Workers injured while driving ground rod into power line

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gadfly56

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GoldDigger

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The article also mentioned that the rod was being driven by a jackhammer (with rod adapter?) which was suspended from an excavator.
Possibly they were using 20' sections of ground rod and the injured person was in or on the excavator bucket. That would allow a 20' vertical fall or a shorter vertical fall and a large horizontal component before hitting the ground.
 

PetrosA

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Jraef

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The article mentioned that one man was thrown 20 feet. Did he fall from that height or was he moved horizontally? If the later, I wouldn't think that an arc could cause enough air displacement to push someone that far. What's the real skinny on this?
"One employee was taken to Harborview Medical Center in serious condition after falling 20 feet from a ladder, Seattle Fire Department said. The man in his 50s suffered a concussion and a shoulder injury.

Medics were also evaluating a second patient at the scene, according to SFD. The second patient is a 63-year-old man with first degree burns. The Seattle Fire Twitter account said a transformer had blown.

A third worker in his 20s suffered cuts and bruises from the blown transformer."
 

big john

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The article mentioned that one man was thrown 20 feet. Did he fall from that height or was he moved horizontally? If the later, I wouldn't think that an arc could cause enough air displacement to push someone that far. What's the real skinny on this?
I would wager if it was horizontal then it was just a case of an injured man staggering for a few steps prior to collapse.

I agree, it would take a heck of a blast to throw someone like that.
 

Jraef

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I would wager if it was horizontal then it was just a case of an injured man staggering for a few steps prior to collapse.

I agree, it would take a heck of a blast to throw someone like that.
He fell off a ladder.
There was an arc blast though, it gave another worker a severe sunburn and knocked a third one into a pit of some sort or out of the cab of the backhoe, the reports are conflicting on that point.
 

Tony S

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All I can say is, I hope non of you have to pick up the mess after an arc blast. Sunburn? try metal embedded in flesh, it’s not a pretty sight.

So, was it coincidental that a transformer failed at the same time as a rod was driven in?
Did vibration from driving the rod cause the failure?
Tap changers do not like vibration, was that the cause?

Things we’ll never know until the incident report is filed which no doubt will be a fudge. You may call me cynical, I was first on the scene for the episode in the first paragraph, the report was a different story.
 

Jraef

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I have friends in the business up there. It appears they know for sure that they pierced a 25kV primary feed to the transformer. What they don't know is why it was not in the location that the drawings said it was (which I think happens a lot).

The the jack hammer they used to drive the ground rod was attached to the bucket of a backhoe and the force of the explosion jerked the arm rapidly, throwing the operator out of the cab and knocking the one guy's ladder out from under him. The one that was burned was just nearby and exposed to the flash only. He was treated for the first degree burn at the scene but was admitted to the hospital for observation anyway as a precaution.
 
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