Case study in importance of maintenance. 1 broken century-old hook => $16,650,000,000 damages.
This electrical transmission tower has a problem
11–20 of 479 posts
Re: This electrical transmission tower has a problem
#12> When the C hook broke and the hanger fell, the steel-reinforced aluminum conductor that carries 115,000 V bounced and shorted out against the metal side of the tower, spraying chunks of white-hot aluminum across the ground underneath the tower. The weather was extremely hot, dry, and windy, and this immediately started a fire. This was the Camp fire, the most destructive fire in California history.
> [...] How long was it rubbing against the hanger bracket? The answer is that we don't know. We think it is about 97 (!) years old, but we're not sure because PG&E didn't keep records about it. After the fire, many of the pieces were taken to the FBI lab's metallurgical unit at Quantico, and they determined that the C hook was made of cast iron. Not all the C hooks on these 100-year old towers were made of cast iron--many were made of steel. but again: no records.
> PG&E knew that this was a problem because at some point they bolted on L brackets and moved the C hooks onto the new brackets, probably concerned that the old bracket hole had mostly worn through. We don't know when they did this because they kept no records. And yes, PG&E is legally required to inspect these towers periodically. We don't know exactly when, because (you guessed it) no records from before the year 2000.
> There's even documented evidence that PG&E knew about the problem with the C hooks and hangers and yet did nothing.
> > [...] to opine the keyhole wear was occurring at a rate of .007 inches per year. Based upon the average wear rate, the PG&E lab scientist determined the useful life of those hanger plates to between 97 and 100 years. PG&E now had scientific confirmation of the body-on-body wear caused by the constant movements of the C hooks within the hanger holes and an estimate of average wear per year. Nothing was done. The report was not distributed through the company and no targeted inspections of older C hooks and hanger holes were ordered. Based upon this report, a reasonable person, knowing they had C hooks which were 90+ years old hanging in hanger holes that were 90+ years old would have taken immediate action to determine the condition of those hooks and holes. The fact PG&E did nothing is evidence of completely and absolute indifference to the inherent danger of a C hook or hanger hole breaking.
> > Despite the efforts of PG&E personnel to distance the company from the "Run to Failure" model, the evidence clearly establishes quite the opposite. [...] Catastrophic failures of the Caribou-Palermo line was not if "if"question; it was a "when" question.
> Sadly, this is not new behavior for PG&E. it's just like the San Bruno gas explosion.
> > PG&E electrical transmission policies and records prior to the Camp Fire mirrored PG&E gas transmission policies prior to the San Bruno catastrophe. [...] The San Bruno investigation also established PG&E intentionally was using the least expensive method of inspection in the least expensive manner. The chosen inspection method also saved money because problems that are not found do not need to be repaired. The investigation also established records relating to inspections, both justifying methods of inspection and the inspection reports, was fraudulent.
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> [...] So despite PG&E's criminal negligence, there's a good chance that Paradise would have burned down anyway, even if they had good records and had kept the tower maintained. [...] It turns out there was a second, unrelated fire that started at almost the same time and almost the same place! This happened when a tree fell on a distribution line (lower voltage, shorter distance), and [...] this was not PG&E's fault. There's no way the inspectors, even if they were competent, could have known that the tree would fall.
> > [...] The arborist determined the disease was internal and likely would not have been visible to PG&E tree inspectors during their vegetation management inspections. According to the arborist the disease likely only would have been discoverable by an advanced inspection.
> > Before the Camp B Fire grew large enough to escape its geographical bowl, it was passed over and consumed by the Camp Fire. Based upon fire indicators and patterns within Camp B Fire and recordings from the fire watch cameras, Cal Fire investigators determines that the Camp B Fire had little, or no, effect on the Camp Fire.
> Here's the second, more insidious cause: climate change. extreme weather->more vegetation->increased fuel load as well as hotter/drier weather. While solving climate change is a good long term goal (although something that the human race is notoriously bad at), we need to improve our forestry management practices. And keep better records! And hold people accountable!
> If you think of PG&E (the organization) as an emergent intelligence, it was set up to optimize only one metric (profit) and utterly failed to take into account another metric (risk). I'm sure there are people who study this sort of thing who could examine PG&E and point out exactly what caused this organizational failure. Again I want to emphasize that taking PG&E and making it state-owned and state-run is not a magic bullet. I mean, c'mon, Chernobyl was state-run! It comes down to organization, accountability, and incentives. They're complex problems but they can be solved.
Source:
* Summary report from the Butte County DA.
https://www.buttecounty.net/Portals/30/CFReport/PGE-THE-CAMP...
Re: This electrical transmission tower has a problem
#13"on June 16 of this year, PG&E pled guilty to charges of unlawfully causing a fire and 84 counts of involuntary manslaughter. their penalty? a $4 million fine."
They also settled for damages from several fires (including the Camp Fire) for $25.5 billion, of which 13.5 billion was earmarked for victims.
Re: This electrical transmission tower has a problem
#14https://threadreaderapp.com/thread/1306359385656946688.html
Re: This electrical transmission tower has a problem
#15(Yes, it failed, but you have to admit that it had a pretty good run! 97 years is not bad for a moving part!)
Re: This electrical transmission tower has a problem
#16Case study in importance of maintenance. 1 broken century-old hook => $16,650,000,000 damages.
That's like blaming the welders for the Lebanon explosion when in reality it was a combination of like 4 different fails over the course of many years.
Re: This electrical transmission tower has a problem
#17Case study in importance of maintenance. 1 broken century-old hook => $16,650,000,000 damages.
Only a $4 million fine, though right? How much do you think a maintenance program would cost?
Re: This electrical transmission tower has a problem
#18Excellent Twitter thread, I'm glad I went down that rabbit hole. I wish it was in blog format though, it's kind of jarring working through little blurbs.
Re: This electrical transmission tower has a problem
#19Tweets make excellent momentary entertainment. Let's stop using them for anything else.
Re: This electrical transmission tower has a problem
#20I guess my takeaway from this is if you're a government building some sort of asset you're going to transfer to the private sector, overengineer it. Nobody is ever going to do maintenance, so your thing essentially has to last forever. Imagine that they made the hooks so they only lasted for 10 years -- we'd have 10 times as many billion-dollar fires. But some engineer in 1918 said "you know, let's make it a little b…