Tuesday, December 30, 2008
Hunan Province China. A tower crane collapsed into a hotel parking lot killing 3 and injuring 5. All cranes in the district were shut down and ordered to be inspected. As usual I am unable to find pictures at this time from a Chinese accident.
Posted by Gaytor Rasmussen at 7:57 PM
Monday, December 29, 2008
New York NY,
The corruption problems in New York continue. Those of us in the US know that Chicago and New York are largely run by those whom have no respect for ethics. Yesterday's story of Michael Carbone having been an employee of James Lomma then making decisions about the suitability of repairs performed by him is an example of questionable ethics. I would suggest that in a case where an engineer (Bethany Klein http://www.nydailynews.com/ny_local/2008/11/17/2008-11-17_she_warned_of_crane_disaster_buildings_d.html
has raised a question in regards to the performance of a repair, the final decision on the repair should be made by someone without ties personally or professionally to the person or company that will be impacted. It's possible that Mr. Carbone was acting as ethically as he knew how, but this is exactly why judges recuse themselves. New York not only needs an overhaul of it's crane and elevator programs, it needs an overhaul of all of it's ethics. The nepotism is rampant and now resulting in the death of people.
Posted by Gaytor Rasmussen at 6:46 AM
A hotel in Sydney was evacuated after concern was raised about the stability of the crane. Upon review the crane was declared safe. I've heard of this coming up a few times in the last year. Cranes have back moment towards the counter jib side, no matter what direction the crane is swung over. Many maximum free standing cranes could lean off of center line plumb up to two feet due to the ductility of the steel. Cranes need to be erected in the US to a tolerance of 1 inch for every 40 feet of vertical, but the weight difference between the counter jib and ballast versus the jib's unloaded weight causes it to lean back. It's good that people are observant enought to notice this but rather than raising the red flag and running away it might be prudent to verify the deflection with a instrument such as a theodolite and the manufacturer's advice. Take a paper clip, straighten it out, hold it straight up and down and bend it a milimeter out of straight and let it go. It returns to vertical and that is an example of ductility. You'll find that you have to move it a quarter of an inch or more before you have permanent deformation and eventual buckling. We've had a good end to the year so hopefully crane safety is making strong strides or the economic slow down has pushed those not qualified out of the industry.
Posted by Gaytor Rasmussen at 6:31 AM