Mobile crane collapses while installing billboard, with possible dozer assist - GIF

**Jon** · Dec 25, 2018, 01:02 PM

Mobile crane collapses and flips upward while installing or adjusting billboard. The real mystery here is what's going on with that dozer in the lower right? Were they using a dozer to counterweight a crane, and then something went wrong?

Previously:

https://www.homemadetools.net/forum/...209#post115950
Heavy lift ring crane - video
Ferry crashes into crane, crane explodes - GIF
Motion compensating crane for moving cargo containers at sea - GIF
Skid steer dangling from crane, breaking concrete - GIF

**bruce.desertrat** · Dec 25, 2018, 04:59 PM

Honestly it looks like they were lifting the front of the crane with it. Maybe the winch on the crane was jammed, and they were trying to lower the billboard the last few feet into place?

**Frank S** · Dec 25, 2018, 06:00 PM

No if you use the full screen you can see the loader bucket fall slightly after slipping off of the outrigger and breaks off the foot.
It is also clear that they were removing the billboard as just before the calamity happens 2 guys can be seen casually descending the ladder.
@7 axles this was no small crane 125 to 175 ton range at least.
I also noticed that they had the boom extended way farther than needed. judging by the lay of the land I believe the cane could have been several feet closer even with the boom elevated all the way up as it was but retracted about 20 feet would have made all the difference in the world in making that pick. Plus a million dollar crane and a multi million dollar home or building would not have been damaged

**cmarlow** · Dec 25, 2018, 06:10 PM

What we have here is a failure to calculate.

**rossbotics** · Dec 26, 2018, 05:52 AM

Oh My !

Doug

**Toolmaker51** · Dec 26, 2018, 10:16 AM

Originally Posted by Frank S

No if you use the full screen you can see the loader bucket fall slightly after slipping off of the outrigger and breaks off the foot.
It is also clear that they were removing the billboard as just before the calamity happens 2 guys can be seen casually descending the ladder.
@7 axles this was no small crane 125 to 175 ton range at least.
I also noticed that they had the boom extended way farther than needed. judging by the lay of the land I believe the cane could have been several feet closer even with the boom elevated all the way up as it was but retracted about 20 feet would have made all the difference in the world in making that pick. Plus a million dollar crane and a multi million dollar home or building would not have been damaged

Oh you and your 36" or dual monitor guys...Can't see crane outrigger fully. Impression is he had been trying to counter lift of the steering end of crane. But my little knowledge of dozers says, according to the cylinder arrangements, their power is in the lift not resistance to pressure underneath. Boom angle I can't explain, why they aren't more perpendicular to front of sign and therefore vertical as can be with less extension?
If this was completely manual jib or derrick, nobody would be so far off the plumb line. Physics are physics.
I'll bet the crane operator stands on a street corner these days, spinning a pizza sign or wearing a hot-dog costume.

**Frank S** · Dec 26, 2018, 10:36 AM

Just to be clear it is a loader not a dozer from the size relation to the rubber tires I would say possibly in the Cat 966 of John Deere 640 size range

**PJs** · Dec 27, 2018, 11:17 AM

I can see the far side stabilizer @ :14 when the crane is more vertical. Not sure but it looks to me like the bucket is between the front wheels as I can see bucket in front (this side) of the outboard wheel. Either case someones got hell to pay for bad choices.