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, February 12, 2016

How to Park That Crane, Continued

Updating my post on the fatal crane mishap in Lower Manhattan last week ... 

The city has confirmed that the model was a Liebherr LR1300. Reporters at one of the city's press conferences asked if that meant the crane weighed 300 tons, or could lift that much; the answer is that in Liebherr's model numbers the "300" refers to the maximum hoist capacity under ideal conditions, meaning a short boom held at a high angle. It doesn't apply to the way the crane was rigged on Broadway and Worth Street, with a boom and a jib long enough to hoist HVAC gear to the top of a tall building. Here's the laydown zone (photo, FDNY):

Newsday did a good piece with interviews of crane experts on factors that investigators from the city's Department of Buildings will be checking ... things like, what operators should do to reduce the risk that a crane will overturn when lowering the boom and jib. And it may be that local wind-tunnel effects also played a role.

The proper procedure when weather-safing a long boom and jib is for the operator to run out the winch and set the hook block on the ground while the boom is still at a high angle. 

Doing that eliminates a big weight that would otherwise be hanging at the end of a very long arm as the operator lowers the structure to the street. That's a lot of leverage. 

Further, say the experts, the next smart practice is to lower the luffing jib (the smaller lattice structure at the end of the boom) into a vertical position, and only then lower the boom until the tip of the jib touches the street. The terminology makes more sense when looking at the diagram I did after the crane-overturning disaster last September in Saudi Arabia. The Liebherr that fell in KSA was a good deal bigger than the one that fell in New York, and it fell backward rather than forward, but from what I read, it had the same general rigging:

As with lowering the hook block to the street, lowering the jib goes far to reduce the crane's tendency to overturn. 

These two steps are particularly important when the crane lacks a trailer-mounted stack of counterweights. 

Due to the fatality the city's Department of Investigations will issue a report in months to come. 

Saturday, February 6, 2016

Another Large Crane Mishap, NYC

About the fatal crane accident in lower Manhattan yesterday, which happened while the operator was lowering the crane boom and jib to reduce toppling risks from a rising wind ...  From the sparse photos, this unit looks like a Liebherr LR1300, which wouldn't be counted as a supercrane. The crane was rigged for a long reach and light pick.

It was carrying a lot of mast and jib, 565 feet of it according to reports, but it must have handled such a dead load before, since crews had put the sections together on the ground, after which the operator raised it to position. 

Given that the car body flipped over on its back, I'd guess that the luffing cables didn't snap; that is, the falling mast and jib dragged the car body over on its back, with the rising counterweights providing the momentum. 

Some things the NYC investigators will look at: was there extra weight on the hook, mast, or jib that would have overbalanced it; did the pavement collapse under the front of the tracks? I assume that the crane had been sitting on timber mats, but I can't tell from the photos, which show the crane after it overturned. Mats are important to keeping big cranes upright. 

Kudos to news reporters that call this a tip-over rather than a collapse. When a structure falls intact, as this crane apparently did, I wouldn't call that a collapse. 

Second note to reporters: nearly all the photos posted are of the mast and jib in the lay-down zone. Yes, these tell us the tragic damage such a machine can cause, but it doesn't convey much information compared to a close look at the car body, undercarriage, counterweights, crane mats, and hoist rigging. 

Terminology for big crawler cranes like this is available in my post about the crane tip-over near the Grand Mosque at Makkah.

Also, here's a reposting of my item "How to Park Your Super-Crane," fixing a broken photo link.  

Thursday, January 14, 2016

Institutional Memory and the Silver Tsunami, Part 2

How to forge a long-lasting, collective memory that leads to safer operations? That's the subject of this followup post to Part 1.

Physical markers can be valuable memory aids. Old stone monuments on hillsides in Japan, erected following long-ago tsunami, warn those who look for them (photo, CBS News): 

Even better are functional monuments, like this building in Banda Aceh that held up against the 2004 event (photo, Daily Telegraph):

Even temporary markers like lockout tags save lives if in conjunction with physical barriers like locks that prevent a valve wheel from being turned, or a blind being unbolted.

The New London explosion – the worst school catastrophe in US history – illustrates the most costly method to build a memory: high-profile, landmark cases that resonates strongly with the public and lawmakers. Soon after, laws were passed requiring odorants in natural gas for sale, and the registration of professional engineers. Also influential were the gas leak at Bhopal, the collapse of the Quebec Bridge in 1907, the Chernobyl reactor explosion, and the Northeast Blackout of 1965.

But even the most vivid memories fade, and the ranks turn over. How to keep them fresh? On July 6, 1988, Steve Rae was an electrical technician aboard the Piper Alpha rig at the time a chain of mistakes led to a natural-gas leak from a high-pressure pipe. 

The chain of events promptly killed 167 men. Twenty years later he took the podium in front of 130 students at a petroleum technician's school to relive the day, its aftermath, and its costly lessons like the importance of a safety-case approach to prevention. "I attended three funerals on the same day,” he told the newly minted graduates, “and that will never leave me.”

Assuming that institutional memory is important, we have to consider this tough question: Will it always make the critical difference? Not alone, it won't. The loss of Challenger seared across NASA and its contractors and made another solid-rocket booster failure very unlikely, it didn't prevent the loss of Columbia seventeen years later.

A common objection to proposals that would fire up a major effort to gather and preserve an institutional memory is that the effort will drain thousands of hours of otherwise productive time, in additional to consultant costs. And once it's done, who'll have the time to go through a mass of recollections that seems less relevant by the year? Won't the competition take advantage of our hard-won knowledge? That's short-sighted, according to Trevor Kletz: “If we tell other people about our accidents, then in return they may tell us about theirs, and we shall be able to prevent them from happening to us.”

I think two broad types of collective memory are achievable and worthwhile in high-risk industries, each in its way. And they don't have to be a time-burner.

The two types are motivational memory and working memory.

A motivational memory is less about technical details and more about remembering the need to work cooperatively and safely. 

Why do newly graduating structural engineers in Canada join in the ritual of the Iron Ring? It's not a refresher on statics and dynamics, it's a reminder that people die in collapses if experts don't sweat the details. Jack Gillum has given speeches about the catastrophic collapse of walkways at Kansas City's Hyatt Regency Hotel in 1981. Gillum, as the engineer of record, was found negligent in not catching a fatal flaw in revised shop drawings. He lost his Missouri license over it and 114 people lost their lives that night. Many more were injured in the collapse. A firefighter had to perform an amputation with a chain saw. I heard Gillum speak at an engineers' forensic convention fourteen years ago, and what he said that day remains with me. Further, I believe that when employees are injured on the job, managers who controlled the job site are obligated to visit them in the hospital, and attend funerals too.

Working memory: rather than taking aside all employees for long recorded interviews as they approach retirement, consider strengthening the day to day, functional memory as held in the minds of high-performance teams. Confronted with the need to design a new line of cars from scratch, Chrysler split the job among one hundred “tech-clubs,” each responsible for a key component or assembly. By forcing early companionship between design engineers, marketers and suppliers, Chrysler found it could speed development and cut costs. One advantage of a team approach is that expertise is broadly distributed, lowering the risk that a single employee's departure could cripple a critical operation. At its best, that's how the American military works, putting hugely consequential decisions in young hands, mentored by old hands.

Another argument for taking a team approach is that a team is, or can be, much more than the sum of its parts. According to psychologists who study memory formation both individual and collective, people remember an incident most vividly if they've participated in a group that discussed it afterward. Safety-oriented tailgate talks at jobsites are a good time to bring up lessons learned, fresh off the docket.

Group discussions about accidents and close calls also build up the motivational memory. Through such discussions, even people who weren't at the scene of an explosion feel the emotional impact, and it inspires them to go the extra kilometer. As Yogi Berra might have said, no one wants to experience disaster déjà vu all over again.

Saturday, January 9, 2016

Institutional Memory and the "Silver Tsunami," Part 1

If I had to think of one topic that comes up during every public appearance I make, across all industries and specialties, it's the urgency of replacing the baby boomers now heading for retirement: preserving not just the technical skills, but the memory of what works and what fails. 

This story comes to mind. Two months after a wave from the Great Tohoku Earthquake demolished hundreds of towns in northeast Japan, the Washington Post described one that survived: Fudai, a community of 3,000 nestled in a narrow valley that was wide open to the sea. In 1972 its mayor called on the town to build a 51-foot-high floodgate. The project attracted much opposition over the cost ($30 million) and the land required to hold off a big wave -- the next big wave, in the view of then-mayor Kotoku Wamura. 

As a young man he'd seen the aftermath of a 1933 tsunami that killed over 400 in Fudai alone. As mayor, he led the project and faced a lot of hostile questions: Why did the town need it? Why so high? Other Japanese cities had put up gates and seawalls, but none were so high. How could Fudai pay for it?

Wamura was undaunted. A good thing, too: When that next wave arrived on March 11, 2011, water lapped over the top but the damage was inconsequential; the only death was one man who had climbed over to check on his fishing boat. Without Wamura's big wall, Fudai would have been reduced to bodies, trash, and rubble. Again. 

Memory – vivid and awful – carried Fudai's floodgate project forward against all opposition. It needed more than the mayor's individual memory: it was a collective memory of everybody old enough to have seen the effects of the 1933 wave.

The subject of memory and how to hold onto it is a hot topic because the baby boomers aren't babies anymore. Experts warn that the looming retirements, across all sectors of the economy, is a “silver-haired tsunami.”

However much fifty- and sixty-somethings look forward to retirement, they're equally eager for anti-Alzheimer nostrums, whether vitamin packets, red wine, Soduku puzzles, or online memory tests. Worries over memories that slip-side away extends to the largest scale. Consultants are wagging their fingers at companies and agencies like NASA, warning them to capture their “institutional memory” with extended videotape interviews and copious databases. 

They're referring to the unwritten knowledge held by skilled workers, seen-it-all foremen, and hands-on managers. It's trouble-shooting. It's the agility that strikes a balance between handling existing projects and taking on new challenges as conditions change. In short, it's the know-how that gets things done and heads off the ICE, the Imminent Catastrophic Event.

Before looking into what collective memory is, let's think about individual memory. While our brains are sometimes compared to a computer's storage banks, people are radically different from computers in how they collect and store information. In 1861 Abe Lincoln referred to the mystic chords of memory, and he wasn't far off the mark. Memory is not a predictable set of nerve connections. We know more about how it goes away than why it stays.

Experts in mnemonic techniques assure us that with training and jaw-aching concentration just about anybody can erect a memory palace in their minds and then wow their friends by quickly memorizing the order of an entire, shuffled deck of cards. Meanwhile, most of us still have not a memory palace but something more like a drafty house. Even without the affliction of Alzheimer's, facts blow out the back door when we're not looking, and other facts get mixed up like old keys tossed into junk drawers. Check out this “Jaywalking” episode from Leno, for a wacky stroll through history as feebly recalled by the man on the street. 

The good news is that humans are, or can be, quite good at building and holding a body of knowledge. Knowledge is what drives our decisions. It's a combination of skills, recalled facts, and insights, and is unique to each person. 

Recall my drafty-memory-house analogy? Now imagine a snug, warm greenhouse in the back yard, a place for plants to grow and thrive. For an amazing example of how people can amass huge bodies of knowledge when they must, check out Mark Twain's Life on the Mississippi

He describes how each licensed pilot of the 1850s had to know the channels suitable for big steamboats along more than a thousand miles of unmarked river, storing the images for use by day, night, and in the fog … and then absorb new information as channels, snags, and sandbars changed.

Such vast collections fit into a few pounds of brain tissue because they're braced and motivated by personal experiences, vivid stories from trusted sources, reading, and certification courses. 

That's memory and knowledge at the micro level. What about macro: Can an entire company, or even the workers across a single plant, share a “collective memory”? Safety expert Trevor Kletz, author of What Went Wrong? and Still Going Wrong, believed so. 

The tendency of refinery and chemical plants to lose their institutional memory of past disasters, about every ten to fifteen years, has been a concern in the chemical-processing safety literature for years. Writing in Modern Railways, Roger Ford said that accidents happen “when the last man who remembers the previous disaster retires.”

On the other side of the memory-is-good question are advocates of extreme makeover, corporate style. If what Robert McMath calls Corporate Alzheimer's is the collateral damage, so what? To these skeptics, it doesn't matter whether anybody in the organization recalls past problems and how to avoid them, because the key is going forward. Here are their arguments:

Didn't the fabulously successful Henry Ford say in 1916, “History is more or less bunk.... We don't want tradition. We want to live in the present, and the only history that is worth a tinker's damn is the history we make today.” 

Here's how Ford's thinking lives on:

  • “All damage and injuries are due to either (1) unpredictable flukes of fate, never to be repeated and therefore needing no attention, or (2) errors by low-ranking workers who recklessly flaunted their training and operating manuals. So there's nothing to learn.”
  • “Internal histories that capture damage incidents, close calls, and lessons learned would be expensive to assemble, and then plaintfiffs' lawyers might get hold of it, so why go to the trouble? It's better to plead ignorance after the next bad headline, and do it convincingly.”

Now for the other side of the coin. There's a museum called The Collection at New Product Works of Ann Arbor, Michigan, for which people pay a lot of money to tour. The shelves hold more than a hundred thousand products, most of which you can't find anywhere else because they flopped so quickly, like Look of Buttermilk shampoo, Male Chauvinist Aftershave, and a urine-colored bottled tea called “Tea Whiz.” 

Even the museum at Ann Arbor, big as it is, can't display all the ways that firms and governments forget at least as much stuff as we mere humans do. And about as fast. 

The problems of rapid employee loss and turnover are magnified by the loss of supervisors with long and plant-specific experience.It's been said that foremen and supervisors act like synapses of our brains. On the job, they link individuals into functional units that span the organizational charts; along with motivated higher-ups, they can press for prompt action to head off a disaster. Critics like Kevin Foster call the discharge of such experts not downsizing but dumbsizing. But the nation would still have a memory drain problem even if companies reversed direction, because there's a graying workforce that is sure to move on sooner rather than later. Mack Truck built an assembly plant for the Soviet Union, but when the opportunity came to win a contract to refurbish the facility in Russia, Mack lost the bid to another company because the company experts on the original plant had moved on and no working memory remained of how, or why, the truck plant was laid out. 

A plant doesn't have to be halfway around the world to turn into something dangerously unfamiliar, as employees change jobs and memories fade. Disaster annals are full of spectacular events triggered after an incoming worker looks at some pre-existing gizmo, decides it's getting in his way or slowing him down, and changes it without asking anybody. This can be a enormous hazard at an oil refinery, where an peculiar-looking vent stack might be essential to avoiding a vacuum that would cause two chemicals to react and mix at the wrong time. In a perfect world, a complete set of plans would not only show the machine in its actual, “as built, as modified” status, it would also have little tags explaining what the tubes and safety valves in a boiler room or refinery are there for, in case someone has the hankering to tinker.


How to forge collective memory that leads to safer operations? That's the subject of Part 2.

Wednesday, December 16, 2015

What's It Like to Interview Harrison Ford?

Pretty interesting! He's got a straightforward style, and lets you know right away whether he thinks the question is worth answering. While researching my helicopter book The God Machine, I thought it would be good to get a high-profile user's view of the machines, which are expensive to buy and operate. Ford is among a few thousand private owners who can afford it. (Photo, CBS News)

It took six months of back-and-forthing with his executive assistant at HF Productions, but in time we scheduled a half-hour talk. Ford was running early that morning so he called my cellphone to change the time, leaving a voicemail message, which (of course!) I saved.

The subject was strictly helicopters; nary a movie in sight. He talked about his training, his checkride in a Bell, and what it was like to fly out of the notoriously challenging 60th Street Heliport in Manhattan. “Now it's shut down and that’s a good thing,” he said, comparing it to flying in and out of a box with one open side. “When you came out, you were facing an unknown wind, but the wind was usually along the East River, out of the south to the north. It usually needed an immediate pedal turn upon lifting up.”

Being a superstar, while flying cross country, did he feel he could land his Bell 407 just about any vacant field where it would fit, such as near a roadside diner? No, he said, “I don’t do unplanned back-lot landings, because I don’t know the municipal attitude. They all have to have a say in helicopter landings. Plus, I’m getting fuel along the way so I’m stopping at airports.”

I asked him about his favorite times in a helicopter, “Probably mountain flying in Wyoming,” he replied, referring to his volunteer work around Jackson Hole. “One of the more critical flying tasks was helping the mountain rangers pick up their winter stashes of equipment. Density altitude is a factor, because of the height, and also it’s warm by then. It’s pretty technical flying. You get a couple of big guys in there, each 200 lb, and 250 lb of gear. … This is just above the tree line. So it’s a matter of beoing able to pick it up and drop it over a convenient edge – you have to fly down before you can fly up, that kind of situation. Yes, that means setting down pretty close to a dropoff.”

He also enjoyed flying a tiltrotor at the Bell factory. “It's an incredible machine – you tilt the nacelles over and you take off like a drag racer.”

Emergency procedures? He estimated that he'd done 200 “full down” autorotation practices, with a freewheeling main rotor, and the machine gliding all the way to the ground. “I go to the Bell school once or twice a year and they really train you in emergency procedures,” he said. “They’ll have you do twenty-five autorotations in a day.”

During practice in Southern California in 1999 the helicopter he was flying with an instructor hit hard and turned over in a dry riverbed. “We were in a [Bell] 206 at the bottom of autorotation [anticipating only doing an autorotation to power recovery] but when we rolled the power in, there was no response. It kept going down. This area is a helicopter practice area but it has coarse sand, and there are a lot of snags.”

I mentioned that some helicopter pilots never do any autorotation practices all the way to the ground, because their schools consider it too dangerous. “Well,” he said in a voice that sounded just like Han Solo's, “assuming engines won’t ever quit, that’s not a good idea.”

There’s all kind of helicopter traps out there – you’ve got to stay alert.”

Saturday, November 21, 2015

Obscure Lingo from the Machine Frontier

Back from my 42nd public-speaking gig. The one this week was in Miami, doing a keynote for a congress of the forensic engineering division of the American Society of Civil Engineers

While there I added to my collection of trade lingo, accumulated during more than three decades of research into the machine frontier. This first one is from the Miami conference, and was new to me:

Spike-killed ties: These are cross ties in railroad tracks in which the spikes have worked loose, and have been pounded back in repeatedly. After so many times, the wood is weak and the tie has lost its grip. Spike-killed ties are bad because they lead to wide-gauge derailments

Blue line: This is what USAF mission planners call the path that pilots of low-observable (aka stealth) aircraft are supposed to follow while in enemy airspace. The idea is to travel where the radar fence is weak, wherever possible. As all geeks should know, stealthy aircraft aren't "invisible" to radar; they're just hard to pick up. The best route is one where the airplane is lost in the noise, and only resolved for brief intervals, if at all. 

Iron roughneck: Automated tool to attach, and detach, sections of a drill string on an oil rig. This substitutes for human roughnecks who relied on tongs and chains. 

Rabbit tool: Small hydraulic device used by firefighters to force open steel doors in steel frames. 

Burning bar, aka thermic lance: Pipe filled with metal rods, fed by oxygen at the operator's end. Once ignited at the other end the metal burns at a very high temperature. The flame will burn through any substance in its way, including diamond. Here's a video:

Dead leg: A section of pipe that's been left behind, supposedly sealed, after work in a complicated set of piping, typically a refinery or chemical plant. According to the Chemical Safety Board, dead legs can be dangerous because they increase the chances for pipe breaks.

Alarm storm: A wave of automated alarms when a bunch of things going wrong at once. I've heard it used among power-plant operators and surgeons. 

Gin pole: A derrick-like framework that tower builders use. It's installed temporarily on the mast. Because it's massive enough to bring the whole tower down in a collision, they take extra care whenever moving it. 

Jesus nut: A Vietnam-era term for a fastener at the top of the rotor mast in Huey and Cobra helicopters. 

Battle short: A desperate measure in the Navy during combat, in which safeties are bypassed to save the ship, say, overriding a reactor scram. 

Thursday, November 12, 2015

Light a Candle for the 50th Anniversary of the Northeast Blackout

Following is the first section of my article on how the big blackouts of 1965 and 1977 came about (photo credit, The Guardian). 

It was the first time I wrote about a system so complex that no single person could stay on top of it. That realization laid the foundation for Inviting Disaster later. 

The rest of the feature can be accessed at the Invention & Technology issue archive

Learning from the Big Blackouts

Two nights of darkness, in 1965 and 1977, showed how fragile the nation’s power system could be

James R. Chiles

Fall 1985  | Volume 1,  Issue 2

Normally night spreads from east to west with the rotation of the earth, but the evening of November 9, 1965, was different. Darkness also spread from north to south. Southern Ontario went dark first, much of New York State a few seconds later, then most of New England, and finally New York City. By 5:28 P.M., thirty million people were stumbling toward any light available. Subways stopped and furnaces chilled, and America briefly lost one-fifth of its electricity. What was the cause? Maybe a generator failure, maybe sabotage—for several awkward days no one knew.

America’s electric-power network is so vast that solar flares affect it and so convoluted that the start-up of one generator affects others thousands of miles away. It is perhaps our most complex technology. But the 1965 blackout—and others that have followed—taught that complexity does not equal sophistication.

In the twenty years since that catastrophe, power companies have been working with mixed success to prevent more outages. Transmission lines have greater capacity now, control centers are more computerized and hold tighter reins over power flows, utilities cooperate and share more information, generating stations have emergency power to restart generators thrown off the grid by electrical jolts, and operating procedures have been revamped. Still, major outages happen every year, benighting thousands and occasionally, as in New York in 1977, millions of people, but many in the industry are confident that another 1965-scale blackout is unlikely.

Smaller blackouts can be costly too, though, and some observers fear that the stability of the network is threatened by certain utilities’ financial problems and by economic pressure to move electricity long distances from power-rich areas to utilities dependent on oil-fired power plants. In parts of the country, such long-distance purchases of economy power are pushing transmission lines to the limits of safety by straining their capacity.

In 1965 the utility industry was about eighty years old. America’s first central power station had started supplying a small district of Manhattan in 1882. The idea didn’t catch on for several years because building owners could provide for themselves more cheaply by buying generators and putting them in basements. But the price of central service dropped by 1886, and the new electric streetcars were increasing daytime demand dramatically. The same advantages of reliability and savings that then led isolated users to join in a central system also persuaded utilities to link with one another once high-voltage alternating-current equipment was available.

Regional grids started forming: the Pacific states, the Southwest, the Southeast, and the Upper Midwest. The first big interconnection in New England came about in 1913 because the utility at Turners Falls, Massachusetts, had a surplus of cheap hydroelectric power to sell. Interconnections multiplied rapidly across the Northeast during World War I, when defense plants needed power in amounts that isolated utilities could not supply. In 1959 Ontario Hydro joined the Northeast Interconnection, which then changed its name to Canada-United States Eastern Interconnection and acquired the acronym CANUSE.

November 9, 1965, was—until the blackout—an ordinary day. From New York City on the southern end of CANUSE to Ontario in the north, the weather was clear and cool. As the sun dropped, lights went on. Power stations all over the Eastern Interconnected System—CANUSE and the other big systems it was connected to—opened water and fuel valves to meet the need.

One of these was the Sir Adam Beck No. 2 hydroelectric plant, set on the Canadian cliffs near Niagara Falls. Most of its output was going west and north to Toronto, across Lake Ontario. The Beck plant was working a bit harder than usual because the Lakeview power station near Toronto was having problems with its machinery. The load on Beck’s transmission lines reached the point at which an obscure relay, installed in 1951 and last adjusted in 1963, ordered a circuit breaker to disconnect one line. This started a chain of events that no one could have predicted exactly, because alternating current finds its own pathways through the multitude of combinations possible in a large power network, which is itself changing every minute. At 5:16 and eleven seconds, the system began to move with frightening speed.

When the Beck relay ordered the first westbound transmission line cut off, 375 million watts of power crowded onto the four other westbound lines. In less than three seconds they tripped out in turn, and at least 1.5 billion watts rushed into America across two other lines strung over the Niagara River. The surge of electricity tried to reenter Canada at the Massena, New York, interconnection, but that interconnection overloaded, and the surplus power turned south, down the backbone of the CANUSE transmission system.

Relays interpreted the power surge as a short circuit and started signaling circuit breakers to separate the system into islands. Shuddering under the impact of all these circuit breakers and the wildly fluctuating current, generators slowly fell out of the sixty-cycle-per-second, threephase lockstep that the alternating-current networks demanded. One island, which took in southeast New York State, New York City, and much of New England, was suddenly short of generation capacity, with a severe deficit in the northern end pulling great pulses of power from the south. The deficit grew as the electrical chaos forced generators off the network.

Continued here