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RE: Proposed Standard of Care "again"[Subject Prev][Subject Next][Thread Prev][Thread Next]
- To: "'seaint(--nospam--at)seaint.org'" <seaint(--nospam--at)seaint.org>
- Subject: RE: Proposed Standard of Care "again"
- From: "Sherman, William" <ShermanWC(--nospam--at)cdm.com>
- Date: Wed, 4 Oct 2000 20:13:47 -0400
Paul Crocker: Thank you for your comments. Much of what you've said is true - but I don't feel that changes the benefits of what I've proposed. Below are some responses to your comments. > You seem here to equate "unchecked" with erroneous. I believe that it is frequently true that "unchecked" equates to erroneous. I have been involved with checking of structural calculations for over 25 years and rarely find a calculation that does not have errors. Errors may include math errors, erroneous assumptions, misapplication of design criteria or code requirements, design omissions, misapplication of design methods, etc. More experienced engineers tend to make fewer mistakes but no one is immune to mistakes. It is true that not all calculation errors result in significant changes to the resulting structural details but often design changes are required as a result of such errors. > Many of the notable structural failures throughout history were checked by a > number of different engineers, each of whom failed to see the problem for a > variety of reasons. I too have seen designs which have been "checked" which still have inherent errors. I feel we can relate engineering checking to field inspection of construction. Little or no inspection/checking will increase the probability of defects getting thru; frequent inspection/checking significantly reduces the number of defects which get thru; but nothing is 100% effective. Others have recently pointed out that Structural Engineers are responsible for the safety of their designs to protect "thousands of lives". Having defined checking requirements is a small price to pay for this protection. > In that light, I'm not sure on what basis you assume that the designs you > reviewed were "unchecked" unless the engineer's design methodology came out > in a later court case. Perhaps the engineer who checked them also missed > the error. Yes, I have often "assumed" that submitted calculations were unchecked. This assumption was based on the fact that there were no checker's marks on the calculations, if there was a space for a checker's initials on the calc sheets it was not filled in, and there were readily apparent errors in the calculation which affected the results. If the calculation was checked, the checker did not do a good job of it. > In some firms, checking "flows downhill" and thus each level that it passes > through is less capable of finding problems than the one that they received > it from. "Checked" is a very broad term in that sense. I concur that the "quality of checking" can vary according to interpretation and application. But requiring some level of checking is at lease a start. > Like anything else, the reputation and resume of the firm tell more about > their work than anything else. Even if a specific regiment of checking was > mandatory, you would still see wide differences in the standard of service > offered by firms based on staff experience, staff level of education, level > of continuing education, workload and overtime, software used and experience > with it, office conditions, and even general temperment. Checking is > crucial, but it is a long way from assuring a uniform level of service from > different firms. All of this is true. Quality of construction can also vary depending upon the contractor one hires - but field inspection is still a good idea whether you have a "good" contractor or a "bad" one. Even within one engineering firm, quality of design can vary by the individual. In the case of contractor submitted designs, I don't have a choice in "who" the contractor uses to do the design. So again I would ask: Can I require that the contractor's engineer have their calculations checked by a qualified person other than the preparer if it is not explicitly in the written contract? What "standard" can I point to when I receive an "apparently" unchecked design?
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