Comments about technological history, system fractures, and human resilience from James R. Chiles, the author of Inviting Disaster: Lessons from the Edge of Technology (HarperBusiness 2001; paperback 2002) and The God Machine: From Boomerangs to Black Hawks, the Story of the Helicopter (Random House, 2007, paperback 2008)

Friday, September 23, 2011

UARS, Terror Out of Space

There's a remarkable amount of worldwide interest in the uncontrolled re-entry of the Upper Atmosphere Research Satellite, given the infinitesimally small risk. Here's the awkward beast:
For near-Earth-orbit fans, here's a link to my 1999 article for Smithsonian on space debris. It was a fun article to research, and it got me into the NORAD command center in Cheyenne Mountain, Colorado, among many other unique spots. (Sorry, public tours into the mountain are yet another casualty of 9/11.)

According to this AP article, NASA owns every bolt, nut and shred of UARS, so don't think about putting the tank or thrust chamber you find on eBay. (As you can see from the photos on this site, tanks, particularly titanium-walled pressure tanks, have a pretty good chance of surviving the heat of re-entry.) Here's one:
The most famous pieces of American space wreckage derive from the loss of the orbiters Challenger (1986) and Columbia (2003).

Less than a year after the disaster, NASA sealed all pieces of Challenger into two decommissioned missile silos at Cape Canaveral Air Force Station's Launch Complex 31. Here's a NASA photo of Challenger wreckage being put away:

But not all of Challenger went in there, because not all of it was found. A critical piece of the shuttle's right-hand booster was never located, and almost eleven years later three pieces of Challenger washed up on a beach in close proximity, one nearly 13 feet long. 
NASA collected and siloed them as well:
This website at hosted a discussion in 2007 about what NASA should do with such historic pieces. 

What about remnants from the first American spacecraft disaster, the oxygen fire in the Apollo 204 command module that killed three astronauts in 1967? At last report, the singed capsule is in storage at Langley Research Center. While the item has never been displayed in a museum, it is more accessible than are the remnants of Challenger

Saturday, September 10, 2011

World Trade Center: Three visits

I'm sure people have heard and seen plenty about the tenth anniversary of 9/11 by now, but here goes. 

I was in the World Trade Center three times. The first was as a tourist, visiting the observation platform atop the South Tower. 

The second time was in 1983, as a feature writer. I was touring the structure to research a Smithsonian article on how three modern structures would age if abandoned by civilization, like the seven wonders of the ancient world

The three modern wonders I profiled were the WTC towers, the Grand Coulee Dam, and the St. Louis Gateway Arch. My March 1984 article is reprinted here

For my WTC work, a Port Authority staffer let me onto the roof of the North Tower, the one studded with antennas. Based on a lengthy interview with WTC chief structural engineer Leslie Robertson, my article predicted the abandoned, wind-swept Twin Towers tumbling into the Hudson within a thousand years, give or take. Here's an illustration from the "Engineers vs. the Eons" article:
During the interview I asked Les Robertson if he thought the buildings might fall into each other in domino fashion, and he was quite firm that they would never do so. 

The third visit was to research an added chapter to Inviting Disaster about engineering and evacuation aspects of the WTC collapse. In that chapter I explained why the towers didn't fall into each other despite the airliners' trajectories, and why the collapse of the South Tower didn't trigger the immediate collapse of the North Tower.

After some months of deliberation, the Port Authority allowed me to spend a day at Ground Zero, shadowing engineer Pablo Lopez on an inspection visit for his employer, Mueser Rutledge. That was in March 2002. I had less than a day's notice to get to New York; I checked into my hotel at 2:30 a.m. and met Pablo first thing that morning.

Pablo's job was to make the rounds of Ground Zero and ensure that excavation of the rubble didn't jeopardize the concrete slurry walls that make up the perimeter of the big basement. He worked out of an engineers' field office set up in kindergarten classrooms on the second floor of nearby Public School 89. 

Here's an excellent paper by George Tamaro on the slurry walls' construction and how they held up during the collapse and recovery. We spent most of the time on the northern side of the site, in the wreckage of WTC 6, also known as the Customs House. 

The events of 9/11 didn't obliterate the Customs House like the Twin Towers, but did punch a mighty hole all the way through to the basement:
The waffle-like objects are wall panels from the North Tower, a combination of steel columns and spandrel beams that gave the building its extraordinary ability to resist a direct impact from a jetliner at top speed.

As we walked each accessible floor, Pablo showed me cars in the parking garage that had been sheared in half by structural steel falling from the upper floors of the North Tower. Some of that was tightly jammed into the bottom of the big hole; I was reminded of the wreckage that results when two freight trains collide inside a tunnel: twisted and very dense.

The exterior walls on the south were gone so we could see firefighters outside, rooting through rubble with garden rakes. The rubble was a dull-gray mix of metal, fragmented concrete, scraps of textile, dirt, and a great deal of paper that months of weather had aged to parchment. I saw some correspondence from the Green Coffee Association.

One image that sticks with me was the view into an underground coffee shop at the commuter station where the PATH tubes entered the Trade Center. Pablo wanted to check on the tunnels under the Hudson, and we looked into the shop while walking down the track. The snack bar was dusty but mostly intact. There were plates, cups, and newspapers abandoned on the tables. 

I never felt that we were in any danger, but it was sobering to read later that one of the WTC 6 floors we were on had collapsed the next day.

That reminds me of a few unwritten rules when shadowing an expert into uncontrolled areas: stick close; wear the protective gear; help serve as a second pair of eyes to look for hazards; and if he or she says it's time to back up and take another route, don't argue!

Saturday, September 3, 2011

San Bruno Pipeline Blast: NTSB lays out another system failure

The National Transportation Safety Board met on August 30 to discuss findings from its exhaustive investigation into the September 9, 2010 PG&E pipeline blast at San Bruno, CA. For those who want to check out the many documents on file, see the NTSB docket page.

Here's a summary of facts and technical findings presented on Tuesday by Ravi Chattre, NTSB engineer and chief investigator.

To summarize Chattre's message, this was an organizational accident, a failure across the system including state and federal regulatory oversight. Here's how Chattre explains that term:

"Organizational accidents typically have multiple contributing causes, involve people at numerous levels within the organization, and are characterized by a pervasive lack of proactive measures to ensure adoption and compliance with a safety culture. They are generally catastrophic in nature and require complex organizational changes. All these aspects are present in this accident."

At the core were persistent failures by PG&E to chase down and fix pipeline-safety hazards. In the case of the failure of Line 132, those problems date back to construction in 1956. The fabricated section of pups saw some remarkably poor welding (particularly in longitudinal seams) and a simultaneous breakdown of inspection and documentation. Here's my January blog post summarizing the welding errors and omissions. The flaws included a hunk of welding rod left in a bead. 

Despite having experienced two similar accidents before, PG&E did not acknowledge that a much more aggressive approach to old-pipeline safety was needed. This would have been expensive; it would have meant digging up and cutting out unpiggable sections (like the pups at the explosion site) and pressure-testing lines with water. These would have turned up the bad section ("woefully inadequate" according to NTSB chair Deborah Hersman) and prevented the blast. Instead, long stretches of grandfathered pipe received no such attention because state and federal regulators expected, or hoped, that industry would do the right thing under a performance-based approach. (In a performance-based approach, a regulated party is supposed to find its own path to an acceptable outcome.)

In this case, the outcome was that a pressure pulse on Sept. 9 originating at the Milpitas control center opened up a string of half-welded seams. It's amazing the cruddy welds lasted that long.

From Chattre's paper:

"During the course of the investigation, staff discovered systemic deficiencies within PG&E as an organization. ... Many of these same deficiencies were identified in the NTSB’s investigations of PG&E accidents that occurred in 2008 in Rancho Cordova and in 1981 in San Francisco. Consequently, PG&E missed earlier opportunities to make corrections that could have prevented the,San Bruno tragedy."

Early news reports and blog posts (including this one of mine) discussed a wide range of suspected factors, but NTSB reports that the following suspects played no role at the Line 132 blast: corrosion of the steel; damage from the "pipe-bursting" sewer construction work nearby; or seismic activity.

One of the things that most disturbed investigators was the long delay before PG&E shut down the high-pressure gas feeding this ferocious blaze: 95 minutes. During this period the pipe belched as much fuel gas as the entire city of San Bruno burns in a month. Eight people died.

See my recent post about how important it is that dangerous activities (including structures subject to storm collapse, like temporary state-fair stages) have robust and well-tested plans that can shut down energy supplies promptly in the event of catastrophe. 

Many older wooden dwellings in the LA Basin have no seismic gas shutoff valves (SGSVs) that shut down gas feed into the building in the event of a major quake, because local laws do not commonly require them except in new and remodeled structures. Here's an interesting lessons-learned paper about how SGSVs performed in the 1994 Northridge quake.

To their credit, Japanese authorities ordered building and homeowners to install SGSVs after the Kobe Earthquake of 1995.

Thursday, September 1, 2011

The Thousand-Year Lease

Look at the Chrysler Building in NYC, and what do you see?
The Abu Dhabi Investment Council sees a crown jewel among its many holdings - it put together a 90% ownership stake in the iconic building three years ago.

But if you're The Cooper Union, you see the land underneath, which you're renting to someone else. Cooper updated its lease in 1998, and the current sheepskin runs through 2147. That's the time-tested policy of other longstanding groups like the Dutch Reformed Church in Harlem: lease your Manhattan land (lawyers call it collecting ground rent) but never, ever sell it. 

As readers know, I like to contemplate long spans of timeThere are many parcels on Manhattan Island with leases running to 2050 and well beyond: the St. Regis Hotel, the Empire State Building; and the 27 houses of Pomander Walk, a row of Tudors between 94th and 95th Streets, which are under leases expiring after 2100. 

While some long leases have only perfunctory annual payments and are really title transfers in disguise, there are many cases in which the agreement truly acts like a lease even across very long spans. One 200-year commercial lease in New York has a payment term adjusted every two decades, based on a renewed appraisal. Until the Depression, some leases required payment in gold bullion or at least gold certificates.

Lease terms of 200 years are only the short end of the subject. The IRT's 999-year obligations as lessee for its old elevated railway triggered a 30-year court fight, ended only by bankruptcy. The peculiarity known as the ultra-long lease appears in every country that operated under the feudal real estate system of England. That includes Hong Kong, Singapore, India, and Kenya. There are thousands of leases with terms over 700 years. Harvard has one of those, for the Arnold Arboretum, at a dollar a year. It's obligated to make the land available to any resident from dawn to dusk each day of the year for another 800-odd years or so. 

Some medieval leases run 5,000 to 20,000 years, making them members of the “ultra-long lease” group. The longest property leases (one million years) have turned up in Paisley, Scotland.

By law the UK now bans newly-drafted leases from running more than 199 years, though ultra-long leases, if signed before 2001, are still fully enforceable as long as the terms can be calculated objectively.

The reason for the ban on adding to the population of ultra-long-leases is that the reversionary clause in an ultra-long lease (meaning, restrictions that allow the freeholder to terminate the lease and reclaim the land if violated) get harder to interpret as the decades and then centuries roll by. 

One example is a 1929 lease term that required prime London land to be held for the benefit of the “working classes." Decades later, developers who wanted to tear down the subsidized housing on the land and erect houses for the rich sought to overthrow this term as irrelevant to the economy of 2002.

Here's a question for the Crown Estate and the comparatively few fortunate foundations and families that own immensely valuable commercial property in the lower reaches of New York and London: if sea levels rise through 2100, and all the evidence points that way, are the leases enforceable? If mega-engineering a la Venice is held up as the solution, how many people outside of the affected area will be willing and able to pay for it?

It's not academic for lower Manhattan, because the fringes are low-lying landfill that top out a few feet above sea level. Climate Central published this map of New York last week, showing zones that will flood during a storm surge bringing water five feet above high tide:
More to come about what lawyers are saying these days about the Act of God defense to contract enforcement.