Truck + 7200V goes all wrong

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

BobL

No longer addicted to AS
AS Supporting Member.
Joined
Feb 25, 2007
Messages
8,003
Reaction score
4,418
Location
Perth, Australia
Apparently this happened near a place called Mill Creek in WA.
I think the pics tell it all.
attachment.php

attachment.php

attachment.php

attachment.php

attachment.php
 
Marshmellows anyone? It sure blew those saddle tanks appart. Hope the driver got out OK. Is that a wire going up to the power lines in the pics? Wonder if that is what started the fire but the lines look plenty high and shouldn't even come close to the truck unless a loader pushed the lines into it...
 
Marshmellows anyone? It sure blew those saddle tanks appart. Hope the driver got out OK. Is that a wire going up to the power lines in the pics? Wonder if that is what started the fire but the lines look plenty high and shouldn't even come close to the truck unless a loader pushed the lines into it...



Smores anyone????

jerry-
 
This happened Wednesday, July 23rd 2008, out in Mill Creek , WA.

The driver was attempting to throw the logging cable over the logs to secure them.

As you can see, he hooked the electric line instead!

He said the tires began to fry within seconds. A very lucky man he could easily have been fried himself!

Thanks to Sam Latham at Broad River Energy Center for sharing this information.
 
This happened Wednesday, July 23rd 2008, out in Mill Creek , WA.

The driver was attempting to throw the logging cable over the logs to secure them.

As you can see, he hooked the electric line instead!

He said the tires began to fry within seconds. A very lucky man he could easily have been fried himself!

Thanks to Sam Latham at Broad River Energy Center for sharing this information.

Thanks for the extra details CT. The pictures were just sent to me in an email with only a few details.
 
i'm surprised that there was a high voltage line that low on the pole. typically the actual power phase lines are very high up and the lower lines are guy wires/cable tv/etc. those lower lines are waaay low. anyways, that dude is definitely lucky to be alive. two summers ago in madison we had a big summer storm that took down some lines on the north side of town. a woman and child were riding a city bus and stepped out into a puddle of water or saturated ground that was now live because of the downed line. as soon as they stepped off the bus they were electrocuted. another man on the bus tried to rescue them and met the same fate. all three died. high voltage is serious stuff. those linemen do not make enough money in my opinion. stay safe. :(
 
Last edited:
I've been to quite a few "wires down" calls at work. There's nothing quite like watching a high voltage line melt asphalt ..... Except watching a high voltage line melt dirt. Turns to a lava like substance. Very impressive to see. :jawdrop:
Lou
 
We used to have classes in aerial rescue. Now if the area is possibly energized, they call it aerial recovery. Don't attempt rescue untill power is shut off, Joe.
 
That is what we call close it is a good thing he escaped looks like more than 7200 though only one phaze was hooked. It is a good thing the one to the side of it was not the one hooked the one that has all those bells on the insulator. Anyway gotta watch out those lines run un-fused it either blows the sub station transformer or is opened up at the closure. Sometimes knife blades can be opened before the sub not always. Many times people are electrocuted escaping that scene through the ground.
 
A friend of mine has a signature that goes like....

Teach a man to fish and he'll never be hungry,
Teach him how to make fire, and he'll never be cold.
Set him on fire and you'll both be warm.


Doesn't sound as if anyone was hurt physically, which is good.
 
Why would the rubber tires have not kept the vehicle from grounding?

Something just seems wrong.... After all, I have seen(yup, with my own eyes) cars with electrical wires laying on them and no fire.




Scott (photoshop'd maybe) B
 
That much voltage would have leaped from the cable to the upright on the trailer. Definitely close enough.
 
Why would the rubber tires have not kept the vehicle from grounding?

Something just seems wrong.... After all, I have seen(yup, with my own eyes) cars with electrical wires laying on them and no fire.




Scott (photoshop'd maybe) B

Well that is more of an electrical engineering question but in my experience I can give a semi educated guess. High enough voltage will arc which is why climbers and linemen have minimum separation charts to follow. It would be my bet the arc started at the axle pumpkin or the radial tires. It would begin at the closest metal to ground and build from there! Humidity, dew etc. all come into play as well, fortunately the man survived.
 
Why would the rubber tires have not kept the vehicle from grounding?

Something just seems wrong.... After all, I have seen(yup, with my own eyes) cars with electrical wires laying on them and no fire.

I'd say there are two factors involved.
Tyres are not just made of rubber and Truck tyres contain some different carbon compounds compared to car tyres .


There is a voltage difference effect.
At 7200 V, if there is enough moisture in the soil and across the surface of the tyres together with the different carbon compounds in the tyres conduct enough current to generate enough heat to start to decompose the rubber. As soon as the steel belts in the tyres hit the road there would be an even greater current, then the steel cable would really heat up and set fire to the logs.

At 110 V, or more (I have seen a live 440 V cable sitting on a car) there is just not enough current thru the tyres to heat the tyres to decomposition temp.
 
Last edited:

Latest posts

Back
Top