Wednesday, November 10, 2010

September 10th, 2008

Koksijde Brussells A counter jib for a tower crane snapped while being handled killing one man and breaking the hip of a second. The accident was immediately blamed on metal fatigue by the Office of Verune.

The crane appears to be going up. The pick points used look to be substantial and the counter jib is being lifted off of the truck apparently to have it fully unloaded while all of the horizontal structure is prepared to be erected. Often when you have counter jibs consisting of one piece the pick points end up being a wide spread. It would seem that the only things to take away from this in the field is to not choose the widest pick points for stability purposes, and when you ship the piece, be certain that the center of gravity is well supported. If you send a counter jib down the road over bumps, speed bumps and more with no support under the Machine Package, over time it will be weakened. Inspectors should be sure to look at the beams for cracking and stress as well. Sight down the beams to make sure that they aren't twisting or developing creasing as a tell-tale that the stress has weakened the structure. There doesn't seem to be much else to beware of other than to be clear enough of the piece in the event of failure.

Sometimes the accident doesn't have anyone to blame, just ways to be sure that you are protecting yourself. Link to story  

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