Friday, January 2, 2009

Shake, Rattle & Roll

NOTE: We've moved! Visit us at the California High Speed Rail Blog.

So, what happens to a high speed train when - not if - a major earthquake strikes?

California is earthquake country. Most of its faults run parallel to the San Andreas, a right-lateral slip-strike transform fault zone along which the North American and Pacific tectonic plates slide relative to one another. Click through this magic Google link and look at the animation for a sense of how the fault has evolved over the past 20 million years (you may need to allow a pop-up window).

Swarms of small tremors, most imperceptible to all but scientists with sensitive equipment, happen all the time in the American West. But, every once in a while, a major cataclysm occurs. The Hayward quake of 1868 and the Great San Francisco quake of 1906 are well documented in the history books, but the impact on modern infrastructure is more evident in more recent seismic events. Whenever and wherever the ground shakes very violently, buildings may collapse, power lines may be downed, gas mains may break and fires may start. Roads, water mains, sewers, telecommunications lines may be damaged. Old feeways may pancake and old bridges collapse. The economic damage alone is usually staggering.

And sadly, in spite of the consistent application of the best earthquake engineering available at the time of construction, people still die when it happens in California.

Loma Prieta 1989 Part 1 and Part 2

Northridge 1994:

Based on paleoseismic and other evidence, USGS scientists are now virtually certain that there will be another major earthquake at some point in the next 30 years. Unfortunately, they cannot yet pinpoint the time, nor the location of the epicenter. The southern section of the San Andreas fault, which historically has produced a major earthquake every 150 years or so, hasn't done so in 300 and is overdue. The following animation shows the expected surface shake intensities (on the modified Mercalli scale) evolving in real time for the scenario of a magnitude 7.8 quake (on the Richter scale) centered on the Salton Sea.

So what about railroads? After all, the majority of goods arriving from Asia are transported to the nation's interior by freight trains running across the San Andreas fault every day. As examples from around the world show, tracks are bent, buckled or left dangling off a precipice. Massive steel bridge support columns are mangled beyond recognition. Locomotives derail and topple.

Anatolia, Turkey, 1999:

Kobe, Japan, 1995:

Alaska, 1964 (Ceci n'est pas une chaise):

Point Reyes, California, 1906 (narrow gauge railroad):

At first glance then, running trains at high speed if that can happen at any moment would seem extremely irresponsible, even reckless. CHSRA did select a route that allowed both the Garlock and the San Andreas faults to be crossed at grade rather than inside a tunnel. However, based on the above, all that means is that rescue services will be able to reach the scene of a potentially horrific accident that much sooner.

And yet, in 40 years of operation, only a single bullet train has ever actually derailed during an earthquake. This occurred during the 2004 Chuetsu quake in the relatively rural western prefecture of Niigata, Japan - arguably one of the most seismically active regions in the world. The quake registered 6.9 on the Richter and a maximum 7 on the Shindo scale (cp. modified Mercalli scale). There were 40 casualties in all, but none on board the train.

However, make no mistake: the infrastructure in the area did take extensive damage. It is a testament to Japanese civil engineering expertise and earthquake readiness that the Joetsu shinkansen was back in normal operation just two months after the earthquake.

That the train derailed at all was mostly bad luck: it just happened to be very near the epicenter at the time. A few years earlier, JR West had already installed the compact version of UrEDAS, an automatic earthquake response system, for this line. An array of seismographs placed alongside the tracks measures the intensity of the fast-traveling P-waves of an earthquake to estimate the location of the epicenter and predict the severity of the more destructive but slower S-waves. If the P-wave intensity exceeds a threshold, power is immediately cut to the affected sections of the shinkansen line, prompting drivers to execute an emergency brake maneuver.

In the context of developing the "cat-eared" Fastech 360,

JR East developed a formal Earthquake Impact Assessment System to maintain earthquake response safety even at 220mph on the much busier Tokaido shinkansen linking Tokyo and Osaka. This led to the implementation of TERRA-S, a further development of the UrEDAS concept.

Psychologically, the 2004 event forced the Japanese people to realize that even the sophisticated shinkansen infrastructure they are so justifiably proud of cannot guarantee that no-one will ever die on a bullet train. In its aftermath, researchers have explored the dynamic interactions during a derailment. They proposed a concrete curb to minimize the risk of trains with conventional layouts toppling over and jackknifing. It was this catastrophic post-derailment behavior that turned a 1998 accident involving a first-generation ICE train in Eschede, Germany into a disaster that cost 101 lives.

Five years earlier, a previously filled-in and forgotten WW I trench in France had been washed out by heavy rains, but another train had passed by the same location just ten minutes earlier and its driver had noticed nothing untoward.

The train that did derail was traveling at 182mph at the time the sinkhole opened underneath it. Almost miraculously, there was only one slight injury! This result was later attributed in large part to the articulated frame design of the Alstom-built TGV. Its Jacobs trucks are located in-between the cars, supporting a frame that limits the horizontal and vertical angles the cars can make with one another, making the whole train much stiffer. For the technically inclined, this suspension cutaway details the implementation on the TGV Atlantique series (h/t to Clem Tillier's TGVweb):

Conclusion: Thanks to selecting proven steel wheels technology, CHSRA can draw on decades of high-speed rail research, implementation and operation to minimize the risk of a fatal accident during an earthquake and, to resume service as soon as possible after one. The Japanese arguably have the most expertise in earthquake resilience engineering of HSR infrastructure, including the integration of earthquake detection in signaling and train control. The French may have a superior concept for minimizing casualties in the event of a high-speed derailment.

Of course, any earthquake detection and warning system deployed for HSR absolutely must also be made available to all other rail operators in California. It will be their systems' and/or engineers' responsibility to act on this information. Freight trains in particular have long braking distances, especially if an engineer fails to manage the pneumatic brake system properly on a hill descent. Wherever tracks used by different operators are in close proximity to one another, there is a risk of one train running into another that has already derailed on an adjacent track. Therefore, all trains need to frequently and automatically report their position and status to all dispatch centers using open protocols and redundant computer-to-computer telecommunications paths. When strong P-waves are detected, every second counts.

At some point, perhaps even during or soon after construction, California's new HSR network will suffer local damage due to a major earthquake. But take heart: life in the Golden State has always been about taking smart risks - like a one-eyed cat peepin' in a seafood store!

(original version, sung by shout blues master Big Joe Turner in 1954)


Robert Cruickshank said...

I like the approach you've taken here. Because we live in an earthquake prone place we have to accept that HSR, like every other piece of infrastructure in the state, will be affected by an earthquake. We don't stop living here because of the quakes. We didn't let fear of quake damage stop us from building freeways, airports, and aqueducts.

So the focus needs to be on mitigation, best design practices, and ensuring that if damage does occur, it is easily repaired.

Even in the event of a quake, HSR is still a FAR safer method of travel than anything comparable, including air travel, and especially auto travel.

Spokker said...

With the way they were talking during the recent "California Shakeout" everybody is going to die when the big one hits anyway.

The short movie they put together for that campaign was funny. It said something like, "THOUSANDS OF PEOPLE WILL DIE" and I didn't understand whether the thing was saying, "We can prevent such casualties!" or "You're screwed!"

Rafael said...

@ Spokker -

the shake intensity video I included in the post suggests that "only" a strip to either side of the San Andreas fault plus two swaths of land stretching to the Pacific would be subjected to level X or more on the MMS if a 7.8 quake were to strike in the Salton Sea area. Orange County and San Diego would suffer much less than Riverside, San Bernardino, LA and Ventura counties.

Economic damage would be massive, perhaps as much as several hundred billions if you factor in the opportunity cost of lost productivity. There could well a large number of fatalities as well, but that's exactly what the Shakeout and other disaster preparedness efforts are good at reducing.

Note that money spent on appropriate seismic retrofits to residential homes, i.e. stiffening and strengthening cripple walls plus bolting them to the foundation slab, would be a good way to spend economic stimulus funds in the form of long-term loans to or tax deductions for home owners. If a big one hits, the government - i.e. everyone - is always the insurer of last resort, so an ounce of prevention now would reduce FEMA's liabilities.

Note also that it is generally cheaper to restore a rail line - especially one built at grade - than it is to rebuild a freeway. That's largely a function of the smaller land use footprint.

Anonymous said...

The south of France is a seismic country although its seismicity is moderate compared to California's. This is because the African-Asian fault line is fragmented and the south of France is on one of the fragments, not on the main fault line.
Nothing exceeding 7.0 on the Richter scale has been recorded in the last 200 years. The last earthquake (1909) had its epicenter near the little town of
Lambesc which was entirely destroyed with heavy casualties. In the historic city of Aix-en-Provence 1500 houses were either destroyed or so badly damaged
that they had to be rebuilt.
Minor quakes happen all the time but they never make the news, except when some historic monument is damaged. In 1979 there was a mini-tsunami which caused severe damage to Nice's airport and killed 11 people.
Between Valence and Aix the TGV-Méditerranée is on a rift zone and the seismic risk has been taken into account. Along the line there are seismic stations spaced every 10 kilometers and the data are analysed in real time. If the onboard computer judges that track deformation is possible, the train is automatically slowed or stopped before it reaches the dangerous zone.

Anonymous said...

It's all rather academic really, because by the time this bullet train is built, we'll have robocars:
and people won't bother catching a train when they can just travel overnight in their own car and get delivered to their destination.
Mike J.

Rafael said...

@ Andre Peretti -

thx for the info, I did not know SNCF also had a seismic event detection and train control system deployed. Frankly, I wasn't even aware the south of France is considered a seismically active zone.

However, detection and warning are only one part of the equation. The Japanese have had to hone their civil engineering rules and train operations manual in the context of actual significant earthquakes. Personally, I'd still feel more comfortable if there were Japanese consulting engineers on the team.

However, there's no reason not to bring the French on board as well, especially if CHSRA decides to use ECTS signaling protocols. The Europeans will need all the seismic expertise they can get if the Straits of Gibraltar rapid rail tunnel ever becomes reality (overview, Swiss tunneling experts, problematic geology, politics and funding)

@ Mike Jeavons -

please change your name to Mike Jetson. Your vision will appear more realistic that way. At least to those you can fool all of the time, but then those are the ones you want.

Anonymous said...

You might be surprised to learn the Taiwan HSR is European (mostly French) designed. Systra designed
the route and SNCF International trained the staff. 30 French drivers are still working for THSR.
SNCF-I is the SNCF's consulting branch. It practically has a world monopoly due to its large reserve of competent staff, about 1000 engineers and drivers. Thanks to the privileged career terms conquered by their powerful unions, many railwaymen retire at age 50 with full pension. They are young enough to start a second career and many of them join SNCF-I. For the French drivers the Taiwan contract was particularly juicy: a monthly EUR6600 ($8580), paid by "Railway Consultants Limited", an SNCF-I branch conveniently headquartered in the Isle of Man, a tax heaven. This branch has now been dissolved after an inquiry by the finance ministry.
The choice of the Shinkansen was not a simple story, either.
Alstom had decided not to bid, after the scandal involving one of its parents, the armament firm
Thomson-CSF (Now THALES). For details, just google "Taiwan frigates scandal". Instead, it chose to hide behind its ompetitor Siemens in a consortium named
Eurotrain. Their trainset was a mixture of ICE-1 and TGV Duplex. They thought the Taiwanese would logically choose to run European trains on European-designed tracks.
The Eurotrain was an ugly hastily-assembled monster and the ICE Eschede disaster disqualified it even more. The Taiwanese were astute enough to ignore the alleged public aversion for the ex-invaders and chose the Japanese bid.

Anonymous said...

so Raphael (if that's your real name), you can't actually find any real fault in the idea, so you resort to name calling. Typical liberal.
10 years ago the idea of floor cleaning robots was as jetson-like as robotic cars are today. But the bullet train needs billions of dollars of infrastructure just to connect sf to la. robot cars can be invented by college kids and will be valuable world wide.
My car already has GPS nav, a rear view camera and cruise. Before the first dirt has been turned on the bullet train cars will have parking assist and the ability to safely follow other cars on the cruise control.
Mike J.

Alon Levy said...

Rafael, do you have a better summary of the politics of the Gibraltar tunnel than the racist screed you linked to?

Mike, it's not enough to say that cars are making progress. You need to present evidence your idea is viable. A proposal isn't enough - there have been real proposals for a vactrain tunnel from New York to London for about 70 years now.

Rafael said...

@ Mike Jeavons -

sorry, I guess I was out of line. It just upsets me when people summarily dismiss tried-and-true solutions to complex problems because some engineer's twinkle in the eye is supposedly just around the corner and will render everything that came before obsolete overnight. Infrastructure doesn't work that way, the average consumers is not an early adopter. Even when gas was at or above $4 a gallon, the actual total market share of all hyped-up hybrids put together was around 3%.

Specifically, I'm pretty certain that product liability lawyers would litigate any company that put a self-driving car on the market out of business quick smart. They already did so for the assembled light aircraft industry, which is why you can only by such products as kits. Military applications, sure. Civilian - not so much.

Also, self-driving cars would do little to shift transportation from oil to grid electricity because batteries are so expensive and the amount of energy they can store so limited. Electric trains are the only proven technology that can move large numbers of people over large distances (100s of miles) in a matter of hours without using a drop of oil and without any recharges. It's about energy diversification.

@ Alon Levy -

I took another look at the web page I had linked to and on a second read, I have to agree with you that its narrative has an unacceptable undertone. My apologies for missing it the first time around.

Here's a more neutral commentary (in Spanish) focused on the engineering difficulties and the cost-benefit issue. As a commercial proposition, the Gibraltar tunnel is marginal at best.

Spain and the EU appear to be interested in the project for three reasons: one, as a political signal to the Arab world that Europe wants to mend fences with its neighbors. Two, as a conduit for expanding the high speed rail market into Africa. Three, as a conduit for bringing solar electricity to Europe. In effect, the EU is using infrastructure projects and trade deals as tools of foreign policy, which sometimes also happen to deliver economic and environmental gains.

The Moroccan king sees HSR and the tunnel as opportunities for economic development but also as a way to normalize relations with both Spain and its former colonial overlords in France. Many ordinary Moroccans fear the two linked projects may bankrupt their country.

Unfortunately, grand supranational ambitions also elicit nationalist resistance. What schoolchildren in most of Spain are taught to this day is that valiant Christians forced the Moorish invaders out of the Iberian peninsula. The factual history is actually much more complicated, but Spain has no more come clean on the Reconquista and the Inquisition than it has on the Franco era.

Likewise, identity politics are feeding hostility among ordinary French and Austrians toward letting Turkey become a member of the EU. And recall how the Channel Tunnel project was received with very mixed emotions in England, in large part because it challenged long-standing notions of Britain as an island separate from the continent.

Similarly, the Bear Flag Republic was born of a revolt against the Mexican government. You could even argue that California's love affair with ballot propositions and the car is in part a response to railroad barons who abused their positions of power: Southern Pacific was depicted as an oppressive octopus. In 1911, ballot initiatives were added to the state's constitution to break its stranglehold. Today, they represent 80% of disposable state income yet state politicians are still expected to deliver balanced budgets.

A generation after Northern California's battle with SP, Los Angelinos became disenchanted with the deteriorating level of service provided by Henry Huntington's system of Red Car trolleys. He had operated them as a loss leader for his real estate business and disinvested once he had sold all the parcels of land within walking distance of his lines.

There is actually rich irony in voters approving the largest railroad project in state history by way of proposition 1A. In political terms, that represented an earthquake in its own right.

Anonymous said...

Alon, there are videos on that site I linked to showing military robocars navigating real urban environments. It is not my idea, just something I found convincing on the web.
Rafael, why is it unreasonable to allow individuals to enhance their cars with automatic driving, but not unreasonable to build huge railroads across the country? Isn't the infrastructure in favour of cars right now?
If you read the website I liked to, he shows that cars are already nearly the most efficient means of transport available even more efficient than walking! Combined with plug in hybrids for city usage and the existing oil reserves and tar sands would easily supply our needs I think. Anyway, gas is now under $1.8/g so it doesn't really matter.
Your arguments are good, but I don't think they are impossible to defeat.

Rafael said...

@ Mike Jeavons -

just fyi, I'm an automotive engine developer. Cars will always have their place in the transportation mix, precisely because they offer a unique mix of range, speed, safety, all-weather capability, flexibility and affordabilty. However, they are no panacea: roads and parking lots use up enormous amounts of land, are expensive to construct and expensive to maintain. Owning multiple cars is expensive.

Plus, passenger car engines represent an unsatisfactory compromise between rated power, life expectancy and fuel economy. Hybrids are expensive to produce and pure electric cars even more so, while range remains limited unless you sacrifice other benefits consumers have come to expect of their cars.

Just because gas has dropped back down to less than $2 right in the space of a few months does not mean that it will stay there. The recent price drop is largely due to the collapse of a speculative bubble (oil was a long hedge for traders who shorted stock). Once the economy recovers in a few years, prices will go right back up again, just look at the long term trend. Already, the US is so short of refinery capacity that roughly 1 in 7 gallons of gasoline has to be imported from Europe and other places.

In terms of long-term strategy, the US transportation sector should not rely on oil-based fuels as it does today - with China et al rising, it is unsustainable for 5% of the world's population to consume 25% of total oil production. Climate change aside, the US is currently on course for a major (military) conflict with other oil consuming nations later on this century. That would make the Iraq war look like a walk in the park.

And btw, I know quite a bit about military applications of self-driving technology, fostered by DARPA's Grand Challenge. It is also used for civilian R&D (e.g. VW, Fraunhofer Autotram) but product liability is simply too great to make it available to the average consumer or even bus operators.

Electric passenger trains are no panacea, either, but they do have their place in the transportation mix in other industrialized nations (e.g. Japan, Europe) that don't waste nearly as many of their scarce resources on building ever-better mousetraps. The

Commuters in those other countries are increasingly buying folding bicycles (some with electric assist) because they fit in the baggage racks of trains. That way, they can avoid having to own an additional car just for commuting to work and finding parking for it.

It's a lifestyle change, but one California residents should consider for the long haul. It beats sending young men and women to risk their lives half-way around the world just to secure access to the cheap oil needed to make gas-guzzling SUVs and McMansions in the boonies possible.

Alon Levy said...

Rafael: thanks for the explanation.

Mike: it's reasonable to trust HSR, which is operating efficiently and profitably in a number of countries. It's less reasonable to trust a scheme that has yet to be proven in commercial use. The time it takes a technology to become viable is measured in the decades - for example, the internal combustion engine was invented in 1854, but cars only became a major commercial product with the Model T in 1908. Even then, many technologies are never successfully adopted, for example supersonic transport.

It makes a lot of sense for the government to fund research into self-driving and electric cars, as well as many other speculative modes of transportation. Most won't go anywhere, but some will succeed and become major industries - just like the internal combustion engine won over electric and steam engines for cars. However, except in the very long run, it's impossible to know that there will be serious technological change, so the government should go for what's known to succeed.

Yokota Fritz said...

Well done. SOme people might fear the potential damage and loss of life from a quake to an HSR, but most people don't think about driving across a fault line every single day they commute to work (in the SF Bay Area) on CR17, I-80, I-880, I-580, CR24, etc.

Anonymous said...

Thank you Rafael, Alon Levy for your intelligent criticism. I am not sure that people will choose safety over convenience. don't people already use their cellphones and text when driving?

Alon Levy said...

I don't think people will regard the risk of a self-driving car in the same way they regard the risk of texting while driving. The literature on risk distinguishes voluntary risks, in which people can control their actions, from involuntary ones, in which they can't. Voluntary risks include driving, climbing a mountain, and working in a coal mine; involuntary ones include flying, taking public transportation, and living near a nuclear power plant.

Because involuntary risks induce a feeling of helplessness, most people are far more averse to them. By some accounts, a voluntary risk needs to be a thousand times greater than an involuntary one in order for people to fear them equally. That's why there's fear of flying but not fear of driving, even though driving is about twenty times as likely to kill you, or why people are so concerned about nuclear power even though it's never killed anyone in the Western world.

An involuntary risk will be especially salient if people don't understand it well, and if accidents are unpredictable and spectacular. Planes and nuclear power plants are especially affected by this, in ways that involuntary risks involving more mundane technology, like trains or buses, aren't.

Anything that is driven automatically suffers from both of the above problems. Many automation efforts of rail transit have been abandoned due to safety concerns, even when automatic drive was as safe as having a train operator. For example, New York's attempt at automation ended when there was an accident that had nothing to do with automatic operation and didn't even originate on an automatic train.

All this together suggests that self-driving cars will present safety problems that aren't there on regular cars. They may be safer, but because the risk is involuntary and completely uncontrollable, it's unlikely people will tolerate it as much.

Anonymous said...

Alon, Ok, that makes sense.