Crane hit power lines today

[Loadstar]

Putting equipment on roof today. Crane was in front of building reaching to back. There were lines above the roofline directly behind building. Last unit was set and operator was signaled to begin retrieving boom. I was guiding the chains away from the equipment and they started going towards the line. Operator was extending boom instead of retracting! I tried to keep the chains back but it began lifting me so I let go and I barely hit the roof before he sent them into the lines. When I collected my wits after the massive arc flash I quickly got up to run to the roof edge to make sure nobody on the ground was dead. Operator stayed in cab, stayed calm, and got it out. Luckily ground crew was 20ft from crane. Nobody was hurt, just a lot of blank stares.
Just remember to watch those lines and stay away from equipment that could potentially engage them. If someone was touching an outrigger they would have died. Electricity had no issue passing through that crane, through 8" thick timbers under the outrigger, and into the concrete to complete the circuit. Attached is a picture of the burn mark in the new concrete where one of the timbers was.

[texasjohn]

wow! scary!

[groundcover]

Wow is right ! Glad everyone is ok !

[kebo]

Glad no one was hurt!!! What line voltage was that, do you know??

[jaotguy]

a dump truck was lifting the dump and touched the overhead 3 phase wires ... set the truck tires on fire and knocked out the hydro for 4 hours.

driver was OK but the fire dept and police weren't too happy. BTW it was quite a light show !

[Loadstar]

I think they were around 10Kv.

[Mace Canute]

They are so lucky no one was killed or even hurt. Electrical burns are the very worst burns and sometimes never heal, even after decades.

That's likely going to be very expensive for the crane owner. High amperage like that can cause a ton of damage that isn't visible and only shows up after a bit of time has passed. It can easily damage the steel in hydraulic lines and wheel bearings are very susceptible to being annealed at the contact points. The cable itself isn't to be trusted anymore and most definitely should be changed out.

Over the years working for the provincial power utility I've seen quite a few contacts to power lines mostly with 14,400V and 41,600V to ground with amperage up to several thousand amps. Lotsa watts! I saw the aftermath of a gravel truck hitting a line with the raised box, it blew the rear tires out and the air blast blew gravel on the road with such force that a van parked close by was peppered by the small rocks so badly it looked like somebody had shot it hundreds of times with a fairly high powered pellet gun. It took out all the windows that were in the "line of fire"!

[DKCDKC]

Around here most folks call the utility and have a line de-energized if it is too close to a work area. It's a pain and a delay, but a lot cheaper than killing someone or damaging equipment.

[Loadstar]

Around here we do too. We were at the boundary for it nobody planned on the operator extending the boom.

[CliffordK]

The operator was probably relatively safe because being in the cab, his body would not have been a better path to the ground than all the metal around him.

At my old job, if an accident such as that happened, it would mean an immediate drug & alcohol test for the whole crew working in the area.