In 2018, the Camp Fire devastated a huge swathe of California, claiming 85 lives and costing 16.65 billion dollars. Measured in terms of insured losses, it was the most expensive natural disaster of the year, and the 13th deadliest wildfire in recorded history.
The cause of the fire was determined to be a single failed component on an electrical transmission tower, causing a short circuit and throwing sparks into the dry brush below – with predictable results. The story behind the failure was the focus of a Twitter thread by [Tube Time] this week, who did an incredible job of illuminating the material evidence that shows how the disaster came to be, and how it could have been avoided.
Mismanagement and Money
The blame for the incident has been laid at the feet of Pacific Gas and Electric, or PG&E, who acquired the existing Caribou-Palermo transmission line when it purchased Great Western Power Company back in 1930. The line was originally built in 1921, making the transmission line 97 years old at the time of the disaster. Despite owning the line for almost a full century, much of the original hardware was not replaced in the entire period of PG&Es ownership. Virtually no records were created or kept, and hardware from the early 20th century was still in service on the line in 2018.
In the hours after the Camp Fire began, investigators working to establish the cause found a broken C hook beneath Tower #27/222 on the Caribou-Palermo line. The C hook is responsible for supporting an insulator, which holds the high-voltage jumper conductor in position. When the C hook broke, the jumper conductor fell, striking the tower, with the resulting short circuit throwing sparks into the vegetation below, starting the Camp Fire. With a PG&E helicopter spotted in the area, investigators worked fast to secure the area as a crime scene, with evidence collected and sent for further analysis.
The resulting grand jury report released in June of 2020 as PG&E entered their guilty plea is damning in its conclusions. The failed left-side C hook, along with the insulator and jumper conductor that started the fire, were all determined to be original components in continuous service since 1921. Additionally, PG&E were found to have virtually no information or records of the equipment on Tower #27/222. Pictures taken of the hook showed significant wear over time, before finally failing on November 8, 2018.
Further evidence suggested serious negligence on the part of Pacific Gas and Electric. Despite a lack of records, recovered components of Tower #27/222 indicated prior knowledge of a need for maintenance on the line. Both the left and right side C hooks were mounted on plates bolted to the tower, through holes that showed significant wear. These plates had been installed as the original holes for mounting C hooks on the tower were almost entirely worn through with similar keyhole wear. The wear was caused over many years, as the C hook moved back and forth in the slot due to wind. The fact that the plates had been installed indicated that PG&E knew the C hook attachments needed attention over time. Despite this, PG&E were unable to field any records of when, why, or by whom the plates had been fabricated and installed.
The investigation also goes further, revealing a “Run To Failure” ethos within the company, with no regard for potential negative outcomes. It bears remembering that Pacific Gas and Electric were found guilty of six felony charges for the 2010 San Bruno gas line explosion. In both cases, investigators found a radically inadequate approach to safety and maintenance, with fatal results. In the case of the Caribou-Palermo line, largely untrained workers were used to perform trivial inspections by helicopter, that fundamentally consisted of a visual check as to whether or not the tower was still standing. Cost cutting was endemic as far as inspection and maintenance was concerned, aiming to increase the operation’s profitability, with little regard to the possible consequences of an equipment failure.
Overall, the failures of Pacific Gas and Electric in the running of the Caribou-Palermo line were multitude and varied. At the very first instance, with almost no records of the infrastructure’s hardware or condition, it was simply not possible for the company to have any idea if there was a problem in the first place. Additionally, with an approach of saving costs on inspections in order to avoid finding problems that need costly solutions, the company all but guaranteed an expensive and dangerous failure. The fact that it took a full 88 years to happen since the company purchased the line is perhaps more down to sheer luck than anything, and the foresight of whoever did an interim replacement of hanger plates at an unknown point in the past. Fundamentally, the company’s active efforts to cut costs and maximise profits, as well as a total disregard for proper engineering practice, resulted in the deaths of 85 innocent people. It’s a disaster we would do well to learn from.