Well, it's happened again. A second major stage roof collapse in North America in less than a month, this time at the Indiana State Fair, and this time resulting in five deaths and over forty-five injuries.
http://www.snap1037.com
What I keep reading in "statements" from the stage roof suppliers in all these and other cases is that they claim the collapses were caused by sudden gusts of wind that exceeded design limits. What also seems to be common is that at these locations, many other tents in the general vicinity have remained standing and unharmed. So what is going on? There are a couple of possibilities:
1. The design of the stage roof does not meet the standards of ANSI E1.21 - 2006 regarding wind loading as well as other support requirements.
2. The wind really was higher than expected and also there was insufficient time to remove roof components to prevent damage.
At least initially, my thought is to ignore possibility #2 and focus on the design of the structure.
Now I come from an engineering background so this stuff is pretty important. While in the Air Force, I was assigned to investigate two aircraft crashes in the course of my career. The first thing that happened when an aircraft went down was that all the flight and engineering logs of that aircraft were immediately impounded pending a formal investigation. I recommend that our industry (special events) initiate the same requirement for any incidents such as stage roof collapses that result in injury or death. This would require that the event manager impound and demand copies of, all applicable subcontractor documentation for any contractors directly involved with the construction or erection of this type of structure, ideally within no more than two hours of the incident (leaves little time to "cook the books"). This documentation would include such paperwork as contracts with other subcontractors, engineering drawings and calculations supporting the design of the structure and the wind load ratings, proof of compliance with material design standards (e.g. trussing, roof fabric), and proof of compliance with personnel safety regulations.
There is another issue involved here and that is the difference between what is required by law and what is voluntary. Usually, within a province or state, personnel safety regulations are enforceable by law, whereas standards are only voluntary. That subtle difference may make a gigantic difference in these latest cases when it comes to litigation and placing blame as well as claiming damages.
My soapbox - and this is a continuing theme in my books - is that compliance with standards should be written into all contracts so that everyone from the event manager down is covered as much as possible with respect to disasters. This is what proper risk management is all about, and it makes the compliance legally enforceable under the terms of the contract.
It will be interesting to see what the investigations dig up in all these recent cases
http://www.snap1037.com
What I keep reading in "statements" from the stage roof suppliers in all these and other cases is that they claim the collapses were caused by sudden gusts of wind that exceeded design limits. What also seems to be common is that at these locations, many other tents in the general vicinity have remained standing and unharmed. So what is going on? There are a couple of possibilities:
1. The design of the stage roof does not meet the standards of ANSI E1.21 - 2006 regarding wind loading as well as other support requirements.
2. The wind really was higher than expected and also there was insufficient time to remove roof components to prevent damage.
At least initially, my thought is to ignore possibility #2 and focus on the design of the structure.
Now I come from an engineering background so this stuff is pretty important. While in the Air Force, I was assigned to investigate two aircraft crashes in the course of my career. The first thing that happened when an aircraft went down was that all the flight and engineering logs of that aircraft were immediately impounded pending a formal investigation. I recommend that our industry (special events) initiate the same requirement for any incidents such as stage roof collapses that result in injury or death. This would require that the event manager impound and demand copies of, all applicable subcontractor documentation for any contractors directly involved with the construction or erection of this type of structure, ideally within no more than two hours of the incident (leaves little time to "cook the books"). This documentation would include such paperwork as contracts with other subcontractors, engineering drawings and calculations supporting the design of the structure and the wind load ratings, proof of compliance with material design standards (e.g. trussing, roof fabric), and proof of compliance with personnel safety regulations.
There is another issue involved here and that is the difference between what is required by law and what is voluntary. Usually, within a province or state, personnel safety regulations are enforceable by law, whereas standards are only voluntary. That subtle difference may make a gigantic difference in these latest cases when it comes to litigation and placing blame as well as claiming damages.
My soapbox - and this is a continuing theme in my books - is that compliance with standards should be written into all contracts so that everyone from the event manager down is covered as much as possible with respect to disasters. This is what proper risk management is all about, and it makes the compliance legally enforceable under the terms of the contract.
It will be interesting to see what the investigations dig up in all these recent cases
Whether wind speed was higher than expected is not of much solace to the dead and maimed.
ReplyDeleteEven though wind force varies with the square of wind speed, a structure designed (with appropriate safety factor) for 50 mph wind should easily withstand 70 mph wind (and greater) without total collapse.
Per news reports, neither the State Fair Commission nor any other state authority required a permit or inspections for this very large structure that anyone with not even half a brain should have known could cause death if it were to blow over when thousands of persons were in the vicinity.
Key questions that remain are; (1) Who (if anyone) was responsible for design of the assembled structure to resist wind?, (2) Were plans produced to specify complete construction, especially for wind resistance? and (3) If there were plans......did peron responsible for construction install the stage roof per plan requirements?
Thanks for the comment, John. You are spot on. I think those are going to be the big questions surrounding all of this summer' collapses. The standards are already in place. I suspect that either nobody knows about them or event organizers have chosen to ignore them, as have city/state/provincial officials.
ReplyDeleteI agree, a structure designed for 50 mph wind should easily withstand 70 mph wind (and greater) without total collapse. Tragic that life was lost.
ReplyDelete