Official 2015 NFL News and Notes for Offseason Non FA Non Draft

[Patler]

Yes. High wind blew over a crane that should not have been operating in the conditions of that day.

Three men died, and a statue outside Miller Park commemorates them.

For anyone not interested in machines, physics and the like; don't bother reading the rest of this, because I am going to drone on about the accident a bit. I followed the accident investigation as close as I could. I still read articles about it, when I find a new one. I am fascinated by it.

This wasn't just "a crane", it was the largest mobile crane in the world. As tall as a 50 story building. Using it required building runways for it to travel on, because the counterweight alone, not including the crane itself, was something like 2 million pounds. They were lifting a 500 ton section of the roof, which actually was an "easy" lift for the crane weight-wise, depending on conditions, crane configuration for the lift, etc. The crane collapsed, it wasn't blown over by the wind. Everyone agrees that wind was a factor, but it was very likely not the only reason, as is often the case in catastrophic failures.

[pbmax]

I thought the final verdict was that no lifting should have been done that day due to wind velocity?

[Joemailman]

I thought the final verdict was that no lifting should have been done that day due to wind velocity?

I remember an article in the Wausau Daily Herald after that happened. They interviewed some local crane operators. The consensus was that they wouldn't have been lifting anything with the kind of winds they had in Milwaukee that day.

[Patler]

I thought the final verdict was that no lifting should have been done that day due to wind velocity?

I think most, if not all, agree with that. However, the complete failure of the crane itself probably was not solely caused by the wind. Lifting in winds can be unsafe, but not because the crane will collapse. There are lots of issues about load stability and the like, which can be extremely dangerous for workers, but not because you expect the crane to collapse, especially with the load not being near the cranes capacity.

More than likely, the wind set into motion a string of events that caused the collapse. Other issues mentioned include:

• Unstable areas of the crane runway, which caused them to move the location, and required a higher lift and longer reach.
• A broken water main that no one can say for sure if it broke before or because of the crane collapse. If before, it may have caused the runway issue.
• The use of a softer material spacer in the kingpin assembly. The king pin is solid steel, a foot in diameter and 10 feet long. It is primarily a pivot point, but also bears the weight of side loading. Credible evidence indicated the first loud snap heard on video of the accident was likely the spacer shattering. The second bang was the kingpin dislodging, Thereafter, the crane collapsed.
• A malfunctioning anemometer on the crane at a critical elevation.

They should not have lifted because of the wind, but if all else had been right, would the crane have collapsed? Maybe, maybe not. Maybe the only result would have been an unsuccessful lift and an aborted attempt.

The issue that has always intrigued me is the decision to use a half inch thick spacer ring of softer material in the kingpin assembly. Had that not failed, would the collapse have occurred? Without side loading because of wind it might not have mattered. Secondarily, did a soft runway increase the side loading problem? I'm not sure anyone knows the answers to these questions.

It was agreed that the lift should not have been performed because of the wind, but did the result have to be a complete collapse of the crane?