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.

 

[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.

 

[Renze]

3 years ago the scrapyard in the city drove their long boom clamshell wheeled excavator to a nearby village to get it serviced. It was at a dark winter night, so they rode with the long boom upright in the air to keep it close to the operators line of sight. that would do for the 3 mile drive to the equipment dealer in the nearby village. Unfortunately they forgot about the power lines crossing the road, which they hit with that boom rising 8 yards into the sky. the boom looked like someone used a torch on it, the electricity just burned metal away. the slewing ring went out within a few months because the balls were pitted because the current welded them to the rings, and within a year they tossed scrap on a heap, when their dipper stick and clamshell grab flew onto the scrap pile, releasing itself from the main boom exactly where these burn marks were repaired.

The next year their insurance gave them money for a brand new waste handler, because they didnt want to keep paying the repairs...