Tires Explode After Power Line Contact

[Jim Patterson]

Tires may explode after contact with power lines. We are a utility contractor, and on two occasions, tires on our subcontactors' dump trucks have burned after contacts. In researching this, articles and accident reports state that after contact, the vehicle should be left sitting in an open space and no one should approach the unit for 24 hours. However, I can not find the source for this recommendation. Anyone know who promulgated this warning?

 

[RUWIREDRITE]

Cool time

Cool time

Jim ,
I dont want to bust on this, but it was just dying for a post.
I think you must wait 24 hours for the smell of the guys shorts who got hit by a live one exploding the tires. lol sorry.

 

[mdshunk]

They're probably worried about capacitive charging of the truck, and want time for the potential charge to drain off. This is the same reason we ground our bucket trucks when working near primary, even though the boom is insulated. The truck can still charge up. Lacking time to wait, I suppose you could hang a Mac on the dump truck someplace with an Extendo and drain it off right quick.

 

[realolman]

Tires may explode after contact with power lines. We are a utility contractor, and on two occasions, tires on our subcontactors' dump trucks have burned after contacts. In researching this, articles and accident reports state that after contact, the vehicle should be left sitting in an open space and no one should approach the unit for 24 hours. However, I can not find the source for this recommendation. Anyone know who promulgated this warning?

The subcontractors really oughta quit doing that.

How do you get the truck to an open area and then get out of it?

I don't get the whole thing.

I used to be a lineman and I never heard of that.. would the truck charge up on capacitance on AC? Ours used to have outrigggers.. what would you ground the truck to?

 

[mdshunk]

I used to be a lineman and I never heard of that.. would the truck charge up on capacitance on AC? Ours used to have outrigggers.. what would you ground the truck to?

:-? :-?
How long ago were you a lineman? Who did you work for? Grounding your truck has been SOP for a long time now. Drive your own stake or hang your mac on the leg of the metal structure or the butt ground rod. The bucket trucks either have a grounding bail built under the rear end, or have a ground cable reel permanently built onto them. Never heard of guys getting killed from stored energy in de-energized lines? The semi-con of buried MV cable can still have quite a charge until you ground it out.

 

[realolman]

circa 1973-1977

Never heard of it ... sorry.

The truck will charge up capacitively on AC for 24 hrs?

How would you get it to an open space and get out of it?

 

[mdshunk]

The truck will charge up capacitively on AC for 24 hrs?

How would you get it to an open space and get out of it?

I was guessing that it might take 24 hours to bleed off. Maybe you need to bunk in the truck for those 24 hours? :grin: I'm just speculating anyhow. The 24 hours wait could just as easily be to let the truck cool off from heat buildup.

 

[don_resqcapt19]

I expect that the issue is caused by the fact that the tires are somewhat conductive. When the vehicle is in contact with the power lines current is flowing through the tires and heeting them and the air inside. This will increase the pressure and weaken the tire. The tire may fail as a result. I doubt that the truck acts as a good capacitor storing the voltage for 24 hours.
Don

 

[dbuckley]

I doubt that the truck acts as a good capacitor storing the voltage for 24 hours.

And even if it did, it would hold no more charge than it does with static buildup. And that certainly wont smoke the tires.

 

[robbietan]

those guys probably want to err on the side of safety, hence that '24 hour' rule......

 

[boater bill]

Bryan posted video of a bucket truck with the boom on utility lines a while back. I think the 24 hour wait was for the tow truck to sweep away the ashes.