Saturday, February 26, 2011

Hotel Grand Chancellor: NZ earthquake's touchiest problem

New developments are underway at the 85-meter-tall Hotel Grand Chancellor in Christchurch, which Tuesday's earthquake seriously damaged on one corner. It's still standing. It had been settling and progressively leaning in the first 24 hours, but has stabilized enough for search teams to commission a contractor to brace a damaged wall that could allow searchers to enter the lower floors to check for survivors.

Such situations are monitored by setting up laser rangefinders around the site, and measuring the distance and angle to key points high up on the structure. If these points hold position over time, even with aftershocks, engineers may decide the building has worked itself into a temporarily stable position. It's analogous to the angle of repose that a pile of gravel assumes when emptied out the back of a dump truck. 

Gravel finds its resting angle in seconds, but settlement is slower in complex structures, particularly when (as in the World Trade Center) a fire is progressively weakening the frame. When researching the WTC collapse for the special edition of Inviting Disaster, I was struck by comments from witnesses about sounds they heard in the South Tower. This snip from my book:
"It's a peculiar fact that buildings that are about to collapse often give audible warnings of distress minutes or hours beforehand, as gravity loads shift away from failing columns and girders. Some people in the stairwells in the South Tower heard these spooky noises of impending failure. One man compared it to the crackling sound a handful of uncooked spaghetti makes when snapped during preparation of dinner."
Meanwhile, demolition companies have offered suggestions on what to do with the Grand Chancellor, if authorities decide to bring it down. This one suggested a large crane to drop a headache ball on the structure. We can expect many novel ideas if the situation goes on. 

Conventional demolition of skyscrapers, not likely in this case, relies on crews who take it down one floor at a time, or on experts to place explosive charges among the supports. A vital tool for such work is the linear shaped charge - see my post on that.

Wednesday, February 23, 2011

Major Damage in Christchurch NZ from 6.3 Temblor

Brief note on the emergency response to this week's 6.3 temblor in New Zealand, which according to some experts could be a long delayed aftershock from the September quake (a very important question to insurers). The quake on Tuesday wasn't as powerful as the one four months ago, but the September quake's epicenter was deeper and more distant from major population centers, and therefore wasn't as destructive as this week's shake.

One of the international urban search and rescue teams dispatched to Christchurch is CATF-2, housed out of the Los Angeles County Fire Department

Five years ago I had the chance to shadow a deployment exercise by sister team CATF-7, housed out of the Menlo Park (CA) Fire Department. These are elite groups that train constantly and are set up to launch as fast as possible, which can be as little as six to eight hours from the incident. They bring everything they need by way of portable equipment, food, and supplies onto an Air Force transport. Local authorities only need to provide heavy equipment such as cranes and tracked excavators with hydraulic concrete breakers. 

FYI, here's a link to standard search markings used by the US&R task forces, which might help make sense of images you see on TV or on the Net. Photos on Boston.com are here. Collapse-rescue video posted by the Associated Press is here.

All eyes are on the Grand Chancellor Hotel in downtown Christchurch, which is gravely damaged, is noticeably leaning, still settling, and could come down at any moment. Thankfully, no survivors are stranded inside the hotel. 

The Grand Chancellor if it falls -- when it falls -- will be one of the tallest structures ever to succumb to an earthquake. Mexico City lost a 22-story building in 1985. News accounts for the Grand Chancellor give its height as somewhere between 22 stories and 27 stories, so I'm guessing it's more than 300 feet tall.

When it comes to high rises, the most vulnerable tend to be unreinforced ones 10 to 15 stories in height, particularly when their resonance frequencies are matched to the ground motions. (Update: I'm advised overnight that the cause of the damage to the Grand Chancellor could not have been due to resonance because the ground motion on Tuesday was a significantly higher frequency than the building's tendency to sway.)

Here's an article I wrote on lessons in earthquake engineering from the Mexico City quake and earlier ones.

Because the hotel's collapse could bring down nearby buildings with debris or even a ground shock, the collapse danger is interfering with searches of buildings as much as four blocks away. Among these is the CTV Building, where much of the death toll occurred. 

My article on the social and technological history of collapse rescue can be found here. Once while writing a feature on firefighting I had the opportunity to put on some bunker gear and crawl through the nooks and crannies of a collapsed-building training facility in Los Angeles: claustrophobia city!

Friday, February 18, 2011

AIG Building: Just the place to fall from grace

See this Opinionator piece that appeared in the NYTimes on Wednesday with fascinating details drawn from the investigating commission's financial crash report on how a cut in the valuation of mortgage-backed securities by Goldman Sachs in 2007 set off a chain disaster that led to the collapse of American International Group (AIG), among other shocks. Taxpayers put up more than $180 billion to save AIG and its investors and insureds.

The 79-year-old building that served as ground zero for that particular disaster wasn't always called the AIG Building, but rather Cities Service Building or Sixty Wall Tower. Though the Sixty Wall skyscraper is a full block from Wall Street (on Pearl, Cedar, and Pine Streets), a skyway joined it to a building that had a genuine Wall Street address, and that was enough for developer Henry L. Doherty to put a Wall into the name of a building whose postal address was 70 Pine Street. For the full history, see the book Skyscraper Rivals.

Like all buildings until the advent of air conditioning, Sixty Wall Tower had windows that slid open for ventilation, and unauthorized exits. In June 1933 it would contribute to the tally of window-leaping suicides of the Great Depression.

Perhaps coincidentally, the case happened one day after Time Magazine published yet another article on the national suicide problem. The Time article described the difficulties that life insurance companies were having when faced with fatal falls of ambiguous origin. Just 15 years before, suicidal individuals had favored gas or guns, but after the 1929 Crash, falls were on the rise.
 
Time had waggishly suggested a year before that reporters employ a new word, flump, meaning 'to fall or jump,' when circumstances were unclear and family members insisted the fall had been unintentional, perhaps when the decedent had been reaching for a butterfly. This ambiguity would have served well when reporting the death-by-window of Samuel Feiber, an official from the Hoover Administration, who had flumped from the seventeenth floor of the Savoy-Plaza in February 1933 without witnesses in attendance.

There was little doubt, however, about the bona fides of the case that happened four months later, high up on Sixty Wall Tower.

On the evening of June 20, 1933, a luggage porter named Herman Marquardt walked into the 40th-floor offices of Batchelder & Co., Stockbrokers. He found George L. of the family firm standing on the window sill in his office. Heedless of his low status among the elite, Marquardt ordered the broker to step down. Instead Batchelder called for him to leave and shut the door. 


The porter summoned the building's security force. Marquardt and three house detectives attempted to cajole Batchelder from his perch. But Batchelder toppled out and came to rest on a tenth-floor setback roof.
 

This case matched national suicide patterns fairly well. According to Dr. Harry Marsh Warren of the Save-A-Life League, who had been studying patterns emerging from thousands of American post-Crash suicides, the most common day of the week for suicides was Tuesday. The most common month was June. Batchelder's case did diverge from the most common time of day, which was 11 a.m.

Tragedies like Batchelder's received much publicity. Mental health professionals asked for a halt, saying that it was inspiring copycats. 


Heedless of all that, many writers and cartoonists embraced the idea of despair at high altitude. Will Rogers suggested that Wall Street brokers were having to take their place in line at windows. Cole Porter's Depression-era musical Anything Goes included a scene in which magnate Elisha Whitney tries to console the widow of a suicider by telling her that while leaving the Stock Exchange he looked up to see her husband jump off the ledge; Whitney assures her that his dive showed all the style "of a Yale man."
 

New Yorkers could draw a small measure of solace from a detailed study of Depression-era suicides assembled by the remarkable Frederick L. Hoffman, then a statistician for Prudential Life Insurance. Surprisingly, Hoffman found that Davenport, Iowa, had a far worse suicide problem during that era than did any borough of New York. At a rate of over 50 suicides per 100,000 people, that bucolic city on the Mississippi led the entire nation in sudden-self-death during 1932 and 1933. Davenport was even up there with the world's most suicidal city, Vienna. (Hoffman, who died in 1946, also achieved a measure of fame among actuaries and public health experts for his early deduction from statistical correlations that smoking and workplace dust were hazardous to health.)
 

Despite all the publicity about the plungers of Manhattan, New York City's suicide rate for 1933 continued a steady decline first identified in 1930, and finished the year lower even than the national average.

Saturday, February 12, 2011

Super 8, The Movie: 35 boxcars and 1 monster off the rails

The ad for Super 8 caught my eye during the Super Bowl and I hunted up the trailer, curious about its depiction of a train off the rails. Using the pile-up in The Greatest Show on Earth as a bench-wreck, how does Super 8 compare? To its credit (at least as edited in the trailer) the crash in Super 8 didn't drag on like some movie wrecks, in which engines and cars seem to slide across two states and a county after leaving the track.

Trailer summary: The USAF has dispatched a creature from Area 51 to Secret Base, Ohio, on a Midnight Special. It's locked in a boxcar secured by a twirly wheel on the door. As is fated in most plots with prisoners shackled on planes, trains or buses, there's going to be a wreck so that somebody or someThing can run free.

Liberation comes courtesy of a pickup that whips onto the track and, thumping down the ties, goes headlight to headlight with the road engine. The pickup vanishes in the obligatory fireball and the train leaves the track in high-energy fashion, with either a boxcar or the engine sent flying and spinning. Silence falls, flames flicker.

Energized by a falling power line, our ambidextrous alien starts pounding on the steel door and simultaneously twisting a big wheel to get out of a boxcar labeled, in the interest of full disclosure, "US Air Force."

So, to three questions:

Can a passenger vehicle derail a train? Yes, there have been multiple cases in which passenger trains were sent off the track by a car or pickup in the way. Among the most tragic of the recent cases happened in 2005 in Glendale, CA, when a Metrolink commuter train struck an SUV left on the track, causing a wreck that killed 11. 

In most cases the car will be reduced to flying fragments while the train suffers only a dent, but derailments are not out of the question if a stout piece like a broken axle gets jammed under a rail.

What happens to boxcars during a derail – do they really get tossed high into the air like police cars in a Die Hard movie? Not that I know of. While there are witness reports of boxcars and even 250-ton engines tumbling end over end, a freight train is not nearly as fast as a bullet train and the physics don't favor tossing a few dozen tons high in the air from a level track. 

What happens to a locomotive upon departing the rails? This may of some comfort to those who suffer from siderodromophobic nightmares: Locomotives once off the rails aren't good chase vehicles. As they topple over, their narrow wheels dig in and tear up the track thoroughly. Depending on the terrain they might roll down an incline or slide a short distance on their sides, flattening obstacles and gouging a furrow.

So, regarding the segment in The Fugitive in which a locomotive hits a bus, leaves the track, and while leaning crazily manages to pursue Harrison Ford along the right-of-way, halting only when it slams into a ditch ... in reality, locomotives can't remain upright in such circumstances. But it's a heart-stopper of a scene.

Thursday, February 10, 2011

The Blue Line: A new simile for business and politics

In this post last summer I called for editorial writers to be pithier in their use of shopworn analogies such as the red flag of danger, as in "our so-called regulators sure missed that red flag!" I pointed out that it's been many years since railroads relied on men with red flags to mark danger spots. I suggested that the railroad torpedo is a better simile when arguing that a hazard is so obvious only a fool could miss it. 

Here's another simile so obscure Wiki doesn't even have a page on it: the blue line. In business a project manager might use it like this: 
"The bean counters at corporate thought they could kill off my project, but I had a buddy in Procurement who showed me a blue line right through the middle of 'em."
The blue line is a critical element behind successful stealth-bomber missions. I was briefed about it while visiting Whiteman AFB to write about the B-2 bomber. (I had the chance to climb into the rather compact flight deck; here's a link to a 360-degree cockpit view on the Air&Space/Smithsonian website.)

When Lockheed began working up stealth technology (a combination of cunning geometry and a low-reflective skin) in the late 1970s, proponents believed that no radar could pick out such a plane; ergo, the plane could fly just about any route during night.

But a more skeptical look at its radar signature suggested, and the shootdown of an F-117A during a mission over Yugoslavia in 1999 by a well-commanded SA-3 battery proved, that this wasn't a safe assumption. Planners had to acknowledge that no solid object can be totally invisible to radar all the time, particularly when painted from ahead or behind. 

An important part of the solution was to work out specific approach and departure routes with the lowest likelihood of detection, based on measured characteristics of the adversary's air-defense network. 

This is the blue line. I'm not sure of the name's origin but it might be because Lockheed's original project name for stealth technology was Have Blue

The blue-line database to each major target must be assembled well before the shooting starts, then updated rigorously.



Saturday, February 5, 2011

Texas Sheds a Load: ERCOT and rolling outages

Watching with interest the slow trickle of information from trade magazines and the Electricity Reliability Council of Texas (ERCOT) about how 50-odd power plants in the Texas grid could have tripped in a short time, requiring load shedding of distribution sectors that cut off millions. Some zones lost power repeatedly, some just a single time for 45 minutes. Some zones never lost power.

The official story continues to evolve and emerge. A few operators like Luminant have identified plants that went offline. One of those was Oak Grove, a lignite-powered 1,600 MWe facility that won an award from POWER Magazine in 2010 for Plant of the Year.

Meanwhile, most of the 50-odd plants that tripped remain anonymous ... says ERCOT, they can't tell because that's proprietary information under "market rules." 

Market rules? Texas is one of those states that began deregulating its electricity market in the pre-Enron-fraud age of optimism. Post-Enron (centered in Houston, by the way), few regulated-market states continued down the path of full deregulation; the current trend is more of a hybrid. Some fully-deregulated states have been unpleasantly surprised by retail price hikes.

So in the last few days ERCOT-bashing has been underway, but in such a crisis, load shedding is the right thing to do. A federal report analyzing the August 2003 Northeast blackout determined that had FirstEnergy or the ISO quickly shed about 1,500 MW of power going to the Akron-Cleveland area, a full blackout probably wouldn't have happened. (FirstEnergy responded that a bigger factor was a lack of reactive power across the region, a phenomenon unique to alternating-current systems that can be analogized to the momentum of a moving body.) 

Load-shedding is disruptive and should have been avoidable, but it was a big storm and it's a lot better than losing a major portion of the grid, which can happen if the 60-hz frequency drops too low. In such situations big plants can take the better part of a day to come back up. 

Load shedding orders having gone out under a declared emergency, ERCOT did what it could to summon all available electrons to service: allowing some plants to run beyond their normal rating given air pollution control equipment; it drew a few hundred megawatts from Northern Mexico through the brand-new Sharyland direct-current intertie crossing the Rio Grande, and even requested black start generators to join the busbars. (Black start generators are relatively small and inefficient plants, normally used only to energize big power plants and get them going ... something like the little gasoline starter-motors that diesel-powered bulldozers used to employ.)

In 1985 I wrote an article about blackouts that noted DC interties can be critical in sharing power that prevents massive blackouts. They're "asynchronous," meaning that a disturbance in one grid doesn't spread to the other. 

Many theories have been echoing around the Net about possible causes: frozen water pipes, too little gas getting to gas-fired generators because of dastardly old state regulations that favored residential accounts, wind not providing enough power because some were idled due to ice on the blades, and unexpected demand that swamped ERCOT's day-ahead planning. 

Hmm. ERCOT and all such independent system operators say they are obsessed with weather reports, and this blizzard was well advertised. Here's an article from 2003 about ERCOT's control room and how they have the Weather Channel up at all times. 

Even more than what happened in ERCOT's control room, I'm  intrigued about why dozens of plants would go off line about the same time. Gas shortages don't go far in explaining it. 

Here's one theory I find plausible for some of the generator trips: the control systems. Specifically, water vapor freezing in unheated instrument-air lines and gas-pipeline valves. Water vapor can play havoc with instrument-air lines. See this article for a detailed explanation of how water that got into instrument-air lines initiated a chain of events leading to the Three Mile Island Unit 2 near-meltdown.

Thursday, February 3, 2011

GPS and the Way to Dusty Death

The Sacramento Bee has a good article on death by GPS syndrome, in which visitors to a place like Death Valley arrive by car or SUV and follow their GPS units onto abandoned tracks marked on the electronic map as passable roads. This from the article, quoting Death Valley wilderness coordinator Charlie Callagan:
"People are renting vehicles with GPS and they have no idea how it works and they are willing to trust the GPS to lead them into the middle of nowhere." 
Two groups of sufferers are mentioned, four Germans and a mother and her boy. And there others whose bodies are yet to be found.

While people have always gotten themselves lost, it's easy to see how this happens even quicker with GPS units lacking current road information: 
  1. Regardless of what the "road" is like in the real world, the map functions on these direct the driver onto whichever road appears to provide the shortest distance between origin and destination; and
  2. The driver sets off without survival supplies, expecting a swift and easy passage through civilized country; and
  3. Instead gets stuck somewhere in the wilderness halfway down a rutted track that none of the locals use, since they know better; and
  4. This being a wilderness, there's no water, fuel, roadside assistance, and no cellphone communication either.
And all this at temperatures that can exceed 120F. The area where one driver got stuck is shown on this map in the Sac Bee. She survived long enough for rescue but her son didn't. 

Here's a satellite photo from Google showing the proper route in blue:
It's rugged and unforgiving country. One would hope travelers in such a strange land would bring with them the judgment and situational awareness to turn around when things are going bad, but sometimes they press on.

In 1998 while writing for Smithsonian I toured Nevada's Black Rock Desert, which can be another dangerous hot-spot. Okay, I did tote a GPS unit; it was a handy way to navigate between camps on and off the playa. But I also took topo maps and a compass, and lots of water.

During those meanderings I had the chance to visit with Washoe County Justice of the Peace Phil Thomas in Gerlach. Thomas showed me his aging pickup for desert travel, nicknamed the Grapes of Wrath. This snip from my article:
It's a brown and white four-wheel-drive Chevy of indeterminate age, and the bed is heaped with the stuff of survival: split firewood, an old washing machine tank that serves as a fire ring, jerricans of spare gasoline and water, two spare tires, an axe, chains, jacks, flares, assorted tools and a hose for transferring gasoline from one vehicle to another. This kind of gear is essential for the distant reaches of the Black Rock, but those venturing there better bring along a few other things, Thomas says: namely, "common sense and a knowledge of when to panic and when not to panic."
Another bit of sagebrush advice from Justice Thomas always stuck with me, and I quoted it later in Inviting Disaster:
"I use the four-wheel to get out of trouble, not get into it."