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My boss says look the other way?
17

My boss says look the other way?

My boss says look the other way?

(OP)
I am a structural engineer and have been working for over 30 years analyzing transmission towers and poles that support wire.  My boss is an Electrical Engineer with a PE.  His boss is a business major. The Vice President is a Mechanical Engineer.

The problem is the analysis of towers with a skewed wind angle.  Due to geometry, a wind at an angle will produce maximum loads and cause leg failure.  If the wind is only considered normal to the wires, the legs are OK.

Back in the old days, we did not have the software tools to consider skewed wind.  With better PC's and better software, we can now analyze hundreds of wind angles and determine which wind angle will control.

My EE boss says it is a management decision of risk vs reward and it costs too much to fix the towers when adding more equipment to the tower.  As a PE, I feel it is my duty to inform him that it is my opinion that the tower will fail if the wind hits the maximum design wind speed and at the most critical direction.

The NESC code we work under has some generic guidance that the wind at an oblique angle may cause higher loads.  Guying the tower inline will help brace it and reduce the leg loads to acceptable levels, but it costs more and the construction folks don't like to do it and are concerned with trucks running into the guy wires.

I have been told to ignore the oblique wind direction and allow the extra equipment to be installed on the towers.  I have a few options:
1) State my concerns to the manager and let him decide
2) Run the oblique wind cases and note the failures, then run the normal wind case and note the loads and write a note in the file that the tower will fail in the right conditions.
3) Prepare a letter and have it signed by the EE and his boss that they are aware that the tower may fail.
4) Report my EE boss to the State Board of Registration for ethics violations.

Is it ethical for the EE to order me to look the other way?

_____________________________________
I have been called "A storehouse of worthless information" many times.

RE: My boss says look the other way?

If the modern analysis methods you're using are generally recognized and accepted among peers in your dicipline then you're pretty much going to have to take it to the next level, particularly if you are a licensed PE.

In Texas and Colorado the fundamental basis for licensing is for the PROTECTING THE PUBLIC.  You could be held liable if you don't.  I'd pick through the respective engineering LAWS and quote chapter and verse but that would take too long.  The wording is there though; think wistle blower protection laws.

You've probably already thought beyond the just a tower failure clear though to the guy on the operating table with his chest spread open when the lights go out (no UPS).

Check your engineering law; it should describe the necessary action you should take.  Start documenting everything (gotta love email) but make sure your analysis is valide.  How likely is the bad wind angle? Too bad the NESC code isn't less generic.

Go option 2 just to be sure then go back to your immediate supervisor and keep climbing until you have no recorse but to contact your state board.

RE: My boss says look the other way?

Now that the geenie is out of the bottle i dont think you have any choise to to refuse to stamp the documents (or however this works in the US).

If it is a management decision then it shouldnt be your name on the documents - because im pretty sure that they wont remember the details if an accident should occur and your name is on the document.

Best regards

Morten

RE: My boss says look the other way?

If your calculations indicate it will fail, then you have no choice but to document the findings and report it to management.

What is the wind and angle that will cause failure?  What is the likelyhood of it occuring?  

Greg Lamberson
Consultant - Upstream Energy
Website: www.oil-gas-consulting.com

RE: My boss says look the other way?

Good topic.

Risk vs. Reward:  An analysis needs to be done to find out what the likelihood of that particular wind angle is.  If the risk is within acceptable limits, then fine, but it is a management decision.  You have done your due diligence and I agree with dtn, document EVERYTHING.  Take copies of emails home, print them, put them in a safe, whatever you have to do to protect yourself.

I also agree with Morten, stamping drawings (i.e. taking responsibility) is a personal decision.  Anyone can direct an engineer to stamp something, but the engineer has the right to refuse - without punishment.  It has to be right.

In your case, if the management is satisfied with the risks, then that is their decision and someone else should stamp the drawings who is comfortable.  It is tricky to balance financial obligations with safety.  While I sympathize with your management, safety should always be a prime consideration.

I assume that they have listened to your concerns and reviewed the calculations.  Hopefully it is not a case of them immediately dismissing it.

RE: My boss says look the other way?

Citing Texas "Law" purely as an example:

137.55 ENGINEERS SHALL PROTECT THE PUBLIC
(c) Engineers shall first notify involved parties of ANY engineering decisions or practices that might endanger the health, safety, property or welfare of the public.  When, in an engineer's judgement, any risk to the public remains unresolved, that engineer shall report any fraud, gross negligence, incompetence, midconduct, unethical or illegal conduct to the board or to proper civil or criminal authorities.

RE: My boss says look the other way?

I think one of the issues here is the question of what are the governing codes?  

Does the IBC incorporate by reference the TIA/EIA standards for example, or do any state or US regulations specify transmission tower design?  If there are regulations in force and stamped calcs or drawings need to be submitted to a reviewing authority, then in my opinion the design needs to  meet these design requirements.  If there aren't specific legal codes but there are applicable industry standards then you and your company would have to defend, if there was a failure, why generally accepted engineering practice was not followed.  

Regards,
-Mike

RE: My boss says look the other way?

And that's the point I was making, I agree with sdl, if it is a 1,000 year occurrence that would cause a failure and you are looking at a 100 yr occurence (only an example) for the design, then it is a management decision.  

Assuming it is a management decision, then a risk assessment should be undertaken.  You mention the guys may cause a risk, all of that should be part of the equation.  

Greg Lamberson
Consultant - Upstream Energy
Website: www.oil-gas-consulting.com

RE: My boss says look the other way?

I think Mike has identified the issue correctly.  A risk vs. reward analysis is appropriate only if the there are no regulations, codes, or industry standards that apply.  If there is a design standard, then the design should be evaluated on that basis, either yes it does meet the standard or no it doesn't.

If you sign and stamp an inadequate design as the engineer in charge, you will be held responsible and no memos or letters to management will absolve you.

If there is no required design criteria, then you should calculate the wind speeds and directions that the structure will support and include that information on the plans that you sign.  Then management could dexide whether or not to go ahead with construction.

RE: My boss says look the other way?

With 30 years in the business, let's assume transmissiontowers knows what he or she is doing.  If he didn't, he wouldn't be a PE and still be in that field.

The question originally asked is a matter of ethics, not of his analysis method or approach.  We've all offered our heads-up on being sure there's really a problem.  Now, let's deal with the issue as presented, there's a problem.

RE: My boss says look the other way?

6
(OP)
Didn't want to give too much personal data but I am in Texas and a PE.  I don't stamp drawings or calcs since the work is done for a large Electric Utility for internal use.  We are adding PCS antennas to the top of our towers to generate revenue for the corporation and I have to analyze the tower for the extra loads.  Lattice towers that are rectangular based have a problem with the narrow face not having sufficient leg spacing to resist a wind load on the wide face.  There is a critical wind angle that produces maximum leg compression.

Back in the old days when it took days to calculate one load case and do an analysis by hand, we did not consider the wind at skewed angles because it was so calculation intensive.  With modern software I can run 100 wind directions all around the tower in a few minutes.

We work under the NESC code book which has a few vague statements that an oblique wind may cause higher loads.  With the ability to study the phenomenon in detail, I feel it is prudent to blow the wind all around and see which case is worst then strengthen the tower as required by replacing members or guying inline.

A few years ago, we had convinced the boss's boss that it was prudent to consider oblique wind but he transferred somewhere else and we now have a BA in charge and my EE boss wants to stop using oblique wind.

AFA risk, we design for a 50 year return period storm per NESC and just assume the wind direction can be anything possible.

I'm hoping that I can convince the managers that it is still prudent to blow the wind at oblique angles.

Thanks for the replies.

_____________________________________
I have been called "A storehouse of worthless information" many times.

RE: My boss says look the other way?

http://onlineethics.org/moral/lemessurier/index.html

If you have the capability to analyze oblique winds, you can't ignore the findings.  This is ENG101 at most colleges - the Citicorp Tower in NYC.  Print it out and let your EE boss read it.  That's why EE's aren't SE's...   smile

RE: My boss says look the other way?

If I were involved with this, I would inform the EE that with current improved methods of analyzing the system that it fails with the addition of new equipment and that a consequence of the new equipment that it requires modification.  I would also ask him if the equipment be modified so that it works?

You should be confident of your analysis and suggest that you would be pleased if someone else review your findings.  If you simply pass the problem on to others,  you could still be unethical and also liable.  If you refuse to seal or sign off on the design and someone else does, you can still be liable... If the design only marginally fails, then it is an engineering judgement if the possiblilty of failure is acceptable.

What is the EE's reason for suggesting that it is acceptable?  Modification of something due to a change should be fairly common.  Does it open another can of worms?  I would approach the EE (It might be that he's EE and doesn't have an appreciation for the structural problem.) and let him know that the system is unsafe explaining to him why (if it is) and that for ethical and legal reasons, the problem must be addressed and that he should move the problem upward to the ME.   

RE: My boss says look the other way?

I preface this with I'm not a structurual engineer so I don't know the depth of the calculation issues and their relationship to "will if fall down", but I will comment on the chain of command and lack of action.

Engineers are employed to bring technical issues to the fore when the situation warrents it.  This seems like the time!  If your bosses don't want to get into this critical problem then you need to find someone who understand the scope of the problem.  As you mount more of the PCS units the probability that one of the towers experience a problem will go up greatly.

I have been to Federal Court over a business matter, trust me it's not fun.  Ask you bosses if you can check the findings with the company legal department and the general insurance provider for some feedback.  If it is OK with them then you will let it go.  Of course this will not occur with either of these groups.  Also ask you bosses to sign off on you analysis and have them direct you to other "more important" work.

Maybe this will call them (your bosses) to act on what I feel is a very, very critical engineering discovery.  This is not an easy spot for a moral person to be in. Good Luck.

jck26

RE: My boss says look the other way?

"NOTE: Under the extreme wind conditions of Rule 250C, an oblique wind may require greater structural
strength than that computed by Rules 252B and 252C."

I suppose it might be possible to misconstrue the "may" above, but to me it is pretty clear they intend for you to build for the worst case. If you really see two interpretations, please contact IEEE for a formal interpretation.

Please note utility commissions try to make penalties high enough that compliance is cost effective. Are you really quibbling over the cost of guying? Guy markers will lessen the truck incidences. See 217C.

RE: My boss says look the other way?

(OP)
The EE boss is hanging his decision on the fact that we have analyzed and built these towers for 40 years and have not had widespread failures during hurricane wind events, but my point is we have not had a major storm hit with the PCS sites installed.  Plus the fact that he will retire within a year or 2 and leave the mess behind for others to deal with.

The section 252D you cited above is the section that I interpret to mean I must consider wind at an angle.  I am on ASCE committees with the people that write these sections of the NESC and the phrase you quoted has been in the code since 1977.  The code is not a design standard but is a public safety code and has words that say in effect that I must design the structure to withstand all expected loadings.

I think I'll prepare a paper and note my assumptions and interpretations and present it to management.  I am the highest ranking structural engineer at the company with bosses having EE's and BA's.

_____________________________________
I have been called "A storehouse of worthless information" many times.

RE: My boss says look the other way?

star for transmissiontowers. your last post is taking your years of experience and using them to protect your company and the public. keep up the good work.

ZCP
www.phoenix-engineer.com

RE: My boss says look the other way?

transmissiontowers:

I am another that does not have an appreciation for the calculations and work involved (i.e. I am one of those idiots who hopes the bridge stays up when I drive on it).  What I do have an appreciation for is our obligation: moral, legal AND ethical to do everything in our power to protect ourselves and others from harm.

Adding to the towers as "a revenue generator" is a change to the design and requires the due diligence you are talking about.  It also sounds like it is not on every tower so I can't see the cost impact being that significant (compared to all towers).

Safety is being compromised for the sake of economics and should not be acceptable to anyone.

If it were me (thank you it is not), I would follow the suggestions of dik and approach him in a way that will help him understand.  I come from an electrical and instrumentation background, so I cannot understand the technical issue without guidance.  What are the costs?  What are the schedule impacts?  How much will the extra work increase the return on investment?

I will leave it with this comment:

BP at Texas City never had a serious problem before they killed 15 people.  We simply cannot rely on past history as an indicator of our safety record.  It deserves a pat on the back if it is good and lessons learned if it is less than desirable but that is all.

RE: My boss says look the other way?

Years ago I was working on a safety issue for a piece of portable equipment that would fold up to be transported down the highway.  As I was working on this the general manager walked in to see what I was doing.  He became upset that I was adding cost to the equipment and said that I might as well just go out and tape dollar bills to machine.  He mentioned that we had only one fatality with our equipment and that there are always risks.  Out of disgust I found another job and left the company before the project was finished.  I found out much later that the first machine built collapsed right where I thought it would when they pulled it out of the parking lot.  Thankfully no one was injured.  Of course the general manager blamed it on a poor design by engineering.

So transmissiontowers gets a star from me for his concern for public safety.  Hopefully he can resolve this satisfactorily.

Regards,
-Mike

RE: My boss says look the other way?

Since you have about 30 years experience, what method do you use for analyzing transmission towers?  What frame progra?  Is there a standard for loading/design?  Is there an on line *.pdf file?

Dik

RE: My boss says look the other way?

Ha....here's a VERY similar example for you - a building where the diagonal winds weren't first considered, then later considered and found to be a huge problem....this is one of those classic ethics text-book cases.

Read it:

http://onlineethics.org/moral/lemessurier/4.html

RE: My boss says look the other way?

(OP)
"...what method do you use for analyzing transmission towers?  What frame progra?  Is there a standard for loading/design?  Is there an on line *.pdf file? "

I can talk on this subject for hours, so be prepared to be bored.  The software is from Power Line Systems and can be found here:
http://www.powline.com/products/tower.html

It is a comprehensive line design program.  You do a structural model of the lattice tower or pole (steel, wood, concrete) and we have over 5000 individual structural models in our library.  You place the towers in a line and string a cable element between the structures.  You then can pick a structure or range of structures to analyze with a FE program.  The program runs a sag & tension program to determine the wire tensions for the wind and temperature and passes the loads to the tower program which runs the analysis for each load case you have specified which can include wind from an arbitrary angle.

All this takes place in about a minute depending on the number of joints in the tower and the number of load cases you specify.  The work done in 5 minutes is equivalent to what took weeks to do when I started analyzing towers 30 years ago.

The prep work of modeling the lattice towers is what takes the time (about a week for each one) and the line layout takes several days.  Browse around the PLS web site to get an idea of the graphics and I think there is a PDF demo available.

_____________________________________
I have been called "A storehouse of worthless information" many times.

RE: My boss says look the other way?

Thanks, Dik

RE: My boss says look the other way?

I saw the term whistle blowing in one of the earlier posts.

I think it's good to not be naive. It may not be so much what you need to do, but how you do it that makes the difference.

I found this old article, I think it contains some good advice and references.

http://kontikilink.home.mindspring.com/01279195.pdf

RE: My boss says look the other way?

"Safety is being compromised for the sake of economics."

Impossible in my opinion, at least in the USA. In the long run, fines and jury awards make safety the most cost effective alternative.

RE: My boss says look the other way?

   Transmission lines and the associated towers are designed with the knowledge that a simultaneous breaking of the conductors on one side of the tower will fail the tower,(or winds greater than assumed in design or wind on ice). A moderation element is usually incorporated in every tenth or so tower, a "fuse", which stops the progressive failure,(domino like collapse).  This strong tower is able to with-stand dead end forces, (all conductors on one side, wind, etc.). The spacing of the strong towers is an actuarial decision, taking into account the cost of replacing X many towers and lines vs. frequency of failure.

RE: My boss says look the other way?

"Safety is being compromised for the sake of economics."

Well at some point you have to, you can't build everything like a nuclear shelter. But it has to be a conscious and transparent decision.

RE: My boss says look the other way?

What is the cost of replacing a several miles of line and several dozen towers, once every 50 years, compared to the one-time cost of adding a few braces and/or guy wires on each tower that is already having a crew working there to tie antenna structures to it?

Being a resident of the Seattle area, and having survived 8 days without power after our big windstorm last month, I'm considering copying your post and emailing it the the local papers.  Wondering if similar decisions resulted in our area's main towers over the mountains going down.  Geez, now I'm simmering.  To my first paragraph add: what is the cost of the extra PR funds the utility will have to spend to recover from the public opinion debacle if a Seattle-like disaster was linked (even if only tenuously) to a decision like the one you're debating with them.

RE: My boss says look the other way?

Oh let's not get the media involved.  Next thing you know the State of Texas will catch wind of it and subpoena the site for as much information about transmissiontowers as its got.  I'm not paranoid but I could see it play out that way or something close to it.

RE: My boss says look the other way?

(OP)
btrueblood; Please don't send my frustrations to the media.  I can just ignore the request and analyze the tower for the loads I want and no one above me would know the difference.  This is one of the plusses of having more knowlege than the people that manage your work, they have no clue if I did what they told me to do or not.

Civilperson;  Yes, some utilities in heavy ice areas will use "stop" structures especially in H-Frame lines where the longitudinal strength is so low there is a possibility of a cascade failure.  If the latice tower has enough long. strength and the insulators are long enough, the cascade will not go past 2 or 3 towers where the tension will drop off due to the slack in the system in the case of a broken wire.

_____________________________________
I have been called "A storehouse of worthless information" many times.

RE: My boss says look the other way?

My comment "Safety is being compromised for the sake of economics" was meant for that particular situation and not meant as a generality.  We cannot remove all risk from any situation.  What we can do is manage it and reduce our exposure to risk by taking certain steps, in this particular case, engineering.  It does sound like the EE is making a decision that he might not be qualified to make and leaning towards what he does know - financial impact.

The term ALARP (As Low As Reasonably Practical) comes to play.  If the towers are not reinforced, what is the likelihood they will fail?  The next question is: Is that likelihood something we (the company) can accept?  If it is, then they will not guy the towers.

Just because we get hit with a 1/100 year storm, do we now upgrade all of our design to meet that, even if what we are building probably will not be standing 100 years from now?

The reason I posted to this discussion was the view point that someone was making a decision that could injure or otherwise affect people without "really" considering all of the facts.  Safety must be paramount in our designs and our work.  We must perform our work in such a manner that we are reducing the risk to humans to a level that is socially acceptable.  We do not have an obligation to reduce it further.

RE: My boss says look the other way?

"Just because we get hit with a 1/100 year storm, do we now upgrade all of our design to meet that, even if what we are building probably will not be standing 100 years from now?"

The NESC is pretty clear on this point. Old installations must be maintained at least to the level of the code in place at the time of installation. New must meet the latest code.

Please understand this particular safety decision is not one that transmissiontowers or his boss can make. In most states, the code has the force of law behind it. Try to visualize your turn on the witness stand explaining to Johny Cochran why laws and standards representing accepted engineering practice were ignored.

RE: My boss says look the other way?

Umm, Johnny Chochran died a couple of years ago...

And I watched the OJ trial, he'd have figured out a way to get you off...


RE: My boss says look the other way?

Btrueblood:  to say "I'm considering copying your post and emailing it to the local papers" compromises the engineer's ability to anonymously gather peer opinion.  An accusation has not been made, only an ethical question raised.  

RE: My boss says look the other way?

     Safety is a nebulous concept when interjected into engineering decisions. That is why we lean so heavily on codes and standards.  The following of a code is what a prudent engineer will do when no other knowledge is available.  The code is risk based in that some level of loading will compromize the integrity of the structure and this upper level of loading is rare and acceptable.
     The electrical transmission sytem is built in the middle of generous ROWs that usually confine any failure to the utilities land,(protecting the public).  Lack of power for some interval is an inconvenience not a hazard.  That is why hospitals and casinos have generator back-up, they can not afford to be out of business due to electrical gaps.

RE: My boss says look the other way?

I agree that these discussions should remain within the forum and be discussed by people who have an interest being here.  

-Mike

RE: My boss says look the other way?

(OP)
I took btrueblood's comment as a joke due to his frustration and my response was in a joking manner.  Life is too short to be serious all the time.

To answer a couple of the points raised, the towers fail on paper (pixels on the screen) if the wind is at the correct oblique angle.  Whether they would fail during an actual wind event is the big question.  The design of lattice towers is covered in ASCE Std 10.  The big unknown is the way wind on the structure is calculated.  The towers are so large that there is no wind tunnel large enough to hold them.  We apply our best guess and calculate wind on the members and assume a drag coefficient on the members.  

Full scale tests are done to verify designs, but the application of the calculated wind loads is done with cables and winches, so you do not really apply a distributed wind on the structure.  You are applying a point load meant to represent a uniform load which you calculated based on many assumptions.

Will the tower fall during a real wind event?  We make every effort to make sure it does not.  We use a pseudo LRFD approach in design.  Overloads are applied to the loads and for the high wind they are 1.1 or 1.2 and the members are allowed to go to their yield or limiting condition such as buckling.  The NESC specifies a minimum OLF of 1.0 so there is not a huge safety factor on high wind.  When full scale tests are done, the ideal failure point is between 100% and 110% of the load.  Any greater than 110% is cause for a redesign to remove extra weight.

The idea of wide ROW in a rural setting is true for some areas, but the territories in urban areas cross freeways and are near people, so a failure does not just inconvenience a few cows, it can come down on a freeway.  There are not many cars on the road in a 140mph wind storm, but ice events do have the possibility to drop on cars.

_____________________________________
I have been called "A storehouse of worthless information" many times.

RE: My boss says look the other way?

To all...

I note in the threads that there is some confidentiality required.

I often use google for research and occasionally end up with an Eng-Tips hit.  This is the result of a Google search... If you don't want the material to be visible to anyone at any time, you might want to redflag this thread... Your postings here are not unique to this forum...

Tip: Try removing quotes from your search to get more results.
Professional Ethics in engineering Forum - Eng-Tips
My boss says look the other way? Helpful Member! Helpful Member! Helpful Member! Helpful Member! Helpful Member! cjd97 (Structural). 13 replies ...
www.eng-tips.com/threadminder.cfm?pid=765 - 34k - 26 Jan 2007 - Cached - Similar pages


Dik

RE: My boss says look the other way?

I definitely wouldn't be (4) reporting your superior to the state board.  Since utilities are exempt from building code requirements, and no documents are being sealed, it is somewhat questionable whether a state board would have any power over this situation.  Also, since utilities are exempt from building code requirements, correct me if I am wrong, but utilities have no legal obligation to follow the NESC code or any other.  If something bad happened, and a tower fell down and killed someone, the utility still needs to have a backup for what they've done.  Typically, following an up-to-date code would be the best way to provide back up, but another method could be argued in court.

I have no problem with your boss taking responsibility for making an economic decision based on the above.  I do believe you are ethically required to make sure he has all the information needed to make an educated decision.  I would run all the numbers ((2) oblique and non-oblique) and present them to him and make sure he is aware of the risk he is taking if something were to fail.  If he still decides to do it the old way, I would follow up with either doing what you suggested in (3) or just turning your numbers into an e-mail and sending it to him thus providing a paper trail for yourself.

It should be noted that typically the wireless communication providers like going on top of transmission towers because they can get them permitted much easier, and much faster due to the utilities exemption.  If your utility had good salespeople, they would realize this and getting the wireless people to pay for the price of tower upgrades.  The wireless people (your customer) also does not want the bad publicity of their antenna falling and killing someone and knocking out service to a region.  Or maybe your utility does have good salespeople, and by not upgrading the tower, your company is even pocketing more money.

It would make sense that if a tower is in the middle of nowhere that it could be designed to lesser loads than one within falling distance of a busy road.  I've heard rumors that certain codes will eventually be implementing some sort of a factor to acount for this.  You could maybe convince your boss to look at wind from any direction in the cases where a failure has a significant probability of a subsequent death.  

RE: My boss says look the other way?

I don't design transmisso towers, but have designed structures of various types and done significant utility work.
1.) Tirty years ago when designs were done by hand (Wow! is that one of those new pocket calculators? Can I try it?) oblique wind angles were handeled by the design details to ensure they were not the weakest point in the structure. Since design software has made analsyis more exact, design stadards have moved away from this emoperical design. So what was acceptable practice 30 years ago is no longer true.
2.) Codes are established to define risk reward ratios. Based on years of research by a small army of starving grad students, acceptable limits have been established that work. It is impossible to arbitrarily say "30 psf wind load may be code, but 25 psf is good enough for me"
3.) Havng seen this more times than I care to count, if there ever is a failure everyone will forget that some one made a descion not to follow the code. It will be a structural failure and will be laid at your feet. Protect yourself. If you do not like the design do not stamp the drawings. that is your obligation as a PE.
Good Luck with a sticky situation.

RE: My boss says look the other way?

(OP)
Yes, when I started 15 Engineers shared 2 Friden/Singer 4 function calculators that had a 3" dia green CRT and a 4 stack RPN.  It did have a square root button but did not do Sin or Cos.  For Trig functions we shared a book of Smoley's tables.
http://www.oldcalculatormuseum.com/friden1162.html

One load case took hours to do using the graphical method of joints just to find the loads in the members.  Allowable loads in the members was done by hand calculations.  The graphical method was a 2D truss analysis and we did each face of the tower separately.  After a few years we got fancy and used the program Stardyne to analyze towers, but had to calculate allowable loads with HP45 pocket calculators.

All the Utilities that I know of follow the NESC as a minimum and I believe some States require the NESC to be used by law.  I've never had to go to court and I hope I never do.  Lawyers being what they are and people waiting to sue big companies over anything that will make a buck may force stronger structures, but it seems like no matter how strong you make a structure, if it falls down some lawyer will try to prove that the engineer could have made it stronger.

AFA my problem, I think I'll go ahead and run the wind at oblique angles and report and document my findings and note my objections if the boss decides to neglect the oblique wind.

_____________________________________
I have been called "A storehouse of worthless information" many times.

RE: My boss says look the other way?

If you are legally obligated to design to the NESC, I have more of an issue with what your boss is doing than what I stated in my last post.  You interpret the design code that you `must' design for oblique angles, and he is telling you to neglect your code interpretation.  I think the path you are going down at the end of the last post is the correct one, and see where it goes from there.  Make sure your boss is aware of all the risk he is potentially taking on, and that if he is going to take that risk he is going against the structural department to take that risk.

If you are not legally obligated to design to the NESC, I have less of a problem with what your boss is doing, but I would still make sure your boss is aware of all the risk he is potentially taking on, and that if he is going to take that risk he is going against the structural department to take that risk.

RE: My boss says look the other way?

Modern steel is often stronger.  If you are using 36ksi steel when 50ksi is what you are getting there may be some room for you to absorb the higher loads.

RE: My boss says look the other way?

The angles used in lattice towers are 36 ksi yield.

RE: My boss says look the other way?

Is there much of a cost in specifying them as Grade 50?  Our standard grade of steel here is 350MPa or Grade 50.

Dik

RE: My boss says look the other way?

Where the strength is governed by buckling of one kind or another, is there really much increase in design strength for 36ksi or 50ksi?

RE: My boss says look the other way?

(OP)
The steel yield does not matter for the compression capacity when the L/r is above Cc.  It does matter a little for small L/r values but it is not very practical to change out a leg member on an existing tower.

50 ksi is generally used for the leg members anyway and 36 ksi is used for the lacing and redundants.

The statement in NESC Rule 252D that the oblique angle may cause more stress is in a Note and as such does not carry the mandatory strength of the Code and is only a suggestion according to most interpretations of the Code.

It is my interpretation that I should consider the most severe wind direction and it is his interpretation that we did not do this in the past and should not do it now.

_____________________________________
I have been called "A storehouse of worthless information" many times.

RE: My boss says look the other way?

I design elevated bins containing cement, sand and gravel, typically being four column structures.  While the  code provisions for quartering winds and orthogonal seismic have become more specific in the last decade or so, I think the codes have said to design wind (and seismic) for "horizontal loads from any direction" for a long time, at least from what I could find in the UBC published in the 70s.  

Even though transmission towers and I design different products to different design criteria, I think you have to be aware of the physics of what's going on, and what the worst case loading would be.

Regards,
-Mike

RE: My boss says look the other way?

JStephen... once the slenderness is within the Euler range... fy matters nothing, only E... It is unlikely that all members are in that range, and it may be possible to economically add some local bracing to strengthen these members...

Dik

RE: My boss says look the other way?

Like anything else in life, what you say may be heard by others. A forum such as this is open to the public. Anyone can come here and take what you say, and use it for their own purpose.

When you signed on to a project, or your employment contract, or similar situations, one of the things typically required of you is to keep certain things confidential. That also extends to engineering forums, where you ask for other's opinuions. You need to use your own professional judgement to determine how much information to give (to get a useful answer) versus confidentiality.

"Do not worry about your problems with mathematics, I assure you mine are far greater."   
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

RE: My boss says look the other way?

"I took btrueblood's comment as a joke due to his frustration and my response was in a joking manner.  Life is too short to be serious all the time."

Thanks, transmission.  That is what I intended.  I like journalists less than I like lawyers (though, I do like the idea of stirring up a hornet's nest here at home, and then standing back to watch and laugh; how to keep it from backfiring onto some poor schlepper like you or me is the rub).  Thus, the follow-up comment about cost of hiring a PR firm, was intended to also be tongue-in-cheek, but pointing out the "hidden costs of failure" that the MBA types like to gloss over during design reviews.  My frustration was not over spending 8 days w/o power (I live in an area that experiences at least one 1-2 day outage per year, on average, and so like any good engineer have my own generator), but more with your descriptions of the people who you have to "sell" your design experience and knowledge to.

Good luck with your efforts, but I agree with some of the other posts here, and would advise you to keep your own copies in a safe place somewhere, just in case the finger-pointing starts.

RE: My boss says look the other way?

(OP)
I figured you were joking around and was joking back at you.  I am in the process of writing a paper to document my concerns and reasoning to give to management so they have the facts and will be able to make a decision.

_____________________________________
I have been called "A storehouse of worthless information" many times.

RE: My boss says look the other way?

(OP)
Very good news.  My Boss has decided not to over rule my decision to run the analysis the way I want.  I just have to write up a paper stating my reasons for using the oblique wind.

_____________________________________
I have been called "A storehouse of worthless information" many times.

RE: My boss says look the other way?

transmissiontowers,

For me it's always nice to hear the conclusion to these threads in particular when there is a good ending to the story.

Thanks,
-Mike

RE: My boss says look the other way?

good resolution... Dik

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