Heathrow Power Failure: A Lesson in Infrastructure

 

Around midnight Thursday evening, Mar. 20, a transformer at the North Hyde substation in west London caught fire and failed, interrupting power to some 67,000 customers.  Power outages are not that unusual, and this one would not have made the news except for the fact that one of those customers was Heathrow Airport.  Although airport authorities claim that the backup emergency-power systems worked as expected, they decided to close the airport, which is the fifth busiest in the world. 

 

It took seven hours for firefighters to quench the blaze, and another twelve or so before power could be fully restored.  Consequently, all flights into and out of Heathrow were diverted or canceled until around 6 PM Friday.  The knock-on effects from this major disruption will be felt for several more days as stranded travelers find alternate routes and the transportation system strives to return to normal.

 

One engineering expert interviewed about the incident expressed surprise that there were not alternative supply paths for such an important load as the airport.  Apparently one terminal did not lose power, but the expert said that the grid in that area of London is "highly constrained" and has recently been stressed by increased development in the region. 

 

Admittedly, the failure of a substation transformer is an unusual event.  Such transformers can be the size of a small bus and cost on the order of a million dollars.  Utility companies normally monitor their condition remotely and perform routine maintenance on them such as cleaning or replacing the cooling oil that bathes the tons of steel and copper inside the sealed container that is visible to the eye.  Dropping the ball on any of these precautions can lead to a dangerous situation.  Impurities such as water can get into the oil, weakening insulation and leading to a sudden arcover and failure.

 

We will have to wait for investigation results to discover exactly why the transformer caught fire.  But another question is: why did Heathrow not have sufficient backup power to continue normal operations? 

 

The best guess is simple economics.  A modern airport uses a great amount of power for moving sidewalks, elevators, security equipment, and lighting.  Maintaining enough backup generators to provide the entire normal load would be expensive, probably complex because of the load's distributed nature, and would show up as a dead loss on the books of the private company, Heathrow Airport Holdings, which runs the airport.  So the bottom line is probably that the firm decided the temporary fallout from a short-term shutdown would be less expensive than paying for a large number of emergency generators that might be used only once every few decades. 

 

No one died or was even injured in the Heathrow shutdown, and in retrospect the decision to limit emergency backup resources was probably a wise one.  Nevertheless, this incident brings up an interesting issue with regard to how seriously we should take preparing for unlikely infrastructure failures.

 

In cases where a power failure could be deadly or extremely costly, institutions and organizations usually buy enough backup power to keep things running almost without interruption.  For example, most hospitals have enough backup power to keep operating rooms running normally, although the lights may go out in hallways and patient rooms if the main power fails.  You don't want a power failure in the middle of your brain surgery, and so most responsible hospitals make sure this can't happen.

 

Huge semiconductor plants also typically have enough backup power to keep their essential processes running without a hitch, although the emergency power system forms a costly and seldom-used aspect of the installation.  A former student of mine is heading the electrical installations at a major semiconductor plant, and showed me a photo of the ranks of large backup generators that are being installed.  If power were to go out in an operating semiconductor fab facility, the entire inventory all along the process lines would have to be scrapped, and this multimillion-dollar potential loss justifies spending extraordinary amounts to ensure that the machines keep running. 

 

On the other hand, while Heathrow is a vital part of Europe's transportation infrastructure, closing it for less than a day has not had many permanent ill effects.  The systems that communicate with airliners were unaffected and flights were successfully diverted, so other than a lot of travelers whose plans were disrupted and deliveries delayed, the incident will have few lasting consequences.

 

Once the cause of the fire has been determined, we may learn something about ways of preventing such fires in the future.  If the oil was dirty and led to deterioration in insulation, better maintenance is called for.  If the substation was overloaded due to new construction, maybe another substation is needed, or the North Hyde facility needs to be expanded with a second transformer.  And if there was some sort of transient or network disturbance that led to a stress failure, new smart-grid technologies can be brought into the picture to alleviate such incidents in the future. 

 

A transformer fire is one of the worst things that can happen to a power grid, but it does seem like some fairly minor changes in the distribution infrastructure could keep this from happening again.  A friend of mine who used to work in an aerospace job uses a phrase that would apply to this situation:  "single-point failure."  If a system has one component whose failure brings down the whole system, that single point is a vulnerability that should be addressed.  And maybe last week's shutdown of Heathrow will motivate changes that will keep it from happening again. 

 

Sources:  I referred to an Associated Press article on the incident at https://apnews.com/article/britain-london-fire-heathrow-airport-6d63b2f6615e8ff39f2647641bfbc160, a website called Open Conversation at https://theconversation.com/heathrow-closure-what-caused-the-fire-and-why-did-it-bring-down-the-whole-airport-expert-panel-252834, and the Wikipedia article "Heathrow Airport Holdings."

Terrorism and the U. S. Power Grid

 

Modern life in advanced industrial societies depends on the availability of certain basic utilities such as water, sewage service, and electric power.  Probably the most vulnerable of these infrastructures is the electric grid, as the others are mostly underground, and the transmission towers, distribution poles, and substations are right out there in the open just asking for someone to come along and shoot them up.  And that's exactly what happened on Saturday, Dec. 3, when two substations operated by Duke Energy in Moore County, North Carolina were sabotaged by unknown intruders.

 

These were no casual drive-by attacks by joyriding teenagers.  The attackers knocked down a gate leading to one of the substations and used high-powered rifles to damage enough equipment so that 40,000 utility customers were without electricity.  Fortunately, Duke Energy repaired or replaced the equipment fast enough so that things were basically back to normal in a few days, but for a while some water utilities were running on emergency power and a local hospital had to switch to its emergency generator.

 

On a larger scale, Russia has been targeting Ukraine's power grid with missiles, and has succeeded in knocking out the power to critical regions of that country, leading to mass evacuations before the coldest winter weather sets in.  Of course, a war is not domestic terrorism, but the extreme vulnerability of power grids make them the target of choice when an enemy wants to get the most harm-inflicting bang for the bucks it spends on missiles and bombs.

 

What can be done to make the grid less vulnerable to terrorist attacks?  It depends on which part of the grid you're examining.

 

Most current power grids consist of relatively few large central generating stations which feed power into the high-voltage transmission lines that cover dozens or hundreds of miles between the generators (generally in rural areas) and the places where most power is used (suburbs and cities).  Where power is needed, substations transform and switch the high-voltage energy into lower-voltage distribution lines, which are the familiar one or three cables at the top of power poles, which connect to the transformers that step the voltage down further to 120 and 240 V for homes and somewhat higher voltages for businesses and industries. 

 

The farther upstream you go in this distribution chain, the more damage you can do, but the harder it gets.  Every now and then, a driver accidentally runs into a power pole and knocks it down.  This results in an outage affecting perhaps a few dozen customers, and is fairly easily repaired in a day or less.  Many localities are wired so that there is more than one pathway from the substation to any given customer, and so power can be restored quite rapidly to most users by isolating the problem and using alternate pathways until the damage is repaired. 

           

On the other hand, an attack on one substation can put thousands of people in the dark, because substations are typically the only source of power for a given region.  But as the Moore County incident showed, service can be restored in a few days, assuming enough spare parts are available.  The most critical component is the substation transformer, because these cost hundreds of thousands of dollars and take a long time to manufacture and transport.  You can't just order one on Amazon and get it in a couple of days.

 

Attacks on high-voltage transmission lines, while not unheard of, are (a) difficult and (b) dangerous, which is why they are so rare.  And as with distribution lines, the utilities have designed multiple pathways for energy to get to most places, so the net harm from one transmission line going out is usually not that widespread, unless the grid is already stressed. 

 

Finally, disabling an entire power plant can cause serious but not catastrophic outages.  Again, most grids are resilient enough to take up the slack with other generating stations, and for terrorists to disable a power plant would be a grand-scale exploit comparable to the 9/11 attacks on the World Trade Center.  The payoff in terms of domestic disruption would be much less, however, which is another reason you don't see a lot of terrorists going after power plants.

 

Nothing was mentioned in the news reports I saw as to whether any security-camera photos were obtained of the perpetrators of the Moore County attacks.  Virtually all substations are probably now equipped with such cameras, but a systematic terrorist would note their locations in advance and make sure to shoot them to pieces before leaving.  The knowledge that they'd be caught sooner or later will discourage some kinds of terrorists, but not others.

 

Finally, there's what you might call the fear factor.  Working with limited budgets, terrorists want to produce the most anguish in the most people for a given effort.  Having your power go out for a couple of days is inconvenient, surely, but it's not in the same league as having your head blown off by a bomb.  There is some speculation that the Moore County attacks were connected with a local drag-queen show, but if all the terrorists wanted to do was to douse the lights at the drag-queen show, it would have been easier to cut off the power for a particular building than to wreck two substations.  Terrorists are not always logical, however.

 

While the power grid is probably one of the more vulnerable types of infrastructure we have, it looks like the kinds of damage that can be done with a small-scale terrorist operation are relatively minor and short-term.  And doing anything that would cause extensive long-term outages would take the operation out of the terrorist class into the civil-war class, because it would require multiple widely-separated and coordinated attacks, or else a concerted effort by what would amount to a whole militia. 

 

I hope they catch the people who knocked out Moore County's power, not only for reasons of justice, but to find out why they chose that particular approach, and to see if we can get ahead of the next bunch who wants to damage the grid.  In the meantime, terrorist attacks on power grids are not going to be high on my worry list, and they shouldn't be on yours either. 

 

Sources:  The online version of the Austin American-Statesman of Dec. 11 carried an editorial by Myron B. Pitts of the Fayetteville Observer entitled "After attacks, how safe are substations?"  I also referred to the Wikipedia article "Moore County substation attack." 

Obliging Bridge Makes Political Point

 

If you had to have a bridge collapse, it was just about the best collapse President Biden could ask for.  Nobody was killed, but enough people were injured to garner headlines.  And it happened about four miles away from where the President was scheduled to speak in Pittsburgh, Pennsylvania later the same day, Friday Jan. 28.  I'm sure the bus riders, motorists, and joggers who were involved didn't think it was funny to see the Forbes Avenue bridge over Frick Park resolve itself into several large disjointed chunks.  An articulated bus slid backwards into the rubble, necessitating a rescue of the bus riders by first responders.  But later in the day, President Biden made the collapse site the first item on his tour of the city, reiterating that the $1 trillion federal infrastructure bill passed last November has money to pay for replacing old bridges such as the Forbes Avenue structure, which was reportedly two years beyond its 50-year design life when it collapsed.

 

For years now, the American Society of Civil Engineers has displayed on their website a report card on the nation's infrastructure, and I don't recall ever seeing a grade higher than C.  They estimate it would take some $125 billion to completely clear the backlog of aging and deficient bridges that the nation has accumulated since its roadbuilding frenzy of the mid-20th century, when most of the interstate highway system was built. 

 

The Forbes Avenue bridge doesn't carry interstate-highway traffic, but its construction was no doubt made easier by the abundant highway money that prevailed in the 1970s.  No bridge can last forever, and steel bridges in regions where salt is used on the roads have to be monitored with special care because of problems with corrosion.  Not being a civil engineer, I can't tell from the news photos of the collapse just what kind of a bridge it was, but obviously it was the kind that can wear out right after its design life lapses.  Traffic on the bridge was not especially heavy at the time, so my uneducated guess is that a critical structural element simply decided to let go, causing a sequence of events that led to the failure of the whole bridge.  It will be weeks or months before forensic engineers get a chance to analyze the pieces and figure out what gave way.

 

But in a way, it doesn't matter, if you look at the broad picture of bridge infrastructure in the U. S.  The coincidence that a President who signed a bill that is going to do something about it visited the city where a bridge collapsed the same day simply draws attention to the fact that the built environment is a measure of the society that builds it.  The society that devoted such energy to building the bridges and roads of the 1950s through the 1970s was a different society than the one we have today, and unique in many ways. 

 

The farther we get from that era, the more unusual it looks in comparison to either the decades before, during the Great Depression when about the only public-works projects were Federal programs, and the decades after, when the rest of the world's industrial capacity recovered after World War II and removed the exceptional economic advantages that favored projects in the U. S. such as the interstate highway system.

 

But our economy depends on roads and bridges to be there, so it is only doing the responsible thing to maintain them.  And last fall's infrastructure bill was recognized as a sorely-needed act by some Republicans as well as Democrats, which is why it passed despite the huge price tag.  Only about a tenth of the $1 trillion will go to roads and bridges, but $110 billion is a good bit of the $125 billion that the ASCE says the nation's bridges need.  It won't "fix them all," as President Biden said about Pittsburgh's decaying inventory of remaining bridges, but it will go a long and useful way in that direction.

 

The park that the Forbes Avenue bridge spanned is named after Henry Clay Frick (1849-1919), a nineteenth-century industrialist who chaired the Carnegie Steel Corporation, and is most well-known now for his charitable bequests, such as his former mansion which became the home of the Frick Collection of fine art in New York, as well as the land which became Pittsburgh's Frick Park. 

 

Frick's name is indirectly connected with a much worse disaster than last week's bridge collapse, incidentally.  As a founding member of the South Fork Fishing and Hunting Club, a private club that named among its members many of the wealthy men of Pennsylvania, he was partly responsible for alterations of what was then the world's largest earthen dam, holding back the waters of Lake Conemaugh, where the club members liked to fish.  Despite warnings by engineers that the dam was defective, the club reportedly lowered the level of the dam by three feet.  After unusually heavy spring rains, on May 31, 1889, the dam broke, sending most of Lake Conemaugh roaring through a valley that led directly to the doomed town of Johnstown, Pennsylvania, killing 2200 people and devastating the town.

 

The disaster that happened last week in Pittsburgh was nothing like the Johnstown Flood, but there are a few parallels.  Engineers knew that the bridge deck and superstructure were in "poor condition" from a recent inspection.  But as it carried 15,000 people a day, they were reluctant to shut it down to make repairs, even if funds had been available. 

           

Now the choice has been made for them, and residents of Pittsburgh are going to have to find another way to go where they're going if they were used to crossing Frick Park on the Forbes Avenue bridge.  But President Biden pointed out that Pennsylvania is slated to receive $1.6 billion over the five-year span of last fall's infrastructure bill, and surely that will help to repair not only the Forbes Avenue bridge, but others that are time bombs set to collapse at an unknown date in the future. 

 

Sources:  I referred to articles on the bridge collapse and President Biden's visit at The Guardian's website, https://www.theguardian.com/us-news/2022/jan/28/pittsburgh-bridge-collapse-biden-infrastructure-speech and the York, Pa. Daily Record at https://www.ydr.com/story/news/2022/01/28/bridge-pittsburgh-collapses-forbes-avenue-frick-park-biden-infastructure/9252129002/.  I also referred to the ASCE website at https://infrastructurereportcard.org/cat-item/bridges/,

reporting of the infrastructure bill on CNBC at https://www.cnbc.com/2021/11/15/biden-signing-1-trillion-bipartisan-infrastructure-bill-into-law.html and the Wikipedia articles on Henry Clay Frick and the Frick Mansion. 

Not Grading On the Curve: The White House's Infrastructure Report Cards

 

Since at least 1988, the American Society of Civil Engineers (ASCE) has maintained what they call an Infrastructure Report Card that highlights critical shortcomings in the nation's public built environment.  The reasons for this are pretty obvious:  civil engineers and the construction industry in general live on the development and maintenance of infrastructure, and because so much of it is paid for by government funding, which in a democracy is supposedly under the control of the people, you should let the people know what they ought to be spending money on, infrastructure-wise. 

 

The ASCE report-card list found itself blinking in the spotlight of publicity last week when the Biden administration lifted it bodily and made it part of their promotional efforts to pass a multi-trillion-dollar spending package that is focused nominally on infrastructure.  The ASCE's definition of infrastructure and the Biden administration's definition are two different things.  To the best of my knowledge, the ASCE has no public position on the government's funding of child care, for example, but there is money in the spending package for that.  Let's focus on the grades themselves, though, and what role public engineered infrastructure plays in the body politic.

 

As someone who has handed out grades for more than thirty years, I would not be caught dead with a grade roster like the one the ASCE gave out.  The highest grade was C+ and the lowest was D-.  The first problem is that what you might call the dynamic range is very limited.  Whatever criterion was used to obtain the grades was rigged to produce basically the same score with only minor variations from state to state.  It's easy to guess why the ASCE avoided the extremes of the grade scale.  Giving out A's would be the same as saying, "You're fine, no need for any public works projects next year."  And an F would say that a state's infrastructure is a total failure.  I've been in one or two places around the world where something like those conditions prevail, but even Puerto Rico (the lone recipient of a D-) is better than that.

 

But why no B's?  I guess the ASCE wants to create at least some sense of alarm even in the states with the best infrastructure, such as Georgia or Utah.  There's enough variation in the grades to make people want to see how their state did, which is the main purpose of the exercise.  Beyond that, I don't believe there are too many profundities lurking in the various grades for the different states.  And thirteen states didn't even get a grade, either on the ASCE's own ranking or the identical one handed out by the White House. 

 

Looking beyond the short-term publicity aspect of the situation, what is the proper role and scale for public spending on engineered infrastructure?  There are extremes on both ends of the political spectrum.

 

Absolute libertarians would have us live in a totally private world—private companies would build roads and bridges, even municipal infrastructure like water and sewer systems, and the only publicly funded activities would be outward-facing things such as national defense.  I'm not aware of such an extreme being tried on a large scale in recent history anywhere in the world, and anyway, the complications of getting hundreds of bills every month for every little thing you did would be nightmarish from an individual point of view.

 

On the other extreme is socialism, in which everything from infrastructure to retail to manufacturing and services is run by the government.  Unlike extreme libertarian regimes, people have tried strict socialism a number of times, most spectacularly in the old USSR.  That regime gave rise to unprecedented misery and death and collapsed in 1990, which is not a strong recommendation. 

 

Most governments of varying political stripes tend to a mixture of private and public investment, as has been the case in the U. S.  During the 19th century, the main transportation network was built by private railway companies, which were however heavily subsidized by the federal government and eventually regulated by the first quasi-independent executive-branch agency, the Interstate Commerce Commission.  The railways were displaced in the 20th century by roads and eventually the Interstate Highway System, which was a federal-state partnership that most would agree was a success, though it forever changed the face of America.  President Eisenhower, who was one of the Interstate's main proponents, had the good fortune to propose his system at an all-time high of national prosperity, but we don't have that advantage now.

 

Nevertheless, the Biden administration is proposing to pay for the approximately $4 trillion infrastructure bill with higher taxes, mainly on corporations.  Corporations can pay higher taxes only if they charge higher prices, or else go out of business.  Neither eventuality is desirable from the consumer's point of view, but one or another will have to happen, probably some of both.

 

There is one school of thought that says the federal government could pay for true infrastructure improvements by simply printing money (or borrowing it from the Federal Reserve, which in my limited understanding of finance amounts to the same thing).  Distributist John C. Médaille claims that this move would not be as inflationary as it sounds, because the expansion of the economy that results from improved infrastructure would absorb the rise in the money supply.  If twice as much money is injected into an economy which soon produces twice as much value, any inflation will be temporary.

 

Médaille's theory would seem to apply mainly to new infrastructure, not just repairs on the same old infrastructure we've been putting up with all along.  But it's an interesting thought, and would avoid some of the negative consequences that higher corporate taxes will surely have, such as companies fleeing the U. S. altogether.  Another of Médaille's principles is that if you tax something, you're going to get less of it, and I don't think we want fewer and less profitable corporations, but that's what you'll get if you raise their taxes.

 

Other things being equal, fixing America's broken infrastructure is a good thing, but how to pay for it is a problem with no easy solution.

 

Sources:  I referred to a report on U. S. News's website at https://www.usnews.com/news/best-states/articles/2021-04-13/biden-administration-issues-state-infrastructure-report-cards and the ASCE website's report cards on the states at https://infrastructurereportcard.org/.  John C. Médaille's Toward a Truly Free Market is the best current exposition of the economic and social principles of the political philosophy called distributism that I know of.

The Morani Bridge Collapse: Style Over Substance?

Riccardo Morani (1902-1989) was an Italian civil engineer and bridge designer who was one of the earliest proponents of designs that used mainly prestressed concrete, rather than mostly steel.  In 1967, a bridge he designed was put into service in Genoa, Italy.  It spanned a river, some railroad tracks, and other portions of the city with three tall pylons, each of which had concrete stays reaching diagonally down to the roadway, which was suspended some 145 feet (44 m) above the ground.  It came to be known as the Morani Bridge, after its designer.

On Tuesday, August 14, during an intense rainstorm one of the tower-supported sections of the bridge suddenly collapsed.  As of today (Aug. 26), a total of 43 people have died as a result of the accident, not to mention injuries and property damage, which will total in the millions.  Government officials have called for the revocation of the contract with Autostrade per l’Italia, the private firm that handles highway maintenance in Italy.  One mourner at the state funeral held for many of the victims said that “In Italy, we prefer ribbon-cuttings to maintenance.” 

Engineering experts consulted by the media all said it was too soon to draw any conclusions about what might have caused the bridge to fall.  Bridges designed by Morani have a history of requiring more maintenance than more common designs do.  The stark elegance that may have appealed to clients around the world who were looking for something distinctive to add to a city skyline was achieved at a cost of asking a lot of the material that was used in the bridges Morani designed.  As we have mentioned before, pure concrete has almost no strength in tension, so to use it as a structural material, it has to be reinforced with steel “rebars” and other components that can withstand pulling stresses.  This would be especially true of the stays that slanted down from the tops of the towers to support the roadbed.  Over time, corrosion can attack these tension members, sometimes invisibly deep within a vital member of the structure. 

The evidence of why the bridge collapsed is buried inthe huge piles of rubble that workers will need to clear meticulously and carefully, and because such work is both a huge project on its own and demanding of attention to detail, it may be months or even years before we have an answer to the question of why the bridge collapsed.  After a bridge in Minneapolis collapsed in August of 2007, it took over a year for the U. S. National Transportation Safety Board to issue its final report on the accident, which attributed the collapse to a design flaw that made a gusset plate too weak. 

The problem with forensic investigation of prestressed-concrete bridges is that concrete is a much more complex material than steel.  Unlike steel, which is fabricated under carefully controlled conditions in a steel mill, concrete is often formed onsite, and the way it is mixed, poured, and treated after pouring can influence its ultimate strength and other properties.  Nevertheless, most prestressed-concrete bridges withstand the stresses they were designed for, and so the reasons for the Morani collapse will be interesting to discover, if they can be found.

While we still do not know whether the collapse was due to an initial design flaw or faulty maintenance, the question of maintenance for bridges and other vital pieces of infrastructure is an urgent one that industrialized nations all around the world are struggling with.  In 2017, the American Society of Civil Engineers (ASCE) gave the U. S. a D+ in its “infrastructure report card,” saying that 56,000 bridges (about 9% of the total) were “structurally deficient” in 2016.  While the situation has not reached such a crisis that we see bridges falling down every month, tragedies like the Morani collapse remind us that the price of deferred maintenance is sometimes much higher than anyone would like to pay. 

It’s a little bit like preparing for war.  The only way you know you didn’t spend enough money on preparing for a war is if you lose it.  You can win with barely enough resources, or with three times more resources than you need, and the result is the same.  The art and science of maintenance consists in doing enough to prevent nearly all major tragedies and to do something about minor problems fast enough, while not simply wasting resources on painting a wall that doesn’t need painting, for example. 

Judging by the rarity of bridge collapses, most bridges were either built well enough to start with to survive many decades with whatever maintenance they’ve received, or have been maintained well enough to keep standing.  But the shock value of a major bridge collapse is one of the main motivators for public funding of infrastructure maintenance, which has none of the appeal of new construction. 

Engineers are mostly used to working out of the limelight, doing dull but necessary things like scheduling expensive maintenance that takes money away from more flashy and popular government activities.  Riccardo Morani was somewhat an exception to this rule, attaching his name to striking bridge designs that caught the eye of the public time after time.  If there’s the equivalent of an Internet connection wherever he is, I’m sure he’s sorry to see what has happened to his creation in Genoa, whether the failure is due to him personally or due to insufficient maintenance over the five decades the bridge has carried traffic since it opened.  But maintenance is a job for the living, not the dead, and engineers in charge of maintenance owe it to their constituent publics to be sure that tragedies such as the Morani bridge collapse don’t happen.  We look forward to finding out what went wrong in Genoa a couple of weeks ago, and applying those lessons to future problems so that they can be avoided before more people get killed.

Sources:  I referred to news reports on the accident carried by Time’s website at http://time.com/5367757/italy-genoa-bridge-collapse-death-toll/ and The Guardian at https://www.theguardian.com/world/2018/aug/14/unusual-span-of-collapsed-genoa-bridge-had-seen-frequent-repair-work.  I also referred to Wikipedia articles on Riccardo Morani and the I-35W Mississippi bridge, and the ASCE report card at https://www.infrastructurereportcard.org/.

Dodging Solar Bullets

Massive blackouts—pipeline explosions—whole regions of Europe or North America plunged into the nineteenth century, but without even the rudiments of that century's technology.  Elevators that don't elevate, ventilators that don't ventilate, gas pumps that don't pump, hospitals that turn into charnel houses.  Entire cities evacuated and their populations dying on their frantic attempts to escape to nowhere.

No, this isn't a movie review of the latest mega-disaster flick.  It is a fairly realistic scenario of what could have happened on July 23, 2012, if a certain cluster of sunspots had been facing directly toward the earth, rather than pointing out away from us toward a space probe called STEREO A.  As it happened, STEREO A had a front-row seat at a performance that engineers hope we will never witness here—but one that could happen any time.

What happened that day was not just one, but two coronal mass ejections (CMEs).  Often associated with, but distinct from, the brilliant solar flares that arc above the sun's surface every now and then, coronal mass ejections contain the energy of millions of nuclear bombs and send tons of charged particles flying out into space.  Entangled with the particles are spaghetti-plates full of tangled magnetic field lines, and the magnetic fields are what can damage our electrical and mechanical infrastructure. 

When a CME encounters the earth's magnetic field, the normally fairly stable domestic field jumps around like the proverbial cat on a hot tin roof.  And as every electrical engineer knows, changing magnetic fields near conductors induce voltages and currents in those conductors.  Substitute "power lines" and "pipelines" for "conductors" and you begin to see the problem. 

While these structures are protected against the normal kinds of mishaps that can befall them—lightning in the case of power lines, breaks in the case of pipelines—relatively few such installations are also protected against the unique sort of stresses that a record-breaking geomagnetic storm can induce.  And geomagnetic storms, along with brilliant auroras near the polar regions, are what happens when a large CME hits the earth. 

The last major geomagnetic storm that did considerable damage occurred in 2003, knocking out a series of electric-grid transformers in Sweden.  Utility operators usually have on hand one or two spare transmission transformers­—the big boxes in substations that cost upwards of millions of dollars each—but not a dozen.  And even if they did, hauling those multi-ton pieces of gear around the country to replace ones burned out by a geomagnetic storm is not the light task of a few hours' time.  Multiply this actual event by a factor of two or ten or twenty, and you can see how bad things could get.

What can be done from an engineering point of view to protect infrastructure assets from a large geomagnetic storm?  We will concentrate on the protection of the electric grid, since its loss would be by far more immediately consequential than the loss of pipelines.

If grid operators are given enough warning, they can call for a pre-emptive voluntary blackout that disconnects vulnerable transformers from the long lines that will pick up the high currents and voltages that would otherwise cause damage.  The problem with this is, nobody wants to be the one to decide to pull the switch, especially if the storm turns out to be less severe than expected.  Another problem is that there is currently no good way to predict the exact effects of a given geomagnetic storm on a particular part of the grid.  So the safe thing to do would be to shut down the whole system for the duration of the storm, which usually lasts only a few hours.  But a region-wide blackout lasting several hours is a serious disruption of its own, and few grid operators are currently willing to do such a thing based on only the fuzzy and general forecasts of geomagnetic storms that are presently available.

Another alternative is to install special protective gear designed to bypass the large energy generated in power grids by geomagnetic storms.  This would allow the grid to keep working right through the storm, but has the disadvantage of costing millions of dollars and not doing a blessed thing until the storm hits.  This reminds me of those vending machines you used to see at airports where you could buy $50,000 of life insurance for something like a quarter, valid only during your upcoming flight.  I suppose somebody may have collected on one of those policies, but I doubt it.  Still, this would be the safest course, all things considered.

Healthy societies have institutions that look ahead to unlikely eventualities, so that when they happen, as sooner or later they surely will, the society rolls through the crisis while maybe sustaining some damage, but otherwise stays intact.  The closest we have come in the U. S. to a crisis like the one a geomagnetic storm might cause was Hurricane Katrina, the one that devastated New Orleans in 2005.  Sad to say, New Orleans was grossly unprepared for Katrina.  Its infrastructure of dikes and canals had been neglected for decades, despite warnings that if something like Katrina hit, large parts of the city would be underwater, and they were.  Over 1,800 people died in a disaster that was, fortunately, of limited geographic extent.  Multiply Katrina by ten or twenty times the area, and you can begin to see what a perfect geomagnetic storm might do.

In a recent issue of National Review, Christopher DeMuth points out that past generations of U. S. citizens allowed the federal government to go into debt, but always for a reason that was forward-looking:  to win a war, for example, or to finance infrastructure improvements such as canals, railroads, and interstate highways.  By contrast, today we are continually warned of our crumbling infrastructure, but the massive debt we are incurring is going mainly for payments to persons—consumption, in other words, not investment for the future. 

The amount of money it would take to improve geomagnetic-storm forecasting and power-grid protection to the point that we could cross a geomagnetic-storm disaster off our list of things to worry about, is not large.  Whether public or private funds, or a combination, should pay for it is not the question.  The question is whether society still has enough foresight to avoid needless disasters—or whether we have to experience them first before we do anything about them.

Sources:  A good brief description of the nearly-disastrous CME event of July 23, 2012 was carried online by IEEE Spectrum at http://spectrum.ieee.org/tech-talk/aerospace/astrophysics/earth-dodged-solar-magnetic-storm-bullet-in-2012.  The technical paper on which the report was based is Liu, Y. D. et al. "Observations of an extreme storm in interplanetary space caused by successive coronal mass ejections." Nature Communications 5:3481 (doi: 10.1038/ncomms4481) (2014).  The problem has not gone entirely unnoticed by government officials, as the threat evaluation report on geomagnetic storms at the U. S. Department of Homeland Security found at https://www.dhs.gov/xlibrary/assets/rma-geomagnetic-storms.pdf shows.  I also referred to Wikipedia articles on coronal mass ejections, solar rotation, and Hurricane Katrina.  Christopher DeMuth's article "Our Democratic Debt" appeared on pp. 28-34 of the July 21, 2014 issue of National Review.