Did PG&E tower fail­ure spark fire?

Loose trans­mis­sion line could spray molten metal over fo­liage, ex­perts say

The Mercury News - - Front Page - By Matthias Gafni and Thomas Peele Staff writ­ers

PULGA >> With winds gust­ing around 50 mph in the morn­ing hours of Nov. 8, por­tions of a PG&E steel lat­tice trans­mis­sion tower — ex­posed to the el­e­ments high on a ridgetop and orig­i­nally built when Woodrow Wil­son was pres­i­dent — failed.

As high-volt­age lines got loose and whipped around, strik­ing the metal tower, molten alu­minum and metal sprayed across tin­der-dry veg­e­ta­tion, ig­nit­ing the brush. Ar­riv­ing fire­fight­ers could only watch as the blaze un­der­neath the power lines quickly spread to wild tim­ber and brush.

That’s the hor­ror story about the ig­ni­tion of the Camp Fire that at­tor­neys, sources and ex­perts have be­gun to con­struct af­ter vis­it­ing the tower and re­view­ing records, fire trans­mis­sions and other data.

Now a month af­ter the blaze first roared to life along the North Fork of the Feather River, near the re­sort town of Pulga, sources fa­mil­iar with a Cal Fire probe say in­ves­ti­ga­tors are ze­ro­ing in on this “trans­po­si­tional” tower that helps switch power among trans­mis­sion lines on the Cari­bou-Pa­lermo cir­cuit, orig­i­nally built in 1919. The fo­cus is on whether a tiny O-ring that holds up rows of disc­shaped in­su­la­tors, or pos­si­bly fa­tigued steel from one of the tower’s arms, caused the ac­ci­dent.

“It’s there that the likely (O-ring) con­nec­tion failed,” said Dario de Ghetaldi, an at­tor­ney su­ing PG&E on be-

half of dozens of res­i­dents who lost their homes in the Camp Fire. “It could also be cor­ro­sion on the sup­port ex­ten­sion. This is high in the moun­tains, you get very strong winds and they had ex­treme winds that night.”

PG&E has re­ported to state reg­u­la­tors that at 6:15 a.m. Nov. 8, a 115,000volt trans­mis­sion line mal­func­tioned. About 15 min­utes later, fire ra­dio trans­mis­sions in­di­cate some­one at Poe Dam, a lit­tle more than 1,000 feet away from the tower and down a steep canyon wall, re­ported the fire un­der­neath the power lines amid high winds.

Within hours, the town of Par­adise was nearly wiped off the map. At least 85 peo­ple died in the fire, and it has de­stroyed more struc­tures than any other wild­fire in this flammable state’s his­tory.

As in­ves­ti­ga­tors nar­row their fo­cus on the cause, Cal­i­for­nia Pub­lic Util­i­ties Com­mis­sion mem­bers next week will re­visit poli­cies in­volv­ing emer­gency power shut­downs in ad­vance of dan­ger­ous fire weather. PG&E had for two days re­peat­edly warned cus­tomers in Butte County it might shut off power the morn­ing of the Camp Fire but de­cided to keep the power on.

Cal Fire also is in­ves­ti­gat­ing a pos­si­ble sec­ond ig­ni­tion point in the fire, near a PG&E dis­tri­bu­tion line that failed about half an hour af­ter the Pulga tower mal­func­tion, ac­cord­ing to fil­ings with the CPUC.

Nu­mer­ous law­suits have been filed against the util­ity, and its stock price has im­ploded. CPUC in­ves­ti­ga­tors also have be­gun in­ves­ti­gat­ing if PG&E’s equip­ment and the com­pany’s main­te­nance of its equip­ment played a role in the fire, and how it ar­rived at the de­ci­sion to keep elec­tri­cal power on that morn­ing. Si­mul­ta­ne­ously, a fed­eral judge over­see­ing PG&E’s pro­ba­tion in the 2010 San Bruno pipe­line ex­plo­sion case is work­ing to de­ter­mine if the util­ity com­mit­ted any crimes that may have caused the Camp Fire.

PG&E re­peat­edly has said it is co­op­er­at­ing with the in­ves­ti­ga­tion, but it could not com­ment on specifics as the cause of the fire was still be­ing de­ter­mined.

Shower of metal

On Thurs­day, a re­porter and pho­tog­ra­pher left Pulga and drove up the wind­ing, dirt Camp Road, name­sake of the deadly fire, that snaked un­der­neath the Cari­bou-Pa­lermo trans­mis­sion lines be­fore reach­ing the dam­aged tower on a ridge­line high above High­way 70. The tower is one of three par­al­lel struc­tures po­si­tioned on a steep in­cline above the road at an el­e­va­tion of more than 2,100 feet.

Loose wires dan­gled from the tower, sev­ered af­ter in­ves­ti­ga­tors re­moved var­i­ous parts as ev­i­dence. Pri­vate PG&E guards were sta­tioned at three points along the road. The re­mote­ness and rugged ter­rain around the tower would make any fire­fight by hand crews nearly im­pos­si­ble.

Cat­a­strophic fire ex­pert Dr. John DeHaan, owner of Fire-Ex Foren­sics, said an arc­ing trans­mis­sion line cre­ates much more dan­ger than your av­er­age res­i­den­tial power line atop a wooden pole.

“There’s so much en­ergy there even green veg­e­ta­tion could ig­nite be­cause it fries the mois­ture out of any­thing it hits,” he said. “It chars that, and then the char­coal be­comes the con­duc­tor.”

DeHaan said he has seen ex­am­ples where a trans­mis­sion line hit the ground and trans­formed the sand into a glassy col­umn, sim­i­lar to a ful­gu­rite, a form of fused soil cre­ated by a light­ning strike.

“All of those tow­ers fa­tigue, and they can get a fa­tigue crack and with high winds it can start flex­ing back and forth un­til it fails,” DeHaan said, de­scrib­ing what would hap­pen when the en­er­gized line slapped into the struc­ture or the ground. “That would melt the con­duc­tors and gen­er­ate a shower of molten metal as well as the ex­tremely hot plasma in the arc it­self.”

If an O-ring hook or other struc­ture is weak­ened by metal fa­tigue and breaks, the in­su­la­tors are no longer sup­ported and can come in con­tact with the lines and the tower.

De Ghetaldi said “jumper” ca­bles, which are used to switch cur­rents be­tween trans­mis­sion lines on the tower, as well as the trans­mis­sion and dis­tri­bu­tion lines them­selves, should be in­su­lated with rub­ber coat­ing, sim­i­lar to a lamp cord. He said the util­i­ties balk at the safety mea­sure be­cause it’s more ex­pen­sive and adds weight to the lines.

“If the jumper wire had been in­su­lated, the whole thing would’ve been pre­vented,” he said.

Sec­ond start

Cather­ine San­doval, a for­mer CPUC com­mis­sioner who teaches en­ergy law at Santa Clara Uni­ver­sity, wrote an ar­ti­cle Wed­nes­day rec­om­mend­ing 10 reg­u­la­tory goals to help pre­vent util­i­tys­parked wild­fires. For the six years she served on the com­mis­sion, end­ing last year, she warned of safety risks in­her­ent in the main­te­nance and mon­i­tor­ing of equip­ment. In an in­ter­view Fri­day, she said she wor­ried PG&E and other com­pa­nies are “run­ning to fail­ure.”

“Cer­tain con­di­tions can lead to metal cor­ro­sion. (In­ves­ti­ga­tors) will look at age and pre­vi­ous ex­po­sure to wind,” she said. “Mak­ing sure util­i­ties are pay­ing at­ten­tion to ag­ing in­fra­struc­ture is ab­so­lutely im­per­a­tive. They should’ve been as­sess­ing if there were risks to … the ag­ing tow­ers, par­tic­u­larly since nearby tow­ers suf­fered wind da­m­age.”

In 2012, a win­ter storm top­pled five tow­ers on the same trans­mis­sion line. Those crum­pled tow­ers were re­placed in 2016, but other tow­ers were not, at­tor­neys have al­leged.

San­doval called a fail­ure on a metal trans­mis­sion line “ex­tremely un­usual,” es­pe­cially com­pared to more frag­ile dis­tri­bu­tion lines on wooden poles.

“Was the cross arm show­ing signs of stress? Should equip­ment have been more quickly re­placed?” San­doval asked.

Fire in­ves­ti­ga­tors also have re­trieved a power pole and other ev­i­dence from the lo­ca­tion of the sec­ond power line mal­func­tion in Con­cow on the Big Bend 12,000-volt dis­tri­bu­tion line, about 2 miles west of Pulga. Trees and two wood power poles lit­ter the ground near a sin­gle orange con­struc­tion cone that marks the spot.

In San­doval’s ar­ti­cle, she in­cluded pho­tos she took of dan­ger­ous power lines. Some­thing must change, she con­cluded.

“Stem­ming util­i­ty­caused wild­fires is a le­gal and eth­i­cal im­per­a­tive to pro­tect the safety and health of the peo­ple of Cal­i­for­nia,” she wrote, “and the fu­ture of our state and planet.”


The PG&E trans­mis­sion tower at right re­port­edly mal­func­tioned min­utes be­fore the Camp Fire was first re­ported.


Orange ar­rows point to a miss­ing arm of the trans­mis­sion tower at the Camp Fire ori­gin site near Poe Dam af­ter it was re­moved by Cal Fire for ev­i­dence. Red ar­rows point to rem­nants of “jumper” ca­bles, which trans­fer power from one line to an­other.

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