$4 million right off

[Rolyd8k]

friend Robbie e-mailed me this last week
[img]There’s a valuable lesson in here men in regard to the importance of always ensuring appropriate engineering input into satisfactory load dispersion when establishing mobile cranes.

As per the attached photo’s, this was a nasty incident on a project out at Castle Hill last Friday.

As we’re all aware, “thorough investigation into load dispersion and back-propping requirements is vital when establishing a mobile crane unit on a suspended slab to eliminate any potential for failure of the supporting deck.”


Incident: Friday Morning 26/09/08 – Castle Hill/Sydney

- 9 Day Old 250t Leibherr Crane (never used before)
- $4mill price tag
- Failure of back propping beneath the 200mm thick concrete deck
- Crane support outrigger punches through slab causing crane to lose balance and collapse across the site and onto adjoining property
- Crane balanced in the air for approx 1 hour before entire rig & boom collapse completely across site and rigs falls through to the basement level.

Amazing that no-one was seriously injured or killed.

Please take a moment to learn from one of our competitors unfortunate mistakes.[/img]

[BulldozerD11]

Very good Roly

Definitely a lesson in how not to do it.
The have a massive grillage under the props and then no bracing or top grillage/spreaders.

Should use tressels., like for bridge decks or roofs. (the crane may be a bit big as well for that slab just driving it into position)

SCAN0146.JPG

The Needles are 250 UC sections. (its only got 3 floors above it).

oh and a sewer, storm drain, HV electrics, BT, and a watermain below ground. (and restricted access)

Just had to squeeze a 14 mtre girder in one side and a 8 tonne one at the back and a few misc bits of trimming steel between the props, grout it up and strip the props.

Nice little simple job.

Dave

[John Gaunt]

What a mess, would be interesting to see how they set about recovering it.

[§wishy]

Martin Haz hiz ear to the ground n sez:

Well they say a picture says a thousand words and this is the facts.
1.This was the 5 th trip to site to do this job .
2.26 of the panels had been stood up in the previous 5 trips.
3.There was only 6 to go.
4.The whole job was palnned by an engineer who had marked on the slab an x to show the placement of the crane.
5.The builder was responsible for propping the slab .As they were in the 5 previous visits.
6.This lift plans and safe work method statements had been approved by the engineers(probably thre same ones who marked x)and the builder.
7.The crane crew were doing as they had done on 5 previous trips except they had a new crane.

Gillespies is a fine family buisiness with a fleet of cranes and a reputation that is envied by the crane world.The owner is tall poppy in the industry and other like to chop the tall poppy but they are a biy jealous of the reputation thy enjoy and probably the rates they get forthe crane hire.

it appears the bracing may not have been up to scratch.This was a bigger crane with the other trips to site done with a 225 tonner and this is a 250 tonner ebut the wortk method was changed to suit and the x on the concrete to show the crane crew where to set up was adjusted accordingly.

They pulled it out last Sat with a 400 tonner and a 225 tonner.Both up on the slab.
On a site next door to that there is another 200 tonner up on a supended floor lifting panels as this one was.


The biggr the gear
The biggr the F.U.

cya
§wishy
HasBeen