There will be a lot of speculation about this

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This will be interesting to follow--Possible faulty weld cited in New York City crane accident:http://www.nytimes.com/2008/05/31/ny...1crane.html?hp
Reply:“Construction is a dangerous business and you will always have fatalities,” Mayor Michael R. Bloomberg said at a news conference.
Reply:Originally Posted by sail2uThis will be interesting to follow--Possible faulty weld cited in New York City crane accident:http://www.nytimes.com/2008/05/31/ny...1crane.html?hp
Reply:Mt tig instructor does crane repairs for a living. Shortly after the march crane collapse in NY, he was showing the class a section of boom he just removed due to some one making an unqualified repair/addition. Whole piece of high tensile steel (120  ksi+) was a spiderweb of micro cracks that showed up under magnaflux. He went into specific details on how these special steels needed to be preheated and post heated to maintain their strength and that special rod/wire was required. Improper procedures could lead to loss of temper, hydrogen embrittlement of stress cracks in the heat affected zone. I am sure he is quite familiar with the crane company from his comments on the other accident. It's a shame my tig class has ended for the semester. I'd be interested in what his thoughts are on the matter from the stand point of someone who makes these repairs all the time.My guess, is that someone who did not know the required techniques attempted a repair on the old crack, if there was a crack. The steel failed in the HAZ due to cracking of some sort. Purely my speculation based on no evidence, and comments from my instructor on what sorts of things he encounters.
Reply:We are surrounded by ignoance.Just because a man in a nice suit tells you to do something you better find out EVERYTHING and make sure you are doing it the right way. there is no shame in not knowing something and having to look it up.Doctors have to do that all the time.I have been asked to do unsafe and illegal things all the time.I tell the man in the suit he will have to sign a paper to authorize it. They always say "Lets wait and get more info"  See how it works?
Reply:Assuming this all was the cause of the accident, it could be a good illustration of a point made a month or so ago, when somebody was making boat-engine parts, with absolutely no knowledge of what he was doing, but doing it anyway because "the boss told me to".People died here, possibly because "the boss told me to do it" ..........
Reply:Well from what I have read regarding the accident the same machine had recently failed two load tests (apparently shortly before the accident occurred). In addition to the possible failed weld they are also looking at the bolts. I am waiting to see what they come up with. All equipment has a service life and having worked in construction for more than just a few years there are those who will disregard it if it means making a buck. Construction is dangerous, but I would bet it comes down to being a preventable accident.Equipment such as this should be inspected frequently and I am sure there are mandatory inspections. With that said sometimes deficiencies are purposely overlooked. I went on a call once to install a wellhead. This is done on the surface casing of oilwells. You do this under a drilling rig as there is still a lot of drilling to go once the surface has been set. Anyhow, I got down in the cellar and looked up at the substructure (this supports the entire rig as well as the drill string which is measured in thousands of tons hanging on the blocks), and this was a rather large rig. What I saw was I beams that had the entire bottom flange as well as portions of the web completely rotted off. Definitely would not have passed any inspection. When I got in off the job I told my boss to never send me out on it again because it was going to collapse. They finished that hole and on the very next one they were setting casing (probably intermediate or long string as they don't generally use a casing crew on surface) and the rig collapsed killing almost every man on the casing crew and mangling those it didn't kill. I can't remember if it got any of the rougnecks, but if they were under it or on the floor I'm sure it did.  I turn down jobs all of the time that are out of my area of expertise, that I am not properly equipped for, or appear to me to be a possible danger to myself or others. One mistake is all it takes to destroy your business.Last edited by Jolly Roger; 06-03-2008 at 05:47 PM.Reason: Additional contentThe difference between art and craft is the quality of the workmanship. I am an artist.
Reply:You know, many times a part can handle the load it is meant to carry, under its' normal circumstances, and have a good dose of cushion capacity built in for safety. But, then add things unseen, like a heavy gust of wind, a heavy lateral load not anticipated, etc. and the part will hold, but it will be weakened. And then, though it looks good to go, it will fail under a relatively minor load at some later date. This is more prevalent in heavily tempered materials, and in aluminums, which have less memory and much less spring qualities in the material. I busted quite a few motorcycle chassis when roadracing, frames that were never crashed. They just eventually failed. Some cracked slowly, some let go really fast.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Originally Posted by mark8310Assuming this all was the cause of the accident, it could be a good illustration of a point made a month or so ago, when somebody was making boat-engine parts, with absolutely no knowledge of what he was doing, but doing it anyway because "the boss told me to".People died here, possibly because "the boss told me to do it" ..........