08.10.2019

California crane overturn UPDATED

An All Terrain crane overturned in a residential area of Long Beach, California yesterday.

The crane a five axle Grove GMK owned and operated by local crane rental company Bob Hill, had been working with local utility SoCal Edison and was lifting a fully rigged wooden telegraph pole, into the back yard of the homes, when then crane went over. Its fully extended boom came down across a number of properties, but miraculously it missed a good number of the tightly packed buildings, by falling between them. It did however bring down some of the power lines.
The overturned crane


One man – a homeowner - was struck, apparently by flying debris and suffered a cut to the head and a couple of broken ribs but we believe he was discharged from hospital last night.


Several cranes were brought in to recover the overturned machine, with the boom cut into sections and removed. Last night the neighbourhood was getting back to normality, with the power restored and most of the overturned crane removed.
It seems from the information we have received that the incident is related to the crane being short rigged on the load side of the lift. It looks as though the front – retracted – outrigger jack, just slipped off the cribbing and overturned. Although it must be said the beam could have retracted when the crane tipped forward?
Close up of the front lift side outrigger


We will of course update this item, if and when we learn more.
Raw video footage below shows the full extent of the incident.


UPDATE

We managed to track down the closed circuit video footage of the crane overturning and it confirms that the crane was indeed set up with all four outriggers beams fully extended, and that the rear load side beam retracted as the crane began to tip forward. This indicates that the crane was overloaded for the boom and counterweight configuration being used, and that the incident was not related to the outrigger set up at all.

Comments

Pemby
bdunham
Looks like its a 5130 (it has five telescoped sections)...
Looks like they're using: 2,5t baseplate, 2,5t slab, 5,0t slab, 2x 3,75t slabs and the second hoist instead of 1,0t plate for total of 18,5t ballast configuration.
The 5130 with 18,5t boom configurations based on 1,0t, 2,0t and 4,0t loads:

50,71m boom length 1,1t to 46m radius - best radius for 1t
60,00m boom length 1,0t to 42m radius - full boom

45,99m boom length 2,0t to 42m radius - best radius for 2t
60,00m boom length 2,2t to 36m radius - full boom

50,71m boom length 4,1t to 32m radius - best radius for 4t
60,00m boom length 4,6t to 28m radius - full boom

They have all the boom out (does the 130 do 90% pin or is it just ~50% and 100% positions?), so thats 60m. The boom angle looks rather low, lower than 40 degrees for sure. *I dont know what that translates to given several factors but I'm doing best guess from the duty chart... they're beyond the 40m range. because 60m boom, at 40m, gives under-hook height on the chart as 43m. so... 40m on full boom is probably the 45 degree mark... and *there* with just 18,5t ballast, the 130 only has a capacity of **1,4t.** It's maximum radius is 42m!!!

The maximum ballast on a 130 is 40,1t, and with full boom, this extends the radius' for 1t, 2,2t and 4,6t from 42/36/28m to 56/50/40m! Thats +14/+14/+12 metres extra!

Given a 4t maximum load, on 40,1t ballast, a boom length of 55,39 would net a maximum radius just shy of 44m, 2 metres more than full boom.

The above is what happens when they don't know what they're lifting weighs beforehand, nor look at the duty chart to get the best duty... and the planners haven't accounted for ballast.
Without the cheekweights, that's still 28,5t ballast, so a 4t lump will still go to 36m radius (45,99m length), a 2t load to 44m (50,71).


This is purely from five minutes with the cranes' duty chart on the manitowoc grove website!

9 Oct 2019

bdunham7
There is video available now from a house across the street. It shows the load side outriggers were fully extended and the truck chassis pivoted fully up on them as the boom tipped, then they collapsed by sliding in as they obviously aren't designed to hold a load in that direction. There wasn't much load, so it would seem insufficient counterweight would be the issue--can anyone tell by looking if there was room for more?

9 Oct 2019

Pemby
I do think that the riggers came in once it began overturning. Perhaps that rigger begna to sink, or the mats gave way (too old?)

8 Oct 2019

Sherm
The photos are excellent. Tremendous torque/force was needed in the lift to prise the fr. left tire from it’s wheel. Shame this happened. Investigation follow-up will be interesting to learn...looks like insufficient planning for crane capability and counterweight need. Time will tell.

8 Oct 2019

Tmayes
Clearly the operator hadn’t read Mike Ponsonbys letter the other day or this wouldn’t of happened lol

8 Oct 2019
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