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u/PM_ME_A_NUMBER_1TO10 9d ago
It's always morbidly fascinating how soft things look once there's some dynamic forces involved. They barely move when under the expected loads, but once it collapses it flops like a wet noodle.
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u/cmad182 9d ago
I asked a mate of mine who's a crane operator how this could happen, this is what he said:
Ok…. So, all cranes have limit sensors in them like all machinery. Most of them in cranes have to do with overloading and such in front of the crane. However every crane has a maximum boom angle, which is also controlled by a sensor. You are correct, for that to happen, the operator would have had to hold to override key to boom up that little bit more. Typically the allowable boom angle for that type of crane would be between 78 and 80deg MAX. Reason for doing this is to reach something that’s too close to the crane…. So instead of relocating the load, old mate has done the ol’ she’ll be right I’ll get it and gone too far. Again, cranes are designed to keep the boom from tipping forwards, there generally isn’t much in the way of design to stop the boom from tipping backwards.
Basically, override key and stupidity
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u/badknitter 9d ago
Thankfully everyone okay, crane operator was eventually able to self evacuate with High Angle Rescue team on standby.
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u/stanleymodest 9d ago
Is it pronounced Derri-MUTT (like a dog) or Derri-MOOT (like a bogan girls growler)??
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u/CO_Fimbulvetr 9d ago
The former unless everyone here is collectively wrong. Wouldn't be the first time coughtruganinacough
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u/Global-Plankton7150 9d ago
Its a Favco500...they have Deadman switches whenever it gets to Max on any of its outer limits....there' doesn't seem to be any cable in the boom..I'd say it's lost its cable, whether snapped or drum brake kaput, then boom may have Counter bounced and hey..the first ever Crane scorpion
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u/VanillaIcedTea 9d ago
That's gonna be a fun clean up for someone. Glad it sounds like nobody got hurt.
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u/March_-_Hare 9d ago
Damn I saw “Derrimut” and “collapse” and initially assumed this was about the gym. That crane operator’s gonna have a helluva story to tell for years to come.
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u/CuckGunn79 9d ago edited 9d ago
I've been a Rigger for 27 years and I've never seen a boom break off like that. The driver jibbed up to high then the wind pushed the boom the backwards
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u/HobRob-Biscuits 9d ago
Sent this to my landlord, who's on cranes. Said that's the third accident in that particular site.
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u/IWHBYD_skull 9d ago
I'm not crane engineer but the only way I can think how this would happen is if the crane arm was up at a high angle, released or even lost a load near its maximum weight too quickly. The recoiling forces could flip the arm over backwards. Any way the investigation concludes someone is getting fired or worse.
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u/Super_Human_Boy 9d ago
Looks to me like the boom went over backwards.
I saw this happen to a tracked crane many years ago. The operator jumped out of the cabin to talk to the foreman and knocked the lever as he got out. While they were talking, with their backs to the crane, the boom continued to climb to the vertical and boooom, it went over backwards. It made a hell of a mess and just lucky no one was in the way.
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u/CO_Fimbulvetr 9d ago
I am suddenly significantly more worried about the crane quite close to my house.
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