or all of the fatalities could have been averted.

Largely as a result of this accident, in the last days of the Obama administration the U. S. Environmental Protection Agency (EPA) issued what became known as its "Chemical Disaster Rule."  According to a recent report in the Texas Tribune, this rule required that companies storing large quantities of potentially explosive chemicals make the fact known to local first responders and the public, and called for companies to make specific emergency plans and conduct meetings on a regular basis about emergency planning.

The rule was delayed until President Trump took office, and now the EPA is saying it's going to roll back many of its provisions.  After the rule was proposed, affected industries complained about it loudly, and so the modified rule eliminates the requirement for public access to information on dangerous chemical inventories.  Corporations claimed, with some justification, that making their inventory quantities public is an invasion of privacy, and could lead to increased threats by terrorist groups wanting to target locations where large quantities of explosive materials are kept.

One reason that news reports mentioned for the rollback was the finding of the accident's cause by the U. S. Bureau of Alcohol, Tobacco, and Firearms (ATF), which was made public to a limited extent in May of 2016.  The ATF concluded that the accident was caused by arson, but the way they concluded that is curious, to say the least. 

According to a 2017 Houston Chronicle article, the agency reportedly spent about $2 million on the investigation and interviewed hundreds of witnesses .  In this way, the ATF says it systematically eliminated any natural and accidental fire scenarios.  Having eliminated all natural and accidental causes, the agency's conclusion was that the fire was deliberately set by a person or persons unknown.  However, there is not a smidgen of direct evidence that indicates the fire was actually arson.

In science, there is an adage that goes, "Absence of evidence is not evidence of absence."  Logically speaking, the ATF is justified in concluding that arson was the cause if and only if they have actually eliminated absolutely every other conceivable possible cause of the fire.  For example, I suspect they did not consider any possible supernatural causes, as those are outside the purview of modern science.  However, since a supernatural cause is still a cause, it counts in the list of other causes they should have considered and actively eliminated, and they didn't.

Apparently, this sort of thing is so common in arson investigations it has a nice Latin legal name:  "negative corpus."  Meaning, I suppose, the body wasn't there, so you can draw some conclusions from its absence.  The Chronicle article says that negative corpus findings are no longer recommended by standards published by the National Fire Protection Association (NFPA) adopted in 2011.  But local and even federal arson investigators still use it.

The convenient thing about the conclusion that arson was at fault is that it absolves the facility operator from a large burden of responsibility.  It's one thing if your own faulty practices cause an accident, but legally it's quite a different thing if somebody sneaks in and sets your place on fire deliberately. 

To be fair, I would not have the slightest clue of how to investigate an explosion so violent that it left a large crater where the plant used to be and scattered it over a good part of a square mile.  It's quite possible that some tiny critical piece of evidence—a frayed extension cord, for example—would be entirely obliterated in the blast, making a successful investigation of the cause impossible.  But I would also not want to spend two million dollars on an investigation and end up saying, "We dunno." 

The West explosion revealed serious deficiencies in how ammonium nitrate and other explosive materials are stored and how such information is shared, or not shared.  Although I do not have direct access to the revised EPA rule, I can only hope by reading between the lines of the summaries that it still has some provision for informing local first responders about the presence of dangerous chemicals.  That was the most harmful missing factor in what led up to the tragedy at West. 

And as the NFPA now recommends, investigators should be able to say, "Look, we tried, but there's just no way to figure out what caused this," instead of defaulting to a spurious conclusion of arson simply because it's legally convenient and lets companies off the hook.  While arson is also one of the logical possibilities, it shouldn't be shoved to the front of the line simply because it alleviates liability problems.

The town of West was forever changed by the explosion in 2013, and I expressed the hope at the time that something good would come of the tragedy in the form of tightened regulation of facilities that were potential bombs, such as the West Fertilizer Company plant.  It's entirely possible that the original EPA regulations were excessively burdensome to companies that are already doing more or less what they should do because their private insurers keep them in line.  But I hope the newly revised regulations still make sure that the local first responders, whose lives will be on the line if anything goes wrong, at least have the information they need to take suitable precautions for their own safety and the safety of others.

Sources:   I referred to articles in the Texas Tribune at and, and in the Houston Chronicle at, as well as the Wikipedia article on the West Fertilizer Company explosion.

Monday, November 18, 2019

No Do-Over for New Orleans Hard Rock Hotel

There is a saying I've heard more than once from fellow engineers involved in a rush job:  "There's not enough time to do it right, but there's always enough time to do it over."  In other words, sometimes the only way managers will give engineers enough time to do a thing right is if it fails the first time.  Unfortunately for three construction workers who died and numerous other people injured and otherwise harmed by the collapse on Oct. 12 of the Hard Rock Hotel under construction in New Orleans, there will not be any do-overs.  On Nov. 13, New Orleans officials announced that the severely damaged hotel structure will be imploded and razed to the ground.  This will bring to a sad end the physical aspects of the tragedy that began last October, but won't by itself answer the questions of why the collapse happened. 

In the weeks since the collapse, a video emerged that was made by a construction worker on site just two days before the accident.  It shows severely bowing supports between the just-poured top floor and the floor below it.  A reporter for WWL-TV posted a story in which another construction worker said that temporary supports between the top two floors were removed only three days after the concrete was poured.  The same report cites industry standards that say the minimum time between pouring and removing temporary supports should be two weeks.  Reportedly, workers were under heavy pressure by supervisers to complete the building before the busy Mardi Gras tourist season in February. 

Another WWL report says that a large swimming pool was apparently lifted by crane to the top of the building just hours before the collapse.  Even if empty, a swimming pool shell must weigh several thousand pounds, adding additional stress to concrete that was possibly already weakened by the premature removal of supports. 

While these facts raise suspicions, no definite conclusions can be drawn until the official investigations now underway are completed.  Nevertheless, the accident and what is known about it so far serve as reminders of some age-old truths about engineering that are always helpful to remember.

First, practical engineering is always a business of compromises.  Any engineering project is an attempt to stay within multiple limits:  limits of cost, limits of time, limits of physical capabilities of materials, limits of hazards, and so on.  A project is deemed to be successful when it achieves something desirable without exceeding any of the important limits that applied to it.  Sometimes one or two limits are exceeded, but if the consequences of exceeding these limits are minor, they can be neglected.  For example, if a project slightly exceeds budget or is completed only a few days late, usually those involved just absorb the cost and keep going.

It begins to look like the Hard Rock project put speed above a lot of other priorities, including safety.  Now, construction projects can be completed faster than the average time that is usually allotted to them.  To some extent, money can be traded for time.  I recall a passage from the autobiography of Albert Speer, Hitler's architect who later became Germany's Minister of Armaments and War Production during World War II.  Right after Hitler hired him in the 1930s, Speer was handed the job of redecorating the official residence of the Minister of Nutrition for Hitler's associate Joseph Goebbels, and Speer promised to do the job in the exceptionally short time of only two weeks.  In order to impress his new boss, Speer spent extra money on three shifts of additional workers and rented big fans to blow drying air through the building to dry the paint faster, and reported completion to his boss right on schedule.

Not that Nazis are moral exemplars by any means.  This is just a historical anecdote showing how construction projects can be safely sped up at additional cost.  But concrete is not as forgiving as paint.  There are special fast-setting concrete mixtures, but even those require the specified minimum time to set, and tests are required to verify that the concrete is firm enough to hold its own weight without extra supports that are installed during the pouring process. 

It's easy to watch a construction site with workers swarming around it like bees, and think that everything just goes smoothly by default or instinct.  What is not visible to the eye is the complex management structure that has to be in place in order for the dozens or hundreds of lowest-level workers to know what they are supposed to do, and when and how they are supposed to do it.  Having engaged in management myself just enough to know I don't like it, I can only imagine what it takes to run a large-scale building project such as the hotel that collapsed in New Orleans.

In the coming months and years, lawyers as well as official investigators will dissect the management structure, the physical structure, and the complex sequence of events that led to the tragedy of Oct. 12.  Major disasters rarely have a single cause without which everything would have been just fine.  A combination of factors is usually at fault, so we may find that schedule corner-cutting, weather conditions, and an unfortunate sequencing of events such as raising the swimming pool to the top of the building were all partly responsible for the collapse.  But until this information is made public, we can only speculate.

In the meantime, the loved ones and friends of two workers whose bodies remain in the rubble will have to wait until after the intentional implosion of the building to find if there is anything recoverable.  The structure is still unstable and too dangerous to search in, even after an attempt to implode the damaged construction cranes on the site.  And the construction and engineering communities await the post-mortem on this major tragedy to learn whatever lessons can be learned from it. 

Sources:  I referred to an article carried on on Nov. 1 at, an article republished by USA Today from the Lafayette Daily Advertiser on Nov. 13 at, and an article on the WWL-TV website describing the swimming-pool lift at  The anecdote about Goebbel's official residence is on p. 32 of Albert Speer, Inside the Third Reich (Macmillan, 1970).  I thank David Jenkins for bringing my attention to some of this additional information.

Monday, November 11, 2019

Is Vitamin E Acetate Killing Vapers?

Officials at the U. S. Centers for Disease Control announced Friday that they may have found a cause for the lung injuries and deaths in people who use e-cigarettes.  Since the problem arose last March, a total of 39 people have died from what is now being called "e-cigarette, or vaping, product use associated lung injury," (EVALI for short) and over 2,000 more have become ill or hospitalized.  A report by National Public Radio says that a compound called vitamin E acetate (tocopheryl acetate) has been found in lung-fluid samples from 29 individuals who were hospitalized as a result of vaping.  While the CDC has not reached any definite conclusions that vitamin E acetate is the sole cause of EVALI, the fact that it has been found in all 29 samples is significant.  The compound is known to be used by off-label manufacturers who sell vaping products containing THC—the active ingredient in marijuana.  Most but not all EVALI victims admit using vaping mixtures containing THC.

Vitamin E acetate is a more stable form of pure vitamin E (tocopherol), and the acetate is used in a wide variety of consumer products meant to be applied to the skin or swallowed.  It is an oil-like substance that is innocuous in these applications, but inhaling vaporized oily materials can lead to serious lung problems.  The syndrome called "lipoid pneumonia" can strike people whose job involves breathing vaporized oils.  For example, a performer who "eat sfire" by sticking flaming objects in his mouth will often prepare for his stunt by coating his mouth with a petroleum-jelly-like substance called kerdan.  If the hot object happens to vaporize some of the kerdan and the unfortunate performer breathes the vapor, the oil can coat the inside of his lungs and cause lipoid pneumonia.  A less exotic way of getting the disease is to take a mineral-oil laxative and have it go down your trachea instead of your esophagus (the wrong way.)  So it's entirely reasonable to believe that lipoid pneumonia is what the sick vapers are getting, and that vitamin E acetate may be the cause.

This situation is beginning to resemble another famous incident in which manufacturers involved in making a psychoactive substance turned to what they thought was a harmless chemical in order to cut corners, only to find that it poisoned their customers. 

During Prohibition in the U. S. (1919-1933), it was illegal to sell intoxicating beverages containing more than a few percent of ethyl alcohol.  One of the few exceptions was made for extracts of essential oils such as vanilla and ginger, which were typically 70% alcohol.  When sales of such products boomed and it became clear that people weren't just making lots of vanilla ice cream and gingerbread cookies with the extracts, the Food and Drug Administration required makers of these extracts to adjust their formulas so that they were undrinkable in concentrated form, a process called denaturing.  In particular, makers of Jamaica ginger had to add bitter-tasting substances like castor oil that would not interfere with the intended use for ginger flavoring, but would discourage would-be alcohol consumers from drinking the stuff just to get a buzz.  In order to enforce these rules, the FDA would audit samples of Jamaica ginger to make sure that when the alcohol boiled off, the remaining solids were heavy enough to satisfy the auditors that the makers were still denaturing their product properly.

Thus the matter stood until the price of castor oil went up in the late 1920s.  One Jamaica-ginger maker named Harry Gross looked around for a substitute chemical and found one called tri-ortho cresyl phosphate (TOCP for short).  He asked the manufacturer, Celluloid Corporation, if the chemical was toxic, and they told him they didn't think so.  But this was simply based on the fact that no one involved in the making of the chemical had become seriously ill, not that any tests on animals or humans had been made.  TOCP had a suitable specific gravity to be substituted for castor oil, so Gross made up a large batch of several barrels and sold it to retailers, who in turn sold it to their mostly poor customers who couldn't afford good bootleg liquor.

In a few months, doctors in the poorer areas of cities, especially in the South, began seeing patients whose legs were not working right.  It turned out that TOCP was a slow-acting neurotoxin that selectively attacked the nerves going to the leg muscles.  Over the next year or so, thousands of victims of what came to be called "jake-leg syndrome" turned up.  Many were permanently paralyzed and spent the rest of their lives in wheelchairs, if they could afford one. 

Gross eventually served a two-year jail sentence for adulterating his product, but there were no other major legal consequences for the manufacturers, or compensation benefits for the thousands of mostly poor victims of the syndrome. 

The parallels to the current vaping crisis may not be as obvious as they seem.  But in both cases, there is a chemical being sold under dubious circumstances by shady operators.  In both cases, the chemical involved was not previously suspected of being harmful.  And in both cases, serious injuries occurred to thousands of people before anything substantial was done to get to the source of the problem.

In contrast to the jake-leg episode, the CDC has been issuing warnings about vaping products almost since the first victims of EVALI were identified.  But the drive that some people feel to get high can overpower caution and common sense, and there will always be those around who are willing to cater to such desires with a potentially dangerous product.

It looks like the CDC may be getting to the bottom of the problem, and if they do, we can expect quick action against anyone selling vaping products that can harm users.  While the free market has its uses, regulations to protect the public typically arise only after serious widespread harm has been done due to lack of regulation, and that may be what happens in this case. 

Sources:  The NPR article "CDC Finds Possible Culprit In Outbreak Of Vaping-Related Lung Injuries" appeared on Nov. 8, 2019 at  I also used material from the health website Healthline at  I blogged on this matter on September 9, 2019 at  And an excellent longer article detailing the saga of jake-leg syndrome ("Jake Leg" by Dan Baum) appeared in The New Yorker magazine's Sept. 15, 2003 issue beginning on p. 50, to which I referred for some of the information above, as well as Wikipedia articles on Jamaica ginger and vitamin E. 

Monday, November 04, 2019

Moral Exemplars Still Wanted: "The Current War: Director's Cut"

One way of teaching engineering ethics that is less grim than picking through wreckages of failed projects is to portray moral exemplars:  engineers who did the right thing in a critical situation and benefited people thereby.  For example, William LeMessurier, a structural consulting engineer, played a prominent role in determining that the 60-story Boston skyscraper formerly known as the John Hancock Tower was unstable in certain types of wind loading.  The analysis he and his colleagues produced convinced the owners to install millions of dollars' worth of cross-bracing, and the building is still standing today. 

For many generations both in the U. S. and abroad, Thomas Edison was a heroic inventor whose ideas benefited millions.  In 1940, at the height of the inventor-as-hero period in U. S. history, MGM brought out a pair of panegyrics based on his life: "Young Tom Edison" starring Mickey Rooney, and "Edison the Man" with Spencer Tracy.  I must confess that seeing the the former film on TV played a disproportionately large role in my decision to become an electrical engineer, around the age of eight.

However, cinematic heroes today tend to be mainly of the comic-book variety, so when "The Current War:  Director's Cut" was finally released after a two-year delay connected with the fall of Harvey Weinstein, whose production company financed the film, I could hardly wait to see what a present-day director and actors would do with the raw material.

And some of it is pretty raw.  There was no hint in the MGM flicks that Edison was ever anything less than selfless as he enthusiastically searched for innovations that would be boons for humanity.  In particular, there was nothing about the admittedly sordid tricks he pulled to make George Westinghouse's rival AC system look like a threat to public safety, up to and including killing horses and pigs (but not an elephant, as was falsely attributed to him by some confused reports of an elephant's electrocution he filmed at Coney Island in 1903).  But in "The Current War," Benedict Cumberbatch's Edison is no one's idea of a moral exemplar, though he would qualify as perhaps an object of pity.

Just the kind of historic rabbit-trail I took you on about the elephant is one of the problems with the film.  Despite the director's thoughtful inclusion of little side-titles when new characters are introduced (I particularly liked "Nikola Tesla, futurist"), the people I saw the film with all complained that it was very hard to follow.  Although I have made somewhat of an amateur study of Edison, Westinghouse, and that era of the history of technology, I myself had trouble figuring out who was who unless the side-titles were there to help.  In particular, there was an older bewhiskered gent who seemed to be Westinghouse's technical Svengali, but who was only addressed as "Frank."  At the time I guessed it was Frank Sprague, who played a prominent role in early electric tramways.  But later in the film it turned out he was Franklin Pope, an "electrician" (which was what electrical specialists sometimes called themselves back then) who died, not trying to get Westinghouse's electric fan motor to work as the film implied, but in trying to fix a motor-generator installed in the home of his own basement.

As most historical films have to do, this one takes dramatic license with the facts, but stays reasonably close to the main narrative, which is the battle between Edison's first-to-the-market but ultimately unsuccessful DC system, and Westinghouse's cheaper and better alternative of AC, which is still with us today.  The climax of the MGM Spencer Tracy flick, which was Edison's invention of the light bulb, is relegated to a long speech by Cumberbatch at the 1893 World's Columbian Exposition in Chicago.  Westinghouse won the bid to light up the fair, and that triumph symbolized the end of the current war.  Westinghouse and Edison run into each other at the Japanese exhibit, and Westinghouse asks Edison what it felt like to invent the light bulb.  What ensues is perhaps the best piece of classical acting I've seen Cumberbatch do—no special effects, no superhero action, just a man painting a picture of a scene with words that answers the question better than any number of adjectives. 

Cumberbatch seems to be making a career of portraying emotionally peculiar geniuses:  first as the legendary Sherlock Holmes, then as the eccentric mathematician and code expert Alan Turing, and now as Edison.  Critics of the film say he does a good job of portraying our era's idea of the corporate genius:  the Steve-Jobs-type disrupter of the status quo who nevertheless betrays his usually-suppressed emotional life by playing back the voice of his dead wife on his new invention, the phonograph.  Edison's first wife Mary did die in the midst of the current war, which only added to his distress and frustration.  But he didn't let her death slow him down in pursuing his goals by whatever means he thought necessary, including secretly cooperating with a man who thought electrocution would be better than hanging condemned criminals.

I suppose I should have put a spoiler alert on that last paragraph.  But it's unlikely that too many people will see the movie just for the suspense.  To techno-nerds such as myself, who are familiar with many of Edison's lesser-known inventions, the film was a feast of seeing cinematic reproductions of things like the first kinetograph projector (an early form of motion-picture machine) and his electric pen for writing on paper for mimeograph reproduction.  And the film gets some humor out of the Edison family's alleged habit of secretly communicating with each other via Morse-code taps. 

But for the average viewer who has little or no prior knowledge of the era, I'm afraid the film will be a rather confused mish-mosh of mysterious devices, obscure motives, and hard-to-identify characters. A strength of the film is that everything takes place against a lovingly-reproduced CGI background of 1890s America, including a panoramic view of the Columbian Exposition, complete with the original Ferris wheel, that ought to be issued as a two-by-three-foot poster on its own.  I'm not sure what effect the movie will have on eight-year-olds, but don't look for there to be a flurry of young people flocking to be electrical engineers in about ten years.  Actors, maybe, but not engineers.

Sources:  "The Current War:  Director's Cut" was released on October 24, 2019, and stars Benedict Cumberbatch as Thomas Edison.  I referred to a review of the film posted at for details of the delayed release, and also Wikipedia information concerning the 1903 elephant electrocution of Topsy.